生物材料体外动态血清接触对CH50及补体的影响

选用硅橡胶管（ＳＲ）、涤纶纤维材料（ＰＥＴＦ）、聚氯乙烯管（ＰＶＣ）及用醋酸纤维素（ＣＡ）、聚醚砜（ＰＥＳ）、聚氨酯涂层的聚氯乙烯管，分别与血清在３７℃下进行循环接触，根据接触前（０ｍｉｎ）、接触后５、１５、６０、１８０ｍｉｎ取血清，用ＩＬ－Ｍｏｎａｒｃｈ７６１型生化分析仪测定Ｃ３、Ｃ４，用试管法测定ＣＨ５０，实验结果表明，ＣＡ，ＰＥＴ，ＳＲ材料接触后血清的Ｃ３、Ｃ４，ＣＨ５０明显低于接触前，其中     

Experimental data regarding macroporous biphasic calcium phosphate ceramics

Summary Macroporous biphasic calcium phosphate ceramics are biocompatible. Their physico-chemical structure is close to the mineral phase of the bone and provides bioactivity. Shortly after implantation in osseous area, dissolution appears with precipitation and formation of apatite crystals. Soon after osteoclastic resorption begins osteoconduction inside the macropores. Mechanical studies reveal a significant improvement in the mechanical properties due to the growth of the trabecular bone. Animal experiments in the spine have demonstrated bone penetration which allows a postero-lateral fusion. The rigidity of the fusion is equivalent to that obtained with bone graft. Macroporous biphasic calcium phosphate can be applied to fill bone defects and for postero-lateral spine fusion.     

Xenograft use in reconstructive pelvic surgery: a review of the literature

Xenografts, bovine or porcine acellular collagen bioprostheses derived from dermis, pericardium, or small-intestine submucosa, were introduced to overcome synthetic mesh-related complications. Although there are eight commercially available xenografts, there is a paucity of empiric information to justify their use instead of the use of synthetic grafts. In addition, limited data are available about which graft characteristics are important and whether graft-reinforced repairs reduce recurrences and improve outcomes. To address these knowledge gaps, we conducted a Medline search of published reports on xenografts in animal and human trials. Histologic host response to implanted xenograft material depends primarily on chemical cross-linking and porosity, and it is limited to four responses: resorption, incorporation, encapsulation, and mixed. No clinical data unequivocally demonstrate an improved benefit to graft-reinforced repair.     

压电生物材料在组织再生领域的研究与应用进展

人体的内源性电场调节着相关生理过程。电刺激已被证明能够促进组织修复和再生。压电生物材料作为一种能将机械能转化为电刺激的智能材料,在组织再生领域有着良好的应用前景。该文综述了目前压电生物材料的分类和其促进组织再生的作用机理,以及压电生物材料在骨组织、神经组织、皮肤组织、肌肉组织和心血管等组织再生领域的最新研究与应用进展,最后总结分析了目前压电生物材料在实际应用中存在的不足和相应的改进措施。     

几丁质膜的研制与临床应用

几丁质是一种具有良好组织相容性的生物材料,采用几丁质生物膜治疗皮肤缺损,具有止血、制菌、促进创面愈合、减少瘢痕形成的功能,临床应用53例62处创面,效果满意。     

Osteoclasts and Biomaterials

Abstract There is a growing market of biomaterials for orthopedic applications. As soon as these materials are surgically introduced into the constantly remodeling bone of the patient, they start to interact with the local cells: osteoblasts and osteoclasts. At the first glance, the bone building osteoblasts seem to be the more important cells for osseointegration of implants. However, it is mainly the bone resorbing action of osteclasts that determines the longevity of the implant. In this paper, we give a short overview over the current understanding of osteoclast biology; we review the interaction between biomaterials, biomaterial particles and osteoclasts, and the effects of treatment with antiosteoclastic agents like bisphosphonates on biomaterial implant healing.     

硅胶假体与膨体聚四氟乙烯并用隆鼻术治疗鼻尖过低

目的探讨硅胶假体与膨体聚四氟乙烯并用隆鼻术治疗鼻尖过低、鼻孔显露整形的手术方法，以减少传统手术方法的并发症。方法在鼻硅胶假体上的鼻尖部附加一膨体聚四氟乙烯补片，用5-0尼龙线将两者缝合固定后行隆鼻术。结果硅胶假体与膨体聚四氟乙烯并用为228例患者行隆鼻术，并治疗鼻尖过低、鼻孔显露。术后随访3个月至2年，满意者225例，占98．68％；鼻尖发红者3例，占1．32％，其中取出鼻假体于3个月后再次行隆鼻术者2例，于2周后修整膨体聚四氟乙烯补片厚度者1例，术后效果较理想。结论硅胶假体与膨体聚四氟乙烯并用隆鼻术，是治疗鼻尖过低、鼻孔显露有效的手术方法。     

Crystal dissolution of biological and ceramic apatites

Summary High resolution transmission electron microscopy (Hr TEM) studies on biological and synthetic calcium phosphate have provided information on the dissolution process at the crystal level. The purpose of this study was to investigate the dissolution of ceramic hydroxyapatite (HA) after implantation using Hr TEM. Recovered HA ceramic implanted in bony and nonbony sites in animals and in periodontal pockets in humans were used for the study. For comparison, sections of human fluorotic enamel with caries and sections of shark enameloid previously exposed to 0.1 HCl were similarly investigated. Hr TEM studies demonstrated that in both the biological and ceramic apatites, the lattice and atomic defects were the starting points in the dissolution process. However, significant differences in the process of dissolution were observed: (1) biological apatite crystals showed preferential core dissolution whereas ceramic apatite crystals showed nonspecific dissolution at the cores and at the surfaces; (2) the dissolution of biological apatites appeared to consistently extend along the crystal's c-axis whereas dissolution of the ceramic HA did not appear to be correlated with the crystal's c-axis. The observed differences in crystal dissolution between biological and ceramic apatites may be attributed to the following: (1) the unique crystal/protein interaction present with biological apatites but absent in ceramic HA; (2) differences in defect distribution between biological and ceramic apatites which are due to the differences in the original of these defects; and (3) the longer morphological c-axis of biological apatites compared with that of ceramic apatites. This study provided for the first time, information on the dissolution process of implanted ceramic HA crystals and suggests that the crystal defects resulting from the sintering processes during the preparation of ceramic HA affect itsin vivo degradation and performance.     

Defining and designing polymers and hydrogels for neural tissue engineering

The use of biomaterials, such as hydrogels, as neural cell delivery devices is becoming more common in areas of research such as stroke, traumatic brain injury, and spinal cord injury. When reviewing the available research there is some ambiguity in the type of materials used and results are often at odds. This review aims to provide the neuroscience community who may not be familiar with fundamental concepts of hydrogel construction, with basic information that would pertain to neural tissue applications, and to describe the use of hydrogels as cell and drug delivery devices. We will illustrate some of the many tunable properties of hydrogels and the importance of these properties in obtaining reliable and consistent results. It is our hope that this review promotes creative ideas for ways that hydrogels could be adapted and employed for the treatment of a broad range of neurological disorders.     

Biomaterials as novel penetration enhancers for transdermal and dermal drug delivery systems

Abstract

The highly organized structure of the stratum corneum provides an effective barrier to the drug delivery into or across the skin. To overcome this barrier function, penetration enhancers are always used in the transdermal and dermal drug delivery systems. However, the conventional chemical enhancers are often limited by their inability to delivery large and hydrophilic molecules, and few to date have been routinely incorporated into the transdermal formulations due to their incompatibility and local irritation issues. Therefore, there has been a search for the compounds that exhibit broad enhancing activity for more drugs without producing much irritation. More recently, the use of biomaterials has emerged as a novel method to increase the skin permeability. In this paper, we present an overview of the investigations on the feasibility and application of biomaterials as penetration enhancers for transdermal or dermal drug delivery systems.