Effect Of DCMTSA On The Expression Of BMP-2 And BMP-7 In Rats With Traumatic Femoral Head Necrosis

Background Fracture healing is a complex biological repair process. Climically fracture delayed union/nonunion remains unsolved. The intervention of Traditional Chinese and Western medications is time-consuming and the effect is not ideal. Recently, bone morphogenetic protein is the best cell factor for promoting fracture healing.Experimental studies show that bone morphogenetic protein could induce the differentiation of bone marrow stromal cells into osteoblasts. Sodium alginate(SA) is a natural polysaccharide polymer extracted from brown algae. Should part of hydroxyl sodium alginate uronic acid unit tranform aldehyde, improve the biocompatibility of the sodium alginate,and, and reduce its degradability, that’s the dicarboxmethyl trisodium alignate (DCMTSA), sodium alginatewould be an effective drug in inducing bone morphogenetic protein.Objective To improve the biological properties of sodium alginate, to explore the effect of dicarboxmethyl trisodium alignate on bone morphogenetic protein expression and to clarify The promoting role of DCMTSA in the differentiation of bone marrow stromal cells to osteoblast in order to introduce a fracture preventive and curable drug which can be simply produced and has DCMTSA group wide raw material source, to provide laboratory evidence for clinical prevention and treatment of diseases such as fracture. The experimental also provided a simple preparation method for drug which has a wide material source. The study also provide laboratory evidence for clinical application in the prevention and the treatment of bone diseases.Methods1. Preparation of DCMTSA:SA through oxidation of potassium permanganate solution or hydrogen partial oxidation, part of the hydroxyl of uronic acid units into aldehyde group, may improve the degradation properties of SA.2. Preparation of animal model and grouping:45 body weight (261±12)g,2～3month old SD rat model with traumatic avascular necrosis of the femoral head were randomly divided into the DCMTSA group,the alginate group and the controlled group,15 rats in each group.DCMTSA group,rats were treated with DCMTSA O.lg.kg-1.d-1 ig at a dose, perday a day;the alginate group,rats were treated daily with SA 0.0g.kg-1.d-1 gavage model group, was the controlled group,rats of 0.1g.kg-1.d-1 glucose gavage every day.3. Experimental methods:Among each group 5 rats were killed on 7d,14d,21d respectively. Femoral fracture of the rats was divided into two parts:One after 10% formaldehyde fixed decalcification, the fracture callus growth structure can be observed with HE staining, the callus bone formation protein expression can be detected by immunohistochemical SP method; immunohistochemical SP method was used to detect the callus bone formation protein expression; tissue homogenates after a decalcified bone softening, RT-PCR was utilized to detect the mRNA formation in callus tissue.Result1. HE staining results:Fibrous hyperplasia of broken ends, formation of trabecular bone Liang, bone matrix and bone structure in the DCMTSA group is better than Those of the alginate group.Those of the alginate group than that of the controlled group, at 7d, 14d and 21 d after surgery.2. Immunohistochemistry experiment results:the expression level of BMP-2 and BMP-7 protein in the DCMTSA group is higher than that in the alginate group,the alginate group than that in the controlled group, at 7d,14d and 21d after surgery.3. Results of RT-PCR:The expression of BMP-2 and BMP-7 mRNA in the DCMTSA group the alginate group, the controlled group is higher than in the alginate group, the alginate group than that in the controlled group, at 21d after surgery.4. The results of bibliometrics of femur:The number of mean trabecular bone Liang,mean trabecular bone Liang Houdu and mean trabecular bone area in the DCMTSA group is greater than Those of the alginate group,Those of the alginate group than that of the controlled group And the the controlled group of cancellous bone and cortical bone volume decreased significantly,the number of trabecular bone decreased considerably,the bone marrow cavity was expanded obviously, trabecular thickness and bone cortical thinning.Conclusion DCMTSA could raisethe expression level of BMP-7 and BMP-2,promote osteoblastic differentiation and inhibit bone absorption caused by osteoclast,which is beneficial for bone mass increase and damaged bone tissue repair.