Antibacterial Polyurethanes in Biomedical Applications

Polyurethanes and their counterparts, polyurethane-ureas (PUUs), a favorable group of polymers, are prepared from a wide variety of materials. PUs/PUUs offer a wide range of controllable properties and therefore, are known as good candidates for a broad range of applications. Among the very broad field of applications known for this group of polymers, biomedical devices and prosthesis, drug delivery vehicles and tissue engineering scaffolds have attracted most attention over recent decades. This study systematically reviews the current literature for biomedical applications of polyurethanes (PUs) and polyurethane-ureas. On the other hand, in addition to different qualities that are required for successful performance of a biomaterial (including biocompatibility, bio-stability and/ or biodegradability, hydrophilicity and/or hydrophobicity, adjustable mechanical properties, etc), antibacterial behavior is considered as an inevitable prerequisite in many applications. Therefore, the especial emphasis of this review paper is placed on polymers with antibacterial activity and the strategies towards preparation of antibacterial PUs and PUUs, in particular. Current strategies applied for preparation of antibacterial polyurethanes and polyurethane-ureas are reviewed. Among such approaches, adoption of nano-silver, blending with natural polymers of well-known inherent antibacterial activity such as chitosan, loading of antibacterial drugs and surface modification with antibacterial agents are discussed in details.