Advances in Conducting, Biodegradable and Biocompatible Copolymers for Biomedical Applications

Abstract

Electroactive biomaterials are a new generation of "smart" biomaterials based on intrinsically conducting polymers (ICP). Among them, poly(3,4-ethylenedioxythiophene) (PEDOT), polypyrrole (PPy) and polyaniline (PANI) are well known conducting polymers that present excellent electrical and optical properties emerging as main candidates for potential biomedical applications. Additionally, the biodegradability of biomaterials is very useful and desirable. In this context, biodegradable polymers based on polyesters, such as poly(D,L-lactic acid) (PDLLA), polycaprolactone (PCL), and poly(glycolic acid) (PGA) appear to be promising candidates because of their good biocompatibility and, as a consequence, they have been attracting attention as sustainable alternatives for applications in medicine. Weak molecular interaction with cells, biocompatibility, biodegradability, mechanics and topography are some of the main challenges for the use of conducting polymers as biomaterials. In order to improve their own biocompatibility, the main strategies are whether by doping with specific counter ions (biodopants) or chemically modifying the monomers with different molecules. Although conventional ICPs still present low or none biodegradability, there are relatively few examples of biodegradable electroactive polymers in the literature. Recently, novel approaches have been applied to solve the problem of lack of biodegradability of conducting polymers, mainly through (1) synthesis of a modified electroactive oligomers connected via degradable ester linkages creating block copolymers and (2) synthesis of modified electroactive and biodegradable macromonomers based on polyesters used in a second step copolymerization with conductive monomers. This mini-review focuses on developing trends, challenges and summarizes the recent advances on synthesis of conducting, biodegradable and biocompatible copolymers in terms of optimizing the chemical properties to improved response toward different cells, aiming biomedical applications.

Biodegradable conducting polymeric materials for biomedical applications: a review

“…These newly tailored materials were named as biodegradable conducting polymeric materials having mixed advantageous properties of both conducting polymers and biodegradable polymers (da Silva & Córdoba de Torresi, 2019). combined by ester linkages, appeared as a promising candidate due to tailored properties of both the polymers and attracted the attention of researchers as sustainable alternatives for application in medical fields (Figure 3).…”

“…to overcome the problem of biodegradability and electroactive performances are (i) block copolymers in which modified electroactive oligomers of conducting polymers were connected with degradable ester linkages and (ii) copolymerization of altered biodegradable and electroactive macromonomers based on polyesters prepared in the first step, with conducting polymers (da Silva & Córdoba de Torresi, 2019).…”

Conducting Polymer Grafting: Recent and Key Developments

“…In order to develop electroactive biomaterials for biomedical applications, grafting of biocompatible and biodegradable polymers such as poly(caprolactone) (PCL), poly(d,l-lactic acid) (PDLA, PLLA), poly(glycolic acid) (PGA) with conducting polymers has gained much attention as a novel approach. To summarize the developing research on the synthesis of conducting polymer-based biomaterials and improvement of their properties after grafting, very recently, Sliva et al [68] presented a good review article. Mainly, there are two ways to generate such conducting graft polymers: (i) attachment of electroactive oligomers to the biodegradable polymers via ester linkage ( Figure 7A) and (ii) subsequent synthesis of electroactive, biodegradable polyesters macromonomer followed by polymerization of conductive monomers ( Figure 7B).…”

“…Schematic illustrations for synthesis of (A) electroactive oligomers and block copolymers and (B) electroactive macromonomers and graft copolymers. Reproduced with permission[68].…”

Biocompatible SWCNT Conductive Composites for Biomedical Applications

“…The idea to mix biocompatible material and conductive polymers to create new composite biocompatible conductive materials is not novel. Conductive polymers allow excellent control of the electrical stimulus, possess very good electrical and optical properties, have a high conductivity/weight ratio, and can be made biocompatible and biodegradable [ 2 , 31 , 32 ]. Moreover, it has been shown that many natural-based polymers like albumin or cellulose and even some synthetic polymers are perfect biodegradable biomaterials [ 33 ].…”