Formation of PLGA–PEDOT: PSS Conductive Scaffolds by Supercritical Foaming

Abstract

The usage of conjugated materials for the fabrication of foams intended to be used as therapeutic scaffolds is gaining relevance these days, as they hold certain properties that are not exhibited by other polymer types that have been regularly used until the present. Hence, this work aims to design a specific supercritical CO2 foaming process that would allow the production of porous polymeric devices with improved conductive properties, which would better simulate matrix extracellular conditions when used as therapeutic scaffolds (PLGA–PEDOT:PSS) systems. The effects of pressure, temperature, and contact time on the expansion factor, porosity, mechanical properties, and conductivity of the foam have been evaluated. The foams have been characterized by scanning electron and atomic force microscopies, liquid displacement, PBS degradation test, compression, and resistance to conductivity techniques. Values close to 40% porosity were obtained, with a uniform distribution of polymers on the surface and in the interior, expansion factors of up to 10 orders, and a wide range of conductivity values (2.2 × 10−7 to 1.0 × 10−5 S/cm) and mechanical properties (0.8 to 13.6 MPa Young’s modulus in compression test). The conductive and porous scaffolds that have been produced by supercritical CO2 in this study show an interesting potential for tissue engineering and for neural or cardiac tissue regeneration purposes due to the fact that electrical conductivity is a crucial factor for proper cell function and tissue development.

Supercritical Impregnation of Mangifera indica Leaves Extracts into Porous Conductive PLGA-PEDOT Scaffolds

“…In the majority of SEM images, a large number of pores can be observed within the scaffold, as it is a cross-sectional image. The distinction between PLGA and PEDOT is not visible to the naked eye, as is common in such processes, due to their dispersion throughout the scaffold, as confirmed in the previous study [ 25 ] that motivated this research. A more organized pore structure is seen in experiments performed at higher pressure, possibly due to the increased ability of CO 2 to penetrate between the polymer chains with less hindrance under these conditions.…”

“…These mixed polymers were investigated for their use in tissue engineering and their influence on cell growth. We highlight the previous study by Montes et al, [ 25 ] where PLGA-PEDOT:PSS were investigated in terms of the effect of pressure, temperature and contact time on the porosity, mechanical properties and conductivity of the conjugated polymeric scaffolds. On the other hand, a very limited number of investigations with PEDOT polymer using scCO 2 have been reported in the literature, e.g., CoS/MXene/PEDOT [ 26 ] composites or for the addition of platinum nanoparticles to PEDOT/C matrix [ 27 ].…”

“…In order to generate scaffolds with an ordered porous structure, suitable mechanical and electrical properties for tissue engineering, coupled with bioactive properties provided by the compounds from Mangifera indica leaves extract, the processes of polymeric foaming and supercritical impregnation were carried out in a single step. The experiments were carried out in a RESS250 lab scale unit (Thar Technologies, Pittsburgh, PA, USA) described in detail in previous works [ 25 ]. This process represents an additional step compared to the work on the formation of conjugated scaffolds.…”

“…The method described in previous works [ 25 , 32 ] with minor modifications was used to determine the conductivity of the different samples. The electrical conductivity of the PLGA-PEDOT-MLE scaffolds was measured using a resistance meter (TRMS Fluke 87-V) by the two-probe method.…”

Synthesis of L-Ornithine- and L-Glutamine-Linked PLGAs as Biodegradable Polymers

“…Therefore, a biomaterial with antibacterial properties that accelerates wound healing with good cell harmony has been developed [10,11]. A good example is also reported in biocompatible conductive and porous PLGA scaffolds, which exhibit stretchable neural or cardiac tissue regeneration functions due to electrical conductivity to improve proper cell function [12]. Poly(lactic acid) (PLA) and poly(glycolic acid) (PGA) are 100% biodegradable, nontoxic, and ecofriendly biopolymers [13,14].…”