A supramolecular coacervate hydrogel was synthesized by simply mixing poly(N-vinylpyrrolidone) (PVP) and tannic acid (TA). Resulting super adhesive properties showed adhesion strength of 3.71 MPa on a glass substrate.

Gelatin nanofibers can be used in the development of a biomimicking artificial extra cellular matrix(ECM) for tissue engineering, wound healing dressings and drug release. However, gelatin nanofibers are water soluble and have weak mechanical strength. Two different cross-linking methods for preparing gelatin nanofibers were used to render gelatin nanofibres insoluble: 1) UV radiation for modified gelatin nanofibers by trans-cinnamic acid; and 2) electrospun gelatin nanofibers cross-linked with genipin. A photo cross-linking method was used to examine the effects of ultraviolet (UV) radiation on the modified gelatin nanofiber scaffolds. A modified gelatin solution containing gelatin, trans-cinnamic acid and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) at a molar ratio of 1:3:30 was prepared. The results showed that the degree of modification in gelatin molecules was 14.5 groups per mol. The modified gelatin was dissolved in 1,1,1,3,3,3-hexafluoro-2-propanol at 20%(w/v) and nanofibrous meshes were obtained by electrospinning. After drying, the nanofibrous meshes were exposed to a commercial germicide UV (=254 nm) lamp for different times. The swelling ratio of each nanofibrous mesh was decreased from 195% to 105% with increasing UV exposure time from 1 h to 10 h. A cross-linking agent method was used to evaluate the effects of the cross-linked gelatin nanofiber scaffolds with genipin. The swelling ratios decreased from 725% to 445% with increasing genipin solution concentration from 0.5%(w/ v) to 2%(w/v). The results of the cell culture suggest that cross-linking gelatin nanofibers with 0.5%(w/v) genipin improves the level of cell proliferation with increasing cell culture time from 1 day to 5 days. Moreover, the cell viability of each nanofiber increased with increasing cell culture time. However, the cell viability decreased with increasing genipin solution concentration.

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ABSTRACT:Biodegradable ABA triblock copolymers of L-lactide and trimethylene carbonate with given compositions were prepared and chain-extended to produce high molecular weight polymer. The polymers were semicrystalline, and exhibited well microphase-segregated morphology with one crystalline poly(L-lactide) (PLLA) and the other soft and amorphous poly(trimethylene carbonate) (PTMC) block segments. The polymers could be cast into flexible and tough film, reversibly stretchable with elongation up to about 300%. This material may provide a novel thermoplastic elastomer possessing desirable properties including biodegradability, biocompatibility and good mechanical properties including two-phase morphology. Also a preliminary result on the hydrolytic degradation behavior was discussed.KEY WORDS Poly(L-lactide) (PLLA) / Poly(trimethylene carbonate) (PTMC) / Block Copolymer / Biodegradable / Thermoplastic Elastomer /

The catechol functional group of dopamine (3,4‐dihydroxyphenethylamine) has the ability to form strong adhesive bonds to inorganic and organic surfaces in aqueous environments. In this study, novel adhesive polyaspartamides containing catechol pendant groups were synthesized from polysuccinimide through successive aminolysis reactions with quantitative dopamine and ethylenediamine. The adhesion and crosslinking of dopamine‐modified polyaspartamide in aqueous alkaline media was used successfully to modify the surface of various materials (including synthetic polymers, metals, metal oxides, ceramics) using a simple immersion method. Contact angle measurements, SEM and X‐ray photoelectron spectroscopy of the modified surfaces were used to verify the surface coating on a variety of materials with very different inherent wetting properties. These novel biocompatible polymers have potential industrial and biomedical applications as adhesives or coating materials for functional surface modification. Copyright © 2011 Society of Chemical Industry