RESUMO
Objective To observe the outcome of an absorbable bioactive bone-inducing material for the treatment of osteonecrosis of the femoral head (ONFH).Methods Thirty rabbits were randomly,evenly divided into three groups,experience group with bioactive bone-inducing material planted into bone collapse,control group 1 with oral ShengMaiJiaoNang and control group 2 with no implantation in the bone necrosis.Results In experiment group,bone necrosis was halted and the collapse was repaired.Meanwhile,cancellous bone and cortical bone were regenerated,necrotic bone was basically healed,and bioactive bone-inducing material was gradually degraded and absorbed.In control group 1,part of the bone marrow vascular was repaired and regenerated,and a little new bone grew,which delayed the process of necrosis.In control group 2,there was no bone tissue regeneration in the bone collapse and further deterioration was observed.Conclusions The bioactive bone-inducing material can not only replace autologous cancellous bone,but also halt the progress of osteonecrosis,which may become an alternative treatment for the stage Ⅱ and early stage of ONFH.
RESUMO
BACKGROUND: Autologous cancellous bone graft remains the most effective grafting material for bone defects because it provides the three elements required for bone regeneration: osteoconduction, osteoinduction, and osteogenic cell. OBJECTIVE: To determine the indications for a cancellous bone like nano-hydroxyapatite/collagen (nano-HA/CO) composite for treatment of osteonecrosis of the femoral head (ONFH). DESIGN, TIME AND SETTING: A randomized controlled animal study was performed at Guangdong Medical Laboratory Animal Center from May to August 2007. MATERIALS: Ten New-zealand rabbits, weighing 1.5-2.0 kg, were prepared into models of ONFH by injection of liquid nitrogen. METHODS: Ten rabbits were randomly, evenly divided into 2 groups: nano-HA/CO composites group, insertion of nano-HA/CO bone substitutes into bone defects, and control group, without any implantation. MAIN OUTCOME MEASURES: The healing processes were assessed with macroscopic examination, X-ray photography and histological examination at days 7 and 14 after surgery. RESULTS: In the nano-HA/CO composites group, osteonecrosis was halted, holes were repaired, and nano-HA/CO bone substitute was gradually degraded and absorbed; but in the control group, osteonecrosis was deteriorated and holes were not repaired, remained the same drilled at the beginning. CONCLUSION: These nano-HA/CO composites can not only replace autologous cancellous bone, but also can halt the progress of osteonecrosis insulted by liquid nitrogen. Experimental results show potent alternative of this nano-HA/CO composites in treatment of ONFH in stage II and earlier stage.
RESUMO
BACKGROUND: A nano-artificial bone imitating cancellous bone has been developed. It is necessary to perform a series of animal experiments regarding this artificial bone prior to clinical trials for providing technical information.OBJECTIVE: To evaluate the biodegradability, osteoconductivity, and osteoinductivity of nano-hydroxyapatite/collagen (nano-HA/CO) composites imitating cancellous bone.DESIGN, TIME AND SETTING: A randomized controlled animal experiment was performed at the Guangdong Medical Laboratory Animal Center between March and June 2007.MATERIALS: The HA powder was synthesized by a co-precipitation reaction. The obtained HA powder was added into collagen solution at a certain ratio under vigorous stirring. The nano-HA/CO composites were frozen-dried to obtain nano-artificial bone. Fifteen New Zealand rabbits were randomly divided into 3 groups, with 5 rats per group: blank control, coral-HA, and nano-HA/CO.METHODS: Following local anesthesia, 10 mm bone defect was made on the right ulnas in all rabbits. HA coral and Nano-HA/CO bone composites were inserted into the defects in the HA and nano-HA/CO groups, respectively. The blank control group received no any implantation. At 30 and 60 days following surgery, biocompatibility and osteoinductivity of cancellous bone resembling nano-HA/CO bone substitute were assessed by macroscopic examination, scanning electron microscopy, X-ray photography, and histological examination after implantation in vivo.MAIN OUTCOME MEASURES: Ultrastructure and degradation condition of nano-HA/CO bone substitute, postoperative wound healing, and osteo-regeneration in defect region.RESULTS: The nano-HA/CO bone composite possessed interconnected porosity and pore size resembling cancellous bone, which benefits in-growth of osteoblasts and blood vessels. At 30 days following surgery, the nano-HA/CO group exhibited that osteoblasts spread around, and ossification occurred in almost all newly formed bone area. At 60 days following surgery, the coral-HA group showed that only connective tissue regenerated without bone tissue regeneration and degradation of grafts.CONCLUSION: This nano-HA/CO bone composite shows great promise in repairing massive bone defect in stead of autograft.
RESUMO
<p><b>OBJECTIVE</b>To study the gene expression profiles of human bone marrow derived mesenchymal stem cells and tendon cells.</p><p><b>METHODS</b>Total RNA extracted from human bone marrow derived mesenchymal stem cells and tendon cells underwent reverse transcription, and the products were labeled with alpha-(32)P dCTP. The cDNA probes of total RNA were hybridized to cDNA microarray with 1176 genes, and then the signals were analyzed by Atlas Image analysis software Version 1.01a.</p><p><b>RESULTS</b>Fifteen genes associated with cell proliferation and signal transduction were up-regulated, and one gene that takes part in cell-to-cell adhesion was down-regulated in tendon cells.</p><p><b>CONCLUSION</b>The 15 up-regulated and one down-regulated genes may be beneficial to the orientational differentiation of mesenchymal stem cells into tendon cells.</p>
