Polymer blends and polymer composites for cardiovascular implants

Modern implantable medical devices have evolved beyond serving as physical surrogates, to also playing an active role in restoring bodily functions. The progress of implantable medical devices is the culmination of advances in various scientific fields such as material science, microelectronics and biomaterials. The use of polymers in biomedical applications is highly attractive, especially in soft tissue applications as polymers have the potential to elicit appropriate host tissue response. However, homopolymers often do not encompass all the desired characteristics such as mechanical properties, degradability, biocompatibility or bio-functionality. The concepts of polymer blending or polymer composites were introduced to overcome the inadequacies when using a single polymer in cardiovascular applications. Through polymer blending, polymer scaffolds made up of two or more polymers can yield scaffold stiffness closer to the human myocardium and improved hydrophilicity for better cell interaction and improved biodegradability. Polymer composites, which utilizes to reinforce the base polymer, have demonstrated improved the compliance of the vascular graft similar to human native vessels. This review presents an overview of fabrication techniques and novel applications of polymer blends and polymer composites in cardiovascular implants, ranging from coronary stents to tissue engineered constructs.