Impact of Sterilization on a Conjugated Polymer-Based Bioelectronic Patch

Abstract

Organic bioelectronics based on conjugated polymers as the active electronic material have been shown to operate efficiently at the biointerface. Their translation into a commercial medical device will hinge on their long-term operation in vivo. This will require the device to be subjected to clinically approved sterilization techniques without deterioration in its physical and electronic properties. To date, there remains a gap in the literature addressing the impact of this critical preoperative procedure on the properties of conjugated polymers. This study aims to address this gap by assessing the physical and electronic properties of a sterilized porous bioelectronic patch having polyaniline as the conjugated polymer. The patch was sterilized by autoclave, ethylene oxide, and gamma (γ-) irradiation at 15, 25, and 50 kGy doses. Autoclaving resulted in cracking and macroscopic degradation of the patch, while patches sterilized by γ-irradiation at 50 kGy exhibited reduced mechanical and electronic properties, attributed to chain scission and nonuniform cross-linking caused by high dose irradiation. Ethylene oxide and γ-irradiation at 15 and 25 kGy sterilization appeared to be the most effective at maintaining the mechanical and electronic properties of the patch and inducing a minimal immune response as revealed by a receding fibrotic capsule after 4 week implantation. Our findings pave the way toward closing the gap for the translation of organic bioelectronic devices from acute to long-term in vivo models.

The future of electronic materials is…degradable!

“…29 Fig. 4 Bioderived supporting materials for electronics-polysaccharides (cellulose, 48,[56][57][58]65 alginate, 66-70 starch, 34,49 chitosan, 14,34,[59][60][61][62][63][64] ), collagen, 71 silk 31,[41][42][43]72 and synthetically derived supporting materials for electronics-polyvinyl alcohol (PVA), 14,16,17,[73][74][75] polyglycolic acid (PGA), polylactic acid (PLA), [19][20][21][22]76 polycaprolactone (PCL). 26,27,38,[77][78][79] On the other part, synthetic substrates provide excellent control for the efficiency and physiochemical properties of the material, as we can change or modulate the preparation according to our needs.…”

“…60 Touch Fig. 5 Bioderived active materials for electronics-Melanine, 43,87 and synthetically derived active materials for electronics-PEDOT:PSS, 31,32,34,48,56,57,59,60,72,75,[88][89][90][91][92][93][94] polyaniline(PANI), 62,95 polyimine, 25,96 (the structure of melanin has been adapted 97 ).…”

“…60 Coupled with lignin for flexible humidity sensors 61 or with polyaniline (PANI) for bioelectronic patch. 62 An edible starch-chitosan-based device has been developed for wearable electronics 34 or a self-healing and injectable hydrogel based on cellulose-chitosan. 63 Chitosan has been found useful even with synthetic polymers like polyvinyl pyrrolidone (PVP) as biodegradable support for flexible devices 64 and polyvinyl alcohol (PVA) for transient electronic devices.…”