纯钛表面激光合成钙磷生物陶瓷涂层的组成与结构

目的 采用廉价的CaCO_3和CaHPO_4·2H_2O作为原料,在激光的作用下通过反应制备HA生物陶瓷涂层。方法 利用X射线衍射仪和电子探针分析仪对涂层进行相分析、组织观察和成分分析。结果CaCO_3和CaHPO_4·2H_2O按20:80的质量比混合时,在功率为600W、扫描速度为3.5mm/s的激光作用下可一步合成钙磷生物陶瓷涂层。结论 在一定实验条件下,CaCO_3和CaHPO_4·2H_2O可合成组织致密、结合状态良好的钙磷生物陶瓷涂层。     

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。     

不同比例羟基磷灰石/β-磷酸三钙涂层支架修复骨缺损

背景：羟基磷灰石/β-磷酸三钙双相磷酸钙陶瓷具有良好的生物相容性与骨传导能力,可以作为涂层材料联合用于超临界骨缺损修复,但羟基磷灰石/β-磷酸三钙涂层的最佳质量比目前尚无明确报道。目的：在兔桡骨超临界骨缺损部位植入不同比例羟基磷灰石/β-磷酸三钙涂层多孔生物陶瓷支架,评估其修复作用,以期获得最佳的涂层比例。方法：采用3D打印技术制备羟基磷灰石多孔生物陶瓷支架,并在其表面使用不同比例的羟基磷灰石与β-磷酸三钙(二者质量比分别为3∶7,5∶5,7∶3)进行涂层处理,然后对支架的细胞毒性、孔隙率、力学强度、涂层厚度等参数进行测试。在36只新西兰大白兔右前肢建立15.0 mm兔桡骨超临界骨缺损模型,随机分4组处理,每组9只：空白组不植入任何材料,3∶7涂层组、5∶5涂层组、7∶3涂层组分别植入对应质量比例涂层的羟基磷灰石多孔生物陶瓷支架,术后4,8,12周,分别进行X射线片及Micro-CT检查、Van-Gieson染色、苏木精-伊红染色及Ⅰ型胶原蛋白免疫组织化学分析。结果与结论：(1)3∶7、5∶5、7∶3涂层支架的细胞毒性均为0级,涂层厚度为(75.2±0.54)μm,孔隙率分别为(54....     

仿生UHMWPE关节软骨材料的静态黏弹性研究

目的 通过蠕变、应力松弛和蠕变回复等实验评价多孔梯度UHMWPE仿生软骨材料的静态黏弹性能。方法 采用模板滤取（T-L）法制备多孔梯度UHMWPE仿生软骨材料,扫描电镜观察多孔组织结构,压汞仪测量多孔层的孔隙率和孔径分布特征,平头压痕实验测定多孔梯度UHMWPE材料的蠕变、应力松弛和蠕变回复性能。结果 T-L法制备的UHMWPE梯度多孔层与基体的结合良好,随NaCl含量的增加,孔隙率增大,孔径尺寸分布范围扩大。蠕变变形和模量随时间呈非线性增加,应力松弛应力和模量非线性降低,对冲击载荷的缓冲能力明显高于致密UHMWPE。实验表明,具有合理孔隙率的U50和U60样品与致密UHMWPE材料回复性能相近,但过高的孔隙率造成蠕变回复的塑性变形增加。结论 多孔梯度结构UHMWPE材料的弹性增加,应变响应速度提高,有利于改善摩擦副的接触润滑状态,减轻材料的磨损。     

HAF/YSZ梯度复合涂层的制备及结构和性能

背景：在钛合金基体表面制备涂层的方法多为等离子喷涂法、溶胶-凝胶法、离子束溅射法等,所制备的涂层性能不稳定、成分单一,且涂层物相组成较难控制。 目的：采用射频磁控溅射技术在Ti6Al4V基体上制备含氟羟基磷灰石梯度复合涂层HAF/YSZ。 方法：在Ti6Al4V基体上以射频磁控溅射技术制备含氟羟基磷灰石梯度复合涂层HAF/YSZ,利用X射线光电子能谱、扫描电镜等对涂层的成分分布、形貌、界面结合进行表征。通过模拟体液实验分析和评价HAF/YSZ涂层、HAF1.2涂层及羟基磷灰石涂层的生物性能。 结果与结论：所制备的HAF/YSZ梯度涂层表面粗糙,呈多孔岛状结构,有利于新生骨组织生长;涂层与基体结合紧密,各层间相互扩散,整体一致性较好;经模拟体液浸泡后,涂层表面有新生物质沉积,表现出较好的生物活性及稳定性,且梯度复合涂层较氟含量单一的氟羟基磷灰石涂层具有更好的抗体液溶解能力及稳定性。     

F掺杂对纳米Al_2O_3/HA复合陶瓷的结构与性能影响

本研究采用化学沉淀法制备了纳米Al_2O_3/HA复合粉体,采用热压烧结法制备了Al_2O_3/HA复合生物陶瓷,并研究了F掺杂量对复合陶瓷物相组成和力学性能的影响。结果证明复合陶瓷的力学性能随着F掺杂量的提高而逐渐增大,当F掺杂量x=1时,复合陶瓷的力学性能最佳,其弯曲强度和断裂韧性分别为147.2 MPa和2.19 MPa·m~(1/2)。当F掺杂量高于0.5时,可以抑制复合陶瓷中HA的分解,并且在烧结过程中有AlF3相生成,可促进复合陶瓷的致密化。F掺杂可以提高复合陶瓷的生物活性,但是F掺杂量对复合陶瓷的生物活性影响不大。     

Varnish XT和ICON渗透树脂对釉质龋白斑微硬度的影响

背景:早期龋的治疗方法中,可以采用氟化物对龋白斑进行再矿化处理。长效释氟玻璃离子保护膜(Varnish XT)和ICON渗透树脂是两种新型的材料,Varnish XT是一种新型的树脂加强型玻璃离子,可以作为再矿化材料的新选择。ICON渗透树脂是一种流动性较好的高渗透系数树脂,借助毛细作用渗入到脱矿釉质的微孔中,利用低黏性的渗透树脂取代由于脱矿而丧失的硬组织并占据微孔的空间,填补釉质脱矿区并阻止病损的进一步发展。目的:观察Varnish XT和ICON渗透树脂两种微创治疗材料对釉质龋白斑微硬度的影响。方法:选择牛门齿100颗,将唇面向下作为观察面,环氧树脂包埋,打磨。暴露至少6 mm×10 mm的釉质牙面,由切端至颈部依次分A,B,C,D,E 5个区,E区用抗酸指甲油封闭。分别采用人工龋脱矿液后,A区不做处理,B区经Varnish XT处理,C区经ICON渗透树脂处理,D区经氟化物处理后,用韦氏硬度仪测量表面显微硬度值。结果与结论:脱矿样本经处理后A,B,C,D区的表面显微硬度值较E区均明显降低(P0.05),B,C,D区样本表面显微硬度值均较A区升高,且表面显微硬度值C区B区、D区(P0.05);B区的表面显微硬度值与D区相比,差异无显著性意义(P0.05)。说明ICON渗透树脂、Varnish XT和氟化物对龋白斑的微硬度都有明显的改善,ICON渗透树脂的改善较Varnish XT和氟化物明显,Varnish XT和氟化物之间无明显差异。     

人体肱骨干显微骨硬度分布特征的实验研究

目的 测量并分析肱骨干不同层面和方位显微骨硬度分布特征及其临床意义。方法 选取新鲜成人尸体标本3具(62岁男性、45岁女性和58岁男性),取其右侧肱骨干部分,垂直于肱骨干长轴水平,使用金刚石慢速锯在每一段精确切取厚3 mm的骨组织标本共7层,分别标记为第Ⅰ~Ⅶ层,进而区分为肱骨干上段(Ⅰ、Ⅱ层)、中段(Ⅲ~Ⅴ层)、下段(Ⅵ、Ⅶ层),并将每层划分为前、后、内、外四个区域;应用维氏金刚石显微硬度压头在标本表面进行硬度测量并分区统计,进而分析不同区域肱骨干显微硬度分布规律。结果 共获得肱骨干84个测量部位420个测量位点的有效测量值。分析显示,肱骨干总体硬度(47.52±6.01)HV,肱骨干中段整体硬度大于肱骨干上段及下段(F=11.594, P＜0.01)。肱骨干7个分层中,Ⅳ层硬度最大(51.34±7.01)HV、Ⅶ硬度最小(45.72±6.25)HV;肱骨中段Ⅳ层内侧部分硬度最大(53.77±8.70)HV,肱骨干下段Ⅶ层后侧区域硬度最小(42.02±7.47)HV。肱骨干后侧整体硬度(45.28±6.47)HV,小于肱骨外侧(49.12±5.22)HV、内侧(48.28±6.10)HV、前侧(47.40±5.55)HV硬度,差异有统计学意义(F=8.347, P＜0.01)。结论 肱骨干骨皮质不同层面及方位骨显微硬度存在差异,该分布规律数据可指导设计适应生理状态下骨骼应力传导特性的3D打印仿生内置入物。亦可对模拟生理状态下骨骼生物力学性能的骨骼建模及有限元分析提供数据支持。     

基于三维打印的磷酸三钙骨组织工程支架烧结工艺研究

磷酸三钙(TCP)是构建骨组织工程支架常用的生物陶瓷材料。三维(3D)打印的TCP支架具有精确可控的孔隙结构,但存在力学性能不足的问题。由于烧结工艺对生物陶瓷支架力学性能的影响至关重要,本文详细探讨了不同烧结温度对3D打印TCP支架的力学性能的影响,测试了不同烧结温度制备的支架的表观形貌、质量和体积收缩率、孔隙率、力学性能以及降解性能。结果表明,当烧结温度为1150℃时,晶粒生长充分、气孔最少,支架具有最大的体积收缩率、最小的孔隙率以及最优的力学性能,压缩模量和抗压强度可以分别达到(100.08±18.6)MPa和(6.52±0.84)MPa,能够满足人体松质骨力学强度的要求。此外,与其他烧结温度下制备的支架相比,1150℃下烧结制备的支架在酸性环境中降解最慢,进一步说明其在长期植入时具有更佳的力学稳定性。该支架可支持骨髓间充质干细胞(BMSCs)黏附和快速增殖,具有良好的生物相容性。综上,本文优化了3D打印TCP支架的烧结工艺,提高了其力学性能,为其作为承重骨的应用奠定了基础。     

掺钕钇铝钙钛晶体激光结合两种再矿化制剂与早期釉质龋的再矿化

背景：近年来，多种激光被广泛应用于口腔医学相关的各种疾病，包括龋病的预防及治疗。目的：探讨掺钕铝酸钇晶体(neodymium-doped:yttrium aluminum perovskite,Nd:YAP)激光联合两种再矿化制剂对早期釉质龋再矿化的作用。方法：将60颗牙釉质块体外建立人工龋模型后，随机分为6组(n=10):A组不进行任何处理，行体外pH循环；B组进行护牙素(主要成分为酪蛋白磷酸钙复合体)再矿化处理，行体外pH循环；C组进行舒适达牙膏(主要成分为生物活性玻璃)再矿化处理，行体外pH循环；D组进行Nd:YAP激光照射，行体外pH循环；E组进行Nd:YAP激光照射，然后进行护牙素再矿化处理，行体外pH循环；F组进行Nd:YAP激光照射，然后舒适达牙膏再矿化处理，行体外pH循环；再矿化处理2次/d，实验周期20 d。G组为正常对照，未致龋，未进行再矿化处理，仅行体外p H循环。实验结束后，检测各组牙釉质表面的显微硬度、形貌与Ca/P比值。结果与结论：(1)B、C、D组牙釉质表面的硬度值高于A组(P <0.000 1),E、F组牙釉质表面的硬度值明显高于B、C、D组(P ...     

Biocompatibility of a functionally graded bioceramic coating made by wide-band laser cladding

The application of plasma spray is the most popular method by which a metal-bioceramic surface composite can be prepared for the repair of biological hard-tissue, but this method has disadvantages. These disadvantages include poor coating-to-substrate adhesion, low mechanical strength, and brittleness of the coating. In the investigation described in this article, a gradient bioceramic coating was prepared on a Ti-6Al-4V titanium alloy surface using a gradient composite design and wide-band laser cladding techniques. Using a trilayer-structure composed of a substratum, an alloy and bioceramics, the coating was chemically and metallurgically bonded with the substratum. The coating, which contains beta-tricalcium phosphate and hydroxyapatite, showed favorable biocompatibility with the bone tissue and promoted in vivo osteogenesis.     

Macroporous bioceramics: a remarkable material for bone regeneration

This review summarises the major developments of macroporous bioceramics used mainly for repairing bone defects. Porous bioceramics have been receiving attention ever since their larger surface area was reported to be beneficial for the formation of more rigid bonds with host tissues. The study of porous bioceramics is important to overcome the less favourable bonds formed between dense bioceramics and host tissues, especially in healing bone defects. Macroporous bioceramics, which have been studied extensively, include hydroxyapatite, tricalcium phosphate, alumina, and zirconia. The pore size and interconnections both have significant effects on the growth rate of bone tissues. The optimum pore size of hydroxyapatite scaffolds for bone growth was found to be 300?μm. The existence of interconnections between pores is critical during the initial stage of tissue ingrowth on porous hydroxyapatite scaffolds. Furthermore, pore formation on β-tricalcium phosphate scaffolds also allowed the impregnation of growth factors and cells to improve bone tissues growth significantly. The formation of vascularised tissues was observed on macroporous alumina but did not take place in the case of dense alumina due to its bioinert nature. A macroporous alumina coating on scaffolds was able to improve the overall mechanical properties, and it enabled the impregnation of bioactive materials that could increase the bone growth rate. Despite the bioinertness of zirconia, porous zirconia was useful in designing scaffolds with superior mechanical properties after being coated with bioactive materials. The pores in zirconia were believed to improve the bone growth on the coated system. In summary, although the formation of pores in bioceramics may adversely affect mechanical properties, the advantages provided by the pores are crucial in repairing bone defects.     

Role of scaffold internal structure on in vivo bone formation in macroporous calcium phosphate bioceramics

Purpose of this study was the analysis of the role of density and pore interconnection pathway in scaffolds to be used as bone substitutes. We have considered 2 hydroxyapatite bioceramics with identical microstructure and different macro-porosity, pore size distribution and pore interconnection pathway. The scaffolds were obtained with two different procedures: (a) sponge matrix embedding (scaffold A), and (b) foaming (scaffold B). Bone ingrowth within the two bioceramics was obtained using an established model of in vivo bone formation by exogenously added osteoprogenitor cells. The histological analysis of specimens at different time after in vivo implantation revealed in both materials a significant extent of bone matrix deposition. Interestingly enough, scaffold B allowed a faster occurrence of bone tissue, reaching a steady state as soon as 4 weeks. Scaffold A on the other hand reached a comparable level of bone formation only after 8 weeks of in vivo implantation. Both scaffolds were well vascularised, but larger blood vessels were observed in scaffold A. Here we show that porosity and pore interconnection of osteoconductive scaffolds can influence the overall amount of bone deposition, the pattern of blood vessels invasion and finally the kinetics of the bone neoformation process.     

锌修饰硅酸钙陶瓷涂层与骨整合

BACKGROUND: Zinc-modified calcium silicate (CaSiO3) bioceramics coating on the titanium surface prepared in preliminary experiments has good chemical stability and antibacterial property. OBJECTIVE: To observe the effects of zinc-modified CaSiO3 bioceramics coating on osteointegration. METHODS: MC3T3-E1 cells were respectively cultured on the titanium with zinc-modified CaSiO3 bioceramics coating (experiment group), titanium with CaSiO3 bioceramics coating (control group) and pure titanium (blank control group). Then, cell adhesion, proliferation, calcification rate and the expression of type I collagen and osteocalcin were detected. The implant materials mentioned above were respectively inserted into the femurs of New Zealand white rabbits, and after 1.5 months, the osteoproliferation and osteointegration between the implants and the host were tested. RESULTS AND CONCLUSION: In vitro experiment: The number of adhesive cells at 12 hours after co-culture was significantly increased in the experimental group compared with the control group and blank control group (P < 0.05). At 14 days after co-culture, cell proliferation ability and ability of calcium nodule formation in the experiment group were significantly better than those in the other groups (P < 0.05). At 21 days after co-culture, there was no significant difference in the expression of type I collagen, but the expression of osteocalcin in the experiment group was higher than that in the control group and blank control group (P < 0.05). In vivo experiment: In the experiment group, a large amount of bone substances were detected, the coating materials directly contacted with the bone interface, new bone tissues and little fibrous tissues were observed at the interface. In contrast, there was a small amount of bone hyperplasia in the control group and almost no bone hyperplase in the blank control group. Moreover, a small part of the implant directly contacted with the bone interface and the most part was separated from bone trabeculae by fibrous tissues. These findings indicate that zinc-modified CaSiO3 bioceramics coating can enhance the ability of osteointegration between titanium implants and the host.      

Structural and morphological study of pulsed laser deposited calcium phosphate bioceramic coatings: influence of deposition conditions, laser parameters, and target properties

Calcium phosphate (CaP) bioceramics, especially hydroxyapatite (HA), have been used as coatings on implants owing to their biocompatible properties. The commercial practice for applying HA coating, plasma spraying, has some disadvantages which limit the long-term stability of the implants. Pulsed laser deposition (PLD) is being investigated as an alternative technique. The purpose of this research was to systematically study the effect of various parameters of the PLD process on the properties of CaP coatings. In this study, three types of HA targets and two laser wavelengths were used to make six categories of coatings. Predominantly crystalline HA coatings were produced under all six categories at optimum conditions, although small amounts of minor phases sometimes were found. Sufficient coating/substrate bond strength was also obtained. A wide variety of coating morphologies was obtained, from rather dense and uniform to rough and porous. The important factors that affected the morphology included target properties, vacuum level, deposition temperature, and laser wavelength and energy density. PLD's ability to produce both amorphous and crystalline, and both smooth/dense and rough/porous coatings may be a unique advantage.     

Perfusion electrodeposition of calcium phosphate on additive manufactured titanium scaffolds for bone engineering

A perfusion electrodeposition (P-ELD) system was reported to functionalize additive manufactured Ti6Al4V scaffolds with a calcium phosphate (CaP) coating in a controlled and reproducible manner. The effects and interactions of four main process parameters - current density (I), deposition time (t), flow rate (f) and process temperature (T) - on the properties of the CaP coating were investigated. The results showed a direct relation between the parameters and the deposited CaP mass, with a significant effect for t (P=0.001) and t-f interaction (P=0.019). Computational fluid dynamic analysis showed a relatively low electrolyte velocity within the struts and a high velocity in the open areas within the P-ELD chamber, which were not influenced by a change in f. This is beneficial for promoting a controlled CaP deposition and hydrogen gas removal. Optimization studies showed that a minimum t of 6 h was needed to obtain complete coating of the scaffold regardless of I, and the thickness was increased by increasing I and t. Energy-dispersive X-ray and X-ray diffraction analysis confirmed the deposition of highly crystalline synthetic carbonated hydroxyapatite under all conditions (Ca/P ratio=1.41). High cell viability and cell-material interactions were demonstrated by in vitro culture of human periosteum derived cells on coated scaffolds. This study showed that P-ELD provides a technological tool to functionalize complex scaffold structures with a biocompatible CaP layer that has controlled and reproducible physicochemical properties suitable for bone engineering.     

HAP-玻璃-α-Al2O3复合梯度生物陶瓷涂层的显微结构及其附着强度

利用涂覆烧结法在 α- Al2 O3陶瓷基体表面制备了 HAP-玻璃 (α- Al2 O3)梯度生物活性涂层 ,并研究了涂层组成对显微结构和附着强度的影响。梯度涂层中玻璃组成采用低膨胀低软化温度的 R2 O- Al2 O3- B2 O3- Si O2 系统 ;涂层中的 HAP含量由里到外逐渐增多 ,并在涂层中添加了适量的超细 α- Al2 O3粉体。实验结果表明 ,使用 R2 O-Al2 O3- B2 O3- Si O2 系统玻璃有利于涂层低温烧结和涂层与基体结合 ,在涂层中添加 α- Al2 O3超细粉有利于提高涂层与基体结合强度 ,所制备的梯度涂层与基体的结合强度为 4 8.2 MPa。     

In vitro studies of plasma-sprayed hydroxyapatite/Ti-6Al-4V composite coatings in simulated body fluid (SBF)

The bioactivity of plasma-sprayed hydroxyapatite (HA)/Ti-6Al-4V composite coatings was studied by soaking the coatings in simulated body fluid (SBF) for up to 8 weeks. This investigation was aimed at elucidating the biological behaviour of plasma-sprayed HA/Ti-6Al-4V composite coatings by analyzing the changes in chemistry, and crystallinity of the composite coating in a body-analogous solution. Phase composition, microstructure and calcium ion concentration were analyzed before, and after immersion. The mechanical properties, such as tensile bond strength, microhardness and Young's modulus were appropriately measured. Results demonstrated that the tensile bond strength of the composite coating was significantly higher than that of pure HA coatings even after soaking in the SBF solution over an 8-weeks period. Dissolution of Ca-P phases in SBF was evident after 24h of soaking, and, a layer of carbonate-apatite covered the coating surface after 2 weeks of immersion. The mechanical properties were found to diminish with soaking duration. However, slight variation in mechanical properties was found after supersaturation of the calcium ions was attained with the precipitation of the calcium phosphate layers.     

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     

Laser cladding of bioactive glass coatings

Laser cladding by powder injection has been used to produce bioactive glass coatings on titanium alloy (Ti6Al4V) substrates. Bioactive glass compositions alternative to 45S5 Bioglass^® were demonstrated to exhibit a gradual wetting angle–temperature evolution and therefore a more homogeneous deposition of the coating over the substrate was achieved. Among the different compositions studied, the S520 bioactive glass showed smoother wetting angle–temperature behavior and was successfully used as precursor material to produce bioactive coatings. Coatings processed using a Nd:YAG laser presented calcium silicate crystallization at the surface, with a uniform composition along the coating cross-section, and no significant dilution of the titanium alloy was observed. These coatings maintain similar bioactivity to that of the precursor material as demonstrated by immersion in simulated body fluid.