Journal Article

Non-invasive surgery techniques and drug delivery system with acoustic characteristics of ultrasound contrast agent have been studied intensively in recent years. Many ultrasound contrast agents are commercially available, and they are usually composed of a microbubble coated by a surfactant or lipid bilayer, i.e., a hollow microsphere. We show that the hollow microsphere with polymer shell can be fabricated just blowing vapor of commonly-used instant adhesive into water as microbubbles.

A general methodology was proposed to prepare highly functionalized poly(alkyl cyanoacrylate) nanoparticles by means of Huisgen 1,3-dipolar cyclo-addition, the so-called click chemistry.

Supercritical carbon dioxide (SC CO2) was used as an aid in fabricating polymer/polymer composites. Using a two-stage process, ethyl 2-cyanoacrylate (ECA) monomer was anionically polymerized within poly(tetrafluoroethylene-co-hexafluoropropylene) substrates. The composite fabrication process involved first infusing triphenylphosphine (the initiator) into the substrate using SC CO2. In the second step, monomer was introduced (again using SC CO2) to the substrate. As the monomer absorbed into the initiator-containing substrate, it polymerized.

The processing of advanced materials such as refractory ceramics and metallic alloy powders has been investigated intensely over the past two decades. Ceramic injection moulding has therefore become a prime method for manufacturing complicated parts from a robust material. Typically, powder is dispersed within a thermoplastic carrier (or binder) before it is moulded at high temperatures and pressures. Further removal of the binder by thermal or solvent degradation methods yields a component that is suitable for sintering.

Supercritical carbon dioxide (SC CO2) was used as an aid in fabricating polymer/polymer composites. Using a two-stage process, ethyl 2-cyanoacrylate (ECA) monomer was anionically polymerized within poly(tetrafluoroethylene-co-hexafluoropropylene) substrates. The composite fabrication process involved first infusing triphenylphosphine (the initiator) into the substrate using SC CO2. In the second step, monomer was introduced (again using SC CO2) to the substrate. As the monomer absorbed into the initiator-containing substrate, it polymerized.

A quasi-solid-state dye-sensitized solar cells (DSSCs) employing a commercial glue (“SuperGlue®”) as electrolyte matrix was fabricated. The cyano groups of the cyanoacrylate can form a supramolecular complex with tetrapropylammonium cations. This immobilizes the cations and therefore might lead to a favored anionic charge transport necessary for a good performance of the iodide/triiodide electrolytic conductor. Obtaining energy conversion efficiencies of more than 4% under 100 mW/cm2 of simulated A.M.

Chitosan–poly(ethylene glycol)–tyramine (CPT) hydrogels were rapidly formed in situ using horseradish peroxidase and hydrogen peroxide to explore their performance as efficient tissueadhesives. A poly(ethylene glycol) modified with tyramine was grafted onto a chitosan backbone to enhance the solubility of the chitosan and to crosslink into three-dimensional networks. The elastic modulus of the hydrogels could be controlled by changing the crosslinking conditions, and the mechanical strength influenced the tissue adhesiveness of the hydrogels.

Hierarchical biological materials such as bone, sea shells, and marine bioadhesives are providing inspiration for the assembly of synthetic molecules into complex structures. The adhesive system of marine mussels has been the focus of much attention in recent years. Several catechol-containing polymers are being developed to mimic the cross-linking of proteins containing 3,4-dihydroxyphenylalanine (DOPA) used by shellfish for sticking to rocks. Many of these biomimetic polymer systems have been shown to form surface coatings or hydrogels; however, bulk adhesion is demonstrated less often.

This study reports the effect of exposure to liquid carbon dioxide on the mechanical properties of selected medical polymers. The tensile strengths and moduli of fourteen polymers are reported. Materials were exposed to liquid CO2, or CO2 + trace amounts of aqueous H2O2, at 6.5 MPa and ambient temperature. Carbon dioxide uptake, swelling, and distortion were observed for the more amorphous polymers while polymers with higher crystallinity showed little effect from CO2 exposure.

The biocompatibility of two cyanoacrylate surgical glues (Glubran and Glubran 2), supplied by General Enterprise Marketing, Viareggio, Lucca, Italy, was tested through cytotoxicity and blood compatibility tests and the evaluation of antimicrobial activity. Cytotoxicity and blood compatibility tests were performed on the polymerized glues. Using the neutral red uptake test, the extracts from Glubran and Glubran 2 after polymerization were non-toxic to L929 cells only when diluted 1 : 10 with culture medium.