Piezoelectric polylactic acid-based biomaterials: Fundamentals, challenges and opportunities in medical device design.

Abstract

Poly(l-lactic acid) (PLLA) has long been identified as a biodegradable, sustainable and biocompatible polymer, with widespread use in a multitude of FDA approved resorbable medical devices. Recently, owing to its piezoelectric properties, PLLA has been employed in a wide range of biomedical applications, such as energy harvesting, biomonitoring, biodegradable sensors and actuators, drug delivery devices and smart scaffolds for tissue regeneration. For many of these applications the electroactive phase of PLLA is derived from the high orientation of the PLLA molecular chain, which is essential for the piezoelectric response. This review describes the potential of piezoelectric PLLA in medical device design, outlines PLLA cytocompatibility and presents the physicochemical characteristics of electroactive PLLA. In addition, the different processing strategies for generating piezoelectric PLLA and the formulation of PLLA composite materials with enhanced piezoelectric responses will be discussed. Finally, the most recent and promising piezoelectric PLLA-based biomedical applications and their advantages, challenges and limitations are presented and discussed.