biomaterial, such as dexamethasone, is shown to increase implant life by preventing inflammation and fibrosis. Incorporation of bioactive molecules Coating the implant surface with biomimetic biomaterial may reduce the foreign body reaction and reduce the device failure rate. Biomaterials that mimic the extracellular matrix can significantly reduce the inflammatory response as well as reduce foreign body giant cell formation. Novel biomaterials Developing materials that resist protein adsorption, fibrous encapsulation, or foreign body giant cell formation is important to resist the foreign body reaction. Commonly used biomaterials like polyethylene glycol and polyhydroxyethylmethacrylate resist nonspecific protein adsorption but are easily degraded in the in vivo oxidative environment. Therefore, scientists are looking for new materials that intrinsically resist the foreign body reaction. Zwitterionic materials Zwitterionic polymers are widely used in surface modification because they can inhibit non-specific protein adhesion. Zwitterionic hydrogels also promote angiogenesis in surrounding tissues. Commonly used zwitterionic materials include sulfobetaine, carboxybetaine, and phosphorylcholine. Zwitterionic polymers have the ability to reduce nonspecific adsorption of proteins and cells at biological interfaces. Zwitterionic coatings are often used to minimize the negative effects of foreign body response for implanted devices and improve the device's biocompatibility. The mechanism is related to surface charge balancing and creation of a strong hydration sphere. Zwitterionic coatings can be covalently attached by “grafting to” and “grafting from” methods. With “grafting to” methods, the surface is modified with the polymer after synthesis, whereas with “grafting from” methods, polymer is directly synthesized on a modified surface. Several “grafting to” methods have been used to covalently attach zwitterionic polymers to surfaces. Anderson group developed attachment to the surface via polydopamine conjugation. In this case, copolymer should contain a thiol group. Nazarova and coworkers synthesized MPC copolymers with 2-methacrylamido-D-glucose, N-vinylpyrrolidone, and N-vinyl-N-methyl-acetamide and grafted them onto the surface of carbon fibre biosorbent using γ-radiation. MPC copolymers with trimethoxysilylpropyl methacrylate can be thermally cured and self-crosslinked. Modian fied alginates Alginates are widely used for their low cost, low toxicity, and tunability. However, implantation of only alginate will trigger serious foreign body reaction. There are a few triazole-containing alginate derivative microspheres that remain clear of fibrotic deposition in mice, but more studies are required to explore the relationship between triazole groups and the inflammatory response. Polypeptide materials Polyethylene glycol peptides and zwitterionic peptides have immunomodulatory functions that help to resist the foreign body reaction. Gallery See also Foreign body List of cutaneous conditions References External