可降解吸收骨科高分子材料研究进展

作为替代、修复人体硬组织的生物材料,骨植入材料广泛应用于骨科、整形外科及牙科领域.本文综述了可用作骨科领域可降解吸收高分子材料,主要对天然高分子材料、合成高分子材料及复合高分子材料的性质特点进行了阐述.并对可降解吸收骨科高分子材料的发展趋势进行了探讨,特别是高分子材料与无机材料间进行复合,可取长补短,将是可降解吸收骨科...     

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。     

纳米羟基磷灰石/聚合物复合生物材料的制备方法研究进展

纳米羟基磷灰石是自然骨的主要组分之一,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。但是,由于材料本身力学性能较差制约了羟基磷灰石的进一步应用,且自然骨是由纳米羟基磷灰石和聚合物组成的天然复合材料,因此制备综合性能优越的羟基磷灰石/聚合物复合生物材料是当今研究的热点。综述了羟基磷灰石/聚合物复合生物材料的制备方法,并对其发展趋势进行了简单探讨。     

PLA/nano-SiO_2/HA三元复合生物材料的力学及体外降解性能研究

采用3D打印技术制作聚乳酸/纳米二氧化硅/羟基磷灰石(PLA/nano-SiO_2/HA)三元复合生物材料,研究了复合材料的力学性能及其在磷酸盐缓冲溶液中的体外降解性能。结果表明:当nano-SiO_2含量为PLA/HA复合材料质量的2%时,三元复合生物材料的综合力学性能最好,其拉伸和弯曲强度分别是85.62 MPa、126.66 MPa。随着体外降解时间的延长,三元复合生物材料的拉伸及弯曲强度将下降,但即使如此,经历12周的体外降解试验后,所有强度保持率均在80%左右,且在降解试验过程中,降解液的pH值基本维持在7.35左右,说明PLA/nano-SiO_2/HA三元复合生物材料在缓冲溶液中具有足够高的强度,且对环境影响较小,有望应用于一些组织工程中。     

努力开发磷酸盐系生物材料

作为生物体部分功能或形态修复的材料统称为生物材料。由于磷酸盐作为生物材料具有良好的生物相容性和生物稳定性,而且磷本身就是一切生物和人体所必需的营养元素,加之原料易得,加工容易,因此,近10年来磷酸盐系生物材料的开发和应用研究十分活跃,各种文献与日俱增。磷酸盐系生物材料主要包括两个方面:一是硬组织的替代材料,如人工骨、人工牙齿、骨齿的修复材料等;二是埋入生物体内部的植入材料,如人工心脏、人工血管等医用高分子材料。这些也是磷的精细化工的重要方面。对于救死扶伤、确保人体健康,在医学上具     

3D打印聚（3-羟基丁酸酯-co-4-羟基丁酸酯）/掺锶羟基磷灰石人工骨支架的制备及性能评价

为了促进骨缺损的快速修复,文章利用3D打印技术制造了不同掺锶羟基磷灰石（SrHA）含量的具有多孔隙结构的聚（3-羟基丁酸酯-co-4-羟基丁酸酯）/掺锶羟基磷灰石（P34HB/SrHA）人工骨修复支架,并研究了SrHA含量对复合支架流变性能、体外降解性能和促成骨活性的影响。结果表明：SrHA含量为0～20%时,P34HB/SrHA复合材料的表观黏度随着SrHA含量的增加而逐渐降低,SrHA显著提高了P34HB的可打印性能。3D打印P34HB/SrHA复合支架均具有规则的外观和规整的内部孔隙结构,SrHA在P34HB基体中能够均匀分散。当SrHA含量为20%时,P34HB/SrHA复合支架的压缩强度与P34HB支架相比增加了83.1%,力学性能得到提升。P34HB/SrHA复合支架随着时间的延长而逐渐降解,降解率与SrHA的含量成正比。与P34HB支架相比,P34HB/SrHA复合支架的pH值为7.4±0.1,SrHA在降解过程中起维持p H值稳定的作用。P34HB/SrHA能够促进细胞的增殖和分化,具备较好的成骨诱导活性。     

硅酸钙类骨水泥改性研究进展

硅酸钙类骨水泥材料具有良好的自固化性能，能够作为硬组织修复材料对缺损的骨和牙进行填充和修复，但是由于其力学性能不足、固化时间长等缺点限制了其在临床上的应用范围。该文主要综述了硅酸钙粉体的制备方法及硅酸钙类骨水泥的力学强度、凝结时间、可注射性、降解及生物相容性等，并提出今后的研究重点是利用各体系骨水泥间的性能互补关系，将硅酸钙类骨水泥与其他体系骨水泥进行交叉复合，有望获得综合性能优良的无机复合骨水泥。     

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。     

天然多糖类物质在组织工程中的应用

天然多糖类物质作为一类资源丰富性能优异的天然高分子生物材料,具有无毒、无味、无免疫原等特点,且具有良好的生物相容性和生物可降解性,其分解产物对人体安全无害,从而被广泛的应用于生物材料领域。近年来,天然多糖类物质及其衍生物作为天然高分子组织工程支架,越来越受到重视,并取得一定研究进展。文章综述了天然多糖类物质及其衍生物作为新型生物材料在不同器官(皮肤、肝脏、骨、神经、牙周、软骨等)组织工程中的研究现状。     

复合高分子絮凝剂的研究与应用进展

复合高分子絮凝剂既克服了单一絮凝剂吸附效果差、不易降解等缺点,又实现了不同成分在性能上的互补,在水处理领域发挥着越来越重要的作用。本文对复合高分子絮凝剂进行了分类概述,综述了无机-无机复合高分子絮凝剂、无机-有机复合高分子絮凝剂、微生物复合絮凝剂等复合高分子絮凝剂的研究进展,并对未来复合高分子絮凝剂的发展趋势进行了展望。     

Preparation，properties and applications of hydroxyapatite/synthetic polymer composites

随着生物医用材料的需求量日趋增大,磷灰石与人工合成高分子的复合材料成为组织修复和替代材料的研究热点。以不同单体分类,综述了磷灰石与合成的非降解高分子、可降解高分子复合材料的研究进展;对羟基磷灰石/合成高分子复合材料的制备方法、性能及其应用等方面进行研究,并对此复合材料存在的问题和发展前景进行讨论。说明从分子水平设计出具有良好力学性能、生物活性和生物相容性的医学材料,具有十分重要的意义。     

Current advances concerning the most cited metal ions doped bioceramics and silicate-based bioactive glasses for bone tissue engineering

Studies related to biomaterials that stimulate the repair of living tissue have increased considerably, improving the quality of many people's lives that require surgery due to traumatic accidents, bone diseases, bone defects, and reconstructions. Among these biomaterials, bioceramics and bioactive glasses (BGs) have proved to be suitable for coating materials, cement, scaffolds, and nanoparticles, once they present good biocompatibility and degradability, able to generate osteoconduction on the surrounding tissue. However, the role of biomaterials in hard tissue engineering is not restricted to a structural replacement or for guiding tissue regeneration. Nowadays, it is expected that biomaterials develop a multifunctional role when implanted, orchestrating the process of tissue regeneration and providing to the body the capacity to heal itself. In this way, the incorporation of specific metal ions in bioceramics and BGs structure, including magnesium, silver, strontium, lithium, copper, iron, zinc, cobalt, and manganese are currently receiving enhanced interest as biomaterials for biomedical applications. When an ion is incorporated into the bioceramic structure, a new category of material is created, which has several unique properties that overcome the disadvantages of primitive material and favors its use in different biomedical applications. The doping can enhance handling properties, angiogenic and osteogenic performance, and antimicrobial activity. Therefore, this review aims to summarize the effect of selected metal ion dopants into bioceramics and silicate-based BGs in bone tissue engineering. Furthermore, new applications for doped bioceramics and BGs are highlighted, including cancer treatment and drug delivery.     

Hydroxyapatite–Polyphosphazane Composites Prepared at Low Temperatures

Owing to their similarities to bone apatite, calcium phosphate bioceramics, such as hydroxyapatite (HAp), are used as biomaterials for hard tissue replacements. Composites of bioceramics and biomedical polymers can mimic bone structure and properties. The characteristics of composites comprising HAp and a biomedical polymer and prepared at low temperatures are described. The kinetics of HAp formation in the presence of a polyphosphazene polymer that carries carboxylic acid moieties (acid-PCPP) were established at temperatures from 25° to 50°C. Evolution in the compositions of the solids present, solution chemistry, and microstructure development were established as functions of reaction time and temperature. The polymer participated in HAp formation affecting its rates of nucleation and growth through the formation of calcium cross links. The presence of polymer also enhanced ductility.     

Biodegradable zinc-based materials with a polymer coating designed for biomedical applications

Over the last decades, biodegradable metals have gained popularity for biomedical applications due to their ability to assist in tissue healing. These materials degrade in vivo, while the corrosion products formed are either absorbed or excreted by the body, and no further surgical intervention is required for removal. Intensive research has been carried out mainly on degradable biomaterials based on Mg and Fe. In recent years, zinc-based degradable biomaterials have been explored by the biomedical community for their intrinsic physiological relevance, desirable biocompatibility, intermediate degradation rate, tuneable mechanical properties and pro-regeneration properties. Since pure Zn does not exhibit sufficient mechanical properties for orthopedic applications, various Zn alloys with better properties are being developed. In this work, the combined effect of minor Fe addition to Zn and a polyethyleneglycol (PEG) coating on the surface morphology, degradation, cytotoxicity and mechanical properties of Zn-based materials was studied. There are several studies regarding the influence of the production of Zn alloys, but the effect of polymer coating on the properties of Zn-based materials has not been reported yet. A positive effect of Fe addition and polymer coating on the degradation rate and mechanical properties was observed. However, a reduction in biocompatibility was also detected.     

Advancements in MXene-Polymer composites for various biomedical applications

2D materials have brought about significant technological advancements in the field of biomaterials. ‘MXene’, a ceramic-based 2D nanomaterial, is comprised of transition metal carbides, nitrides, and carbonitrides having a planar structure educed from a ceramic ‘MAX’ phase by etching out ‘A’ from it, has emerged to surpass drawbacks of conventional biomaterials. In spite of their substantial properties like large surface area, biocompatibility, hydrophilicity, metallic conductivity, and size tunability, the use of MXene is restricted in biomedical applications due of its poor stability in physiological environments, lack of sustained and controlled drug release, and low biodegradability, and these limitations lead to the notion of adopting MXene/Polymer nanocomposites. The availability of functional groups on the surface of MXenes enables polymer functionalization. These polymers functionalized MXene nanocomposites exhibit high photothermal conversion efficiency, selectivity, and stimuli-responsiveness towards malignant cells, electron sensitivity, higher antibacterial properties, and the like. This review emphasizes the innovative exemplars of polymer functionalized MXene composites for the burgeoning biomedical applications, which include controlled and sustained drug delivery, antibacterial activity, photothermal cancer therapy, unambiguous biosensing, contrast-enhanced diagnostic imaging, and bone regeneration.     

Synthesis, properties and biomedical applications of poly(glycerol sebacate) (PGS): A review

Poly(glycerol sebacate) (PGS) is a biodegradable polymer increasingly used in a variety of biomedical applications. This polyester is prepared by polycondensation of glycerol and sebacic acid. PGS exhibits biocompatibility and biodegradability, both highly relevant properties in biomedical applications. PGS also involves cost effective production with the possibility of up scaling to industrial production. In addition, the mechanical properties and degradation kinetics of PGS can be tailored to match the requirements of intended applications by controlling curing time, curing temperature, reactants concentration and the degree of acrylation in acrylated PGS. Because of the flexible and elastomeric nature of PGS, its biomedical applications have mainly targeted soft tissue replacement and the engineering of soft tissues, such as cardiac muscle, blood, nerve, cartilage and retina. However, applications of PGS are being expanded to include drug delivery, tissue adhesive and hard tissue (i.e., bone) regeneration. The design and fabrication of PGS based devices for applications that mimic native physiological conditions are also being pursued. Novel designs range from accordion-like honeycomb structures for cardiac patches, gecko-like surfaces for tissue adhesives to PGS (nano) fibers for extra cellular matrix (ECM) like constructs; new design avenues are being investigated to meet the ever growing demand for replacement tissues and organs. In less than a decade PGS has become a material of great scrutiny and interest by the biomedical research community. In this review we consolidate the valuable existing knowledge in the fields of synthesis, properties and biomedical applications of PGS and PGS-related biomaterials and devices.     

Degradable natural polymer hydrogels for articular cartilage tissue engineering

Articular cartilage has poor ability to heal once damaged. Tissue engineering with scaffolds of polymer hydrogels is promising for cartilage regeneration and repair. Polymer hydrogels composed of highly hydrated crosslinked networks mimic the collagen networks of the cartilage extracellular matrix and thus are employed as inserts at cartilage defects not only to temporarily relieve the pain but also to support chondrocyte proliferation and neocartilage regeneration. The biocompatibility, biofunctionality, mechanical properties, and degradation of the polymer hydrogels are the most important parameters for hydrogel‐based cartilage tissue engineering. Degradable biopolymers with natural origin have been widely used as biomaterials for tissue engineering because of their outstanding biocompatibility, low immunological response, low cytotoxicity, and excellent capability to promote cell adhesion, proliferation, and regeneration of new tissues. This review covers several important natural proteins (collagen, gelatin, fibroin, and fibrin) and polysaccharides (chitosan, hyaluronan, alginate and agarose) widely used as hydrogels for articular cartilage tissue engineering. The mechanical properties, structures, modification, and structure–performance relationship of these hydrogels are discussed since the chemical structures and physical properties dictate the in vivo performance and applications of polymer hydrogels for articular cartilage regeneration and repair. © 2012 Society of Chemical Industry     

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.     

Combination of synthetic peptides derived from bone morphogenetic proteins and biomaterials for medical applications

A critical‐size bone defect cannot repair itself. These defects are presently filled by bone grafts or with biomaterials that mimic bone properties. The activity of bone cells is modulated by cytokines like the bone morphogenetic proteins (BMPs). This review described the peptides derived from BMPs or extracellular matrix proteins which can be immobilised on biomaterials to increase their action on bone cells and promote healing. However, the development of such materials requires peptides that can act in synergy. This requires the use of model surfaces to better understand how cells perceive biomaterials.