几丁质-硅胶复合膜引导性骨再生的实验研究

目的通过对GBR连续组织学研究及放射学检查,探讨几丁质-硅胶复合膜在引导性骨再生(guided bone regeneration GBR)中的作用.方法取新西兰兔24只,造成双侧桡骨15mm骨缺损,将48只肢体平均分为A、B、C、D组,每组各12只肢体,分别用几丁质-硅胶复合膜、几丁质膜、硅胶管及空白对照.于手术后2、4、6、8、12、16周处死每组各两只兔,标本行X线及组织学检查.结果几丁质-硅胶复合膜组的骨缺损区在成骨活动的活跃程度、骨再生量和再生髓腔结构等方面均优于单纯几丁质、硅胶管及空白对照组(P<     

人工骨生物材料的研究进展

在骨科领域,由于严重创伤、骨肿瘤、骨髓炎等多种原因所致的骨缺损十分常见,采取何种材料、以何种方式进行骨移植术,一直是人类几个世纪以来不断深入研究的重要课题。然而迄今为止,临床上对大范围骨缺损的治疗仍是较为棘手的难题。自体骨虽然是理想的骨缺损修复材料,但自体取骨增加了患者的创伤和痛苦,并且供骨的来源有限,难以满足大段骨移植的要求;同种异体骨因存在免疫排斥反应,可能传播疾病和术后并发症而受到限制;     

Electrically conductive biodegradable polymer composite for nerve regeneration: electricity-stimulated neurite outgrowth and axon regeneration

Normal and electrically stimulated PC12 cell cultures and the implantation of nerve guidance channels were performed to evaluate newly developed electrically conductive biodegradable polymer composites. Polypyrrole (PPy) doped by butane sulfonic acid showed a significantly higher number of viable cells compared with PPy doped by polystyrenesulfonate after a 6-day culture. The PC12 cells were left to proliferate for 6 days, and the PPy-coated membranes, showing less initial cell adherence, recorded the same proliferation rate as did the noncoated membranes. Direct current electricity at various intensities was applied to the PC12 cell-cultured conductive membranes. After 7 days, the greatest number of neurites appeared on the membranes with a current intensity approximating 1.7-8.4 microA/cm. Nerve guidance channels made of conductive biodegradable composite were implanted into rats to replace 8 mm of sciatic nerve. The implants were harvested after 2 months and analyzed with immunohistochemistry and transmission electron microscopy. The regenerated nerve tissue displayed myelinated axons and Schwann cells that were similar to those in the native nerve. Electrical stimulation applied through the electrically conductive biodegradable polymers therefore enhanced neurite outgrowth in a current-dependent fashion. The conductive polymers also supported sciatic nerve regeneration in rats.     

Development of a bovine decellularized extracellular matrix‐biomaterial for nucleus pulposus regeneration

Painful intervertebral disc (IVD) degeneration is a common cause for spinal surgery. There is a clinical need to develop injectable biomaterials capable of promoting IVD regeneration, yet many available biomaterials do not mimic the native extracellular matrix (ECM) or promote matrix production. This study aimed to develop a decellularized injectable bovine ECM material that maintains structural and compositional features of native tissue and promotes nucleus pulposus (NP) cell (NPC) and mesenchymal stem cell (MSC) adaption. Injectable decellularized ECM constructs were created using 3 NP tissue decellularization methods (con.A: sodium deoxycholate, con.B: sodium deoxycholate & sodium dodecyl sulfate, con.C: sodium deoxycholate, sodium dodecyl sulfate & TritonX‐100) and evaluated for protein, microstructure, and for cell adaptation in 21 day human NPC and MSC culture experiments. Con.A was most efficient at DNA depletion, preserved best collagen microstructure and content, and maintained the highest glycosaminoglycan (GAG) content. NPCs in decellularized constructs of con.A&B demonstrated newly synthesized GAG production, which was apparent from “halos” of GAG staining surrounding seeded NPCs. Con.A also promoted MSC adaption with high cell viability and ECM production. The injectable decellularized NP biomaterial that used sodium deoxycholate without additional decellularization steps maintained native NP tissue structure and composition closest to natural ECM and promoted cellular adaptation of NP cells and MSCs. This natural decellularized biomaterial warrants further investigation for its potential as an injectable cell seeded supplement to augment NP replacement biomaterials and deliver NPCs or MSCs. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:876–888, 2016.     

介孔氧化硅纳米材料在骨组织工程中的应用

组织工程骨作为一种极具潜力的新型骨移植材料,有效弥补了现今骨修复材料的缺陷。其中介孔氧化硅纳米材料由于具有比表面积大、生物相容性好、可进一步加工修饰等优点,适合骨组织工程对材料的需求,具有较好的应用前景。针对前期已开展的基础科学研究成果,本文综述了介孔氧化硅纳米生物材料的基本特性和其在骨组织工程中的应用优势,并从药物载体和支架成分两个方面综述了其在骨组织工程中的研究现状,其中药物载体方面主要介绍负载药物的种类和负载方法,支架成分方面则将含有介孔氧化硅纳米材料的支架分为无机支架、有机支架和复合支架三类,并标注了各种支架在微观结构、药物释放动力学、力学性质以及所培养细胞的分子学和细胞学行为等一个或多个方面的突出优点。此外,本文还介绍了介孔氧化硅纳米材料在骨粘合剂中的应用,以及金属离子的引入。最后对介孔氧化硅纳米生物材料在骨组织工程领域的发展方向提出了设想。     

Vascularized periosteum and bone regeneration

The osteogenic potential of periosteum is widely recognized. During development, it plays a prominent role in the radial growth of long bones. Similarly, it has a key role in the consolidation of fractures. The physiological function of periosteum in the healthy, mature skeleton remains relatively subtle; however, its detachment from the bone surface reactivates its potential for fibrogenic and osteochondrogenic regeneration. This discreet anatomical structure is actually a reservoir of mesenchymal progenitor cells capable of proliferating and differentiating, by reinitializing cellular and molecular cascades of embryogenesis in mesenchymal tissues. However, given the hitherto limited knowledge of the quantitative potential of periosteum and of the pathways regulating tissue differentiation during regeneration, human applications have remained anecdotal. The findings of several in vivo and in vitro experiments indicate that the maintenance of the periosteum's vascularization stimulates its quantitative potential. The structural organization of the regenerated material in vivo is governed by locoregional biological and mechanical regulatory mechanisms that serve to make it capable of performing its new functions. The increasing awareness of periosteum's potential is stimulating active research in the fields of cellular biology and tissue engineering. The demonstration of its regenerative potential in animals gives reason to believe that strips of vascularized periosteum could become part of the developing armamentarium of regenerative medicine.     

Fibrin glue and bone regeneration

The osteoinductive property of fibrin glue with and without admixture of aprotinin was proven in animal model. Aprotinin as an inhibitor of the fibrinolysis is supposed to be an inhibitor of the osteogenesis, too. Three holes of 4 mm diameter and 2 mm depth were placed into the diaphysis of both femura in 12 adults dogs. The defects were filled with either pure fibrin glue or with glue containing aprotinin (3000 KIE), or with nothing (vacant). After 8 weeks the quantity of the new built woven-bone was examined by plane geometry and the "Bone Metabolising Unit (BMU)" (Frost) which are crossing the border of lamellar bone and new woven bone were counted out. There was seen no statistical significantly between the three groups neither in the quantity of new bone nor in the BMU. Therefore the fibrin glue has no osteoinductive property.     

Nanobioengineered electrospun composite nanofibers and osteoblasts for bone regeneration

Abstract:  Bone defects represent a medical and socioeconomic challenge. Engineering bioartificial bone tissues may help to solve problems related to donor site morbidity and size limitations. Nanofibrous scaffolds were electrospun into a blend of synthetic biodegradable polycaprolactone (PCL) with hydroxyapatite (HA) and natural polymer gelatin (Gel) at a ratio of 1:1:2 (PCL/HA/Gel) compared to PCL (9%), PCL/HA (1:1), and PCL/Gel (1:2) nanofibers. These fiber diameters were around 411 ± 158 to 856 ± 157 nm, and the pore size and porosity around 5–35 µm and 76–93%, respectively. The interconnecting porous structure of the nanofibrous scaffolds provides large surface area for cell attachment and sufficient space for nutrient transportation. The tensile property of composite nanofibrous scaffold (PCL/HA/Gel) was highly flexible and allows penetrating osteoblasts inside the scaffolds for bone tissue regeneration. Fourier transform infrared analysis showed that the composite nanofiber contains an amino group, a phosphate group, and carboxyl groups for inducing proliferation and mineralization of osteoblasts for in vitro bone formation. The cell proliferation (88%), alkaline phosphatase activity (77%), and mineralization (66%) of osteoblasts were significantly ( P  < 0.001) increased in composite nanofibrous scaffold compared to PCL nanofibrous scaffolds. Field emission scanning electron microscopic images showed that the composite nanofibers supported the proliferation and mineralization of osteoblast cells. These results show that the fabrication of electrospun PCL/HA/Gel composite nanofibrous scaffolds has potential for the proliferation and mineralization of osteoblasts for bone regeneration.     

含锶可降解生物陶瓷及生物玻璃骨植入材料研究进展

人体微量元素锶(Sr)具有抑制破骨和促进成骨的作用,已成功用于临床治疗骨质疏松症.Sr可取代骨植入材料中钙(Ca)而广泛添加于各类骨植入材料中,以提高材料生物活性,其中含Sr羟基磷灰石是最经典的含Sr陶瓷类骨植入材料之一.由于陶瓷类骨植入材料降解性能差而影响所含Sr有效释放,近年越来越趋于可降解生物玻璃中掺Sr的研究,...     

Angiogenesis in bone regeneration

Angiogenesis is a key component of bone repair. New blood vessels bring oxygen and nutrients to the highly metabolically active regenerating callus and serve as a route for inflammatory cells and cartilage and bone precursor cells to reach the injury site. Angiogenesis is regulated by a variety of growth factors, notably vascular endothelial growth factor (VEGF), which are produced by inflammatory cells and stromal cells to induce blood vessel in-growth. A variety of studies with transgenic and gene-targeted mice have demonstrated the importance of angiogenesis in fracture healing, and have provided insights into regulatory processes governing fracture angiogenesis. Indeed, in animal models enhancing angiogenesis promotes bone regeneration, suggesting that modifying fracture vascularization could be a viable therapeutic approach for accelerated/improved bone regeneration clinically.     

富血小板血浆与骨再生

富血小板血浆是自体血离心后的产物,其最初被作为一种生物凝胶和屏障膜应用于临床,主要作用为提高止血效果。近几年有研究发现富血小板血浆对骨再生有促进作用,这使其成为骨科领域又一热门的研究课题。本文简要综述了富血小板血浆在组成成分、临床应用、对骨再生的作用机制、最佳作用浓度等方面的研究进展,并讨论了其目前主要存在的问题。资料表明富血小板血浆含有多种高浓度的骨生长所需要的生长因子,它们在骨再生的各个不同阶段通过直接或者间接的作用促进着细胞的分化与增殖,从而促进新骨的生存,而这种促进骨再生的作用在血小板处于中等浓缩浓度时作用最强。目前在国外已有部分学者将富血小板血浆应用于临床,并取得了一定的疗效,这有可能使其成为促进骨缺损修复的又一有效方法,具有良好的应用前景。     

Long-term evaluation of nerve regeneration in a biodegradable nerve guide

Nerve regeneration using artificial biodegradable conduits is of increasing interest. The aim of this study is to evaluate the regeneration and maturation of a nerve after long-term implantation (2 years) of a biodegradable poly-L-lactide/poly-e-caprolactone (PLLA/PCL) copolymeric nerve guide in the sciatic nerve of the rat. After harvesting, we evaluated both the regenerated nerves and the controls, using light microscopy, transmission electron microscopy, and morphometric techniques. Remnants of biomaterial were still present after 2 years of implantation, but the foreign body reaction was very mild at this stage, due to the rounded shapes of the polymer debris. Morphometric analysis showed significant differences between the regenerated nerve and the normal sciatic nerve: the number of myelinated fibers is higher, and the mean fiber diameter of the myelinated fibers in the regenerated nerve is smaller. In conclusion, the results demonstrate that the new PLLA/PCL nerve guide can provide optimal conditions for regeneration and maturation of damaged nerves. © 1993 Wiley-Liss Inc.     

Meniscal tissue regeneration using a collagenous biomaterial derived from porcine small intestine submucosa

Purpose: The present investigation is a preliminary study designed to evaluate the use of a collagen-based biomaterial, chemically unaltered porcine small intestine submucosa (SIS), as a scaffold for meniscal tissue regeneration. Type of Study: Basic research. Methods: Surgical defects were created in the lateral menisci of 12 mature New Zealand white rabbits. The defects were repaired with a similarly shaped and sized wedge of a new collagenous biomaterial (SIS) and sutured in place. The opposite knees served as controls by creating a defect in the lateral meniscus without filling with SIS graft. Full cage activity was allowed until the animals were killed at 4, 12, and 24 weeks. Results: At 4 weeks, the graft material retained its physical position and grossly appeared soft and translucent. Histologically, cellular elements had infiltrated between the laminates of the graft. At 12 weeks, the graft grossly appeared more solid and opaque. Histologically, the host meniscal fibrochondrocytes were seen streaming into the peripheral margin of the graft. Early repopulation of the graft with apparently differentiated meniscal tissue was observed. At 24 weeks, the meniscus defect was grossly healed across and looked virtually normal: the normal meniscal shape, contour, consistency, and color had been replicated. Histologically, the healing tissue showed infiltration of what appeared to be meniscal fibrochondrocytes and connective tissue resembling the host meniscal tissue. The graft was nearly totally replaced by host tissue. Conclusions: This pilot animal study demonstrates that the multilaminated collagenous graft is conducive for cellular repopulation with host meniscal elements, and, by 24 weeks, is capable of supporting complete healing of a large meniscal defect.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 17, No 2 (February), 2001: pp 151–159     

Natural coral used as a replacement biomaterial in bone grafts

Natural coral, submitted to rigorous protocols of preparation and purification, can be used as a replacement biomaterial for bone grafts both in orthopaedic surgery and maxillo-cranio-facial surgery and neurosurgery. Experimental studies commenced in 1977 and human clinical applications, commenced in 1979, have largely demonstrated the biocompatibility of the material and its entirely original nature. This biomaterial is progressively and totally replaced by newly formed bone with, after completion of the restoration process, has the characteristics of the recipient bone.