In vitro interaction of human Wharton's jelly mesenchymal stem cells with biomimetic 3D scaffold.

Study of cell-biomaterial interaction is a crucial aspect of bone tissue engineering to find a state-of-the-art functional substitute. In present study, the Wharton's jelly mesenchymal stem cells (hWJ-MSCs) behavior on three-dimensional biomimetic nano-hydroxyapatite/chitosan/gelatin (nHA/CS/Gel) scaffolds was investigated. The outcome was assessed by histological, biochemical and morphological tests. Results indicated that hWJ-MSCs attached onto the scaffold surface through membrane filopodia, uniformly spread throughout the contacting surface. It only took 3 days for the seeded cells to appear deep inside the scaffold, reflecting proper hWJ-MSCs adhesion and migration, evidenced by both scanning electron microscope and hematoxilin and eosin assessments. Additionally, the present fabricated nHA/CS/Gel scaffold proved to be non-toxic as it supported cell proliferation measured by 3-(4,5-dimethylthiazoyl-2-yl)-2,5-diphenyltetrazolium bromide assay. Moreover, 3-week culture of hWJ-MSCs on scaffolds, immersed in osteogenic medium, rendered the microenvironment in favor of hWJ-MSCs differentiation into osteoblast cells and extracellular matrix secretion. Finally, osteoblasts were immunologically positive for various osteogenic markers including osteocalcin, osteopontin, osteonectin, and alkaline phosphatase. Present findings indicate that nHA/CS/Gel scaffold appropriately harbored hWJ-MSCs, stimulating their growth, migration, proliferation, and differentiation. hWJ-MSCs-loaded nHA/CS/gel substitute may therefore be considered as a suitable platform for the rising demand in in vivo bone repair studies. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1166-1175, 2019.

Preparation and evaluation of novel nano-bioglass/gelatin conduit for peripheral nerve regeneration.

Peripheral nerves are exposed to physical injuries usually caused by trauma that may lead to a significant loss of sensory or motor functions and is considered as a serious health problem for societies today. This study was designed to develop a novel nano bioglass/gelatin conduit (BGGC) for the peripheral nerve regeneration. The bioglass nanoparticles were prepared by sol-gel technique and characterized using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction analysis. The interfacial bonding interaction between the nano-bioglass and gelatin in the developed conduits was assessed by FTIR. The surface morphology and pore size of the nanocomposite were investigated through scanning electron microscopy with the pore size of the conduits being 10-40 µm. Biocompatibility was assessed by MTT assay which indicated the BGGC to have good cytocompatibility. The guidance channel was examined and used to regenerate a 10 mm gap in the right sciatic nerve of a male Wistar rat. Twenty rats were randomly divided into two experimental groups, one with the BGGC and the other being normal rats. The gastrocnemius muscle contractility was also examined at one, two and three months post-surgery in all groups using electromyography (EMAP). Histological and functional evaluation and the results obtained from electromyography indicated that at three months, nerve regeneration of the BGGC group was statistically equivalent to the normal group (p > 0.05). Our result suggests that the BGGC can be a suitable candidate for peripheral nerve repair.