Cyano Acrylate Polymers in Medical Applications
Cyano Acrylate Polymers in Medical Applications
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Cyanoacrylates are solvent free adhesives that cure rapidly when pressed into a thin film between two surfaces. Their ease availability and use in various formulations made them attractive to manufacturers a wide variety of medical devices. Unfortunately, earlier generations of cyanoacrylates had several limitations, such as poor thermal resistance and peel strength. Subsequent developments in cyanoacrylate technology have greatly expanded the performance of these adhesives. This rubber-toughened, surface-insensitive, thermally resistant cyanoacrylate offers advantages over earlier toughened products which has been recently patented.
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186
Recent Patents on Materials Science 2008, 1, 186-199
Cyano Acrylate Polymers in Medical Applications
Rajendra P. Pawara, Swapnil R. Sardaa, Ravikumar M. Boradea, Ashok E. Jadhava, Satish A. Dakea
and Abraham J. Dombb,*
a
Organic Chemistry Synthesis Laboratory, Dnyanopasak College, Parbhani-431 401, MS, India; bDepartment of
Medicinal Chemistry and Natural Products, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem91120, Isreal
Received: April 29, 2008; Accepted: May 5, 2008; Revised: May 6, 2008
Abstract: Cyanoacrylates are solvent free adhesives that cure rapidly when pressed into a thin film between two surfaces.
Their ease availability and use in various formulations made them attractive to manufacturers a wide variety of medical
devices. Unfortunately, earlier generations of cyanoacrylates had several limitations, such as poor thermal resistance and
peel strength. Subsequent developments in cyanoacrylate technology have greatly expanded the performance of these
adhesives. This rubber-toughened, surface-insensitive, thermally resistant cyanoacrylate offers advantages over earlier
toughened products which has been recently patented.
Keywords: Cyanoacrylates, polyglycerol sebacate acrylate (PGSA), folate-HNPEGCA-co-HDCA, control multifunctional
nano device (CMND’S), fine particle fraction (FPF), actively targetable nanoparticles (ATN).
INTRODUCTION
compatiblity that flexes with the skin and remains inherent
for longer time. This stronger, flexible bond may allow its
use on longer incisions. This technology has a proposed the
production of several cyanoacrylate adhesives of different
ester radical lengths, by introducing a new degradation and
stabilization system of cyanoacrylate oligomers depolymerisation. As compared to the known methods the
cyanoacrylate technology is cleaner, faster and simple.
The usage of cyanoacrylate medical adhesives as a replacement for the classical suture has been reported because of
its good cosmetic effect, reduced pain and recovery period,
and preference by patients. These techniques are more
efficient, offers low surgery time and therefore, reduced cost.
Still cyanoacrylates tecnology has some demerits. The low
homologues of the cyanoacrylate family form brittle
adhesive layers in vivo which may cause biodegradation of
polymer by adverse tissue response. Biocompatible and more
flexible bonds are formed using higher cyanoacrylate but
these are more expensive. Therefore, there is a need to get
high quality medical adhesives based on cyanoacrylates at an
affordable price. For this, alkoxycarbonyl group of the
molecule cyanoacrylate monomers are modified to obtain
different ester residue chain length compounds. Short chain
derivatives show a higher degree of tissue toxicity than the
longer chain derivatives. Inflammation and histologic
toxicity is related to the by-products of degradation of
cyanoacrylates and alcohols. The concentrations of these
breakdown products are proportional to the rate of degradation. Therefore, slow degradation rate results in decrease
in toxicity to the tissues.
Various cyanoacrylate homologues with ester radical
length in the C1-C8 range are obtained using this technology
for direct application as medical adhesives with diverse
setting times, bond strengths, degradation rates and
biocompatibilities. Another advantage of this technology is
used in the synthesis of nanostructured homo and copolymeric poly(cyanoacrylates). It’s usefulness in drug delivery
and targeting systems and in other various medicinal
applications are discussed here.
Currently, n-butyl-2-cyanoacrylate was the only
commercially available cyanoacrylate tissue adhesive. As the
n-butyl-2-cyanoacrylate is effective in closing superficial
lacerations under low tension, it also has certain limitations.
It produces brittle adhesive film on some specific medical
applications and increases the cytotoxicity. The n-octyl-2cyanoacrylate was formulated to correct these deficiencies.
Slow degradation of cyanoacrylate polymer results in
lowering the concentration of by-products in the surrounding
tissues and produces less inflammation. Additionally,
plasticizers are added for more pliablity and tissue
A series of lipophilic derivatives of gemcitabine poly
(H2NPEGCA-co-HDCA) nanospheres and nanocapsules has
been synthesized. More lipophilic derivative such as, 4-(N)stearoylgemcitabine are incorporated a high yield. Their
cytotoxicity study was done on two human cancer cell lines
and compared to gemcitabine and free 4-(N)-stearoylgemcitabine [3].
*Address correspondence to author at the Department of Medicinal
Chemistry and Natural Products, School of Pharmacy, The Hebrew
University of Jerusalem, Jerusalem-91120, Isreal; Tel: 972-2-5429410;
Fax: 972-2-5428688; E-mail: avid@ekmd.huji.ac.il
1874-4656/08 $100.00+.00
The use of polyglycerol sebacate acrylate (PGSA) as a
biodegradable and biocompatible tissue adhesive has been
reported [1].
Clinical applications of ‘Topical Tissue Adhesives’ synthetic cyanoacrylate in various medical devices was
approved by the US FDA. It includes cyanoacrylate liquid
bandages, dental cements etc. [2].
The few multifunctional nano device (MND) are
discussed here. The folic acid MND is used as ligand, which
conjugated to terminal amido of poly(aminopoly(ethylene
glycol)cyanoacrylate-co-hexadecyl cyanoacrylate) (poly
(H2NPEGCA-co-HDCA)) to synthesize poly(FolateHNPEGCA-co-HDCA), protamine sulfate (PS) for nuclear
© 2008 Bentham Science Publishers Ltd.
A. Cyano acrylate Polymers
transfer and DNA condenser. The experimental result shows
optimum complexation of DNA i.e. about 97%. The MND
loading pDNA/PS shows the luciferase activity over 0.5 ng
luciferase/mg protein in KB cells. MND shows the highest
transfection efficiency in KB cells as compared to A549
cells and other formulations such as LipofectAMINE, free
pDNA/PS. Also, the transfection efficienecy of Controlled
Multifunctional Nano Devices (CMNDs), is found higher
than lipid film coated poly (HNPEGCA-co-HDCA) and
DOPE. In addition, during encapsulation MND also shows
good protection and low cytotoxicity. Overall, MND is a
more potential non-viral vector used for DNA delivery [4].
A technique of latent fingerprints using controlled
cyanoacrylate vapor exposure in fuming cabinets is used for
artifacts recovered in investigations of forensic crime-scene.
This technique involves the deposition of monomeric
cyanoacrylate under warm, moist conditions onto the object
to polymerize and produce a white film which renders the
fingerprint visible. Raman spectroscopic study shows several
bands in the spectra of poly(ethyl-cyanoacrylate) which
indicates the presence of residual monomer and other species
formed of the polymerizing material. The possible effect of
unreacted monomer and other polycyanoacrylate film
impurities on spectral analalysis is also highlighted [5].
An actively targetable nanoparticles (ATN), PEG-coated
biodegradable polycyanoacrylate nanoparticles (PEGnanoparticles), conjugated to transferrin for paclitaxel
delivery, has been studied. PEGylated paclitaxel loaded
nanoparticles were prepared using solvent evaporation
technique. ATN were prepared by coupling of transferrin
with PEG-nanoparticles. The result shows an average
encapsulation efficiency of ATN. A low burst effect of
paclitaxel loaded ATN exhibited only 16.2% drug release
within the first phase. Subsequently, paclitaxel release
profiles displayed a sustained release phase. The amtount of
cumulated paclitaxel release over 30 days was 81.6%. ATN
exhibited a markedly delayed blood clearance in mice, and
the paclitaxel level from ATN remained much higher at 24 h
as compared to free drug from paclitaxel injection. Distribution profiles of ATN in S-180 solid tumor bearing mice
after i.v. administration shows the tumor accumulation of
paclitaxel increase with time, and the paclitaxel concentration in tumor was about 4.8 and 2.1 times higher than
those from paclitaxel injection and PEG-nanoparticles at 6 h
after i.v. injection. The tumor burden with ATN-treated mice
was much smaller compared with free paclitaxel or NTNtreated mice. In addition, the life span of tumor-bearing mice
was significantly increased when they were treated with
ATN. Thus, PEG-coated biodegradable polycyanoacrylate
nanoparticles conjugated to transferrin could be an effective
carrier for paclitaxel delivery [6].
Nanoparticles of poly(isobutylcyanoacrylate) with
dispersed insulin in pluronic acid solution has been reported.
The results show a decrease in particle diameter by
increasing the pluronic acid concentration. Nanoparticles
prepared in the presence of 2.5% pluronic acid results in
particles of 85 nm diameters and 59% intra-particular insulin
load without the use of the oily core. Streptozocin induced
diabetic rats were used for in vivo study. Sub-cutaneous
injection of insulin nanoparticles prolonged the duration of
Recent Patents on Materials Science 2008, Vol. 1, No. 3
187
hypoglycemic effect from 6 to 72 h. As compared to nonencapsulated insulin, oral absorption of the entrapped insulin
was found significantly better [7].
Spray drying is a common practice of powder preparation
used to deliver particles to the lungs via a dry powder inhaler
(DPI). In present study lactose was used as the excipient and
spray-dried with gelatin and polybutylcyanoacrylate
nanoparticles. In results, some carrier particles were found
hollow while others had a continuous matrix. Gelatin nanoparticles incorporated the matrix and sometimes accumulated
at one end of lactose. The polycyanoacrylate nanoparticles
found clustered in different spots within the lactose carriers.
Dispersion of the powder with an inhouse passive dry
powder inhaler and subsequent cascade impaction measurements showed that incorporation of the nanoparticles did
not affect the fine particle fraction (FPF) or mass median
aerodynamic diam. The nanoparticles were delivered to the
lungs via carrier particles that dissolve after contact with the
aqueous environment of lung epithelium. This opens the way
for new drug-targeting strategies using nanoparticles for
pulmonary delivery of drugs and diagnostics [8].
A molecular simulation of doxorubicin interacting with
butyl-polycyanoacrylate has been studied. Emphasis is put
on the tetrameric, hexameric and octameric oligomers
(PACA's). Aggregation and desegregation mechanism of
doxorubicin release can be summarized as follows: oligomeric PACA's are lipophilic entities facilitate scavenge
amphiphilic doxorubicin already during the polymarization.
The establishment of hydrogen bonds between the ammonium N-H function and the cyano groups is noteworthy. The
cohesion in PACA nanoparticle comes, therefore, from a
blend of dipole-charge interaction, H bonds, and hydrophobic forces [9].
Transferrin conjugated PEGylated polycyanoacrylate
nanoparticles (TF-PEG-nanoparticles) microencapsulation of
has been reported to determine the stability of pDNA against
various conditions in vitro targeting cells association. The
open circular forms of pDNA increased on emulsifing pDNA
with organic solvent. Poly(aminopoly(ethylene glycol)
cyanoacrylate-co-hexadecyl cyanoacrylate) (poly(H2NPEGCA-co-HDCA)) shows a slight influence on pDNA in 0.1M
NaHCO3 at high concentration. K562 cell binding affinity of
TF-PEG-nanoparticles was found greater than of nontargeted PEG-nanoparticles. The results indicate, TF-PEGnanoparticles were useful in pDNA delivery to target cells
[10].
Using poly(Bu-cyanoacrylate) (PBCA) nanoparticles
coated with Polysorbate 80, drugs can be delivered to brain.
These carriers can penetrate blood-brain barrier (BBB) and
deliver drugs of various structures, i.e. peptides, hydrophilic
and lipophilic compounds eliminated from brain with Pglycoprotein. The suspension of polysorbate-coated PBCA
nanoparticles is introduced into blood; apolipoproteins of the
blood plasma adsorb on the particle surface and interact with
low concentrate receptors. Lipoproteins situated in endothelial cells of cerebral vessels, thus stimulating endocytosis
[11].
Nanoparticles of poly(Bu-cyanoacrylate) (PBCA) and
poly(octyl-cyanoacrylate) (POCA) have been reported to
188 Recent Patents on Materials Science 2008, Vol. 1, No. 3
study biodistribution in mice by loading radioiodine125Ilabeled IUDdR. Nanoparticulate injection to brain increases
the counts because of IUdR bioavailability in the brain when
IUdR was loaded into NPs. The result shows nanoparticles
crossed the blood brain barrier and reaches to brain tissues.
[12].
Butylcyanoacrylate adhesive scaffold is used in a porcine
model to enhance the tensile strength of tissue samples
repaired in an ex vivo. The cyanoacrylate doped scaffold
repairs approximately 30% organ tissues and approximately
20% vascular tissues. These scaffold-enhanced adhesive
offers a quick application with less skilled professionals,
paraprofessionals and bystanders in emergency [13].
Application of thermosensitive poly(cyanoacrylate)
nanoparticles at high hydrostatic pressure (HHP) were also
studied. Poly(cyanoacrylate) nanoparticles appeared to be
extremely baroresistant. This process allowed the successful
inactivation of vegetative bacteria, yeast, and fungi. HHP act
as a new method for polymer drug carrier’s sterilization [14].
The combination of polycyanoacrylate with bone
morphogenetic protein-2 (rhBMP-2) nanoparticles injection
is prepared by emulsion method. Their biological activities
were tested in vivo as well as in vitro. It shows that the
rhBMP-2 polycyanoacrylate nanoparticle was homogeneous
and stable. in vivo Study showed 80% of rhBMP is released
in 10 days. Addition of rhBMP nanoparticle to marrow
stromal cell (MSC) system increases ALP level in MSC
cultural significantly [15].
Recently,
biodegradable
poly(ethyl-cyanoacrylate)
(PECA) nanospheres was used as carriers to deliver insulin
orally. Screen absorption enhancers used to protect insulinloaded PECA in vivo after oral administrations of streptozotocin-induced diabetic rats. Orally administered insulin
absorption was evaluated using hypoglycemic effect. Blood
glucose level is significantly reduced on oral administrations
of protease inhibitor with insulin-loaded PECA nanospheres
[16].
PEGylated polyalkylcyanoacrylate nanoparticles easily
penetrate into central nervous system to a larger extent than
other formulations because of their long-circulating properties in blood. Thus, PEGylated polycyanoacrylate nanoparticles are used as a new brain delivery reported system in
neuroinflammatory diseases [17].
Pharmacokinetics study of poly(Bu-cyanoacrylate) nanoparticles loaded with sulfonated aluminum phthalocyanine
(Photosense) as a delivery system has been reported [18].
Poly(Bu-cyanoacrylate) nanoparticles (PBCA nanoparticles) loaded with the hexapeptide dalargin has been
studied. These nanoparticles were coated with apolipoproteins AII, B, CII, E, or J without or after precoating
with polysorbate 80. The antinociceptive threshold was
measured by the tail-flick test on i.v. injection to mice. The
antinociceptive effect found to be reduced in apolipoproteinE deficient mice. Transportation of drugs loaded to poly (Bucyanoacrylate) nanoparticles with apolipoproteins B and E
across the blood-brain barrier has been done [19].
Polycyanoacrylate adhesives were also used in inguinal
hernia repair. Since the evolution of laparoscopic inguinal
Pawar et al.
hernia repair, the total extraperitoneal (TEP) repair is the
most commonly employed technique by laparoscopic
surgeons [20].
A biodegradable poly(iso-Bu-cyanoacrylate) (PIBCA)
colloidal particulate system of pilocarpine, incorporate it into
a Pluronic F127 (PF127)-based gel delivery system has been
developed. Its ability to prolong the release of pilocarpine is
elavuated. The PIBCA-NC of pilocarpine dispersed in the
PF127MC gel delivery system has significant potential to
prolong a delivery of pilocarpine and other hydrophobic
drugs [21].
Allopurinol-loaded poly(Et-cyanoacrylate) nanoparticles
were tested against Trypanosoma cruzi using in vitro
cultures of epimastigotes. Increasing concentration of
unloaded nanoparticles on vero-line cell cultures has done
cytotoxicity study. The result subjected to, shows that the
poly (Et-cyanoacrylate) nanoparticles comprises a good
carrier of drugs against the trypanosoma cruzi. The
allopurinol loaded-nanoparticles significantly increased the
trypanocidal activity in comparison to the free drug [22].
PATENTS ON MEDICAL APPLICATIONS
Tissue Adhesives and Sealants and Method for their Use
US Patent 20070202075 reported the compositions
containing both a biotin and avidin used as adhesives or
sealants in medical or surgical applications. The biotin and
avidin containing components are kept separate and mixed
just prior to use to form a gel matrix for adhering tissue to
tissue or adhering a medical device to tissue or sealing holes
in tissue. Methods sealing a hole in tissue is done by
applying a composition of biotin and avidin component to a
defect tissue. It reports the use of specific apparatus in which
first chamber containing a biotin and second chamber
containing avidin component with one or more outlets for
simultaneously dispensing the first and second compositions.
It covers the use of bioabsorbable polymer to prepare the
avidin containing component. The bioabsorbable polymer
breaks down in the body and gradually absorbed or eliminated from the body by hydrolysis, metabolic processes, or
bulk or surface erosion. These bioabsorbable materials
suitable for making the avidin-containing component includes, polycaprolactone (PCL), poly-D, L-lactic acid (DLPLA), poly-L-lactic acid (L-PLA), poly(lactide-co-glycolide), poly(hydroxybutyrate), poly(hydroxybutyrate-covalerate), polydioxanone, polyorthoester, polyanhydride,
poly(glycolic acid), poly(glycolic acid-cotrimethylene carbonate), polyphosphoester, polyphosphoester urethane,
polyamino acids absorbable cyanoacrylates and other various
biodegardeble polymers [23].
Surgical Adhesive Compostion and Process for Enhanced
Tissue Closure and Healing
US Patent 20070092483 deals with the compositions and
control in vivo degradation behavior, wound healing, and
tissue regeneration. Furthermore, the brush likes pendant
hydrophilic protects the molecule or polymer from
immunological recognition and toxic degradation. The
inclusion of minimal oligopeptide sequences can also impart
specific bioactivity and cell mediated degradation to the
materials. Polymerization of the macromers is initiated by
A. Cyano acrylate Polymers
nucleophiles hydroxyl ions present in the moisture or on
surfaces of biological surfaces or fluids, such as blood to
form a solid polymer.
The present invention reported 1,1-disubstituted electrondeficient olefin macromers and their adhesive composition
reacts with moisture on surfaces or in the presence of
biological surfaces or fluids, such as blood to form a solid
polymer. They are used to form an adhesive bond between
two dissimilar or similar surfaces at the junction of living
tissue. These inventive compositions possess an improved
biocompatibility with controlled biodegradation and
bioactivity. The compositions are used as surgical adhesives
to provide mechanical fixation whereas promoting healing
across the tissue junction. The co-monomer compositions are
of at least one macromer with a pendant oligomeric/
linear/branched polymeric chain of ester linked to an acrylate
group of the reactive olefin. The pendant polymer prevents
non-specific protein adsorption, such as a polyethylene
glycol (PEG). These polymeric grafts improved the biocompatibility of resulting adhesive and decrease the toxicity of
polymer degradation products. The co-monomers of composition 1,1-disubstituted electron-deficient olefins and crosslinkers are different cyanoacrylate and PEG-dicyanoacrylate,
respectively. The composition may have cyanoacrylate
functionalized peptide co-macromers and cross-linkers. Cyanoacrylate pendant cell binding or signaling peptide domains
and cleavable cyanoacrylate enzyme capped domains may
also present in such compositions. Another important
characteristic of these adhesive compositions is, the polymers formed are bioactive and degradable. Non-degradable
cross-linking co-monomers or macromers are also
incorporated in these compositions.
Antibiotic and anti-inflammatory drugs are hormones or
gene-therapy vectors also incorporated in the adhesive
polymer compositions. Polymerization and/or polymer modifying additives such as free-radical stabilizers, anionic
stabilizers, initiators, accelerators, inhibitors, plasticizers,
and rheology modifiers may also be incorporated in the
composition. Formaldehyde scavenging compounds may
also be included in the composition. Furthermore, fiber or
particular filler material may be added in composition to
provide a reinforced polymer composite. The filler material
may be composed of degradable synthetic or natural
polymer, protein, mineral, or bio-glass. Easily releasing drug
or biologic may also be added in the degradable filler
material. It also includes polymer/mineral cement composites, which cure by polymerization and precipitation of
mineral to form an interpenetrating composite micro-structure. Micro-structural with the cell-mediated degra-dation
and bioactive properties of the polymer promotes cell and
tissue growth and provide mechanical stability during healing and replacement of the material by native tissue. It also
covers the preparation methods of monomers and adhesive
compositions and their use as surgical adhesives [24].
Cyanoacrylates and their derivatives are commonly
employed as adhesives because of their fast curing rate, high
bonding strength, wide range of substrates, and ease of use.
Cyanoacrylate adhesives are extensively used in industrial
and commercial applications but their use in medicine is
limited. Short chain alkyl cyanoacrylate adhesives were
Recent Patents on Materials Science 2008, Vol. 1, No. 3
189
showed severe inflammatory effects on tissues. Butyl
cyanoacrylate was the first cyanoacrylate adhesive show low
tissue toxicity and good bonding strength. The toxicity of
cyanoacrylate decreases with increasing alkyl chain length.
2-Octyl cyanocrylate Dermabond®, shows improved
mechanical and biological properties and used in dermal
wound closure and protection. It is also served as haemostatic agent and orthopedic adhesives. Advantages of
cyanoacrylate adhesives over sutures or staples include lower
infection rates, better cosmesis, and faster wound closure.
Cyanoacrylate used to join living tissues result in obstruction
of the healing path and intense foreign body response. When
used for direct bonding, cyanoacrylate adhesives bridge and
block the living tissue junction being adhered. This prevents
cell migration and infiltration and replacement of the
material by native tissue [24].
Microcapsules and Nanocapsules Made from Polymers
for Drug Delivery
CN Patent 101053810 is related with the method that
comprises dissolving aliphatic polyester, polycyanoacry-late,
polyorthoester polymers of mol. wt. of 5000-500,000 in oilsolution to give polymer solution. Mixing water or drug
solution with the polymer solution at volume ratio of 1:(240) forms water-oil emulsion. Resultant emulsion on mixing
with precipitating agents like methanol, ethanol, etc. at 1:1
volume ratio results in suspension of microcapsules. The
microcapsules are separated by washing, freeze drying and
stored in a sealed container. The sealed container on
vaccumization and pressure forms polymer micro-nano
capsule. The polymer capsule realizes compatibility of
water-solution, drug and oil-solution, provides sustained
release function. Thus, these compositions are used for
ultrasonic contract and molcular imaging [25].
Body Fluid Biodegradable Medical Implant and its
Preparation
CN Patent 101015711 deals with the implant made up of
compact or porous Mg-Ca alloy and biodegradable polymer
or biodegradable ceramic coating on the alloy. The Mg-Ca
alloy contains Mg 7-10, Ca 0-3, and Zn, Zr, Ag, or rare earth
elements 0-1 part. The biodeg-radable polymer is
polycyanoacrylate, polyhydroxy acetic acid, polylactic acid,
L-polylactic
acid,
polycaprolactone,
polydioxanone,
polyanhydride, polyphosphazene, poly-hydroxybutyrate,
hydroxyvalerate, and one or more copolymer of polyhydroxy
acetic acid, polylactic acid, L-polylactic acid, polycaprolactone, polycyanoacrylate and polydioxanone. The biodegradable ceramic is hydroxyapatite, -tricalcium phosphate,
-tricalcium phosphate or tetracalcium oxygen phosphate.
The implant is prepared by the mixing of magnesium and
calcium powder with one of Zn, Zr, Ag, Sn, and rare earth
elements. This mixture on smelting at 700-850ºC under
vaccum results in a compact Mg-Ca alloy. The alloy further
on sintering or self-propagating at higher temperature gave
porous Mg-Ca alloy. In coating of biodegradable polymer,
the obtained implant was washed with acid. Biodegradable
polymer is dissolved in trichloroethane solution and is
subjected centrifuging for 10-30 minutes. Electrophoresis
deposition or hydrothermal anodization methods are used in
biodegradable ceramic coating. The implant shows good
190 Recent Patents on Materials Science 2008, Vol. 1, No. 3
histocompatibility and blood compatibility. Thus they can be
used as implanting stenting, bone prosthetic devices, and
dental prosthetic devices [26].
CT-Detectable
Biodegradable
Nanocapsule
for
Controlled Drug Delivery and its Preparation Method
CN Patent 1973832 deals with biodegradable
nanocapsule manufactured from biodegradable polymer, CT
contrast core and hydrophilic or water-drug solution. The
biodegradable polymer used, are polycyanoacrylate poly
(lactic acid), polyglycolide, lactic acid-glycolic acid copolymer, polycyanoacrylate, poly (alkyl cyanoacrylate), polyanhydride, poly(caprolactone) and its copolymer, poly
(hydroxyvaleric acid), polyethylene terephthalate, poly(malic
acid), poly(tartronic acid), etc. The CT contrast agent used is
meglumine adipiodone, meglumine diatrizoate, amipaque,
ultravist or iodized oil. The preperation method comprises
dispersion of CT contrast agent, hydrophilic or water-drug
solution and surfactant or emulsifier in water to obtain
solution A. Mixing of biodegradable polymer with organic
solvent has been done to obtain solution B. Surfactant or
emulsifier on dispersion in water results in solution C.
Solution A on addition to the solution B gave a homogenous
W/O emulsion. Addition of this emulsion into the solution C
results in a W/O/W multiple emulsion system. The emulsion
is stirred to evaporate the organic solvent and cured to obtain
nanocapsule. The nanocapsule realizes in vitro controlled
delivery of drug because of the advantages of high drug
loading capacity, targeted and controllable drug delivery and
detectability due to CT [27].
Novel Compositions of Fat-Soluble Substances
US Patent 20070248683, is related to novel composition
of fat-soluble substances. It includes the novel powder form
of fat-soluble composition of substances and their emulsion
form. These novel compositions are used as additives in
food, beverages, animal feeds, cosmetics or drugs to incorporate fat-soluble ingredients into such items. A important
feature of these novel composition is the encapsulation of the
fat-soluble substance(s) to form an inner phase within an
outer continuous phase of a matrix substance.
In the synthesis of these novel compositions, synthetic
polymers are used from acrylic polymers (methacrylic acid
copolymers and ammonio methacrylate copolymers),
polyethylene, coumarene-indene resins, polylactic acid
(PLA) and poly(lactic/glycolic) acid (PLGA), polyorthoesters, polyphosphazenes, polyanhydrides, polyglycolide
(PGA), poly(epsilon-caprolactone), polydioxanone, trimethylene carbonate, poly( -hydroxybutyrate), poly( -ethyl
glutamate), poly(DTH iminocarbonate), poly(bisphenol A
imino [28].
Immunogenic Compositions Containing Antrhrax
Antigen, Biodegradable Polymer Microparticles, and
Polynucleotide-Containing Immunological Adjuvant
CA Patent 2588089 describes several
compositions. The composition comprises:
derived from bacillus anthracis, 2. Polymer
comprising a biodegradable polymer and 3.
containing immunological adjuvant.
immuno-genic
1. An antigen
micro-particles
Polynucleotide
Pawar et al.
The biodegradable polymer used in these immunogenic
composition is selected from a polycyanoacrylate, poly
(alpha-hydroxy acid), polyhydroxy butyric acid, polycrolactone, apolyrthoester and polyanhydride [29].
Slow-Released Nanoparticles Containing Neurotrophic
Factors Encapsulated in Biocompatible Polymers for
Nerve Repairs
CN Patent 1876175 deals with neurotrophic factors
(NTFs) comprises nerve growth factor, brain-derived
neurotrophic factor, neurotrophin-3, neurotrophin-4/5,
neurotrophin-6, ciliary neurotrophic factor, glia cell linederived neurotrophic factor. In this method encapsulation
polymers of polylactic acid, polyglycolide, poly (lactide-coglycolide), polycyanoacrylate, poly-Bu cyanoacrylate are
dissolved in dichloromethane and envelop with solution of
NTFs in water. The emulsifying mixture was obtained above
in ice water bath for first latex. Drip addition of first latex
into dispersant solution has been done fastly at high stirring
speed (10000-15000 rpm) for 1-5 minutes to obtain an
emulsion. The emulsion is diluted with distilled water and
further stirred at 300-600 rpm for 2-6h. High speed
centrifuging results in nanosized sphere which are washed
with distilled water for 3 times and lyophilized for 24 h.
Slow release nanosized NTFs formulation is used to cure
nerve damage disease, cauyda equina syndrome [30].
Antifungal Nano-Preparation of Amphotericin b (AmB)
and its Preparation
CN Patent 1850032 deals with the process developed by
dissolving 6 mg/ml stabilizing agent dextran-70 or
poloxamer 188 in distilled water. Cosolvent sodium
deoxycholate 0-0.4 mg/ml. may be added or not as per
requirement. Bu- cyanoacrylate is added at pH 3 with stirring
for 4 h. pH of the solution is adjusted to 7.5-8.5 to obtain
Poly(Bu-cyanoacrylate) nanoparticle gel solutions. AmB
powder is added to gel solution and the mixture was further
stirred for 4 h to obtain AmB-Bu polycyanoacrylate
nanoparticle gel solutions. This nano preparation shows good
antifungal activity [31].
Magnetic Nanoparticles Containing Mitomycin C and its
Application
CN Patent 1803133 deals with the nanoparticle prepared
from mitomycin C1 of high molecular weight polymers.
High molecular weight compounds are poly-lactide,
poly(lactide-glycolide), polycyanoacrylate, or amino acids.
The diameter of prepared nanoparticles is maintaining 50300 nm. These magnetic nanoparticles are used to treat
gastric, intestinal and liver cancer [32].
Porous Scaffold Material Composed of Recombinant
Spider Silk Protein and Polymer Used in Tissue
Engineering
CN Patent 1751748 deals with the material prepared by
cross-blending a recombinant spider silk protein 55-95 wt.%
with a biodegradable polymer 45-5 wt.%. The biodegradable
polymer used may be a polylactic acid (PLA), polyglycolic
acid (PGA), copolymer of polylactic acid and polyglycolic
acid (PLGA), polycyanoacrylate, polycapro-lactone, etc.
A. Cyano acrylate Polymers
Recent Patents on Materials Science 2008, Vol. 1, No. 3
191
This porous scaffold material has good biocompatibility,
biodegradability and mechanical property [33].
Nano Granules Adhesive to Mucous
Preparation Method and Application
Composite Polymeric Nanoparticles
CN patent 1760223 is concerned with a synthesis of
mucosa adhesive nanoparticle used in medicine, food and
cosmetics. These are prepared from (alkyl polyacrylate, alkyl
methylacrylate, or polycynoacrylate foam [38].
FR Patent 2872703 deals with the preparation and use of
biodegradable composite polymeric nanoparticles aqueous
suspensions with active ingredient. Preperation of composite
nanoparticles
of
poly(iso-Bu-cyanoacrylate)
/poly(caprolactone)/poly(ethylene glycol) with 1.7% busulfan has been described. The average diameter of composite
nanoparticles was 40 nm and the surface potential of
nanoparticles was 41 mV [34].
Imageable Elements Containing Cyanoacrylate Polymer
Particles
US Patent 20067070902 is related to the lithographic
printing. In this invention binder cynoacrylates polymer are
imaged to form lithographic printing plates.
In the preparation cynoacrylate polymer is dissolved in a
coating solvent and the resulting coating solution coated over
the donor support to form the layer of the cynoacrylate
polymer. The solvents used in this coating are acetonitrile,
dichloromethane, chloroform and methyl chloroform which
are toxic. Thus, there is a need to develop such process
which does not require the use of any toxic organic solvents
[35].
Stabilized Polyester/Cyanoacrylate
Formulation
Tissue
Adhesive
US patent 7,083,634 is deals with the adhesive
formulations of 2-alkoxyalkyl cyanoacrylate. These adhesive
formulations are useful as tissue adhesives/sealants, hemostatic agents, or as a means of patching and anastomotic
coupling of damaged organs.
The basic aspect of this invention is bound to a
bioabsorbable adhesive formulation, which is an admixture
of an alkoxyalkyl cynoacrylates, an absorbable liquid or
solid polymeric modifier, and a stabilizer against premature
anionic polymerization of the cynoacrylate components. In
this formulation the said stabilizers are one or more miscible
acidic compounds, includes pyrophosphoric acid, polyphosphoric acid and phosphoric acid or monobasic organic
sulfonic acids such as p-toluenesulfonic acid, trifluoroacetic
acid, and methanesulfonic at a concentration exceeding 1
ppm [36].
Chemically
Based
Vascular
Occlusion
Deployment with Gripping Feature
Device
CA patent 2551328 deals with a vascular occlusion
device deployment system of polycyanoacrylate foam for the
vasculature of a patient.
The deployment system includes the mixing and dispensing of the reactant into the cavity of interior chamber. It also
covers the deployment system wherein the first dispensing
unit comprises a first lumen and the second dispensing unit
comprises a second lumen [37].
Membrane,
Wound Dressing Comprising a Cyanoacrylate Adhesive
US Patent 2005244366 deals with wound dressing
material of butyl-cyanoacrylate adhesive. The adhesive is
applied directly to the wound site and extend at a distance
beyond the wound site to form a peripheral edge. The
method especially used in pediatric patient or a patient
having poor skin turgor. The dressing also includes a second
layer of a butyl-cyanoacrylate adhesive applied directly to
the first layer and overlapping the peripheral edge of the first
layer. In a moderate tension wound the second layer extends
the entire area of the first layer, but also extends a distance
beyond the peripheral edge [39].
Medical Device with Mechanically Attached Fibrous
Coatings
WO Patent 05079335 is related to nanofibrous polymeric
coatings on medical devices. The medical devices are
surgical mesh or stent, wherein the mechanical coating to the
device is done using thermal methods. The mechanism of
such coating is achieved by causing the fibers to permeate
and entangle with the substrate. The fibrous coating consist
of at least one polymeric component from the group of
polycyanoacrylate polycaprolactone, polylactic acid,
polyglycolic acid, polydioxanone, polyanhydride, poly(hydroxybutyrate), poly(Et-glutamate), poly(DTH iminocarbonate), poly(bisphenol A iminocarbonate), poly(ortho
ester), polyphosphazene, nylons, polyesters, polyethylene
terephthalate, silicon-contg polymers, elastomeric silicone
polymers, polyolefins, etc [40].
Microparticles with Adsorbent Surfaces, Methods of
Making Same, and Uses Thereof
US Patent 20056884435 reported the microparticles
formation and their applications. The microparticles used for
a vaccine, for raising an immune response, for treatment and
diagnosis of a disease. The microparticles are prepared from
a biodegradable polymer polycyanoacrylate, poly(hydroxy
acid), a polyhydroxy butyric acid, a polycaprolactone, a
polyorthoester, a polyanhydride. The detergent used is one
from a cationic detergent and an anionic detergent. Further
the microparticles comprise an antigen adsorbed on the
surface of the microparticle [41].
Microparticle-Based Delivery of Adsorbed Toxoid and
Polysaccharide-Containing Antigen
WO Patent 05020964 is related to immunogenic
compounds microparticles with adsorbed toxoid antigen or
polysaccharide containing antigen. This microparticle
comprises (a) a biodegradable polymer; (b) an antigen
adsorbed on microparticles can be a toxoid antigen such as a
tetanus toxoid, a diphtheria toxoid, or a combination thereof,
192 Recent Patents on Materials Science 2008, Vol. 1, No. 3
Pawar et al.
or a polysaccharide antigen such as a Hib polysaccharide
antigen. A Hib conjugate antigen comprising polysaccharide
and polypeptide regions, a meningococcal polysaccharide
antigen, a meningococcal conjugate antigen comprising
polysaccharide and polypeptide regions, a pneumococcal
polysaccharide antigen, and a pneumococcal conjugate
antigen comprising polysaccharide and polypeptide regions
or a combination thereof; and (c) a pharmaceutically
acceptable excipient. The biodegradable polymer may be a
polycyanoacrylate, poly(hydroxy acid), a polyhydroxy
butyric acid, a polycaprolactone, a polyorthoester, a polyanhydride. The microparticle also used in immunization
against infection by pathogenic organisms and stimulating
immune responses. It also covered the methods of microparticle synthesis using a water-in-oil-in-water emulsion
process [42].
Microparticle Compositions
Manufacture Thereof
and
Methods
for the
RU Patent 2257198 is related to the biologically active
microparticles
composition.
These
microparticle
composition comprises: a) polymer such as polycyanoacrylate, poly-(alpha hydroxyacid), polyhydroxybutyric acid,
polycaprolactam, poly-ortho-ester, polyanhydride and b) the
detergent that is bound with polymer and also complex
adsorbed on microparticles complex that comprises: a) biologically active macromolecules and b) the detergent part
wherein biologically active macromolecule is taken
consisting of polypeptide, polynucleotide, polynucleoside,
antigen, pharmaceutical agent, hormone, enzyme, transcription or translation mediating agent, metabolite, an
immunomodulating agent and adjuvant [43].
Immunogenic Compositions Containing Microparticles
Comprising Adsorbed Toxoid And PolysaccharideContaining Antigens
US Patent 2005118275 is related to immunogenic vaccine compositions comprising biodegradable polymer microparticles possessing toxoid and polysaccharide containing
antigens.
The appearance of vaccines subunit includes polypeptide,
polysaccharide, conjugate, and DNA vaccines. All these
vaccines have been intensified the need for safe and effective
adjuvants containing compositions. Microparticles are
prepared by various techniques, after which the antigen is
adsorbtion to the microparticle. Polymer microparticles
formed from sterilizerable, substantantially non-toxic and
biodegradable materials. Such materials include polycyanoacrylates poly( -hydroxy acid), polyhdroxy butyric acid,
polycaorolactones, polyorthoesters, polyanhydrides.
In this invention an immunogenic composition comprises: a) biodegradable polymer microparticles of a
polycyanoacryalate, poly ( -hydroxy acid), a polyhydroxy
butyric acid, a polycaprolactone, a polyorthoeste, a
polyanhydride; b) an antigen adsorbed to the microparticles
selected from i) a toxoid antigen such as a tetanus toxoid, a
dipheria toxoid, or a combination thereof, an/or ii) a polysaccharide containing antigen such as a Hib polysaccharide
antigen, a Hib conjugate antigen comprising polysaccharide
and polypeptide regions, a meningococcal polysaccharide
antigen, a meningococcal conjugate antigen compmprising
polysaccharide and polypeptide regions, a pneumococcal
polysaccharide antigen, a pneumococcal conjugate antigen
comprising polysaccharide and polypeptide regions, or a
combination threrof; and c) a pharmaceutically acceptable
excipient [44-45].
Continuous Processes and Apparatus for Forming
Cyanoacetate and Cyanoacrylate
US patent 182271 deals with the cyanoacrylate formation
include stripping a solvent from a reaction mass; cracking a
polymer in the reaction mass to form a cracked cyanoacrylate monomer and residue substances; and distilling the
cracked cyanoacrylate monomer to produce a cyanoacrylate
monomer product. These steps can be performed in shortpath, wiped-film evaporators. Polycyano-acrylate used in the
processes is obtained using cyanoacetate produced by
processes for continuously producing cynoacetate by
forming a higher homologue cyanoacetae from a lower
homologue cyanoacetae. The cyanoacetate can be formed in
short-path, wiped-film evaporators [46].
Scretory Vacuole Structured Particles of Poly Cyan
Acrylic Estyers and Method of Duplex Inducing Bionic
Preparation Process
CN Patent 1687151 invention provides a biodegradable
high-molecular polycyanoacryalate (PACA) scretory vacuole
structure particle by utilizing ACA monomer polymerization. Invention also provides the concrete characteristics of
said high-molecular secretory vacuole structure particle [47].
Synthetic Resin for Identification
JP patent 164341 is related to obtain a novel and useful
synthetic resin easily applied to an identifing object
comprising a material of each kind, enhanced in
environmental resistance and having various characteristics,
such as a property being hardly noticed of the applications to
the synthetics resin or the like.
The synthetics resin for identification is selected from
among nylon 6,6, an aromatic polyamide, a formal resin, an
acetal resin and polycyanoacryalate. This synthetic resin for
identification is preliminarily applied to an article, and the
vibration spectrum is read in a non-destructive manner to
decide the genuineness of the article or to certificate the
origin of the article [48].
Solid Cyanoacrylate Adhesive Composition and Method
for its Use
US Patent 20046797107 reported solid cyanoacrylate
adhesives at room temperature are liquefy at higher than
room temperature and further polymerize to form adhesive
bonds or adhesive coatings. The adhesive compositions are
easy to be applied in industrial applications as well to skin or
living tissue. They are useful in medical applications,
includes wound and surgical incision closure, sealants and
void fillers, medical device fixation, embolic agents etc. In
method of the solid cyanoacrylate formation in various
composition is reported. If the substrates are not at above
room temperature, the adhesive polymerizes to form a strong
adhesive bond at higher temperature. The invention also
reports the solid cyanoacrylate adhesive delivering method,
using a suitable dispenser to a substrate. At higher
A. Cyano acrylate Polymers
Recent Patents on Materials Science 2008, Vol. 1, No. 3
temperature, the solid adhesive converts into a viscous liquid
and further polymerizes to form a coating. The invention
provides a cyanoacrylate adhesive composition in a new
form. The adhesives are preferably in a solid form at room
temperature and below room temperature. Room temperature
is considered from 15°C to 37°C and more preferably from
15°C to 25°C. This makes the application of the adhesive
easy and controlled. The adhesive is activated when the
temperature of substrate reaches a temperature above room
temperature, to renders the adhesive in liquid form. The
liquefied adhesive spreads and wets the underlying substrate
surface and polymerize as a typical cyanoacrylate adhesive.
The liquidification and polymerization of the adhesive is
achieved by bringing the temperature higher than 25°C to
30°C. In industry the essential heating is achieved by heating
thermally, IR, UV or by microwave radiation.
The solid cyanoacrylate compositions may contain a
biodegradable or bioabsorbable component. The bioabsorbable cyanoacrylate compositions described in US Patent
6224622 is suitable for inclusion into the solid cyanoacrylate
adhesives of the present invention. One embodiment of this
work is directed for making a cyano-acrylate adhesive
composition in a solid form at room temperature by
dissolving a cyanoacrylate monomer or a mixture of
cyanoacrylate monomers one or more solidifying polymers
or copolymers at elevated temperature. Then the solution is
allowed to stand for a sufficient time at room temperature or
below room temperature to form a solid at room temperature.
The cyanoacrylate monomers are prefer-ably selected from
the group consisting of alkyl 2-cyanoacrylates, alkenyl 2cyanoacrylates, alkoxyalkyl 2-cyanacrylates, and carboalkoxyalkyl 2-cyanoacrylates. The alkyl group of the one or
more cyanoacrylates preferably has 1 to 16 carbon atoms.
The solidifying polymer or copoly-mers is preferably a poly
( -caprolactone) [49].
Embolic
Compositions
with
Rheology Modifying Agents
Non-Cyanoacrylate
EU Patent 1425319 describes a composition comprising a
matrix forming component, a solid aggregate material and a
polymeric rheology modifier. The matrix-forming
component comprises liquid alkyl cyanoacrylate monomers
at least with a stabilizer and a plasticizer. A solid aggregate
material is incorporated in the composition with matrixforming component, comprises at least a radiopaque powder
radiopacifier. A rheology-modifying agent is also
incorporated into the composition, in combination either
with the matrix-forming component or with the solidaggregate material. The rheology-modifying agent used is a
non-cyanoacrylate polymer. A fine inorganic particulate
compound is used as a second rheology modifier present in
the solid aggregate material. This composition is useful in a
therapeutic regimen in the treatment of vascular abnormalities. Administrating the composition includes, AVMs,
aneurysms, fistulas, and tumors treat vascular abnormalities.
In presence of ionic environment, the viscosity of liquid
composition is rapidly increases, forming a solidified
composition of a rubbery polymeric matrix.
The method also described administration of the
composition for tissue bulking, filling, or occluding, either
partially or entirely, a volume or cavity in a mass. The
193
volume or cavity filled by the method is a lumen or
passageway in the body, for example, a blood vessel, a duct,
an aneurysm, or a fistula. The solid composition formed is
useful for abating disease of the vascular tissues or by
cutting the blood supply to undesired tissue. A tumor or
abnormality is occluded by cutting off the blood supply to
the diseased area, resulting in diminished growth or death of
the tumor or abnormality. The method also includes
administration of composition to embolize a vascular space.
The composition is administered to a patient who needs a
treatment for vascular abnormalities, to form an embolic
block at the site of diseased, damaged, or otherwise compromised vasculature. The above aspects, advantages, and novel
features of the invention will become apparent from the
following detailed description.
All the materials used are either incorporated into a
single injectable embolic composition along with the matrixforming components or included in one of the separately
packaged mixtures use to form the embolic composition. The
stabilizing component is comprised of an acidic stabilizer, a
free radical inhibitor, an antioxidant, or their mixture. The
plasticizer used are non-polymeric compounds impart the
flexibility, prevent the brittleness, reduce adhesiveness to
catheter delivery devices, and are compatible with alkyl
cyanoacrylate monomers. The solid-aggregate material
comprises a radiopacifier, includes a rheology-modifying
agent. The rheology-modifying agent has capacity to
increase the Newtonian viscosity of the composition imparting non-Newtonian behavior upon the liquid composition.
The fluids show such behaviors are generally known as
"shear thinning." The rheology-modifying agent also
improves the surface tension of composition as it solidifies.
Different composition is used for embolizing a vascular
space, or cavity. The matrix forming components are
combined with one or more solid aggregate materials. In
particular, the matrix forming components includes liquid
cyanoacrylate monomers, a stabilizer, and a plasticizer,
comprises at least a radiopacifier. The composition is
typically a liquid injectable composition that solidifies in
ionic environment like blood. The matrix forming
component or the solid aggregate material contains a noncyanoacrylate compound, which imparts improved rheology,
cohesiveness, suspension stability, and radiopacity properties
of injectable composition liquid. In addition, the inclusion of
a non-cyanoacrylate polymer compound improved a
hydrolytic stability of the solidified composition rendered in
the body. The composition is useful for stabilizing or
mitigating rupture of an aneurysm. The composition also is
used to occlude the interior space of an unruptured or
previously ruptured aneurysm.
Alkyl cyanoacrylate monomers are prepared by forming
the desired ester from the corresponding alcohol and
cyanoacetic acid. The reaction of the alkyl alcohol with the
cyanoacetic acid forms an alkyl cyanoacetate, which can be
converted into the desired alkyl cyanoacrylate compound.
The preparation of the alkyl cyanoacrylate compounds has
been described in US Patents 20006015541, 20006037366,
and PCT International Publication WO000044287. Starting
materials for preparing the alkyl cyano-acrylate monomer are
commercially available from, Aldrich Chemical Company,
194 Recent Patents on Materials Science 2008, Vol. 1, No. 3
Sigma Chemical Company, or Fluka Chemical Company
[50].
Cyanoacrylate-Capped Heterochain Polymers and Tissue
Adhesives and Sealants Therefrom
US Patent 20046699940 deals with a cyanoacrylatebased tissue adhesive or sealant composition comprising a
cyanoacrylate capped heterochain polymer with two or more
cyanoacrylate ester groups. The heterochain polymer used
for capping is made up of one or more absorbable polymer
such as, polyester, polyester-carbonate, polyether-carbonate,
and polyether-ester. The capped polymer may be synthesized
from polyethylene glycol or polypropylene glycol. Heterochain polymer capping is done using alkyl cyanoacrylate or
an alkoxyalkyl cyanoacrylate such as ethyl cyanoacrylate or
methoxypropyl cyanoacrylate respectively in the presence of
phosphorus acids. Radiochemically sterilized formulations
are used as sterile adhesives, sealants, or blocking agents in
repairing mechanically or pathologically compromised
internal organs or tissues or in blocking body conduits, such
as blood vessels [51].
Cyanoacrylate capped heterochain polymers and their use
as absorbable or non-absorbable tissue adhesives, sealants,
blocking agents, and/or hemostatic adhesives in medical or
non-medical applications has been covered. One aspect of
this invention is covalent binding of cyanoacrylate functionality to a heterochain polymer molecule. The process of
transesterification between a hydroxyl group and a simple
cyanoacrylate ester to yield a cyanoacrylate capped
heterochain polymer in the presence pyrophosphoric acid
catalyst has been done. Another aspect of this invention is
the preparation of cyanoacrylate-capped (CC) polyalkylene
oxide or copolymers to produce a range of anionically fast
polymerizing CC polyethers with a broad range of
hydrophilic/hydrophobic content. The cyanoacrylate used is
in the form of an alkyl or alkoxyalkyl ester. It also deals with
prepartion of sterile adhesive or sealant formulations using
radiochemical sterilization as per US Pat. 5,422,068.
Illustrations of this invention are provided in the two
examples. 1) Preparation and curing of a tissue adhesive
formulation comprising cyanoacrylate-capped polyethylene
glycol-600 (PEG-600) and 2) Preparation and curing of
tissue adhesive comprising cyanoacrylate-capped Triaxial
Poly ( -caprolactone-co-trimethylene carbonate) (TCT) and
Ethyl Cyanoacetate (EC) [52].
Manufacture of Freeze-Dried Colchicine Microparticles
as Anticancer Agent
CN Patent 1533765 deals with the manufacturing of
freeze-dried colchicine microparticles. The preparation of
these microparticles takes place in three steps, Step 1. To the
solution of poly (vinyl alcohol) in distilled water sodium
chloride is added to obtain isotonic solution as like blood
plasma, Step 2. Colchicine and polycyanoacrylate are
dissolved in organic solvent. The colchicine solution is fastly
added to a solution of step 1 with constant heating and
stirring, Step 3. Surfactants and freeze-drying agents are
added and the mixture is subjected to vacuum freeze-drying
to obtain the final products. The surfactants used may be
tween-80, tween-20, span-80, span-20 or poloxamer. The
organic solvent used can be chloroform, dichloromethane,
Pawar et al.
and ethanol. The freeze-drying protecting agents may be one
from glycine, sorbose, sorbitol, glucose, and lactose. As
colchicin inhibits karyokinesis of cells, suppress proliferation of cancer cells. These microparticles used in the
treatment of mammary cancer, primary gout, hepatic injury
and hepatic fibrosis [53].
Biodegradable Polymer Microparticles with Absorbed
Polynucleotides Encoding Antigen and Adjuvant as
Vaccine Against Tumor and Infection
WO Patent 04065578 deals with the synthesis and
applications of microparticles with adsorbed polynucleotide.
The microparticles comprised (a) one of the biodegradable
polymer from a polyhydroxy butyric acid, a polycaprolactone, a polyorthoester, a polyanhydride, or a polycyanoacrylate, (b) a cationic surfactant cetyltrimethylammonium bromide and (c) a polynucleotide species
adsorbed on the surface of the microparticles with at least 5
percent of polynucleotide species of total weight of said
microparticles. Polynucleotide species includes immunological adjuvants, such as CpG oligonucleotides, and
polynucleotide species that encode polypeptide antigens such
as RNA and DNA vector. These microparticles are used for
delivering a therapeutic amount of a polynucleotide species
to the host animal to stimulate an immunogenic response.
They are also used for treating a host animal having a
pathogenic organism infection and used as vaccines [54].
Vaccine Compositions Containing Phospholpid Adjuvant
Against Infection and Cancer
WO Patent 04060396 deals with the immunogenic
compounds containing phospholipid adjuvants, includes
microparticle and emulsion compounds. According to the
aspect of invention, an immunogenic microparticle
compounds is provided that comprises: water; a polymer
microparticle comprising a biodegradable polymer, e.g., a
polymer selected from a poly (hydroxy acid), a polyhydroxy
butyric acid, a polycapro-lactone, a polyorthoester, a
polyanhydride, and a polycyano-acrylate; an antigen
adsorbed to the microparticle; and a phospholipid compd.,
e.g., a synthetic phospholipid compd. comprising: (i) one or
more phosphoryl groups indepen-dently selected from a
phosphato group and a phosphodiester group; (ii) a plurality
of linear alkane groups. According to another aspect of the
invention an immunogenic emulsion compounds is provided
that comprises: water; a meta-bolizable oil; an emulsifying
agent; an antigen; and a phospholipid compounds, e.g., a
synthetic phospholipid compounds. The emulsion compound
is an oil-in-water emulsion having oil and aqoues phases, in
which the oil phase is in the form of oil droplets. The antigen
is viral, bacterial, fungal, parasitic or neoplastic antigen [55].
New
Copolymer-Based
Compounds
and
their
Applications as Blood Substitutes and Cleansing Agents
FR Patent 2844512 deals with the new compounds useful
as blood substitutes and cleansing agents comprise a hemoprotein associated with a copolymer sequence block conting
an oligo or polysaccharide hydrophilic segment connecting
to at least a hydrophobic segment. The nanoparticles of the
title compounds was prepared by polymerisation of dextran
A. Cyano acrylate Polymers
Recent Patents on Materials Science 2008, Vol. 1, No. 3
195
and iso-Bu cyanoacrylate and used to prepare an associated
product with Hbs [56].
composites may be, used, a bone pin, screw, or prosthesis
[61].
Polyester/Cyanoacrylate Tissue Adhesive Formulations
Adherable Biomaterial Patches
Producing and for Using Same
US Patent 20046723114 invention is directed to
bioadsorbable adhesive/hemostatic formulations of a 2alkoxyalkylcyanoacryalate and liquid or solid polymeric
modifiers and adjuvant. The present adhesive formulations
are useful as tissue adhesive/sealants, hemostatic agents, and
as a means for patching or anastomic coupling of damaged
organs.
In one aspect, the present invention is directed to a
bioadsorbable adhesive formulation, which is an admixture
of 2-alkoxyalkylcyanoacryalate and an oxalate polymer of
polyethylene glycol, wherein the polyethylene glycol has an
average degree of polymerization of more than 4 [57].
Polyoxyethylene Grafted Polycyanoacrylate for Drug
Delivery and its Preparation
CN Patent 1417242 is related to the polyethylene glycol
grafted polycyanoacrylate, used to prepare the nanocapsules
of taxol, ibuprofen hydrophobic drug via self-assembly. The
graft is prepared by reacting one side-terminated
polyethylene glycol with maleic anhydride at 65-120°C
under vacuum for 2-8 h. The obtained monoacrylate
polyoxyethylene alkyl ether further refluxed with diisocyanate at 70-90°C for 2-5 h and 2-hydroxyalkyl methacrylate at
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