ABSTRACT
BACKGROUND:With the wide application of bone repair scaffold in the field of medicine, nano-hydroxyapatite (nHA) and silk fibroin (SF) both of which have good biological properties have become research hotspots in recent years.OBJECTIVE:To study the feasibility of nHA/SF composite materials loaded with recombinant human bone morphogenetic protein 2 (rhBMP-2) to restore the initial stability of the spinal segment in rabbits.METHODS: Thirty-six male health New Zealand rabbits were randomly divided into three groups, followed by preparation of spinal instability models. Autogenous iliac bone, nHA/SF composite, and rhBMP-2/nHA/SF composite were implanted into the L4/5 spinal segment in autologous bone group, nHA/SF group and rhBMP-2/nHA/SF group, respectively. X-ray exmaination was performed at 12 weeks postoperatively, and then the animals were killed for gross observation. The stability of the fusion segments was tested through a tensile machine. Histologically, bone graft fusion at the surgical site was observed.RESULTS AND CONCLUSION:(1) Findings from the gross specimen observation showed that the specimens at the fusion site presented with a hard texture. Obvious signs of fusion were visible in the autologous bone group, followed by the rhBMP-2/nHA/SF group, while no signs of fusion were detected in the nHA/SF group. (2) At 12 weeks postoperatively, a large number of trabecular bones grew into the boundary between the vertebral body and the iliac crest graft block in the autologous bone group. A little trabecular bone was found in the boundary in the nHA/SF group, while a lot of trabecular bone tissues were found in the boundary in the rhBMP-2/nHA/SF group. In accordance with the standard of fusion, there were 10, 3, and 9 rats in the autologous bone, nHA/SF and rhBMP-2/nHA/SF groups, respectively. (3) The range of motion of the spine in the rhBMP-2/nHA/SF showed no statistical difference from that in the autologous bone group, but was significantly higher than that in the nHA/SF group (P < 0.05). (4) Osseous connection was found around the bone graft in the autologous bone and nHA/SF groups, but no mature bone tissue was visible in the latter group. In the rhBMP-2/nHA/SF group, a large number of new capillaries was found and permeated into the spinal tissues. In summary, nHA/SF composite materials loaded with rhBMP-2 possess good biocompatibility, mechanical properties and bone induction ability, which can rebuild the initial stability of the spine in a short time.
ABSTRACT
Objective To investigate the effect of glutamine intensified TPN on nutritional state and immunofunction in the postoperative patients with gastrointestinal tract tumour.Methods 20 patients were divided into two groups including standard TPN group (control group,10 cases) and Glutamine intensified TPN group(study group,10 cases). Period of treatment was 8 days.Immunofunction(IgG,IgM,IgA,C 3,C 4), serum albumin , nitrogen balance were tested.Results (1)The patients serum albumin in the study group was increased significantly as compared with control group (P