A mussel-bioinspired multi-functional hyperbranched polymeric coating with integrated antibacterial and antifouling activities for implant interface modification

Abstract

In recent years, the infection-associated implant failures caused by bacteria intrusion and biofilm formation have become one of severe threats to human health. To effectively solve these problems, the functional modification for implant interface is considered as a promising strategy for inhibiting the bacteria infection after the implantation. However, the modification processes still face some limitations including the complicated operation, unitary function and high cost. In this work, the mussel-bioinspired hyperbranched polymeric coatings (TXPDG) are elaborately designed and synthesized through the Michael addition reaction of poly(ethylene glycol) diacrylate (PEGDA) and dopamine (DOPA), utilizing the trimethylolpropane triacrylate (TMPTA) and gentamicin (GEN) as branching and end-capping agents respectively. By means of adjusting the molar ratios of reactants, a series of TXPDG with controllable branching degrees (BD) and GEN contents are successfully obtained and used for interface modification of diverse substrates via a facile immersing process, which can be attributed to the universal adhesion of catechol pedants in molecular structure. The firmly formed T20PDG coating on substrate surface exhibits the excellent antibacterial performance towards both gram-negative Escherichia coli and gram-positive Staphylococcus aureus because of GEN terminal groups. In addition, the BSA protein adsorption assessment confirms that these TXPDG polymeric coatings also perform the prominent antifouling property, rendering the heterogenous resistance of the implant surface to avoid the serious stimulus response. More importantly, TXPDG polymeric coatings present remarkable biocompatibility, having no negative influence on the spreading and proliferation of MC3T3-E1 cells. As a whole, this work not only develops a strategy for the design and synthesis of multi-functional hyperbranched polymers, but also reveals the potential applications of functional polymeric coatings on the interface modification for implants to prevent infection-associated implantation failures.