Dual-Functional Biomimetic Materials:Nonfouling Poly(carboxybetaine) with Active Functional Groups for Protein Immobilization

摘要

We introduce a dual-functional biocompatible material based on zwitterionic poly(carboxybetaine methacrylate) (polyCBMA),which not only highly resists protein adsorption/cell adhesion,but also has abundant functional groups convenient for the immobilization of biological ligands,such as proteins.The dual-functional properties are unique to carboxybetaine moieties and are not found in other nonfouling moieties such as ethylene glycol,phosphobetaine,and sulfobetaine.The unique properties are demonstrated'in this work by grafting a polyCBMA polymer onto a surface or by preparing a polyCBMA-based hydrogel.PolyCBMA brushes with a thickness of 10-15 nm were grafted on a gold surface using the surface-initiated atom transfer radical polymerization method.Protein adsorption was analyzed using a surface plasmon resonance sensor.The surface grafted with polyCBMA very largely prevented the nonspecific adsorption of three test proteins,that is,fibrinogen,lysozyme,and human chorionic gonadotropin (hCG).The immobilization of anti-hCG on the surface resulted in the specific binding of hCG while maintaining a high resistance to nonspecific protein adsorption.Transparent polyCBMA-based hydrogel disks were decorated with immobilized fibronectin.Aortic endothelial cells did not bind to the polyCBMA controls,but appeared to adhere well and spread on the fibronectin-modified surface.With their dual functionality and biomimetic nature,polyCBMA-based materials are very promising for their applications in medical diagnostics,biomaterials/tissue engineering,and drug delivery.