Rolipram and Electrical Stimulation Synergistically Promote Neuronal Differentiation of Adipose-derived Stromal Cells: an in Vitro Study.

Abstract

This study investigates gold-decorated polycaprolactone/chitosan nanofibers as conductive scaffolds for promoting neuronal differentiation of adipose-derived mesenchymal stromal cells (ADSCs) harvested from the dorsal interscapular region of Wistar rats under electrical stimulation (ES) with optimal rolipram concentrations. The scaffold was fabricated through electrospinning and in situ synthesis of gold nanoparticles (AuNPs). Morphology and AuNPs distribution were evaluated using a Field Emission Scanning Electron Microscope (FE-SEM) and energy dispersive X-ray spectroscopy (EDX). Rolipram, known to increase neuronal cyclic adenosine monophosphate (cAMP) activity and reduce inflammation, was loaded into the scaffolds using alginate hydrogel. The scaffolds were subjected to a release study and tests for ADSC proliferation and differentiation into neuron-like cells. Immunostaining of β-Tubulin III and MAP2 was used to assess the effect of ES, alone and in combination with rolipram, on the efficacy of neuronal differentiation of ADSCs. The distribution of AuNPs was uniform within the scaffolds with an electrical conductivity of 0.12 S.cm^-1. Rolipram significantly improved the development of neurons from ADSCs, and this effect was more prominent at higher concentrations (1 and 5 µM). The study revealed that using an electrical density of 100 mV/mm, in combination with 5 µM rolipram and conductive scaffolds, led to a significant increase in the percentage of MAP2 and β-Tubulin III positive cells and the neuronal differentiation of ADSCs, with further elevation of cAMP levels compared to using 5 µM rolipram without ES. We found that combining rolipram and electrical stimulation at optimized doses and voltages can enhance nerve regeneration applications.