Preparation And Characterization Of A Bioadhesive With Polyvinyl Alcohol Crosslinking Agent

As a new class of medical materials, bioadhesives are widely used in thebiomedical field which is attributed to its excellent biocompatibility and goodadhesion. Nowadays, preparing bioadhesive via photopolymerizationtechnology is a novel research direction, and there are only a few literaturesabout this. Compared to traditional medical adhesives such as α-cyanoacrylateand fibrin, photopolymerizable bioadhesives have some advantages in termsof rapid curing speed, less damage to organism and easy operation.In recent years, mussels with super waterproof adhesion performance anduniversal adhesion are of great concern, and their excellent biocompatibilitymakes them prime adhesives candidates. Polyvinyl alcohol (PVA), as a highlyhydrophilic polymer, is used in a large range of pharmaceutical andbiomedical applications which is due to its useful properties, for instance,good chemical, thermal stability and biocompatibility.This study was presented to prepare a bioadhesive inspired by marinemussel through photopolymerizaiton of photocurable3,4-dihydroxy-L-phenylalanine (DOPA) derivatives and photocrosslinkablePVA derivative (UV-PVA), and its properties were also investigated. The conclusions were described as follows:1. Four kinds of photocrosslinkable UV-PVA, esterification products ofPVA and acryloyl chloride, with different degree of acryloyl group substitution(DS) were prepared. Because of its varying solubility in different solvents,such as N, N-dimethyl formamide, dimethyl sulfoxide, N-methylpyrrolidone and water, it could be used as biopolymer crosslinking agent.2. Photocurable monofunctional monomer dopamine methacrylamide(DMA) was synthesized and its chemical structure was confirmed by1H NMRspectroscopy. Then three different kinds of DMA/UV-PVA gels were preparedusing UV-PVA with relatively high DS values (10%,15%,40%) ascrosslinking agent, and their photopolymerization kinetics, swelling behavior,adhesion strength and biocompatibility were studied. Gels were formed about5min under the conditions of20mW/cm2and1.0wt.%photoinitiator D-1173.And the higher DS value, the lower equilibrium swelling ratio. When the DSvalue increased to40%, the adhesion strength reached the highest, andadhesion strength of gels with30wt.%,40wt.%and50wt%DMA reached to0.14MPa,0.44MPa and1.87MPa, respectively. In addition, L929cells seededon DMA/UV-PVA gels not only adhered well, but also assumed the long,spindle morphology characteristic.3. Photocurable difunctional monomer ethylene glycol acrylatemethacrylate-dopamine (EGAMA-DOPA) was synthesized through Michaeladdition reaction, and its chemical structure was confirmed by Fourier Transform Infrared Reflection (FTIR) and1H NMR spectroscopy. Then twodifferent kinds of EGAMA-DOPA/UV-PVA gels were prepared using UV-PVAwith low DS values (2%) as crosslinking agent, and their photopolymerizationkinetics, swelling behavior, adhesion strength and biocompatibility were alsoinvestigated. It took about10min to form gels under the conditions of30mW/cm2and1.0wt.%photoinitiator D-1173. As the content of UV-PVAincreased, volume of gel decreased. UV-PVA crosslinking agent had an effecton adhesion strength, it was obviously observed that the more UV-PVA, thehigher adhesion strength. And in vitro cytotoxicity measurement showed thatEGAMA-DOPA/UV-PVA gels possessed good biocompatibility, which couldbe a candidate for bioadhesives.