ABSTRACT
BACKGROUND: The compounding of RGD polypeptide on the surface of the material can induce the expression of osteoblast integrin gene, promote the adhesion of osteoblasts to the surface of biomaterials and differentiate into mature cells, and promote the formation of new bone. OBJECTIVE: To analyze the effect of domestic porous tantalum modified by RGD polypeptide on integrin/focal adhesion kinase signaling pathway in MG63 cells. METHODS: Porous tantalum material modified by RGD polypeptide was prepared. MG63 cells were inoculated on the surface of porous tantalum and porous tantalum materials modified with RGD polypeptide. MG63 cells cultured alone were used as the blank group. When cultured for 1, 3, 5, and 7 days, the cell proliferation was detected by the CCK-8 method. At 1, 3, and 5 days, the cell growth status was observed under an inverted microscope. At 3, 5 days of culture, cell adhesion was observed with scanning electron microscope. At 5 days of culture, RT-PCR and western blot assay were used to detect type I collagen and integrin β1 and focal adhesion kinase expression. RESULTS AND CONCLUSION: (1) The cell proliferation of the RGD modified group cultured at 3, 5, and 7 days was faster than that of the porous tantalum group and the blank group (P 0.05). (2) Observation by an inverted phase contrast microscope showed that the cells of the porous tantalum group and the RGD modified group were attached to the edge of the material when cultured for 1 day, and the number of cells gradually increased with the extension of the culture time. The number and density of cells in the RGD modified group were better than that of the porous tantalum group. (3) Observation by scanning electron microscope showed that cells adhered to the surface of the porous tantalum group and RGD modified group after 3 days of culture. The cells adhered to the material pore walls and pores, and protruded pseudopods into the pores. When cultured for 5 days, the cells secreted a large amount of extracellular matrix, and the cells were connected to each other through the matrix and gradually covered the surface of the material. The cell growth state, matrix secretion and cell coverage area of the RGD modified group were better than those of the porous tantalum group. (4) Western blot detection results showed that the expressions of type I collagen and integrin β1 protein in the RGD modified group were higher than those in the porous tantalum group and the blank group (P < 0.05). The expression levels of type I collagen, integrin β1, and focal adhesion kinase protein in the porous tantalum group were higher than those in the blank group (P < 0.05). (5) RT-PCR detection showed that the expressions of type I collagen, integrin β1, and focal adhesion kinase mRNA in the RGD modified group were higher than those of the porous tantalum group and the blank group (P < 0.05), and the expression of the porous tantalum group was higher than that of the blank group (P < 0.05). (6) The results showed that porous tantalum modified with RGD polypeptide can up-regulate the expression of type I collagen and integrin β1 on the cell membrane, activate the integrin/focal adhesion kinase signaling pathway, and promote cell adhesion and growth.
ABSTRACT
BACKGROUND: The establishment of coculture system combined with physical factors and scaffold materials and the Induction of cytokines have become the focus of chondrogenlc differentiation of bone marrow mesenchymal stem cells. OBJECTIVE: To observe the effect of bone morphogenetic protein 7 combined with porous tantalum on chondrogenlc differentiation of bone marrow mesenchymal stem cells. METHODS: Bone marrow mesenchymal stem cells of Sprague-Dawley rats (provided by Beijing Huafukang Biology) were Isolated and cultured. Group Intervention: (1) in the experimental group, porous tantalum tablet was added, while In the control group, porous tantalum tablet was not added. At 5 days after culture, cell growth on the surface of porous tantalum tablet was observed by phalloidin staining. At 1, 3,5, and 7 days after culture, CCK-8 method was used to detect cell proliferation. (2) Group A was added with chondrocyte Inducer; group B with chondrocyte Inducer and bone morphogenetic protein 7; group C with domestic porous tantalum material and chondrocyte Inducer; group D with domestic porous tantalum material and chondrocyte Inducer and bone morphogenetic protein 7. At 7,14 and 21 days after culture, the levels of type II collagen, SRY type high mobility group protein and matrix metalloproteinase-13 secreted by cells In each group was detected by ELISA. Western blot assay was used to detect the expression of type II collagen, SRY type high mobility group protein and matrix metalloproteinase-13. This study was approved by the Animal Experimental Ethics Committee of North China University of Science and Technology. RESULTS AND CONCLUSION: (1) The phalloidin staining results showed that bone marrow mesenchymal stem cells grew well on and around the porous tantalum surface. (2) At 3 and 5 days after culture, the proliferation of bone marrow mesenchymal stem cells was slower In the experimental group than in the control group (P 0.05). (3) At 7,14 and 21 days, the expression of type II collagen and SRY high mobility group protein Increased gradually among groups A, B, C and D (P 0.05). At 21 days, there was no significant difference among groups A, B, C and D (P > 0.05). (4) Western blot assay showed that at 7,14 and 21 days after culture, the expression level of type II collagen and SRY high mobility group protein Increased gradually In groups A, B, C and D (P 0.05). (5) The results showed that bone morphogenetic proteln-7 combined with domestic porous tantalum could Induce cartilage differentiation of bone marrow mesenchymal stem cells, facilitate the expression of type II collagen and SRY high mobility group protein, and Inhibit the expression of matrix metalloproteinase-13.
ABSTRACT
<p><b>OBJECTIVE</b>This work aims to investigate the effect of porous tantalum and porous titanium on osseointegration.</p><p><b>METHODS</b>Two kinds of porous materials with same microporous parameters, namely, porous tantalum and porous titanium, were fabricated by computer-aided design (CAD) modeling and 3D printing technology. A defect model was established in 24 New Zealand white rabbits in the bilateral femoral lateral malleolus at the left and right side of each animal. Then, animals were randomly divided into two groups, and bone defects were repaired by porous tantalum and porous titanium (experimental and control groups, respectively). Animals were sacrificed at two, four, and eight weeks after implantation. Gross observation and methylene blue-acid fuchsin staining were used to observe osseointegration of the implant and bone interface, and the osseointegration strength of implant bone interface was tested by push-out test.</p><p><b>RESULTS</b>At two, four, and eight weeks after operation, the new bone tissue in the two groups increased gradually, and new bone trabecula appeared and grew into the pores of the materials. No significant difference (P>0.05) in osteogenesis and the strength of implant bone tissue interface between the two groups was observed.</p><p><b>CONCLUSIONS</b>3D printed porous tantalum implants, which exhibit comparable osseointegration capabilities to porous titanium implants, can form an early biological combination with bone tissue.</p>
ABSTRACT
Objective : To review the basical research progress of porous tantalum in bone tissue engineering. Methods: The related basical research in fabrication, cytobiology, and surface modification of porous tantalum was reviewed and analyzed. Results: The outstanding physiochemical properties of porous tantalum granted its excellent performance in biocompatibility and osteointegration, as well as promoting cartilage and tendon tissue restoration. However, the clinical utilization of porous tantalum is somehow greatly limited by the complex and rigid commercial fabrication methods and extraordinary high cost. Along with the publication of novel fabrication and surface modification technology, the application of porous tantalum will be more extensive, the promotion in bone tissue regeneration will be more prominent. Conclusion: Porous tantalum has advantage in bone defect restoration, and significant breakthrough technology is needed in fabrication methods and surface modification.
ABSTRACT
Objective To study the effect of basic fibroblast growth factor (bFGF) of different concentrations on phenotypes and dedifferentiation of rabbit chondrocytes in porous tantalum-chondrocyte composites in vitro, so as to provide theoretic basis for cartilage defect repair. Methods The articular chondrocytes from 3-week-old rabbit were cultured and identified by type IT collagen immunocytochemistry and Safranin 0 staining. The 3rd generation chondrocytes were implanted in the porous tantalum and was treated with bFGF of various concentrations. The bFGF-chondrocyte-porous tantalum composites (bFGF compostes) were then divided into 5 groups: group A (1 ng/mL bFGF composites), group B (10 ng/mL bFGF composites), group C (50 ng/mL bFGF composites), group D (chondrocyte-porous tantalum), and group E (pure chondrocyte). The proliferation of chondrocytes was measured by MTT and the cell morphology and growth were observed by scanning electron microscopy (SEM). Phenotypes and dedifferentiation (type I, II, IX, and X collagen) of the chondrocytes were detected by immunocytochemical method. Type II and X collagen mRNA was tested by real-time PCR. Results Type II collagen immunocytochemistry and Safranin 0 staining were positive, confirming that the cultured cells were chondrocytes. MTT results showed that chondrocyte proliferation in groups A, B, C, and D were significantly greater than that in group E CP
ABSTRACT
Objective To investigate the effects of Porous tantalum rod implantation and autologous peripheral blood stem cell transplantation on the treatment of avascular necrosis of femoral head (ANFH).Methods Thirty-six cases with early ANFH (19 cases on the left side and 17 cases on the right side) treated by Porous tantalum rod implantation and matrix induced autologous peripheral blood stem cell trans-plantation from July 2009 to March 2011.The 36 cases had osteonecrosis of the femoral head(ONFH) lesions Ⅰ and Ⅱ according to the international bone circulation Research Association (ARCO) classification of ONFH lesion.All patients were followed up for 12-15 months.Clinical evaluation included preoperative and postoperative pain score,the Harris hip score,percentage of low signal MRI area in the volume of femoral head.Results All the patients were followed up for 12 to 15 months.The postoperative Harris hip score was significantly higher than pre-operation ((91.70 ± 6.90) vs.(68.32 ± 7.10) ; t =4.364,P ＜ 0.01).Pain symptoms reduced markedly ((15.55 ±6.60) vs.(29.78 ±5.67);t =3.423,P ＜0.05).Hip flexion and external rotation function was restored.MRI showed that after the operations the volume of areas with femoral head necrosis significantly reduced in compared with the pre-operation ((38.20 ± 8.30) ％ vs.(21.43 ± 5.10) ％ ; t =6.527,P ＜ 0.05).Conclusion Porous tantalum rod implantation and autologous peripheral blood stem cell transplantation can significantly reduce joint pain,dramatically restore joint function,effectively prevent collapse of the femoral head,retard progression and has good clinical efficacy in the treatment of early femoral head necrosis.
ABSTRACT
[Objective]The best treatment method for cemented acetabular component loosening during revision hip replacement has not been established.The purpose of this study is to determine the initial results obtained with a unique implant the modular porous tantalum cup,designed as an alternative treatment for aseptic prosthesis loosening following total hip arthroplasty.[Method]From Apr. 2006 to Nov.2006,porous tantalum cups were implanted during sixteen revision total hip replacements in nine women and seven men who had an average age of 69.2 years at the time of the procedure.Harris score and UCLA activity score were measured before,at 1,2 years and after arthroplasty.Radiographic follow-up was performed simultaneously.All patients were followed-up clinically and radiographically.[Result]The mean follow-up period was 24 month (range18-25months).The mean preoperative Harris hip score(HHS) was 21-54 (32.6) compared with the postoperative HHS of 56-90 (87.5).The mean preoperative UCLA score was 2-5(3.8) compared with the postoperative score of 6-9 (8.2).Radiographic evaluation of the revised components demonstrated no evidence of loosening or subsidence,and all showed radiographic evidence of bone ingrowth.[Conclusion]At the time of short-term follow-up,the porous tantalum cup effectively provided structural stability for acetabular component failure of cemented primary fixation.The potential for long-term biologic fixation may provide durability for porous tantalum cup.Long-term follow-up and comparison with alternative revision techniques will be required to evaluate the true effectiveness of this treatment approach.