Customized Shape-Memory Biopolymers

The technological revolution which is smart biopolymers illuminates the propensity of certain multifunctional materials - shape biopolymers - to change form and move on exposure to a stimulus, and in so doing, perform functions which furnish them with a range of capabilities. Thus, the mechanized uniqueness of these polymers is embodied not only in their macroscopic structural changes, but in their reversible shape change. There is a binary classification of shape biopolymers: shape-memory and shape-changing biopolymers. The focus of this chapter is on shape-memory biopolymers (SMBPs), which possess dual-shape competence. In terms of biomedical applications, SMBPs could have diverse applications in stimuli-sensitive drug delivery systems, intelligent medical and surgical devices, tissue engineering, or implants for minimally invasive surgery. In this chapter, we firstly elaborate on the fundamental molecular mechanisms culminating in the macroscopic dynamics of shape-memory systems bringing about their pertinent action and the recovery of their original shape. Further, we highlight the diverse stimuli instigating the polymeric response such as thermal stimuli, light, magnetism, mechanical stress or moisture. In addition, we discuss the biopolymers exhibiting potential shape-memory capabilities, as well as various modifications, functionalizations and reinforcements to these to customize their biomedical applications. An expert summation of the application of these biopolymers in the design of smart delivery systems, implants and devices, as divulged through recent investigations, is presented. The chapter culminates in current and future trends in the design and application of SMBPs and their overall potential benefits.

Keywords: Biopolymers, external stimulus activation, intelligent drug delivery systems, medical devices, shape-memory polymers, stimuli-responsive systems.