Synthesis and characterization of polypyrrole-hyaluronic acid composite biomaterials for tissue engineering applications

TLDR

Tissue engineering requires biomaterials that support growth and stimulate specific cell functions. The study aimed to develop a composite of hyaluronic acid and polypyrrole that combines biological activity with electrical conductivity to promote angiogenesis and tissue regeneration. PP/HA composites were synthesized and characterized by conductivity measurements, SEM, XPS, IR, HA‑binding assays, and tested for in vitro cell compatibility and in vivo tissue response in rats. The resulting films were smooth, conductive, retained surface HA for days, and enhanced vascularization in vivo, indicating promise for tissue engineering and wound healing. © 2000 John Wiley & Sons, Inc., J Biomed Mater Res 50:574–584.

Abstract

New tissue engineering technologies will rely on biomaterials that physically support tissue growth and stimulate specific cell functions. The goal of this study was to create a biomaterial that combines inherent biological properties which can specifically trigger desired cellular responses (e.g., angiogenesis) with electrical properties which have been shown to improve the regeneration of several tissues including bone and nerve. To this end, composites of the biologically active polysaccharide hyaluronic acid (HA) and the electrically conducting polymer polypyrrole (PP) were synthesized and characterized. Electrical conductivity of the composite biomaterial (PP/HA) was measured by a four-point probe technique, scanning electron microscopy was used to characterize surface topography, X-ray photoelectron spectroscopy and reflectance infrared spectroscopy were used to evaluate surface and bulk chemistry, and an assay with biotinylated hyaluronic acid binding protein was used to determine surface HA content. PP/HA materials were also evaluated for in vitro cell compatibility and tissue response in rats. Smooth, conductive, HA-containing PP films were produced; these films retained HA on their surfaces for several days in vitro and promoted vascularization in vivo. PP/HA composite biomaterials are promising candidates for tissue engineering and wound-healing applications that may benefit from both electrical stimulation and enhanced vascularization. © 2000 John Wiley & Sons, Inc. J Biomed Mater Res, 50, 574–584, 2000.