ABSTRACT
[Abstract] In recent years, scientists have had a deeper understanding of the basic principles of tumor biology and immunology, and immunotherapy for cancer has made great progresses, greatly promoting the development of a series of new immunotherapy drugs for cancer. Cancer immunotherapy aims at eliminating cancer cells by stimulating and coordinating the immune system. However, the promotion and application of cancer immunotherapy are limited because of the uncertain safety and effectiveness of immune regulatory compound delivery. Due to its unique advantages, such as good targeting, less adverse events, and good stability, various nano-targeted delivery systems with different physical and chemical properties have been developed to stimulate the immune system in anti-tumor therapy. In this review, we summed up the research progresses of nanotechnology combined with immunotherapy for cancer in recent years.
ABSTRACT
<p><b>OBJECTIVE</b>To explore a new method for early avascular necrosis of femoral head (AVNFH) therapy.</p><p><b>METHODS</b>Sixty-nine AVNFH New Zealand adult rabbits were randomly divided into three groups with equal number. In Group A, deproteinized bone (DPB) that absorbed with recombinant plasmid pcDNA3.1-hVEGF165 was implanted into the drilled tunnel of necrotic femoral head. In Group B, only DPB was implanted. In Group C, only tunnel was drilled without DPB or plasmid implanted. Femoral head specimens were obtained at postoperative 1, 2, 4, 8, 16 weeks. The expression of VEGF165 and collagen I was detected by immunohistochemistry. Bone formation was detected generally by X-ray. Angiogenesis and the repair of the femoral head were observed histologically.</p><p><b>RESULTS</b>The expression of VEGF 165 could be detected 2 weeks after implantation in Group A, but it was not observed in other groups. The result of collagen I expression had a significantly difference 2, 4 and 8 weeks after operation in Group A from those in other groups (P < 0.01). X-ray results indicated that there was more bone formation in Group A than in other groups. The regenerated capillary vessels staining result of necrotic femoral head in Group A was significantly different from those in other groups at postoperative 2 and 4 weeks (P < 0.01).</p><p><b>CONCLUSIONS</b>Transfection of hVEGF165 gene enhances local angiogenesis and DPB-VEGF compound improves the repair of necrotic femoral head. Deproteinized bone grafting with VEGF gene transfer provides a potential method for the treatment of osteonecrosis.</p>