Fabrication and in vitro evaluation of 3D composite scaffold based on collagen/hyaluronic acid sponge and electrospun polycaprolactone nanofibers for peripheral nerve regeneration

Abstract

Replacement of peripheral nerve autografts with tissue engineered nerve grafts will potentially resolve the lack of nerve tissue especially in patients with severe concomitant soft tissue injuries. This study attempted to fabricate a tissue engineered nerve graft composed of electrospun PCL conduit filled with collagen‐hyaluronic acid (COL‐HA) sponge with different COL‐HA weight ratios including 100:0, 98:2, 95:5 and 90:10. The effect of HA addition on the sponge porosity, mechanical properties, water absorption and degradation rate was assessed. A good cohesion between the electrospun PCL nanofibers and COL‐HA sponges were seen in all sponges with different HA contents. Mechanical properties of PCL nanofibrous layer were similar to the rat sciatic nerve; the ultimate tensile strength was 2.23 ± 0.35 MPa at the elongation of 35%. Additionally, Schwann cell proliferation and morphology on three dimensional (3D) composite scaffold were evaluated by using MTT and SEM assays, respectively. Rising the HA content resulted in higher water absorption as well as greater pore size and porosity, while a decrease in Schwann cell proliferation compared to pure collagen sponge, although reduction in cell proliferation was not statistically significant. The lower Schwann cell proliferation on the COL‐HA was attributed to the greater degradation rate and pore size of the COL‐HA sponges. Also, dorsal root ganglion assay showed that the engineered 3D construct significantly increases axon growth. Taken together, these results suggest that the fabricated 3D composite scaffold provide a permissive environment for Schwann cells proliferation and maturation and can encourage axon growth.

Polymer Scaffolds for Biomedical Applications in Peripheral Nerve Reconstruction

“…Electrospinning is a multi-purpose and cost-effective process for producing non-woven micro/nanofibers, which can provide an excellent ECM-like environment for tissue and cell growth [ 57 , 58 ]. Electrospun fibers can meet various structural requirements for tissue engineering scaffolds, such as porosity, pores that communicate with each other, adjustable void size, functional filaments, and adjustable morphology [ 59 , 60 , 61 ].…”

Natural-Based Biomaterials for Peripheral Nerve Injury Repair

“…Mechanical properties and degradation of HA can be tuned through chemical and physical processes of crosslinking with divinyl sulfone followed by freezing and lyophilization to create a porous structure (Ortuno-Lizarán et al, 2016;Vilariño-Feltrer et al, 2016). Moreover, HA can be solved with sodium chloride and directly poured into a porous sponge (Li et al, 2018;Entekhabi et al, 2020) or suspended in physiological saline solution to obtain a suitable viscosity useful to produce hydrogel fillers for NGCs (Li et al, 2018).…”

HA-coated collagen nanofibers for urethral regeneration via in situ polarization of M2 macrophages

“…Although progress has been made in tissue engineering and regenerative medicine, and it has been observed that HA and collagen-based composite nanofibers show the greatest vascularization and tissue regeneration in vivo, the regenerative biochemical cascade behind them has not been further explored [ 17 – 19 ]. Controlling the interaction between macrophages and biomaterials is very important to promote tissue regeneration in regenerative medicine.…”