Antibacterial Adhesion Of Polymer Materials Modified By Borneol Acrylate

In fields of biomedical and engineering applications,unwanted bacterial adhesion and subsequent bacterial biofilm formation on the surface of the material is a very serious problem which could cause failure or infection of the implant.Antimicrobial and antifouling coatings are the most commonly methods to prevent the attachment and diffusion of microorganisms.At present,varieties of traditional antibacterial agents(metal and its salts,antibiotics,quaternary ammonium compounds,polyhexamethylene biguanide,triclosan,halogenamine compounds)have been ultilized to avoid the adhession.However,these traditional antimicrobial methods have some drawbacks.First,leachable fungicides(such as antibiotics and heavy metals)incorporated or covalently linked to the polymer surface would gradually release over time,which may increase the tolerance of the microorganism to the antimicrobial agent.Second,compared to the same species of plankton,bacterial biofilm is less sensitive to antibiotics.Moreover,sub-lethal doses of antibiotics have exacerbated the formation of bacterial biofilm.In addition,Other antimicrobial agents containing covalent bonds,such as quaternary ammonium compounds,are not environmentally friendly;more seriously,the accumulation of biomacromolecules and dead microorganisms on the surface could diminish the antibacterial functionality.Therefore,to avoid the above shortcomings,we need to develop a new type of antibacterial material to replace the original modification method.Polymethyl methacrylate(PMMA)is a widely used biomaterial.But there is still a challenge facing its unwanted bacterial adhesion,because the subsequent biofilm formation usually leads to failure of related implants.Herein,we present a borneol-modified PMMA based on a facile and effective stereochemical strategy,generating antibacterial copolymer named as P(MMA-co-BA)s.It was synthesized by free radical polymerization and studied with different ratio between methyl methacrylate(MMA)and borneol acrylate(BA)monomers.NMR,GPC and EA etc.were used to confirm their chemical features.Their films were challenged with E.coli(Gram-negative)and Bacillus subtilis(Gram-positive),showing a BA content-dependent antibacterial performance.The minimum effective dose should be 10%.Then in vivo subcutaneous implantations in mice demonstrated their biocompatibilities through routine histotomy and HE staining.Therefore,P(MMA-co-BA)s not only exhibited their unique antibacterial character,but also suggested a potential for the safe usage of borneol-modified PMMA frame and devices for further implantation.The main results are as follows:1.P(MMA-co-BA)s copolymer of five different proportions were successively synthesized;2.NMR,GPC,etc.,were used to confirm the successive synthesis of P(MMA-co-BA)s;3.P(MMA-co-BA)s is a broad-spectrum antibacterial material.It has strong resistance to E.coli(Gram-negative bacteria)and Bacillus subtilis(Gram-positive bacteria).4.The incorporation of BA units is proportional to the antibacterial properties.When the incorporation amount is 25%,the copolymer can reduce the adhesion of 99%E.coli.5.P(MMA-co-BA)s is biocompatible and could be applied for the prevention of bacterial colonization in biomedical devices and applications.At the same time,we modified the zwitterion with pendimic acid to obtain P(BA-zDMAEA)s.Aspergillus niger was imployed to evaluate the antimicrobial adhesion of P(BA-zDMAEA)s.The main research results are as follows:1.P(BA-zDMAEA)s copolymer has a good effect of inhibiting fungal adhesion.Among them,4:1 copolymer could inhibit the adhesion of fungi to up to 30 days or more;2.1:4 copolymer has a spherical structure,which might contribute to the drug delivery system.