Peripheral nerve regeneration in rats by chitosan/alginate hydrogel composited with Berberine and Naringin nanoparticles: in vitro and in vivo study

Abstract

In the current study, we prepared chitosan (Cs)/Alginate (Alg) hydrogel containing Berberine (Ber)-loaded Cs nanoparticles (NPs) and Naringin (Nar)-loaded Cs NPs as the promising biomaterials for peripheral nerve regeneration. The Ber- and Ner-loaded NPs were synthesized via the ion gelation method and incorporated into Cs/Alg hydrogel. The characterizations of NPs showed that Ber-loaded NPs have an average size of 594 nm with the encapsulation efficacy (EE) of 51.6 ± 7.4%, and Nar-loaded NPs have an average size of 636 nm with EE of 47.1 ± 5.8%. The pore size of Cs/Alg hydrogel and Cs/Alg/Ber/Nar hydrogel were 22 ± 11 and 32 ± 13 μm, respectively. It was observed that the swelling and weight loss value of the prepared hydrogels were suitable for nerve regeneration. The compression strength of Cs/Alg hydrogel and Cs/Alg/Ber/Nar hydrogel were 39.7 ± 4.7 kPa and 32.08 ± 6.8 kPa. The releasing measurement showed a burst release at the first days following a sustained release of up to about 90% for 24 days. The in vitro studies illustrated that the hydrogels were hemo- and biocompatible with the significant proliferative effect on PC12 cells. The animal studies showed that the treatment using the hydrogels significantly promoted nerve regeneration. Treatment of the damaged nerve using Cs/Alg/Ber/Nar hydrogel resulted in the sensory function recovery (hot plate latency of 4.66 ± 0.57 s), the motor function recovery (sciatic index function of −14.6 ± 3.7) and anatomical healing (the gastrocnemius muscle cross-sectional area of 2509 ± 142 μm2). In conclusion, the results indicate that the prepared hydrogels possess promising characteristics and significantly enhanced sensory and motor functional recovery, as well as anatomical healing.