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In the field of regenerative medicine, many studies have focused on regenerating peripheral nerves because clinical problems and functional loss of organs are affecting an increasing number of people. Biocompatible polymers can be potentially used for producing biocompatible tubes in order to aid the regeneration of peripheral nerves. This study aims to prepare polymeric composites based on polycaprolactone (PCL), poly (lactic‐co‐glycolic acid) (PLGA), and polypyrrole fibers (PPy) capable of acting as a conduit for regenerating peripheral nerves. Polypyrrole is synthesized by oxidative chemical polymerization with p‐toluenesulfonic acid monohydrate (PTSA) as a doping agent. PCL/PLGA blends (100:0, 90:10, 80:20, and 70:30) (m/m) and PCL/PLGA composites with 10% PPy fibers were prepared by the solvent casting method. PPy with a diameter of 88–974 nm showed electrical conductivity of 2.0 × 10−1 S cm−1. The nontoxic composite films with hydrophilic and porous surfaces presented a thermal stability and degradation period that were suitable for potential use in the regeneration of peripheral nerves.

This study investigated the effects of smooth and microgrooved membrane blends, with different polycaprolactone (PCL)/ poly(lactic-co-glycolic acid) (PLGA) ratios on the viability, proliferation, and adhesion of different mammalian cell types. The polymer matrices with and without microgrooves, obtained by solvent casting, were characterized by field-emission scanning electron microscopy, atomic force microscopy, contact angle and Young's modulus. Blend characterization showed an increase in roughness and stiffness of membranes with 30% PLGA, without any effect on the contact angle value. Pure PCL significantly decreased the viability of Vero, HaCaT, RAW 264.7, and human fetal lung and gingival fibroblast cells, whereas addition of increasing concentrations of PLGA led to a reduced cytotoxicity. Increased proliferation rates were observed for all cell lines. Fibroblasts adhered efficiently to smooth membranes of the PCL70/PLGA30 blend and pure PLGA, compared to pure PCL and silicone. Microgrooved membranes promoted similar cell adhesion for all groups. Microstructured membranes (15 and 20-μm wide grooves) promoted suitable orientation of fibroblasts in both PCL70/PLGA30 and pure PLGA, as compared to pure PCL. Neuronal cells of the dorsal root ganglion exhibited an oriented adhesion to all the tested microgrooved membranes. Data suggest a satisfactory safety profile for the microgrooved PCL70/PLGA30 blend, pointing out this polymer combination as a promising biomaterial for peripheral nerve regeneration when cell orientation is required. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1522-1534, 2018.

No abstract

In this study, microfibers of poly(L‐lactic‐co‐glycolic acid) (PLGA) and PLGA/polypyrrole (PPy) composite (90/10 wt%) are produced by using the solution blow spinning (SBS) technique. PPy is synthesized by the oxidative polymerization method using p‐toluenesulfonic acid (p‐TSA) as the dopant and FeCl3 as the oxidant. The prepared PPy showed microfibers with globular particles morphology. Mixtures of porous and nonporous microfibers and microfibers incorporated with PPy are obtained. A wettability test shows that the PLGA and PLGA/PPy fibrous mats are hydrophobic. The electrical conductivity of the PLGA/PPy composite is of the same order as that of pure PLGA (≈10−10 S cm−1), indicating that the electrical percolation threshold is not reached for PPy loading of 10 wt%. The incorporation of PPy into PLGA microfibers improved the thermal stability of the composite and also increases the PLGA crystalline phase.