生物陶瓷涂层材料的研究进展

目的 本文对生物陶瓷涂层材料的研究进展进行综述。方法 介绍了生物陶瓷涂层的制备方法，并着重对生物惰性涂层和生物活性涂层的研究工作进行评述。结果 近几十年来生物陶瓷涂层发展较快，新方法和新材料不断呈现。结论 发展兼具优良生物学性能和力学性能的新涂层材料，是目前研究的趋势。     

钛基植人物生物陶瓷涂层的研究进展

医用钛合金材料属于生物惰性材料,广泛应用于硬组织的替换与修复领域.采用表面改性技术在钛基材料表面制成生物陶瓷涂层可改善钛基材料的生物活性和生物相容性.羟基磷灰石涂层已在临床上获得应用,但使用效果仍然受其较低的结合强度和结晶度所制约.为了获得综合性能更好的植入材料,制备了多种新型生物陶瓷涂层,其具有良好的生物活性、较好的...     

钛基植入体用生物陶瓷涂层研究进展

本文总结了现有的钛合金植入体用生物陶瓷涂层材料和涂层制备方法。并针对生物陶瓷涂层在制备过程和临床应用中存在的界面结合强度以及化学稳定性差的问题,阐述了可行的解决方案,包括梯度涂层、复合涂层、掺杂改性和参数改进等。     

生物陶瓷材料研究进展

本文综述了生物陶瓷材料研制发展的历史和现状,介绍了生物陶瓷材料在当前临床应用的情况,展望了其应用前景.     

钛基激光涂覆生物陶瓷涂层的生物相容性

TC4基激光涂覆生物陶瓷涂层具有良好的生物相容性及成骨性能 ,无组织增生、坏死及其他排斥反应。该涂层组织细小 ,具一定程度择优取向 ,涂层与基体为化学冶金结合等特征 ,它们对骨组织的生物结合及稳定提供了有利条件     

羟基磷灰石及其复合生物陶瓷材料研究进展

综述了羟基磷灰石陶瓷及其复合生物陶瓷材料方面的最新进展 ,并简单探讨了 HAP生物陶瓷的发展方向     

激光熔凝一步制备复合生物陶瓷涂层的 生物相容性

在钛合金表面上预涂敷 Ca HPO4 - Ca CO3- Y2 O3混合粉末 ,进行激光同步合成和熔覆 ,获得了以 TC4为基材的生物陶瓷涂层复合材料。将该涂层材料植入成年狗的股骨中进行生物相容性试验研究。结果表明 ,该涂层材料对动物的组织和细胞无毒副作用 ,且涂层有良好的生物相容性 ,有诱导骨生长和不影响成骨细胞与破骨细胞活性的特性。     

骨组织工程支架材料聚磷酸钙生物陶瓷研究进展

为修复创伤及病理因素导致的骨缺损,骨组织工程是一项迅速发展、不断革新的课题。多孔聚磷酸钙生物陶瓷是可吸收生物陶瓷的一种,具有良好的生物相容性以及可降解性,在骨组织工程中日益被人们所认识。骨组织工程中细胞生长速率与材料的降解速率相匹配一直是有待解决的问题,聚磷酸钙由于具有独特的结构及降解性能,因此有望解决这个问题。本文对作为骨组织工程支架材料之一的聚磷酸钙生物陶瓷的理化性质、制备方法、研究进展、骨结合机理等进行了综述,并对其研究和发展作出了展望。     

羟基磷灰石生物陶瓷及涂层制备技术的研究进展

羟基磷灰石 (HA)具有较好的生物相容性和生物活性 ,而其涂层材料可作为生物硬组织替代材料 ,有很好的发展前景。对羟基磷灰石及其涂层材料的制备方法作综合介绍 ,并提出一些存在的问题和解决方法。     

医用复合生物陶瓷的研究进展

随着医学研究的进展,人们对因肿瘤及损伤等原因造成的组织或器官的缺损的修复越来越重视。由于自体组织移植作为修复材料的来源受到限制,并存在弊端,许多材料学家与医学工作者相结合把目光集中到各种人工材料上,可吸收的人工材料前段时间研究颇热,但是由于材料吸收速度与人体组织修复之间的时间差异等各种问题而使对其的研究受到了限制,而从20世纪60年代开始研究的人体生物陶瓷由于良好的生物相容性、生物力学性能而得到广泛的关注。但是,陶瓷的脆性始终限制了陶瓷的临床应用。最近,增韧陶瓷及纳米陶瓷材料的研究正进一步深入,并且取得了很大的成功。科学家预言:“纳米技术是改善陶瓷脆性的战略途径”。纳米级复合生物陶瓷的各种生物力学性能更加符合人体硬组织的要求。这给生物陶瓷的研究注入了新的活力。     

Processing-microstructure-property relations in HVOF sprayed calcium phosphate based bioceramic coatings

Hydroxyapatite (HA) based bioceramic coatings were deposited onto titanium alloy substrates using the high velocity oxy-fuel (HVOF) spray technique. This study aimed to reveal the relations among processing parameters, microstructure, and properties of the bioceramic coatings. The processing conditions were altered through changing the starting HA powder size, content of bioinert ceramic additives or composite powder preparation techniques. Coating structure was characterized through scanning electron microscopy (SEM) and transmission electron microscopy (TEM); and the mechanical properties, Young's modulus and fracture toughness, of the coatings were evaluated through indentation techniques. Results demonstrated dominant influence of the melt state of HA powders on the phase composition of resultant coatings, and it was found that the HVOF HA coatings possess competitive mechanical properties. Furthermore, addition of titania or zirconia, as secondary phase in HA, showed promising effect on improving the mechanical properties of the HVOF HA-based coatings. Chemical reactions between HA and titania; and, HA and zirconia during coating deposition were revealed and characterized. Incorporation modes of the additives into HA and their reinforcing mechanisms were elucidated. The relationship among the processing, microstructure, and mechanical properties of the HVOF sprayed bioceramic coatings was summarily examined.     

Bone growth is enhanced by novel bioceramic coatings on Ti alloy implants

Calcium phosphate ceramics are widely used as coating materials to orthopedic implants and are found to enhance initial bony ingrowth by stimulating osseous apposition to the implant surface. In this study, two novel calcium orthophosphate materials were selected for coating onto the commonly used orthopedic implant material Ti-6Al- 4V. One was calcium alkali orthophosphate with the crystalline phase Ca10[K/Na](PO4)7 with a small addition of SiO2 (AW-Si) and the other was calcium orthophosphate composed of 70 mol % fluorapatite, Ca10(PO4)6F2 and 30 mol % CaZr4(PO4)6 (FA7Z). The coated implants were placed in cortical and cortico-cancellous bone of sheep femur for six weeks. Retrieved samples were tested for osseointegration and mechanical strength. It was found that both coatings produced enhanced bone/implant contact rate compared to the control when implanted in cortico-cancellous bone. This study demonstrates that the two coatings have the capability of encouraging bone growth, and hence the potential for being used as coating materials on Ti implants.     

Early healing of nanothickness bioceramic coatings on dental implants. An experimental study in dogs

Thick bioceramic coatings like plasma sprayed hydroxyapatite have been shown to increase the overall tissue response and biomechanical fixation of dental implants. However, the presence and potential fracture of a bone-coating-metallic substrate interface at long times after implantation led these implants to fall from favor in clinical practice. The purpose of this study was to evaluate the biomechanical fixation and biological response of Ca- and P-based, 20-50 nm thickness bioceramic deposition on a previously alumina-blasted/acid-etched Ti-6Al-4V implant surface in a dog model. Cylindrical alumina-blasted/acid-etched (AB/AE) (Control, n = 16), and Nanothickness bioceramic coated AB/AE(Nano, n = 16) implant surfaces were surgically placed in dogs proximal tibia and remained for 2 and 4 weeks in vivo. Following euthanization, the implants-in-bone were mounted in epoxy and pullout at a 0.5 mm/min rate. Following mechanical testing, the specimens were decalcified and processed (Hematoxylin and Eosin) for standard transmitted light microscopy evaluation. Percent bone-to-implant contact (BIC) to the pulled out implant surface was determined through computer software. Statistical analyses were performed by one-way ANOVA at 95% level of significance and Tukey's post-hoc multiple comparisons. No significant differences in pullout force were observed (p > 0.88): 2W Control (212.08 +/- 42.96 N), 2W Nano (224.35 +/- 42.97 N), 4W Control (207.07 +/- 42.97 N), and 4W Nano (190.15 +/- 45.94 N). No significant differences in %BIC were observed (p > 0.94): 2W Control (72.66 +/- 8.51), 2W Nano (69.44 +/- 8.51), 4W Control (70.44 +/- 8.51), and 4W Nano (69.11 +/- 9.09). It is shown that 20-50 nm thickness bioceramic depositions onto previously alumina-blasted/acid-etched substrates did not improve the biomechanical fixation and the BIC at early implantation times, and studies concerning shorter and longer implantation times are recommended for confirmation or before a conclusion can be made.     

骨科内植物多功能涂层研究进展

无菌性松动和植入物周围感染是骨科内固定术失败的两个主要原因,随着手术数量的日益增长,如何降低此类手术失败风险变得格外重要。在这个领域中,近期大量的研究工作致力于研制各种各样的内植物涂层,而这些涂层大多只具有抗感染作用而无骨整合作用;或者只具有骨整合作用而不具备抗感染作用。但是要使内植物长期有效,理想的涂层应兼顾骨整合和抗感染这两个功能。本文将对同时具有骨整合性和抗感染性的多功能涂层近期的研究进展和未来研究方向进行综述。     

Future developments in brain-machine interface research

Neuroprosthetic devices based on brain-machine interface technology hold promise for the restoration of body mobility in patients suffering from devastating motor deficits caused by brain injury, neurologic diseases and limb loss. During the last decade, considerable progress has been achieved in this multidisciplinary research, mainly in the brain-machine interface that enacts upper-limb functionality. However, a considerable number of problems need to be resolved before fully functional limb neuroprostheses can be built. To move towards developing neuroprosthetic devices for humans, brain-machine interface research has to address a number of issues related to improving the quality of neuronal recordings, achieving stable, long-term performance, and extending the brain-machine interface approach to a broad range of motor and sensory functions. Here, we review the future steps that are part of the strategic plan of the Duke University Center for Neuroengineering, and its partners, the Brazilian National Institute of Brain-Machine Interfaces and the école Polytechnique Fédérale de Lausanne (EPFL) Center for Neuroprosthetics, to bring this new technology to clinical fruition.     

Major developments in behavioral diabetes research.

Over the past decade, there has been a major increase in behavioral diabetes research. This review focuses on 6 areas: self-treatment, psychosocial impact, diabetes-specific assessment, psychological stress, weight loss intervention, and neuropsychological effects. There has been great progress in identifying factors that predict self-treatment behaviors and psychological adjustment. This research has produced a number of diabetes-specific assessment tools. Psychological stress appears to affect both the etiology and the control of diabetes, but underlying mechanisms remain unclear. Weight loss studies demonstrate the potential benefits of behavioral interventions for diabetes management. Both acute and chronic abnormalities in diabetic blood glucose cause neuropsychological impairments and may cause permanent deficits. The challenge for the next decade is to translate these findings into interventions that improve quality of life and physical well-being for individuals with diabetes.     

XPS, EDX and FTIR analysis of pulsed laser deposited calcium phosphate bioceramic coatings: the effects of various process parameters

Many techniques have been used to produce calcium phosphate, especially hydroxyapatite (HA), coatings on metallic implant surfaces for improved biocompatibility. Although some techniques have produced coatings used clinically, the long-term stability of the coating/implant is still questionable. As a new technique for making HA coatings, pulsed laser deposition (PLD) shows some advantages in controlling the coatings' crystal structure and composition. In this study, three types of HA target and two wavelengths of laser were used to produce calcium phosphate coatings. Despite PLDs ability to improve the crystal structure by incorporating water vapor into the deposition process, the characterization with EDX and XPS showed that coatings had different Ca/P ratios from that of the pure HA targets, which almost assured the presence of non-HA phases. FTIR spectra also showed differences in phosphate bands of coatings and targets although the difference in data collecting modes might have been a factor. The observed differences might be related to the differences between the surface and bulk chemistries of the coatings. Nevertheless, when evaluating the suitability of the PLD technique for making HA coatings, the possibility of the formation of non-HA phases cannot be excluded, although it may not necessarily be a negative factor.