骨组织工程支架材料的研究进展

综述了骨组织工程支架材料在骨缺损治疗的研究现状,并展望了其未来的发展方向。利用各种材料的优势互补性,将两种或两种以上材料通过恰当的方式组合成复合支架材料,其力学性能和降解速率可根据各组分材料的种类、数量及组合方法的变化进行调节,按照要求制备出具有一定机械强度和降解速率的支架材料。并指出骨组织工程复合支架材料将会成为骨缺损修复中一类富有潜力的生物材料。     

Ultraflexible Near‐Infrared Organic Photodetectors for Conformal Photoplethysmogram Sensors

Flexible organic optoelectronic devices simultaneously targeting mechanical conformability and fast responsivity in the near‐infrared (IR) region are a prerequisite to expand the capabilities of practical optical science and engineering for on‐skin optoelectronic applications. Here, an ultraflexible near‐IR responsive skin‐conformal photoplethysmogram sensor based on a bulk heterojunction photovoltaic active layer containing regioregular polyindacenodithiophene‐pyridyl[2,1,3]thiadiazole‐cyclopentadithiophene (PIPCP) is reported. The ultrathin (3 µm thick) photodetector exhibits unprecedented operational stability under severe mechanical deformation at a bending radius of less than 3 µm, even after more than 10³ bending cycles. Deliberate optimization of the physical dimensions of the active layer used in the device enables precise on/off switching and high device yield simultaneously. The response frequency over 1 kHz under mechanically deformed conditions facilitates conformal electronic sensors at the machine/human interface. Finally, a mechanically stretchable, flexible, and skin‐conformal photoplethysmogram (PPG) device with higher sensitivity than those of rigid devices is demonstrated, through conformal adherence to the flexuous surface of a fingerprint.     

3D Helix Engineering in Chiral Photonic Materials

Engineering the helical structure of chiral photonic materials in three dimensions remains a challenge. 3D helix engineered photonic materials are fabricated by local stratification in a photopolymerizable chiral nematic liquid crystal. The obtained chiral photonic materials reflect both handedness of circular polarized light and show super‐reflectivity. Simulations match the experimentally observed photonic properties and reveal a distorted helical structure. 3D engineered polymer films can be made that reflect both left‐ and right handed circular and linear polarized light dependent and exhibit a changing color contrast upon altering the polarization of incident light. Hence, these 3D engineered photonic materials are of interest for new and emerging applications ranging from anti‐counterfeit labels and data encryption to aesthetics and super‐reflective films.     

骨组织工程用无机支架材料的研究现状

无机生物活性材料作为一种重要的骨组织工程用支架材料,具有明显的优势和广阔的应用前景.从组织工程材料发展历程的角度出发,分别介绍了制备支架的不可降解材料、部分可降解材料和完全可降解材料的演变过程,比较了这3种材料在力学性能方面的各自优缺点,并分析了支架材料在生物相容性方面的改善措施,同时着重介绍了国内外无机组织工程材料近期的研究成果.     

磷酸钙骨水泥的生物学性能

寻求修复各种原因引起的骨组织缺损、畸形的新型材料和技术一直是生命科学和生物材料科学领域的一个重要课题.磷酸钙骨水泥具有良好的生物相容性、骨引导活性和生物降解性,具有一定的抗压强度,是一种较理想的骨移植替代材料.     

形状记忆高分子材料在生物医学领域的应用

形状记忆高分子材料(SMPs)作为一种新型功能材料具有生物相容性好、形变率大、形变温度可调、易于加工、可引入生物降解组分等特点,近年来,特别是在生物医药领域,SMPs已成为研究人员广泛关注的焦点之一。根据SMPs的功能及其应用研究现状,着重综述了近年来SMPs在矫形固定材料、药物缓释体系、手术缝合、微创医疗器械以及组织工程等生物医学领域的主要研究和应用,并展望了SMPs在生物医学领域未来的研究方向和前景,同时,简要介绍了SMPs的发展概况及其具有形状记忆效应的原理。     

Recent Advances in Organic Photovoltaics: Device Structure and Optical Engineering Optimization on the Nanoscale

Organic photovoltaic (OPV) devices, which can directly convert absorbed sunlight to electricity, are stacked thin films of tens to hundreds of nanometers. They have emerged as a promising candidate for affordable, clean, and renewable energy. In the past few years, a rapid increase has been seen in the power conversion efficiency of OPV devices toward 10% and above, through comprehensive optimizations via novel photoactive donor and acceptor materials, control of thin‐film morphology on the nanoscale, device structure developments, and interfacial and optical engineering. The intrinsic problems of short exciton diffusion length and low carrier mobility in organic semiconductors creates a challenge for OPV designs for achieving optically thick and electrically thin device structures to achieve sufficient light absorption and efficient electron/hole extraction. Recent advances in the field of OPV devices are reviewed, with a focus on the progress in device architecture and optical engineering approaches that lead to improved electrical and optical characteristics in OPV devices. Successful strategies are highlighted for light wave distribution, modulation, and absorption promotion inside the active layer of OPV devices by incorporating periodic nanopatterns/nanostructures or incorporating metallic nanomaterials and nanostructures.     

新型可降解钙磷骨水泥多孔支架研究

采用一种特殊的方法制备了孔径、孔隙率和孔形状可控的多孔羟基磷灰石骨水泥支架. 材料的抗压强度可达4MPa, 孔隙率可达70%, 孔与孔之间互相贯通, 大孔壁富含微孔. 细胞在材料表面黏附铺展且增殖良好, 体外模拟实验显示材料的降解速度随孔隙率的增加和Ca/P比的降低而加快, 多孔支架有优良的生物降解性和生物相容性. 该材料可用于修复骨组织缺损和作为支架材料用于组织工程.     

Recent Progress of In Situ Transmission Electron Microscopy for Energy Materials

In situ transmission electron microscopy (TEM) is one of the most powerful approaches for revealing physical and chemical process dynamics at atomic resolutions. The most recent developments for in situ TEM techniques are summarized; in particular, how they enable visualization of various events, measure properties, and solve problems in the field of energy by revealing detailed mechanisms at the nanoscale. Related applications include rechargeable batteries such as Li-ion, Na-ion, Li–O₂, Na–O₂, Li–S, etc., fuel cells, thermoelectrics, photovoltaics, and photocatalysis. To promote various applications, the methods of introducing the in situ stimuli of heating, cooling, electrical biasing, light illumination, and liquid and gas environments are discussed. The progress of recent in situ TEM in energy applications should inspire future research on new energy materials in diverse energy-related areas.     

生物可降解高分子材料

对生物可降解高分子材料的种类、研究现状进行了综述。对生物可降解塑料进行了较详细的论述。介绍了生物可降解高分子材料的应用。     

生物医用眼科材料的研究

主要综述了用于眼科的生物医用材料的种类、结构特点及其在眼科中应用的性能,重点介绍了用于人工角膜的光学镜柱材料和支架材料、人工晶状体材料、人工玻璃体材料、人工眼球义眼台和义眼材料、人工泪道和泪液材料、角膜接触镜材料及眼科药物载体材料,展望了生物医用眼科材料的发展方向.     

航空材料在外科植入物骨关节假体中的应用

在现代材料科学与技术的发展历程中,航空材料一直扮演着先导和基础作用.航空材料中的高温合金(主要是钴基合金)、钛合金、不锈钢、陶瓷、高耐磨非金属等材料以其轻质、高强、高抗疲劳性、高耐热、高可靠性,并且具有良好的生物相容性等优良性能,已成为临床中较为理想的植入材料,并被广泛应用于外科植入物方面.国内外人工关节得以迅猛发展很大程度上依赖于航空材料在外科植入物骨关节假体中的应用.本文旨在介绍目前航空材料在外科植入物骨关节假体应用方面的常用材料、性能及使用要求.     

Nanostructured Silicon Matrix for Materials Engineering

Tin-containing layers with different degrees of oxidation are uniformly distributed along the length of silicon nanowires formed by a top-down method by applying metalorganic chemical vapor deposition. The electronic and atomic structure of the obtained layers is investigated by applying nondestructive surface-sensitive X-ray absorption near edge spectroscopy using synchrotron radiation. The results demonstrated, for the first time, a distribution effect of the tin-containing phases in the nanostructured silicon matrix compared to the results obtained for planar structures at the same deposition temperatures. The amount and distribution of tin-containing phases can be effectively varied and controlled by adjusting the geometric parameters (pore diameter and length) of the initial matrix of nanostructured silicon. Due to the occurrence of intense interactions between precursor molecules and decomposition by-products in the nanocapillary, as a consequence of random thermal motion of molecules in the nanocapillary, which leads to additional kinetic energy and formation of reducing agents, resulting in effective reduction of tin-based compounds to a metallic tin state for molecules with the highest penetration depth in the nanostructured silicon matrix. This effect will enable clear control of the phase distributions of functional materials in 3D matrices for a wide range of applications.