医用生物活性玻璃的红外光谱分析 及其生物活性探讨

生物玻璃在模拟生理溶液中浸泡 ,表面生成与人体骨骼无机矿物成分相似的碳酸羟基磷灰石 ( HCA) [Ca10 ( PO4 ) 6) ( 2 HO-,CO2 -3 ],本实验主要应用傅立叶红外变换光谱仪对其进行测定 ,并辅以扫描电镜 ( SEM)分析手段 ,通过体外实验 ( In Vitro)观察了 HCA的形成过程及其表面形貌 ,探讨了生物玻璃的活性机理     

羟基磷灰石与生物活性玻璃的 口腔临床对比研究

随机选择种植体周围炎和骨缺损的病人进行羟基磷灰石 HA和生物活性玻璃 BAG治疗的对比研究 ,所有病人均采用常规翻瓣手术 ,植入 HA( 10例 )或 BAG( 8例 ) ,通过临床观察发现 HA均存在一定的排异现象 ,而 BAG明显无排异性 ,效果良好。作者认为 BAG具有骨引导和骨形成性 ,与机体骨组织形成化学键合 ,与骨组织和软组织有良好的亲和性 ,有良好的临床运用前景     

壳聚糖/介孔生物活性玻璃多孔膜的制备和表征

背景：壳聚糖和介孔生物玻璃都具有良好的生物相容性和止血性能,但壳聚糖止血作用有限,介孔生物玻璃粉体方式止血,给应用带来不便。 目的：制备壳聚糖/介孔生物玻璃复合多孔膜并检测材料的性能。 方法：采用冷冻干燥法制备壳聚糖/介孔生物玻璃复合多孔膜。 结果与结论：通过冷冻干燥法可以实现壳聚糖和介孔生物玻璃的均匀复合。制备的复合多孔膜的孔隙分布较均匀;多孔膜具有很好的吸水性,吸水率的大小与壳聚糖和介孔生物玻璃质量比相关;多孔膜的孔隙率高。     

新型有序纳米介孔生物活性玻璃在模拟体液中的表面生物活性研究

目的评价新型行序纳米介孔生物活性玻璃（80SMBG）的体外生物活性及其对体液环境的影响。方法以Novabone为对照,利用模拟人体体液体外浸泡实验（SBF）的方法和扫描电镜（SEM）、等离子发射光谱仪（ICP）pH仪等技术,比较80SMBG与Novabone体外生成类似于天然骨中无机矿物的羟基磷灰石（HA）的能力,分析SBF中各离子浓度、pH值的变化情况。结果80SMBG在SBF中浸泡4h表面即有羟基磷灰石（HA）生成,浸泡1～4hSBF中Ca、P、Si的离子浓度迅速达到峰值,8h后逐渐降低直至稳定,pH仅在7．40～7．65范围内变化。结论80SMBG的体外生物活性更高,对体液微环境的影响更轻微,作为骨组织修复替代材料或骨组织工程支架材料具有较高的研究和应用价值。     

新型有序纳米介孔生物活性玻璃的不同浓度浸提液对成骨细胞影响的研究

目的评价新型有序纳米介孔生物活性玻璃（80SMBG）的浸提浓度对成骨细胞的影响。方法采用大鼠成骨细胞体外培养,按细胞增殖度法,取0.25%、0.5%、1%、2%、4%共五种浓度的80SMBG浸提培养液进行检测,分别于3、4、5天用倒置显微镜观察细胞生长情况;用四唑盐（MTT）比色法计数计算细胞相对增殖度,用6级毒性分类法评级;用偶氮偶联法（PNPP）染色,分析碱性磷酸酶活性的变化。结果 80SMBG浸提液在高浓度时轻度抑制细胞增殖,促进细胞分化;低浓度促进细胞增殖,轻度抑制细胞分化。结论 80SMBG的体外生物活性较高,对体液微环境的影响轻微,细胞相容性好,作为骨组织修复替代材料或骨组织工程支架材料具有较高的研究和应用价值。     

A-W生物活性玻璃陶瓷的研究和发展

生物活性玻璃陶瓷和玻璃陶瓷是生物医用材料领域的一个重要研究方向，其生物活性使材料被植入后能与骨形成紧密的化学键结合。A-W(Apatite／Wollastonite)生物活性玻璃陶瓷作为此类材料的杰出代表，不但拥有出色的生物活性和生物相容性，还具有优异的力学性能，因此在临床上得到了大量应用和发展。本文主要介绍了A-W生物活性玻璃陶瓷的研究进展、研制方法、性能、应用及骨结合机理，并对A-W生物活性玻璃陶瓷的研究和发展作出了展望。     

生物活性玻璃/壳聚糖/羟基磷灰石复合骨修复材料制备及细胞相容性研究

目的设计一种生物活性玻璃/壳聚糖/羟基磷灰石(BG/HA/CS)复合材料的骨组织工程支架,并对其理化性能和细胞相容性进行检测。方法不同比例的BG/HA/CS混合液用冷冻干燥法制备成支架。通过计算支架孔隙率;扫描电镜、X线衍射和傅立叶红外光谱分析其微观形貌和组成;采用材料试验机进行支架的机械性能检测,并评价生物活性玻璃的加入对支架的影响。将第3代兔骨髓间充质干细胞接种于支架上,使用扫描电镜检测支架对其粘附作用,采用MTT法检测细胞在支架上增殖,并评价生物活性玻璃的加入对支架的细胞相容性影响。结果合成的BG/CS/HA支架与模具拥有同样的大小及几何形状,具有相互贯通的多孔结构,未见生物活性玻璃聚集,孔隙率最高可达86.96%,孔径大小合适(100~300um),最大压缩强度为(1.95±0.13)Mpa。X射线衍射图可以看到特征性的BG衍射峰;傅立叶变换红外光谱可见特征的BG吸收峰,这表明材料内有明确的BG;第3代兔骨髓间充质干细胞在支架上共培养1天后,细胞在支架表面粘附。部分细胞伸展,并伸出伪足。共培养5天后,可见细胞数目增多,团聚,细胞表面可见微绒毛,细胞已开始向材料内部迁移。采用MTT法测量骨髓间充质干细胞在支架上的增殖情况可以看出骨髓间充质干细胞在BG/CS/HA支架上表现出了明显的增殖。结论采用溶液共混、冷冻干燥法可以制备出BG/CS/HA支架;支架具有良好的孔隙率,较好的机械强度,良好的组织相容性,可用于骨组织工程。     

钛合金表面介孔二氧化钛涂层的制备及表征**◆

背景：介孔结构的二氧化钛涂层除了具有一般介孔材料的优点外,还具有很好的生物相容性和独特的抗菌性,并且在钛及钛合金表面很易形成。 目的：对介孔诱导型二氧化钛涂层和普通的二氧化钛涂层进行形貌结构分析和比较,为钛合金表面介孔结构二氧化钛涂层在生物医学领域的应用提供实验和理论基础。 方法：在Ti-6Al-4V合金表面采用模板法和非模板法制备介孔诱导型二氧化钛涂层和普通二氧化钛涂层,使用场发射扫描电子显微镜、快速比表面积/孔隙分析仪和X射线衍射仪对两种二氧化钛涂层的表面形貌结构进行比较分析。 结果与结论：在Ti-6Al-4V合金表面制备的稳定介孔二氧化钛涂层,其平均介孔孔径、比表面积和孔容分别为6.668 0 nm、124.190 6 m2/g和0.256 470 cm3/g,具有介孔结构大比表面积和孔容的特点,适合对医用钛及钛合金改性。     

新型多孔磷灰石/硅灰石生物活性玻璃陶瓷材料的研究

通过溶胶 -凝胶工艺制备了一种新型玻璃陶瓷材料 ,X衍射图谱及傅立叶转换红外图谱表明该材料主晶相为含羟基基团的氟氧磷灰石 [Ca10 (PO4) 6(OH ,F) ]和 β 硅灰石 [β CaSiO3 ];扫描电镜分析显示材料显微结构含有大量微孔 ,孔径为 2～ 3μm。经造孔后 ,材料大孔孔径为 30 0～ 4 0 0 μm ,且孔道相互贯通 ;采用体外模拟体液浸泡实验表征了材料的生物活性 ,扫描电镜观测发现 ,材料表面 7天内已生成大量羟基磷灰石晶粒。结果表明 :采用新型溶胶 -凝胶工艺制备的磷灰石 / β 硅灰石玻璃陶瓷材料具有良好的生物活性 ,其多孔材料具有适宜的孔隙结构 ,微观孔与宏观孔相结合 ,是一类十分具有发展潜力的骨组织修复材料及骨组织工程支架材料。     

Na_2O-CaO-SiO_2-P_2O_5系统生物玻璃析晶对其生物活性及强度的影响

Na2 O- Ca O- Si O2 - P2 O5系统生物活性玻璃具有较高的生物活性 ,是一种理想的骨缺损填充材料。为了提高该生物玻璃的力学强度 ,对其进行了微晶化处理 ,并利用 XRD、SEM、FTIR分析及 SBF浸泡等技术对其生物活性与母体玻璃进行了分析比较 ,并测定和比较了晶化前后材料的抗折强度和断裂韧性 ,对材料的生物活性机理进行了理论分析     

Characterization and in vitro bioactivity of zinc-containing bioactive glass and glass-ceramics

Zinc-containing glass is prepared by the substitution of CaO in 58S bioactive glass with 0.5 and 4 wt% ZnO, and glass-ceramics are obtained by heat-treating the glass at 1,200 C. The bending strength and in vitro bioactivity of the glass and glass-ceramics are evaluated. The results indicate that Zn promotes the crystallization of SiO(2) and wollastonite in glass-ceramics, and proper crystallization can enhance the bending strength of the glass-ceramic. The in vitro results show that ZnO in glass retards the hydroxyapatite (HA) nucleation at the initial stage of simulated body fluid (SBF) soaking, but does not affect the growth of HA after long periods of soaking, and the ionic products of 58S4Z glass can stimulate the proliferation of osteoblast at certain concentrations. Osteoblasts attach well on both glass samples and glass-ceramic samples, but the high Si ion concentration released from glass samples restrains the proliferation of osteoblasts after 3 days of culture. In contrast, osteoblasts show good proliferation on glass-ceramic samples, and ZnO in glass-ceramics promotes the proliferation rate. The results in this study suggest that the glass and glass-ceramics with different ZnO content might be used as bioactive bone implant materials in different applications.     

Phase composition and in vitro bioactivity of porous implants made of bioactive glass S53P4

This work studied the influence of sintering temperature on the phase composition, compression strength and in vitro properties of implants made of bioactive glass S53P4. The implants were sintered within the temperature range 600-1000°C. Over the whole temperature range studied, consolidation took place mainly via viscous flow sintering, even though there was partial surface crystallization. The mechanical strength of the implants was low but increased with the sintering temperature, from 0.7 MPa at 635°C to 10 MPa at 1000°C. Changes in the composition of simulated body fluid (SBF), the immersion solution, were evaluated by pH measurements and ion analysis using inductively coupled plasma optical emission spectrometry. The development of a calcium phosphate layer on the implant surfaces was verified using scanning electron microscopy-electron-dispersive X-ray analysis. When immersed in SBF, a calcium phosphate layer formed on all the samples, but the structure of this layer was affected by the surface crystalline phases. Hydroxyapatite formed more readily on amorphous and partially crystalline implants containing both primary Na(2)O·CaO·2SiO(2) and secondary Na(2)Ca(4)(PO(4))(2)SiO(4) crystals than on implants containing only primary crystals.     

Hierarchically mesoporous-macroporous bioactive glasses scaffolds for bone tissue regeneration

Hierarchically 2D/3D mesoporous-macroporous bioactive glasses (MMBG) with good molding capabilities and compressive modulus were synthesized by sol-gel method and evaporation-induced self-assembly process in the presence of both nonionic triblock copolymers, EO(70)PO(20)EO(70) (P123) or EO(100)PO(65)EO(100) (F127), templates and methyl cellulose template. P123 or F127 acts as both a template, inducing the formation of mesopore, and an effective dispersant of MC, which produces macropores. In vitro bioactivity studies were carried out in simulated body fluid and showed superior bone-forming bioactivities of hierarchical MMBG. Human osteoblastlike cells, MG63, were seeded on MMBG and were determined using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5,-diphenyl-tetrazolium bromide] assay to confirm biocompatibilities of MMBG.     

A mesoporous bioactive glass/polycaprolactone composite scaffold and its bioactivity behavior

Composite scaffolds of mesoporous bioactive glass (MBG)/polycaprolactone (PCL) and conventional bioactive glass (BG)/PCL were fabricated by a solvent casting-particulate leaching method, and the structure and properties of the composite scaffolds were characterized. The measurements of the water contact angles suggest that the incorporation of either MBG or BG into PCL can improve the hydrophilicity of the composites, and the former is more effective than the later. The bioactivity of the composite scaffold is evaluated by soaking the scaffolds in a simulated body fluid (SBF) and the results show that the MBG/PCL composite scaffolds can induce a dense and continuous layer of apatite after soaking in SBF for 3 weeks, as compared with the scattered and discrete apatite particles on the BG/PCL composite scaffolds. Such improvements (improvements of the hydrophilicity and apatite forming ability) should be helpful for the extensive applications of PCL scaffold in tissue engineering.     

Self-reinforced composites of bioabsorbable polymer and bioactive glass with different bioactive glass contents. Part I: Initial mechanical properties and bioactivity

Spherical bioactive glass 13-93 particles, with a particle size distribution of 50-125 microm, were combined with bioabsorbable poly-L,DL-lactide 70/30 using twin-screw extrusion. The composite rods containing 0, 20, 30, 40 and 50 wt% of bioactive glass were further self-reinforced by drawing to a diameter of approximately 3 mm. The bioactive glass spheres were well dispersed and the open pores were formed on the composite surface during drawing. The initial mechanical properties were studied. The addition of bioactive glass reduced the bending strength, bending modulus, shear strength, compression strength and torsion strength of poly-L,DL-lactide. However, the strain at maximum bending load increased in self-reinforced composites. Initially brittle composites became ductile in self-reinforcing. The bioactivity was studied in phosphate buffered saline for up to 12 days. The formation of calcium phosphate precipitation was followed using scanning electron microscopy and energy dispersive X-ray analysis. Results showed that the bioactive glass addition affected the initial mechanical properties and bioactivity of the composites. It was concluded that the optimal bioactive glass content depends on the applications of the composites.     

Synthesis and in vitro bioactivity of bredigite powders

Pure bredigite (Ca7MgSi4O16) powders are synthesized by the sol-gel method. The bredigite powders are composed of polycrystalline particles with dimensions of 1-10 micro m. The in vitro bioactivity of the bredigite powders are examined by evaluation of hydroxyapatite (HAp) formation ability in simulated body fluid (SBF) and the effect of ionic products from bredigite dissolution on osteoblast proliferation. The results showed that bredigite induced the formation of nanocrystalline HAp after soaking in SBF for 10 days. The Ca, Si, and Mg ions from bredigite dissolution at a certain concentration range stimulates osteoblast proliferation. Our study indicates that bredigite is bioactive and might be used for preparation of new biomaterials.     

Synthesis and evaluation of novel bioactive composite starch/bioactive glass microparticles

The aim of the development of composite materials is to combine the most desired properties of two or more materials. In this work, the biodegradable character, good controlled-release properties, and natural origin of starch-based biomaterials are combined with the bioactive and bone-bonding properties of bioactive glass (BG). Novel, bioactive composite starch-BG microparticles were synthesized starting from a blend of starch and polylactic acid (50%/50% wt) with BG 45S5 powder using a simple emulsion method. Morphological and chemical characterization showed that these particles exhibited a spherical morphology with sizes up to 350 microm and that BG 45S5 was incorporated successfully into the composite particles. Upon immersion in a solution simulating body fluids, for periods up to 3 weeks, their bioactive nature was confirmed, as a calcium-phosphate layer resembling biological apatite was formed onto their surface. The short-term cytotoxicity of these materials was also tested by placing 24-h leachables of the materials extracted in culture medium in contact with a fibroblastic cell line (L929) up to 72 h. At this time period, two biochemical tests--MTT and total protein quantification--were performed. The results showed that these materials are not cytotoxic. These results constitute the basis of future encapsulation studies using bone-acting therapeutic agents such as bone morphogenetic proteins or other bone-relevant factors. The particles developed here may be very useful for applications in which controlled release, degradability, and bone-bonding ability are the main requirements.     

The effect of bioactive glass content on synthesis and bioactivity of composite poly (lactic-co-glycolic acid)/bioactive glass substrate for tissue engineering

Tissue engineering offers a promising new approach to bone tissue grafting. One material that has received attention in this regard is the polymer poly (lactic-co-glycolic acid) (PLGA). It has the advantage of controllable bioresorption and ease of processing. Another material of interest is bioactive glass (BG), which shows the ability to stimulate osteoblastic differentiation of osteoprogenitor cells. In this study, we reported on the optimal synthesis parameters and the kinetics of formation of calcium phosphate (Ca-P) phase at the surface of PLGA/BG composites. The formation of calcium phosphate layer was confirmed using scanning electron microscopy/energy dispersive X-ray analysis (SEM/EDXA). PLGA-30%BG microspheres based porous scaffolds for bone tissue engineering were examined for their ability to promote osteogenesis of marrow stromal cells (MSC). This porous scaffold supported both MSC proliferation and promoted MSC differentiation into cells expressing the osteoblast phenotype. It therefore demonstrates significant potential as a bone replacement material.     

The in vitro response of osteoblasts to bioactive glass

Osteoblasts from neonate rat calvaria migrated in culture from the endocranial surface of parietal bones onto fragments of bone-bonding 45S5 glass or non-bone-bonding quartz glass. These organ culture units were maintained for up to 4 wk. No significant production of extracellular matrix (ECM) was seen on the quartz glass samples. However, osteoblasts colonized the 45S5 samples in multilayers and produced abundant ECM as seen by light (LM), scanning electron (SEM) and transmission electron (TEM) microscopy. The interface developed on 45S5 glass was designated as either Type I (non-collagen-bonding) or Type II (showing direct interdigitation of collagen with the calcium phosphate-rich glass surface). It was concluded that, since this in vitro method is capable of reproducing some aspects of the known in vivo behaviour of 45S5, such techniques may be developed as a means of batch-testing bioactive biomaterials and investigating bone cell/biomaterial interactions.     

Preparation and in vitro bioactivity of hydroxyapatite/solgel glass biphasic material

Hydroxyapatite/solgel glass biphasic material has been obtained in order to improve the bioactivity of the hydroxyapatite (OHAp). A mixture of stoichiometric OHAp and the precursor gel of a solgel glass, with nominal composition in mol% CaO-26, SiO2-70, P205-4, has been prepared. The amounts of components used have been selected to obtain a final relationship for OHAp/solgel glass of 60/40 on heating. Two different thermal treatments have been used: (i) 700 degrees C, temperature of solgel glass stabilisation and (ii) 1000 degrees C, lower temperature of hydroxyapatite sintering. The bioactivity of the resulting materials has been examined in vitro by immersion in simulated body fluid at 37 degrees C. The results obtained show that both materials are bioactive. The apatite-like layer grown is greater for the new materials than for the OHAp and the solgel glass themselves.