Controlled Synthesis Of Dopamine-containing Glycopolymers And Preparation Of Bioactive Surfaces

Carbohydrate plays a key role in many complex biological processes in binding with protein such as cell-to-cell recognition,signal transduction and host-pathogen interactions.Sugar,an important molecule in life,has good interaction with specific protein.However,this specific interaction is relatively weak between a sugar molecule and protein/ receptor.Polymers with pendent carbohydrate moieties prepared by using a chemical synthesis method widely called “glycopolymers” have the sugar multivalent effect to enhance the interaction with proteins.In addition,the catechol group under the alkaline conditions is oxidized into a complex quinoid structure to form polydopamine layer on the surfaces.We integrated sugar and dopamine units into one polymer via living radical polymerisation methods,utilized the specific protein recognition ability of sugar and surface adhesion of dopamine and obtained the surfaces with good biocompatibility and potential application finally.The main content of this paper is as follows:(1)Synthesis of sugar dopamine random copolymer by one-step method.The dopamine-containing glycopolymers were prepared by single electron transfer-reversible addition chain transfer(SET-RAFT)controlled radical polymerization,then the surfaces were modified by functional glycopolymers to form polymer layer on the surfaces.The experimental characterizations show that the side chain of the copolymer prepared by SET-RAFT does contain catechol group and sugar unit,and the molecular weight of the glycopolymer is well-controlled and polydispersity is narrow.Glycopolymers with different functional unit ratios can be obtained by changing the ratio of the sugar to the dopamine monomer,from which it is found that dopamine monomers have a greater influence on the polymerization rate.As we know,dopamine is easy to be oxidized in alkaline conditions,and dopamine-containing glycopolymers can be modified quickly and effectively anchored on the surface of materials to own the ability of sugar bind with lectin/cells.A simple and effective method for the preparation of the functional surfaces is provided.(2)Chemically modified surface having a dual-structured hierarchical topography for controlled cell growth.The physical properties of the porous and oriented dual-structured hierarchical topography on the surface of PDMS are obtained through template replication and releasing prestretching.The dopamine-containing glycopolymers are anchored on the surface due to the adhesion of dopamine,so that the PDMS substrates own physical and chemical double properties after being chemically modified.The experimental results show that the surface of chemically modified PDMS has the ability of specifically recognizing lectin,and this dual-structured hierarchical topography can guide cell morphology during cell growth.The glycopolymer coating increases the adhesion of cells to the morphological surface and the combination of dual-structured hierarchical topography and chemical modification promotes cell orientation.(3)Sunlight-induced RAFT synthesis of multifaceted glycopolymers with surface-anchoring,in-situ Ag NPs formation and antibacterial properties.Silver or silver ions enter the interior of bacteria to kill them through the bacterial cell wall,and silver-based compounds or silver-loaded nanomaterials can be used in biomedical applications universally,durably and safely.The sunlight-induced living radical polymerization in the presence of RAFT agent was successfully applied to obtain well-controlled multifunctional glycopolymers bearing the carboxylic acid,the catechol and the sugar groups,which can complex with silver ion,bind to different surfaces and form silver nanoparticles in-situ,respectively.It shows that the prepared multifunctional dopamine-containing glycopolymer can be effectively modified on the surface,and the silver ions were complexed with and reduced into Ag NPs in situ on the surface of the substrate.It was found that through a bacterial experiment using Escherichia coli as an example the glycopolymer-modified material surface can effectively kill bacteria,and the antibacterial effect is related to the proportion of component in the polymer chain.