ABSTRACT
BACKGROUND:With the promotion of 3D printing technology, 3D printing scaffolds for bone tissue engineering have become the new ideas for jaw bone repair. OBJECTIVE:To compare the physical and biological properties of sheep vertebral bone meal/polyvinyl alcohol (PVA) scaffold, nano-hydroxyapatite (nHA)/PVA scaffold, and sheep vertebral bone meal/PVA nonporous bone plate. METHODS:3D printing technology was used to print sheep vertebral bone meal/PVA scaffold, nHA/PVA scaffold, and sheep vertebral bone meal/PVA nonporous bone plate. Porosity, morphology, water absorption rate and mechanical properties of different scaffolds were detected. Three kinds of scaffolds were al used to culture bone marrow mesenchymal stem cel s, and cel proliferation ability was detected using cel counting kit-8 at 1, 4, 7 days of culture. RESULTS AND CONCLUSION:Under scanning electron microscope, the sheep vertebral bone meal/PVA scaffold and nHA/PVA scaffold exhibited regular and interconnected pores with good continuity and clear network structure;the sheep vertebral bone meal/PVA nonporous bone plate had no obvious pores;however, it had dense and evenly distributed micropores with different sizes on its surface. The porosity of nHA/PVA scaffold was lower than that of the sheep vertebral bone meal/PVA scaffold (P<0.05). The water absorption rate was highest for the nHA/PVA scaffold fol owed by the sheep vertebral bone meal/PVA scaffold and the sheep vertebral bone meal/PVA nonporous bone plate (P<0.05). In contrast, the scaffold toughness was highest for the sheep vertebral bone meal/PVA nonporous bone plate, fol owed by the sheep vertebral bone meal/PVA scaffold and nHA/PVA scaffold. In addition, the cel proliferation activity of cel s cultured on the sheep vertebral bone meal/PVA scaffold was significantly higher than that cultured on the other two kinds of scaffolds. Taken together, the 3D printing sheep vertebral bone/PVA scaffold has good physical and chemical performance.
ABSTRACT
METHODS:Lentiviral vectors carrying bFGF and BMP-2 were constructed to transfect sheep bone marrow mesenchymal stem cells. cells were divided into four groups:bFGF group, BMP-2 group, co-transfection group BACKGROUND:Basic fibroblast growth factor (bFGF) can promote the proliferation of bone marrow stromal cells, and bone morphogenetic protein-2 (BMP-2) has an important significance in the induction of new bone formation. OBJECTIVE:To analyze the effects of bFGF, BMP-2 and their co-transfection on the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells and to compare the relative expressions of col agen I, osteocalcin and osteopontin before and after celltransfection, thereby providing theoretical implications for seed cells in the construction of tissue-engineered bone. and control group. The RNA was extracted using real-time quantitative PCR to detect mRNA levels of col agen I, osteocalcin, and osteopontin. RESULTS AND CONCLUSION:Significant difference in non-specific osteogenic gene expressions was found among the four groups (P0.05). In vitro experiments showed that the relative expression of col agen I, osteocalcin and osteopontin were higher in the co-transfection group, indicating the cells from the co-transfection group have strongest osteogenic capacity that are suitable for seed cells for bone tissue engineering.
ABSTRACT
BACKGROUND:Some studies have indicated that different genes in tooth germ tissue play a role at different time, contributing to tooth germ development. OBJECTIVE:To observe the expressions of dentin matrix protein 1, enamel protein, col agen I and homeobox gene 1 at different stage of in vitro culture of tooth germ cells. METHODS:RNA from tooth germ cells was extracted at days 1, 3, 6 of in vitro culture. After reverse transcription, real-time quantitative PCR detection was adopted to measure relative expression of dentin matrix protein 1, enamel protein, col agen I and homeobox gene 1 mRNA. RESULTS AND CONCLUSION:Dentin matrix protein 1, enamel protein, and col agen I mRNA expressions increased with culture time, and reached the peak at day 3 (P<0.05), whereas homeobox gene 1 mRNA decreased with culture time (P<0.05).