In vitro evaluation of gel-encapsulated adipose derived stem cells: Biochemical cues for in vivo peripheral nerve repair

Adipose‐derived stem cells (ASC) are becoming one of the most exploited cells in peripheral nerve repair. They are fast‐growing and able to protect neurons from apoptosis; they can reduce postinjury latency and the risk of muscle atrophy. This study evaluates laminin‐loaded fibrin gel as an ASC‐carrying scaffold for nerve repair. In vitro, ASC retained their proliferative activity but showed significant increase in proliferation rate when encapsulated in gels with low laminin concentrations (i.e., 1 μg/mL). We observed a linear decrease of ASC proliferation rate with increasing laminin concentration from 1 to 100 μg/mL. We next examined the effect of the ASC‐carrying fibrin gels on in vitro dorsal root ganglia (DRG) neurite extension, then in vivo sciatic nerve regeneration in adult rats. The ASC‐carrying gel was embedded in 15‐mm‐long, 1.5‐mm‐diameter polydimethylsiloxane regenerative conduits for in vivo evaluation. At 8‐week post implantation, robust regeneration was observed across the long gap. Taken together, these results suggest ASC‐carrying gels are a potential path to improve the efficacy of nerve regeneration through artificial guidance conduits and electrode nerve interfaces.