两种不同澄黄滨珊瑚的比较研究

目的 评价致密澄黄滨珊瑚与疏松澄黄滨珊瑚的理化性能及生物学性能。方法 两种珊瑚分别植入大鼠标准颅骨骨缺损区，分别于4、8、12周时行大体观察，X线检查及组织学检查，比较其生物学性能，结果两种珊瑚的成分一致，致密澄黄滨珊瑚与疏松澄黄滨珊瑚相比具有吸收慢，骨引导能力强优点，结论 致密澄黄滨珊瑚是一种理化性能及生物学性能均良好的新型材料，可能成为临床修复骨缺损的有效材料。     

氟化物Y500R珊瑚骨羟基磷灰石复合人工骨在兔颅面成骨效应的实验研究

目的：探讨氟离子对珊瑚骨羟基磷灰石（coral hydroxyapatite,CHA）在兔颅面成骨效应中的影响,了解结合了氟离子后的珊瑚骨羟基磷灰石成骨效能的变化。方法制备含氟Y500R珊瑚骨羟基磷灰石的人工骨及纯钛金属帽,选用新西兰大白兔24只,分为含氟CHA组和CHA组,每组12只。含氟CHA组兔颅面安放并固定2个装有含氟Y500R珊瑚骨羟基磷灰石人工骨的钛帽,CHA组钛帽装入珊瑚骨羟基磷灰石,注射四环素及钙黄绿素荧光双标记物,分别于2、4、6周时各处死8只实验动物（每组4只）,样品处理后作大体标本,观察新骨形成高度和新生骨质荧光带面积,制作硬组织切片行甲苯胺蓝—碱性品红染色,进行组织学观察。结果术后大体标本观察、荧光显微镜观察、硬组织切片染色观察结果显示,术后含氟CHA组新生骨质明显多于CHA组,成骨效应活跃。不同时期新生骨质荧光面积差异具有统计学意义（F=6.36,P=0.019）,含氟CHA组明显多于CHA组（P<0.05）。结论低浓度（1.0×10?7 mol/L～5.0×10?5 mol/L）的氟离子能有效促进骨生成作用。     

A bioreactor for studying negative pressure wound therapy on skin grafts

Negative pressure wound therapy (NPWT) has become the prevailing standard of care for treating complex soft tissue wounds and is now being considered for use in alternative applications including improving skin graft take. While it is generally agreed that negative pressure leads to improved wound healing, universal consensus on its optimal application is not supported in the literature. We describe the design and validation of a bioreactor to determine the prospective benefits of NPWT on skin grafts and engineered skin substitutes (ESS). Clinically relevant pressures were applied, and the native human skin was able to withstand greater negative pressures than the engineered substitutes. Both skin types were cultured under static, flow‐only, and −75 mm Hg conditions for 3 days. While it remained intact, there was damage to the epidermal‐dermal junction in the ESS after application of negative pressure. The normal skin remained viable under all culture conditions. The engineered skin underwent apoptosis in the flow‐only group; however, the application of negative pressure reduced apoptosis. Vascular endothelial growth factor levels were significantly higher in the normal flow‐only group, 152.0 ± 75.1 pg/mg protein, than the other culture conditions, 81.6 ± 35.5 pg/mg for the static and 103.6 ± pg/mg for the negative pressure conditions. The engineered skin had a similar trend but the differences were not significant. This bioreactor design can be used to evaluate the impacts of NPWT on the anatomy and physiology of skin to improve outcomes in wounds after grafting with normal or engineered skin.     

A physiological approach in stabilization and consolidation of unstable femoral neck fracture in osteoporotic elderly patients: a retrospective review

A retrospective review was performed on 46 unstable femoral neck fractures in osteoporotic elderly patients. They were treated with internal fixation using a nail-plate associated with filling of the metaphysis with a biomaterial—natural coral—which undergoes bone incorporation. From 1992 to 1996, the increased knowledge for use of natural coral in the surgical procedures allowed a progressively decrease in the mean time to weight bearing, starting from 26.3 days (1992) to 11.2 days (1996). Primary stabilization at the fracture site was obtained in 42 patients (91.3%), clinically evidenced by the absence of pain from unlimited weight bearing. Only four mild impactions were reported. Consolidation was observed in all cases but one. Among them, more than half of the patients (53.3%) had a time to consolidation equal or lower than to 45 days; 70% healed in 2 months. Biocompatibility of the coral was perfect. Full bioresorbability was observed—partially in five cases, in all other cases from 3 to 18 months. The biomaterial was filled with bone marrow. It acts "as if" it was a real autologous graft. A mechanically perfectly stabilized fracture site, a large amount of biomaterial, a spheric shape, 4 mm diameter, injected with bone marrow, filled in a good environment, are the best conditions to obtain good result with an easily reproducive system.     

皮肤组织工程学在我国

Great progress has been made in the basic research and clinical application of skin tissue engineering in China over the past 20 years. It includes culture of epithelial cells and their preliminary clinicaluse , research and development of various dermal substitutes such as acellular dermal matrix, spongi form collagen membrane and high molecular weight polymer membrane , and modification of physical properties of dermal substitutes for the sake of raising their bioaffinity and vascular ization , based on which composite skin containing epithelial cell layers has been constructed and used successfully in the repair of full-thickness skin defects. More recently , greater efforts have been made in the study of new epithelial seeding cells such as epithelial stem cell and hair follicle stem cell. With the work going into the center, it is hopeful into constructing an artificial skin that mimics the normal human skin in terms of structure and function with better viability of the transplant, so that it can eventually be used in clinical practice as a skin source for large area deep burn patients to improve the wound healing quality.     

Characterization of pigmented dermo‐epidermal skin substitutes in a long‐term in vivo assay

In our laboratory, we have been using human pigmented dermo‐epidermal skin substitutes for short‐term experiments since several years. Little is known, however, about the long‐term biology of such constructs after transplantation. We constructed human, melanocyte‐containing dermo‐epidermal skin substitutes of different (light and dark) pigmentation types and studied them in a long‐term animal experiment. Developmental and maturational stages of the epidermal and dermal compartment as well as signs of homoeostasis were analysed 15 weeks after transplantation. Keratinocytes, melanocytes and fibroblasts from human skin biopsies were isolated and assembled into dermo‐epidermal skin substitutes. These were transplanted onto immuno‐incompetent rats and investigated 15 weeks after transplantation. Chromameter evaluation showed a consistent skin colour between 3 and 4 months after transplantation. Melanocytes resided in the epidermal basal layer in physiological numbers and melanin accumulated in keratinocytes in a supranuclear position. Skin substitutes showed a mature epidermis in a homoeostatic state and the presence of dermal components such as Fibrillin and Tropoelastin suggested advanced maturation. Overall, pigmented dermo‐epidermal skin substitutes show a promising development towards achieving near‐normal skin characteristics and epidermal and dermal tissue homoeostasis. In particular, melanocytes function correctly over several months whilst remaining in a physiological, epidermal position and yield a pigmentation resembling original donor skin colour.