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Photoresponsive polymeric films fabricated by a facile electrostatic self-assembly technique are utilized to switch protein adsorption by light irradiation. The introduction of SiO(2) nanoparticles on the substrate results in a large reversible change of both wettability and protein adsorption.

The thiol-ene photopolymerization, which could be achieved with less ultraviolet (UV) intensity and photoinitiator content was first introduced into the application of injectable intraocular lenses (IOLs), thus the damages to the eye from the UV radiation and photoinitiator toxicity were greatly reduced. The bulk samples were obtained from the mixture of poly(ethylene glycol) diacrylate (PEGDA) and pentaerythritol tetrakis(3-mercaptopropionate) (PTMP) by the thiol-ene photopolymerization. It was found that PEGDA-PTMP bulk samples had the similar transparency and the hydrophilicity as the ones from PEGDA by homophotopolymerization. Meanwhile, when PTMP was added into PEGDA, the elastic modulus of the bulk samples was decreased and their flexibility was improved. The experimental results indicated that the thiol-ene photopolymerization was one potential method to obtain the ideal injectable IOLs, although many works have to be done in the future study, such as selecting proper monomers and testing the biocompatibility of polymerized samples. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers

In this article, hydrogels were prepared by compounding polyvinylpyrrolidone (PVP) with poly(vinyl alcohol) (PVA), which is used as artificial cartilages, by means of repeating freezing and thawing and irradiation, for improving their mechanical and surface lubricative properties. The structures and properties, including gel content, crystallized degree, elastic modulus, and frictional coefficients of the compound hydrogels with different PVP contents and irradiative conditions, were examined and compared. The existence of PVP macromolecules interfered with the crystallization of PVA hydrogels resulted in the decrease of gel contents and elastic modulus, as well as the unstable external frictional coefficient in water. After irradiation treatment, these performances increased with irradiation intensity in lower dose ranges. The solubility and exudation of PVP in water were prevented and reduced because of the chemical crosslink of PVA and PVP, and the lubricative properties of PVA/PVP hydrogels in water were improved. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

A novel ionic crosslinking sodium alginate (SA)/carboxymethylated bacterial cellulose (CM-BC) composite with a semi-interpenetrating polymer network (semi-IPN) structure was developed in this study. The composite was prepared through the blending of an SA gel with CM-BC then crosslinking by Ca2+ followed by a freeze-drying process. Scanning electron microscopy showed the composite matrix organized in a three-dimensional network of CM-BC interpenetrated against SA molecular chains with a quantity of calcium alginate microspheres upon the surface. The swelling ratios of the composite were enhanced by 183, 198, and 212% with the supplementation of CM-BC weight fractions of 25, 50, and 75%, respectively; the swelling ratios changed with changing pH. The tensile modulus, tensile strength, and elongation at break of SA were enhanced by 165, 152, and 188%, respectively, with the addition of 50 wt % CM-BC. This study demonstrated that the semi-IPN structure dramatically changed the swelling and mechanical properties of the composite, and the semi-IPN will be a promising candidate for biomedical applications such as wound dressings and skin tissue engineering. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39848.

Biopolymer nanocomposites of carbon nanotubes (CNTs) which reinforced poly(hydroxybutyrate-co-valerate) (PHBV) were developed. Multiwalled carbon nanotubes were modified by an acid oxidation treatment (A-MWCNTs) to improve their dispersal in the polymer. The thermal properties, crystallization behavior, microstructure, and cross-sectional morphology of the composites were investigated. Their mechanical properties and surface contact angles were tested. The cytotoxicity of the composites to murine fibroblast L929 cells was also evaluated. The results show that A-MWCNTs are homogeneously dispersed in PHBV which demonstrate strong heterogeneous nucleation on the dynamics and kinetics of crystallization of PHBV. With the addition of A-MWCNTs, the crystallization temperature, heat of crystallization, and thermal stability of the composites increase. Consequently, the mechanical properties of the composites have been substantially improved. The composites become hydrophilic and have no obvious toxicity to the murine fibroblast L929 cells when the content of A-MWCNTs is below 1.5 wt %. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012