ABSTRACT
BACKGROUND: Repair materials for bone tissue engineering should hold good biocompatibility and degradability. There are various related studies, but the Chinese medicine composite cellular bioscaffolds are little reported. OBJECTIVE: To detect the in vitro cytotoxicity of rabbit bone marrow mesenchymal stem cells-cuttlebone bioscaffold based on the Biological Evaluation of Medical Device, and assess its cytotoxicity level in order to provide the theoretical support for its clinical application. METHODS: Bone marrow mesenchymal stem cells-cuttlebone bioscaffold extract was prepared according to an ISO standard — material area: extraction medium volume = 3-6 cm2:1 mL. L-929 cell suspension was prepared, and the cells were then cultured with a density of 1×107/L. There were three groups: positive group (DMEM medium containing phenol), experimental group (material extract), and negative group (DMEM culture medium). The absorbance value of L-929 cells was detected by MTT assay after 24, 48 and 72 hours of culture. The relative proliferation rate of cells was then calculated and the toxicity level was valued in each group. RESULTS AND CONCLUSION: The absorbance values in the experimental, negative and positive groups were not exactly same at different time points (P=0.000 < 0.01). The absorbance values in the experimental and negative groups were significantly higher than those in the positive group (P < 0.01).The cytotoxicity of bone marrow mesenchymal stem cells-cuttlebone bioscaffold was grade 1. To conclude, the bone marrow mesenchymal stem cells-cuttlebone bioscaffold has no obvious toxic effects, and meets the requirements of biomaterial application.
ABSTRACT
Objective To construct a extracellular matrix-like collagen mimetic peptide-PEG hybrid hydrogel and to study the usage of this hydrogel in 3D culture of rabbit bone marrow mesenchymal stem cells (rBMSCs).Methods The hybrid hydrogel was synthesised by conjugating the cysteine at the end of the collagen mimetic peptide with the maleimine-modified multi-arm PEG.The circular dichroism spectra were used to characterize the triple helix structure and thermal stability of the collagen mimetic peptides.The rheology test and scanning electron microscopy were used to study the gelation process,mechanical strength and internal structure of the hydrogel.The rBMSCs were embedded in the hybrid hydrogel for 3D culture.The cell compatibility of the hydrogel and its effect on differentiation of the cells was studied.Results Collagen mimetic peptides could promote spontaneous formation of triple helix structure in the natural collagen,and the thermal transition temperature was 49.4 ℃.The formation process of the collagen mimetic peptides-PEG hybrid hydrogel was rapid,in which the porous network-like fibrous structure was formed.After the encapsulation of rBMSCs within the hydrogel for 24 h,most of the cells remained viable.Gene expression analysis showed that the hybrid hydrogel could affect the differentiation of rBMSCs.Conclusions The collagen mimetic peptide-PEG hybrid hydrogel possesses the characteristics of mild preparation condition,good mechanical strength and good cell compatibility,and is favorable to chondrocyte differentiation of rBMSCs.