OBJECTIVETo investigate the effect of co-expression of bone morphogenetic protein 2 (BMP2) and Sox9 on chondrogenic differentiation of mesenchymal stem cells (MSCs) in vitro and provide experimental evidence for tissue engineering of cartilage.

METHODSMouse embryonic bone marrow MSC C3H10T1/2 cells were infected with recombinant adenovirus expressing BMP2, Sox9 and green fluorescent protein (GFP) for 3-14 days, with cells infected with the adenovirus carrying GFP gene as the control. The mRNA expression of the markers of chondrogenic differentiation, including collagen type II (Col2a1), aggrecan (ACAN), and collagen type X (Col10a1), were determined by real-time PCR. Alcian blue staining was used for quantitative analysis of sulfated glycosaminoglycan in the cellular matrix. The expression of Col2a1 protein was assayed by immunohistochemical staining and Western blot analysis.

RESULTSAdenovirus-mediated BMP2 expression induced chondrogenic differentiation of C3H10T1/2 cells. Overexpression of Sox9 effectively enhanced BMP2-induced expression of the chondrogenic markers Col2a1, aggrecan and Col10a1 mRNAs, and promoted the synthesis of sulfated glycosaminoglycan and Col2a1 protein in C3H10T1/2 cells.

CONCLUSIONCo-expression of BMP2 and Sox9 can promote chondrogenic differentiation of MSCs in vitro, which provides a new strategy for tissue engineering of cartilage.

Animals ; Bone Morphogenetic Protein 2 ; genetics ; metabolism ; Cartilage ; cytology ; Cell Differentiation ; Cells, Cultured ; Chondrocytes ; cytology ; Humans ; Mesenchymal Stromal Cells ; cytology ; metabolism ; Mice ; SOX9 Transcription Factor ; genetics ; metabolism ; Tissue Engineering

Objective To investigate the effect of co-expression of bone morphogenetic protein 2 (BMP2) and Sox9 on chondrogenic differentiation of mesenchymal stem cells (MSCs) in vitro and provide experimental evidence for tissue engineering of cartilage. Methods Mouse embryonic bone marrow MSC C3H10T1/2 cells were infected with recombinant adenovirus expressing BMP2, Sox9 and green fluorescent protein (GFP) for 3-14 days, with cells infected with the adenovirus carrying GFP gene as the control. The mRNA expression of the markers of chondrogenic differentiation, including collagen type II (Col2a1), aggrecan (ACAN), and collagen type X (Col10a1), were determined by real-time PCR. Alcian blue staining was used for quantitative analysis of sulfated glycosaminoglycan in the cellular matrix. The expression of Col2a1 protein was assayed by immunohistochemical staining and Western blot analysis. Results Adenovirus-mediated BMP2 expression induced chondrogenic differentiation of C3H10T1/2 cells. Overexpression of Sox9 effectively enhanced BMP2-induced expression of the chondrogenic markers Col2a1, aggrecan and Col10a1 mRNAs, and promoted the synthesis of sulfated glycosaminoglycan and Col2a1 protein in C3H10T1/2 cells. Conclusion Co-expression of BMP2 and Sox9 can promote chondrogenic differentiation of MSCs in vitro, which provides a new strategy for tissue engineering of cartilage.

Objective To investigate the effect of co-expression of bone morphogenetic protein 2 (BMP2) and Sox9 on chondrogenic differentiation of mesenchymal stem cells (MSCs) in vitro and provide experimental evidence for tissue engineering of cartilage. Methods Mouse embryonic bone marrow MSC C3H10T1/2 cells were infected with recombinant adenovirus expressing BMP2, Sox9 and green fluorescent protein (GFP) for 3-14 days, with cells infected with the adenovirus carrying GFP gene as the control. The mRNA expression of the markers of chondrogenic differentiation, including collagen type II (Col2a1), aggrecan (ACAN), and collagen type X (Col10a1), were determined by real-time PCR. Alcian blue staining was used for quantitative analysis of sulfated glycosaminoglycan in the cellular matrix. The expression of Col2a1 protein was assayed by immunohistochemical staining and Western blot analysis. Results Adenovirus-mediated BMP2 expression induced chondrogenic differentiation of C3H10T1/2 cells. Overexpression of Sox9 effectively enhanced BMP2-induced expression of the chondrogenic markers Col2a1, aggrecan and Col10a1 mRNAs, and promoted the synthesis of sulfated glycosaminoglycan and Col2a1 protein in C3H10T1/2 cells. Conclusion Co-expression of BMP2 and Sox9 can promote chondrogenic differentiation of MSCs in vitro, which provides a new strategy for tissue engineering of cartilage.

Objective This paper aims to investigate the application of intraoral scanning and cone beam computed tomography(CBCT)registration implant robot in dental implant surgery.Methods The data of 40 cases with dental de-fect of robot-assisted implantation from November 2023 to May 2024 were retrospectively analyzed.Before the opera-tion,the intraoral scan data and CBCT data of the posi-tioning markers were automatically fused with the initial CBCT images,and the registration error was calculated.The average registration error of positioning markers was determined during the operation,and the implantation ac-curacy was analyzed after the operation.Results The intraoral scan data and CBCT data of 40 patients with dental defect wearing positioning markers were successfully registered with the initial CBCT image,and the registration errors were(0.157±0.026)mm and(0.154±0.033)mm,respectively.Statistical analysis showed no statistical significance between them.The registration errors of the marker was(0.037 3±0.003 6)mm.A total of 55 implants were performed,and the total deviations of the implant point and the apical point were(0.78±0.41)and(0.89±0.28)mm,respectively.The transverse deviations of the implant point and the apical point were(0.44±0.36)and(0.58±0.25)mm,respectively.The depth deviations of the implant point and the apical point were(0.51±0.32)and(0.54±0.36)mm,respectively.The devia-tion of the implant angle was 1.24°±0.67°.Conclusion The fusion technology based on intraoral scanning and CBCT registration can meet the accuracy requirements of preoperative registration of oral implant robots.The technology in-creases the choice of registration methods before robot-assisted dental implant surgery and reduces the multiple radiation exposuresof the patient.

This paper is aimed to investigate the effect of titanium (Ti) particles and tumor necrosis factor alpha (TNF-alpha) on the expressions of MMP-1, 2, 3 in human synovial cells, so as to explore the possible mechanism of osteolysis post-operation of metal-on-metal total joint arthroplasty in human synovial cells induced by Ti particles. In vitro cell cultures, human synovial cells were treated by Ti particles and/or TNF-alpha. The total RNA was isolated at 2 hours after the treatment. The gene expression of MMP-1, 2, 3 was analyzed by Semi-quantitative Reverse-transcriptional PCR and quantitative real-time PCR. Cell supernatant was collected at 12, 24, 48 hours after the treatment and Gelatin zymography was performed to detect the activity of MMP-2. Compared to those in the control group (untreated), Ti particles and TNF-alpha increased the gene expression of MMP-1, 2, 3 respectively (P < 0.05), and the effect of combination of the two was even more significant (P < 0.01). The trend of activities of MMP-2 is similar with gene expression. Ti particles and TNF-alpha increased MMP-2 activities by 1.3 times and 1.5 times respectively (P < 0.05), and the combination of the two increased by 1.7 times (P < 0.01). Ti particles and TNF-alpha-induced the stimulation of MMP-1, 2, 3 expressions and MMP-2 activities in human knee joint synovial cells may be involved in aseptic loosening after metal-on-metal arthroplasty through increasing the degradation of bone matrix and declining of osseous support structure mechanics.
Cells, Cultured ; Humans ; Joint Prosthesis ; Knee Joint ; cytology ; Matrix Metalloproteinase 1 ; genetics ; metabolism ; Matrix Metalloproteinase 2 ; genetics ; metabolism ; Matrix Metalloproteinase 3 ; genetics ; metabolism ; Matrix Metalloproteinases ; genetics ; metabolism ; Particle Size ; Prosthesis Failure ; adverse effects ; RNA ; genetics ; metabolism ; Synovial Membrane ; cytology ; enzymology ; Titanium ; pharmacology ; Tumor Necrosis Factor-alpha ; pharmacology