纳米羟基磷灰石/聚合物骨修复材料的研究进展

纳米羟基磷灰石因其具有良好的生物相容性和生物活性,被广泛应用于骨组织的修复与替代材料.但由于磷灰石本身力学性能较差限制了其应用范围,因此,提高及制备综合性能优越的纳米羟基磷灰石/聚合物复合生物材料是当今研究的热门领域.本文综述了近年来n-HA/聚合物复合材料的国内外研究进展情况,并对此类材料存在的问题进行了分析,探讨了n-HA骨修复材料的发展方向.     

羟基磷灰石生物医用陶瓷材料的研究与发展

自然骨的主要无机矿物成分为纳米羟基磷灰石[Ca10（PO4）6（OH）2，HAP]针状晶体。人工合成的羟基磷灰石材料具有与自然矿物相似的结构，形态，成分，表现出良好的生物相容性和生物活性，广泛应用于医药和牙科领域。对近年来羟基磷灰石生物材料的制备和应用进行了综述。     

纳米医用生物陶瓷的制备研究进展

本文综述了牙科用氧化铝基生物陶瓷、羟基磷灰石生物涂层、多孔羟基磷灰石、羟基磷灰石/聚合物可降解生物复合材料、羟基磷灰石/ZrO2生物复合材料、β-Ca2P2O7生物材料等6种纳米医用生物陶瓷的制备研究进展,并对其制备研究进行了展望.     

羟基磷灰石/聚乳酸类复合材料

聚乳酸(PLA)类高分子是一类重要的生物降解聚合物，羟基磷灰石(HA)是人体骨骼的基本成分，以PLA类高分子为基体、以HA为增强材料的HA／PLA复合材料是复合生物材料中无机／有机复合材料的典型代表，其具有良好的生物相客性，在骨修复领域有重要的应用。笔者在介绍HA／PLA类复合材料的制备、性能和应用等研究近况的基础上，指出使用新型的复合工艺，采用纳米级和改性的HA增强是其发展趋势。     

羟基磷灰石生物材料的性能及制备方法的研究进展

羟基磷灰石生物材料具有良好的生物活性和生物相溶性,是一种比较好的骨修复或替代材料。本文主要阐述了羟基磷灰石的结构、性能及制备方法的研究进展概况。     

一种新型复合医用乳胶膜的制备及其生物学性能研究

将纳米羟基磷灰石与天然胶乳复合,制备出羟基磷灰石/天然胶乳复合医用乳胶膜。采用广角X射线衍射（XRD）和透射电子显微镜（TEM）对纳米羟基磷灰石进行表征,结果表明与人体内羟基磷灰石纳米晶非常相似。对羟基磷灰石/天然胶乳复合医用乳胶膜的力学性能、蛋白质含量以及生物相容性进行的测试表明这是一种非常有前途的医用复合材料,有望获得广泛应用。     

纳米羟基磷灰石材料的制备与性能测试

以饱和氢氧化钙上清溶液、磷酸为主要原料，在室温，pH值为9，反应时间6小时条件下，采用共滴定法制备纳米级羟基磷灰石，并通过XRD、TEM、IR检测等测试手段对材料进行分析表征。结果表明：材料中的羟基磷灰石为类似于自然骨矿物相结晶度低的含微量碳酸根的纳米晶体，制备的六方晶型纳米羟基磷灰石长轴约为80nm，短轴约为30nm，粒径均匀且分散性较好。     

纳米羟基磷灰石应用研究进展

羟基磷灰石是人体和动物骨骼的主要无机矿物成分,当羟基磷灰石的尺寸达到纳米级时将表现出一系列的独特性能。纳米羟基磷灰石具有良好的生物相容性和生物活性,是较好的生物材料,被广泛应用于骨组织的修复与替代技术,在生物医学领域具有非常广阔的应用前景。文章综述了纳米羟基磷灰石的应用研究,指出了目前纳米羟基磷灰石材料中存在的主要问题,并对纳米羟基磷灰石的发展前景进行了展望。     

高分子复合生物材料的研究进展

本文综述了近年来用于骨修复的各类高分子复合生物材料的研究状况,并从力学性能的改善和降解速率的可调性等角度,总结了高分子复合生物材料与单一组分的材料相比在生物医用领域应用中所表现出的综合使用性能的优越性,提出将与人骨中磷灰石微晶类似的无机纳米粒子与具有降解性能的有机生物材料进行复合,能够得到具有优越骨修复性能的新型骨生物材料。     

羟基磷灰石/壳聚糖复合材料研究进展

综述了羟基磷灰石/壳聚糖复合材料的研究现状,对其制备、特点、性能进行了探讨,羟基磷灰石基人工骨作为最有前途的生物硬组织替代材料之一,在生物医用材料和医学研究领域有着广泛的应用前景。主要从化学的角度对材料复合、表征、应用进行了阐述。进而对壳聚糖/羟基磷灰石复合材料的研究发展前景予以展望。     

Nano-hydroxyapatite formation via co-precipitation with chitosan-g-poly(N-isopropylacrylamide) in coil and globule states for tissue engineering application

With the excellent biocompatibility and osteoconductivity, nano-hydroxyapatite (nHA) has shown significant prospect in the biomedical applications. Controlling the size, crystallinity and surface properties of nHA crystals is a critical challenge in the design of HA based biomaterials. With the graft copolymer of chitosan and poly(N-isopropylacrylamide) in coil and globule states as a template respectively, a novel composite from chitosan-g-poly(N-isopropylacrylamide) and nano-hydroxyapatite (CS-g-PNIPAM/nHA) was prepared via co-precipitation. Zeta potential analysis, thermogravimetric analysis and X-ray diffraction were used to identify the formation mechanism of the CS-g-PNIPAM/nHA composite and its morphology was observed by transmission electron microscopy. The results suggested that the physical aggregation states of the template polymer could induce or control the size, crystallinity and morphology of HA crystals in the CS-g-PNIPAM/nHA composite. The CS-g-PNIPAM/nHA composite was then introduced to chitosan-gelatin (CS-Gel) polyelectronic complex and the cytocompatibility of the resulting CS-Gel/composite hybrid film was evaluated. This hybrid film was proved to be favorable for the proliferation of MC 3T3-E1 cells. Therefore, the CS-g-PNIPAM/nHA composite is a potential biomaterial in bone tissue engineering.     

Nanostructured biomaterials for tissue engineered bone tissue reconstruction

Bone tissue engineering strategies are emerging as attractive alternatives to autografts and allografts in bone tissue reconstruction, in particular thanks to their association with nanotechnologies. Nanostructured biomaterials, indeed, mimic the extracellular matrix (ECM) of the natural bone, creating an artificial microenvironment that promotes cell adhesion, proliferation and differentiation. At the same time, the possibility to easily isolate mesenchymal stem cells (MSCs) from different adult tissues together with their multi-lineage differentiation potential makes them an interesting tool in the field of bone tissue engineering. This review gives an overview of the most promising nanostructured biomaterials, used alone or in combination with MSCs, which could in future be employed as bone substitutes. Recent works indicate that composite scaffolds made of ceramics/metals or ceramics/polymers are undoubtedly more effective than the single counterparts in terms of osteoconductivity, osteogenicity and osteoinductivity. A better understanding of the interactions between MSCs and nanostructured biomaterials will surely contribute to the progress of bone tissue engineering.     

Research progress regarding nanohydroxyapatite and its composite biomaterials in bone defect repair

Bone defects are very common, and there has been a great deal of research in the field of orthopedics to find ideal materials to repair such defects. Nanohydroxyapatite is a good bone substitute material; it has a number of structural similarities to natural bone, can promote new bone formation, is noncytotoxic, and has good biodegradability and biocompatibility. The use of composite and polymeric biomaterials can overcome the problems associated with the brittleness and weak mechanical properties of nanohydroxyapatite. Nanohydroxyapatite and its composite biomaterials were confirmed to play important roles in bone defect repair. This review presents a comparison of research regarding use of nanohydroxyapatite and its composite biomaterials in repairing bone defects. The goal is to identify the artificial bone substitute materials with the best biocompatibility and clinical repairing effects for various individuals and clinical situations.     

Fabrication and characteristics of hydroxyapatite reinforced polypropylene as a bone analogue biomaterial

Composite biomaterials, which consist of a polymer matrix and a particulate bioactive phase and are hence analogous to bone microstructure, have been developed for human hard tissue substitution. In this investigation, a manufacturing route employing injection moulding was established for producing bone analogue biomaterials. Using this manufacturing technology, a potential bone replacement material, hydroxyapatite (HA) reinforced polypropylene (PP) composite (HA/PP), was made, with the HA volume percentage being up to 25%. The characteristics of the HA/PP composite were studied using various techniques including scanning electron microscopy (SEM), differential scanning calorimetry (DSC), tensile testing, microhardness testing, and dynamic mechanical analysis (DMA). It was demonstrated that with the use of the established manufacturing route, HA particles were well dispersed and homogeneously distributed in the PP matrix. Properties of the composite were affected by the amount of HA incorporated in the composite. The melting temperature and crystallisation temperature of the composite were slightly affected by the addition of HA particles, and the crystallinity of the PP matrix polymer was decreased with an increase in HA content. Young's modulus, microhardness, and storage modulus increased when the HA volume percentage was increased from 10 to 25%, with corresponding decreases in tensile strength, elongation at fracture and loss tangent. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

In situ synthesis of bone‐like hydroxyapatite/polyamide 6 nanocomposites

BACKGROUND: Polymer/hydroxyapatite (HA) nanocomposites have emerged in recent years as a new class of biomaterials that can be used as artificial bone. Compared to pure HA or HA‐based bioceramics, and metallic implants, they exhibit good plasticity, improved toughness and good mechanical compatibility with natural bone. Compared to their microcomposite counterparts and the pristine polymer matrix, they show increased tensile strength and modulus, and enhanced bioactivity. RESULTS: In this study, polyamide 6 (PA6)/nanoscale HA (n‐HA) nanocomposites were prepared via in situ hydrolytic ring‐opening polymerization of ε‐caprolactam in the presence of newly synthesized n‐HA aqueous slurry. The synthesized n‐HA, which is similar to bone apatite in chemical composition, microscopic morphology and phase composition, dispersed uniformly in the composites even if its loading was up to 60 wt%. The PA6/n‐HA composites show a similarity to natural bone in chemical composition to a certain extent. Mechanical tests show that the composites are reinforced considerably by the incorporation of needle‐like n‐HA, and the composites have mechanical properties near to those of natural bone. CONCLUSION: The PA6/n‐HA nanocomposite with high n‐HA content shows a similarity to natural bone in terms of chemistry and mechanical properties. This makes it a possible candidate for biomaterials suitable for bone repair or fixation. Copyright © 2008 Society of Chemical Industry     

3D-printed barium strontium titanate-based piezoelectric scaffolds for bone tissue engineering

In order to promote bone healing, new generations of biomaterials are under development. These biomaterials should demonstrate proper biological and mechanical properties preferably similar to the natural bone tissue. In this research, 3D-printed barium strontium titanate (BST)/β-tricalcium phosphate (β-TCP) composite scaffolds have been synthesized as an alternative strategy for bone regeneration to not only induce appropriate bioactive characteristics but also piezoelectric behavior. The physical, chemical and biological performance of the scaffolds have been examined in terms of mechanical, dielectric properties, apatite-forming ability, Alizarin Red Staining (ARS), Alkaline Phosphatase activity (ALP), and cytotoxicity. The samples composed of 60% BST and 40% β-TCP showed the highest compressive strength, bending module, elastic modulus and the Young's modulus. The dielectric constant increased with further addition of the BST phase in the constructs. Scanning Electron Microscope (SEM) and energy dispersive X-ray (EDX) analyses showed that 60% BST/40% β-TCP sample had the highest amount of bone-like apatite formation after 28 days in simulated body fluid (SBF). Moreover, the results of ARS proved that 60% BST/40% β-TCP composite could present higher quantities of mineral deposition. The ALP activity of osteosarcoma cells on 60% BST/40% β-TCP sample showed higher activities compare with the other composites. None of the samples demonstrated any sign of toxicity using MTT test. It can be suggested that BST/β-TCP composite scaffolds can be potentially used as the next generation of bone tissue engineering scaffold materials.     

Use of Enzymes for the Processing of Biomaterials

Ceramic/polymer composites and hollow ceramic microspheres are receiving attention as biomaterials as a bone/tissue substitute and cancer remedy. This article describes the advantages of the use of enzymes as "controllable precipitant supplier" in the processing of such biomaterials. It has been demonstrated that hydroxyapatite (HA)/polymer composites and hollow microspheres of Y₂O₃, Fe₃O₄, and HA may be fabricated in a shorter time and using a simpler operation.