3D打印技术用于不规则骨缺损的重建与修复

为研究3D打印技术对不规则形状骨缺损模型的重建程度,和3D打印的可降解生物材料对脊椎骨缺损在12周内的修复的效果,本文随机选取一名病人,用其电子计算机断层扫描（computed tomography, CT）数据构建出不规则的三维脊柱缺损模型,选用聚己内酯（polycaprolactone, PCL）作为支架材料,运用3D打印技术打印出高度符合该病人骨缺损部位的人工骨支架。同时建立一个简单的兔子脊椎缺损模型,运用3D打印技术打印缺损尺寸的支架移植兔子体内,术后观察3个月,将兔子处死取出缺损部位,制作切片进行苏木素和伊红（Hematoxylin and Eosin, H&E）染色,染色结果表明缺损部位修复良好。     

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.     

二维晶体Mxene的制备及催化领域的应用研究进展

二维材料是指电子仅可在两个维度的非纳米尺度上自由运动的材料,由于其独特而优异的物理化学性质,很快成为近年来的研究热点.二维晶体MXene材料具有良好的导热导电性、高热稳定性和抗氧化性,在催化领域显示出巨大的潜能可用于降解污染物、水解制氢、以及还原二氧化碳.介绍了MXene的结构及化学液相刻蚀、高温分解和气相刻蚀的制备方法,综述了MXene在催化领域的应用研究进展,展望了MXene在催化领域的应用前景和未来的研究方向.     

改性HA纳米粒子在骨组织工程中的应用[ ]

羟基磷灰石(HA)具有优异的生物活性和生物相容性,广泛应用于骨修复、再生和置换等骨组织工程,但HA纳米粒子难分散、强度低、高分子相融性差等缺点限制了其应用。为了克服这些缺点,研究员致力于探索改性或复合HA的方法,以改善其分散性、亲水性、抗菌性以及机械强度等,来满足临床应用的要求。本篇综述总结归纳了当前主流的HA纳米粒子改性方法,包括离子掺杂、表面改性、材料复合等。最后,我们还讨论了当前HA复合材料的研究热点,以期为HA复合材料相关基础研究提供有益的借鉴与启示。     

骨组织工程中的碳纤维材料

归纳了聚合物支架材料在提高其力学性能方面的一些研究工作,并综述了碳纤维材料在骨组织工程上应用的进展.分析表明,骨组织工程是修复骨缺损的有效方法之一,而碳纤维材料的结构性能优势使其成为提高组织工程支架性能的首选材料之一.在提高聚合物支架力学性能的同时,进一步提高材料的生物活性和促进骨的修复是目前研究的重点和难点.指出可通过对碳纤维材料的改性、有序排列等手段来进一步提高碳纤维材料的作用.     

磷酸钙骨水泥的临床应用与研究进展

磷酸钙骨水泥是一种新型的自固型、非陶瓷型骨水泥。它克服了钙磷陶瓷脆性大、塑型困难、不能降解等缺点,有良好的生物相容性、可降解性和骨传导能力,且可任意成型,反应不生热,使用方便,临床上用于非负重部位骨缺损的修复、松质骨螺钉加固、药物或生物因子载体等领域。本文对近年来CPC的临床应用与研究进展进行了综述。     

Advanced graphene ceramics and their future in bone regenerative engineering

The outstanding properties of graphene materials rely on an exceptional two-dimensional honeycombed lattice. The lattice allows for electrical, thermal, and mechanical reinforcement effects when applied to the ceramic matrix. The biocompatibility of the material allows for providing multifunctional bioceramics applications. However, the potential of graphene lies in its ability to be homogenously distributed as part of a ceramic matrix. Therefore, appropriate processing techniques are important for attaining desired graphene ceramic properties applicable for regenerative biomedical purposes. This article provides an inclusive review of the current knowledge of advanced graphene-based ceramics for bone regenerative engineering. In this review, the opportunities and challenges in utilizing graphene materials in combination with ceramics suitable for applications in load-bearing bone defects are discussed.     

A comprehensive review on the preparation and application of calcium hydroxyapatite: A special focus on atomic doping methods for bone tissue engineering

Hydroxyapatite (HAP) has been considered to be one of the most preferred scaffold materials among many in the last decade for the bone tissue engineering. Be it prosthetic implants, scaffolds or artificial bone cement, hydroxyapatite has received highest attraction among all due to its chemical and physical properties similar to that of human bone. Although it can be used in the bone tissue engineering as the original composition; for enhancing its different properties relevant to in vivo applications, the calcium in HAP may also be replaced by other atomic dopants depending on usage. Here, we review various HAP coating agents and methods, their merits and demerits. We also review various HAP doping materials, including both cationic as well as anionic materials. We discuss the effects and usage of substitution of hydroxyapatite and their subsequent usage in both bone tissue engineering and maxillofacial surgeries. We consider various research articles published in recent times to accomplish detailed discussion on the subject.     

3D printing of polycaprolactone/bioactive glass composite scaffolds for in situ bone repair

3D printing technology can fabricate customized scaffolds based on patient-derived medical images, so it has attracted much attention in the field of developing bone repair scaffolds. Polycaprolactone (PCL) is a suitable polymer for preparing bone repair scaffolds because of its good biocompatibility, thermal stability, excellent mechanical properties and degradable properties. However, PCL is a bioinert material and cannot induce new bone formation at the defect site. In this study, the bioactive material 58s bioactive glass was mixed into PCL to form PCL/bioactive glass composite material. The results of contact angle showed that the hydrophilicity of the scaffold was significantly enhanced with the increase of bioactive glass content. In vitro experiment results showed that, with the increase of bioactive glass content, cell adhesion and proliferation were enhanced, the expression levels of Runx2 and Collagen I(COL-I) were upregulated. The experimental results of in vivo radial defect repair in rats also showed that the effect of bone repair was improved with the increase of bioactive glass content. In conclusion, PCL customized bone repair scaffold containing 20% bioactive glass has widely potential used in the field of clinical bone repair.     

Three-dimensional printing of a β-tricalcium phosphate scaffold with dual bioactivities for bone repair

β-Tricalcium phosphate (β-TCP) had been widely used in the field of bone defect repair because of its osteoconduction and osteoinduction properties. However, for critical-sized bone defects, β-TCP scaffolds need to be functionalised to enhance osteoinduction and antibacterial activity. In this study, we proposed a protocol for mimicking a mussel adhesion mechanism to immobilise bone morphoprotein 2 mimetic peptide (BMP2-MP) and Ornithodoros savignyi (OS) on a three-dimensionally printed β-TCP scaffold. BMP2-MP and the OS polypeptides containing the YKYKY tail were converted into 3,4‐dihydroxyphenylalanine (DOPA) molecules via hydroxylase. The surface morphology and phase composition of the different scaffolds were analysed via scanning electron microscopy and X-ray diffraction. In addition, the binding activity of BMP2-MP and OS containing the DOPA tail to the scaffold were evaluated. The antibacterial activity of the different scaffolds was studied in vitro by performing bacteriostatic experiments against Escherichia coli and Staphylococcus aureus. The osteoinduction capability of the different scaffolds was evaluated by detecting osteogenesis-associated genes via quantitative polymerase chain reaction and by determining alkaline phosphatase expression levels. Our results demonstrated that introduction of the DOPA tail enhanced the binding capability of BMP2-MP and OS with the β-TCP scaffold, thereby enhancing the antibacterial and osteoinduction capabilities of the scaffold. A scaffold with strong antibacterial and osteoinduction capability will have good application prospects in the field of critical-sized bone defect repair.     

Iron-doped brushite bone cement scaffold with enhanced osteoconductivity and antimicrobial properties for jaw regeneration

Critical success factors for the restoration of jaw defects depend on scaffolds with high levels of osteoconductivity and antimicrobial properties due to the special oral microenvironment. Brushite cement (dicalcium phosphate dihydrate, DCPD) is a bioceramic with good self-setting properties, plasticity, bioabsorbability, and biocompatibility, but with poor osteoconductive and antimicrobial properties. It has been reported that elemental iron doped into DCPD is effective for overcoming this critical deficiency. Herein, iron-doped dicalcium phosphate dihydrate (Fe-DCPD) was prepared and its physicochemical properties characterized. The time required for Fe-DCPD to set was significantly prolonged, and its in vitro degradability increased compared with DCPD. Additionally, the effects of Fe-DCPD on cell adhesion, migration, proliferation, alkaline phosphatase activity, biomineralization, its antimicrobial properties and relative expression of osteogenic genes in MC3T3-E1 cells were evaluated. In addition, the ability to promote restoration of the jaw in vivo was evaluated, to provide the experimental basis for its preclinical application. The incorporation of iron promoted the adhesion, proliferation, and migration of MC3T3-E1 cells, and increased their ALP activity and expression of osteogenic-related genes. Furthermore, both agar plate and broth anti-bacterial tests revealed that Fe-DCPD displayed a significantly greater antibacterial effect on typical Gram-negative and Gram-positive bacteria than DCPD. The in vivo study indicated that Fe-DCPD scaffolds displayed superior antimicrobial and bone repair properties in a rabbit jaw defect. The study established that DCPD doped with iron is a suitable modification for conferring antimicrobial and osteoconductive properties on scaffolds. Thus, the Fe-DCPD scaffold has excellent potential for applications in jaw repair.     

可注射nHA/PU复合多孔骨修复支架制备及表征

兼具良好孔隙率和原位任意塑形固化的可注射复合多孔骨修复材料在临床不规则骨缺损的治疗方面显示出巨大的优势。本研究通过优化双组分设计,以水为发泡剂制备可注射纳米羟基磷灰石/聚氨酯（nHA/PU）复合多孔支架。利用扫描电子显微镜（SEM）、傅里叶变换红外光谱（FTIR）、X射线衍射（XRD）、力学测试及Gillmore针测试等手段对制备的支架进行结构形貌、化学组成、力学性能和固化时间表征。结果表明,本研究制备的可注射nHA/PU复合多孔支架孔隙率高、孔隙贯通性好,孔径分布在100~700μm,适宜细胞和组织向孔内生长;添加20% nHA显著提高了PU支架的力学强度,但降低了支架的孔隙率;可注射支架在8h固化,适宜临床操作。本研究制备的可注射nHA/PU复合多孔支架在不规则骨缺损修复领域具有较大的应用潜力。     

Superior biological performance and osteoinductive activity of Si-containing bioactive bone regeneration particles for alveolar bone reconstruction

Bone grafting materials for repair of alveolar bone deficits have improved markedly in recent years, increasing the applicability and success of oral implantology. The long-term success rate of dental implant surgery is strongly dependent on the quality and stability of residual bone tissue. Therefore, reconstruction of resorbed alveolar bone is a challenge for clinicians. In the present study, we have developed bioactive bone regeneration particles (BRPs) using amorphous calcium phosphate and 58S bioglass as raw materials. The structural characteristics, biocompatibility, and osteoinductivity of these BRPs were compared to commercially available bovine spongy bone (BSB) without organic components. X-ray diffractometry (XRD) and scanning electron microscopy (SEM) showed that BRPs were composed of β-tricalcium phosphate (β-TCP) and calcium silicate in the form of hexagonal crystals, while BSB was mainly hydroxyapatite (HA) arranged in orderly nano-sized crystals. The viability of human bone marrow mesenchymal stem cells (hBMSCs) cultured in BRP-containing medium was roughly equal to that of hBMSCs in control medium. Moreover, hBMSCs in BRP medium exhibited greater proliferation rates, substrate attachment, alkaline phosphatase (ALP) activity, alizarin red staining intensity, and expression levels of osteogenic-related genes (COL-I, OCN, Runx-2, ALP, BSP) than hBMSCs in BSB medium, indicating the superior osteoinductivity of BRPs. Silicon ions released from BRPs during cell culture were crucial for these enhanced biological properties. BRPs also demonstrated superior osteoconduction and osteoinduction properties for bone defect repair, suggesting promise for alveolar bone repair surgery.     

Modified calcium magnesium phosphate bone cement with improved microenvironment

Calcium magnesium phosphate bone cement (MCPC) has been widely used in bone defects restoration and attracted much attention due to excellent mechanical properties and biodegradability. However, excessive MgO tends to cause a local alkaline microenvironment which is adverse for cell growth and differentiation. In this work, we constructed the MCPC composites with improved microenvironment, enhanced osteogenic differentiation and biomineralization by introducing various concentrations of gelatin solutions. Gelatin played important roles in the improvement of physicochemical property, biodegradability, biocompatibility, osteogenic differentiation activity and biomineralization of MCPC. When incorporated with 1% and 5% of gelatin, the MCPC composites exhibited higher compressive strength and osteogenic differentiation ability of BMSCs in vitro. In conclusion, the modified MCPC composite is a potential candidate for bone defects repair and regenerate.     

钙-磷系自固化材料改性研究进展

由创伤、肿瘤和感染等原因引起的骨缺损通常面积较大,超过了骨自愈范围而不能自修复。因此,需要使用骨水泥对面积较大的骨缺损部位进行填充修复。磷酸钙水泥(calcium phosphate cement, CPC)是目前临床常用的一种骨水泥,可任意塑形,具有良好生物活性和生物相容性,近几十年来得到国内外学者的广泛研究。然而,从临床实践经验来看,CPC的应用范围有限,仍需要对其进行性能改进。本文主要分为两部分:在理化性能部分总结了CPC在力学强度、可注射性、抗溃散性和放射不透明性等四方面的改性方法;在生物学性能方面讨论了CPC成骨活性、生物可降解性和载药性方面的改性研究。     

生物质基含硅骨修复复合支架材料的制备、特性及评价

模仿天然骨的精密结构制备有机-无机复合骨修复支架材料已成为骨组织工程发展的重要方向。生物质材料如胶原、明胶、壳聚糖、丝素蛋白等由于具有优良的生物学性能而得到广泛关注。含硅生物活性材料由于具有良好的骨传导性和骨诱导性,成为骨修复支架材料中重要的无机组分。本文主要介绍了粉体复合和原位复合两种骨支架材料组分的复合技术,阐述了冷冻干燥、静电纺丝、仿生矿化以及3D打印等骨支架材料结构的构建策略,着重总结了生物质基含硅骨修复支架材料研究进展,阐明当前骨支架材料制备的难点在于支架材料的力学性能和多孔性结构以及生物降解性能与新骨生成速率之间的匹配性问题,并对骨支架材料的发展进行了展望。     

Biological and mechanical enhancement of zirconium dioxide for medical applications

Extensive research in global biomedical industry has been driven rapidly due to problems faced in bone implants such as loosening of implants in knee and hip prosthesis as well as short service life of orthopaedic implants. Advances in biomedical engineering have resulted in formation of various materials utilized for orthopaedic transplants and artificial implants. Among the various available materials zirconium dioxide is observed as potential material for biomedical application due to its superior biocompatibility, good compression resistance (2000 MPa), good viability of cell culture, good opacity, and radiopacifying capacity showcasing it's diverse applications in bone and tissue regeneration, orthopaedic implants as well as bone resorption. Bone tissue regenerative modifications is accompanied with coating of zirconium dioxide on metal alloys or 316 L SS substrate, composite formation with silica carbide or organic acids (usnic acid), surface propargylation achieved using chemical treatment of propargyl bromide, electrochemical treatment of zirconium dioxide to evaluate corrosion resistance, etc. Zirconium dioxide is also recorded for exhibiting enhanced mechanical properties as well as biocompatibility in hip arthroplasty as well as bone implants; it also serves application in bone cement to provide adhesion between the biomedical implants. The review paper majorly focuses on effective utilization of zirconium dioxide with various additive materials and functionalization techniques used for enhancement of properties, enabling the application of material in orthopaedic implants as well as bone tissue applications. The mechanical and biological performance analysis of various orthopaedic implants containing zirconium dioxide has been elaborately discussed along with possible measures implemented to enlarge the life of biomedical implant.     

聚合物基MXene复合材料的光热性能研究进展

MXene是一种新兴的二维纳米材料,具有组成可调、结构可控的特性和优异光热性能。MXene可吸收入射光并将其高效转换为热能,这为太阳能的有效利用提供了新途径。将MXene加入聚合物基体中,可赋予聚合物基复合材料优异光热性能,并拓宽复合材料应用范围,因而被广泛研究。具有光热性能的聚合物基MXene复合材料在海水淡化、个人热管理、光热抗菌和光热治疗肿瘤等方面有着广泛的应用前景。本文总结了MXene及聚合物基MXene复合材料的制备方法,介绍了光热材料的光热转换机理,综述了聚合物基MXene复合材料在光热转换方面的研究进展,展望了具有光热性能的聚合物基MXene复合材料在应用中存在的挑战和未来的发展方向。