Induction of Osseointegration by Nacre in Pigs

Nacre is a biomaterial that has shown osteoinductive and osteoconductive properties in vitro and in vivo. These properties make nacre a material of interest for inducing bone regeneration. However, information is very limited regarding the introduction of nacre to dental implant surgery for promoting osteogenesis. This study investigated the potential of nacre powder for peri-implant bone regeneration in a porcine model. Ninety-six dental implants were placed into the tibia of twelve male domestic pigs. The dental implants were coated with nacre powder from the giant oyster before implantation. Implantations without nacre powder were used as control groups. Euthanization took place at 2, 4 and 6 weeks after implantation, after which we measured bone-to-implant contact (BIC) and bone volume density (BVD) of the implanted bone samples using micro-computed tomography (micro-CT), and examined the histology of the surrounding bone using histological sections stained with Stevenel’s blue and Alizarin red S. The micro-CT analyses showed that the BIC of dental implantations with nacre powder were significantly higher than those without nacre powder, by 7.60%. BVD of implantations with nacre powder were significantly higher than those without nacre powder, by 12.48% to 13.66% in cortical bone, and by 3.37% to 6.11% in spongy bone. Histological study revealed more peri-implant bone regeneration toward the surface of the dental implants after implantation with nacre powder. This was consistent with the micro-CT results. This study demonstrates the feasibility of using nacre to promote peri-implant bone regeneration in dental implantation.     

Cytoprotective Silica Coating of Individual Mammalian Cells through Bioinspired Silicification

The cytoprotective coating of physicochemically labile mammalian cells with a durable material has potential applications in cell‐based sensors, cell therapy, and regenerative medicine, as well as providing a platform for fundamental single‐cell studies in cell biology. In this work, HeLa cells in suspension were individually coated with silica in a cytocompatible fashion through bioinspired silicification. The silica coating greatly enhanced the resistance of the HeLa cells to enzymatic attack by trypsin and the toxic compound poly(allylamine hydrochloride), while suppressing cell division in a controlled fashion. This bioinspired cytocompatible strategy for single‐cell coating was also applied to NIH 3T3 fibroblasts and Jurkat cells.     

PLLA Coating of Active Implants for Dual Drug Release

Cochlear implants, like other active implants, rely on precise and effective electrical stimulation of the target tissue but become encapsulated by different amounts of fibrous tissue. The current study aimed at the development of a dual drug release from a PLLA coating and from the bulk material to address short-term and long-lasting release of anti-inflammatory drugs. Inner-ear cytocompatibility of drugs was studied in vitro. A PLLA coating (containing diclofenac) of medical-grade silicone (containing 5% dexamethasone) was developed and release profiles were determined. The influence of different coating thicknesses (2.5, 5 and 10 µm) and loadings (10% and 20% diclofenac) on impedances of electrical contacts were measured with and without pulsatile electrical stimulation. Diclofenac can be applied to the inner ear at concentrations of or below 4 × 10⁻⁵ mol/L. Release of dexamethasone from the silicone is diminished by surface coating but not blocked. Addition of 20% diclofenac enhances the dexamethasone release again. All PLLA coatings serve as insulator. This can be overcome by using removable masking on the contacts during the coating process. Dual drug release with different kinetics can be realized by adding drug-loaded coatings to drug-loaded silicone arrays without compromising electrical stimulation.     

Bioinspired Nitroalkylation for Selective Protein Modification and Peptide Stapling

Nitroalkanes react specifically with aldehydes, providing rapid, stable, and chemoselective protein bioconjugation. These nitroalkylated proteins mimic key post‐translational modifications (PTMs) of proteins and can be used to understand the role of these PTMs in cellular processes. Demonstrated here is the substrate scope of this bioconjugation by attaching a variety of tags, such as NMR tags, fluorescent tags, affinity tags, and alkyne tags, to proteins. The structure and enzymatic activity of modified proteins remain conserved after labeling. Notably, the nitroalkane group leads to easy characterization of proteins by mass spectrometry because of its distinct fingerprint pattern. Importantly, the nitro‐alkylated peptides provide a new handle for site‐selective fluorination of peptides, thus installing a specific probe to study peptide–protein interactions by ¹⁹F NMR spectroscopy. Furthermore, nitroalkane reagents can be used for the late‐stage diversification of peptides and for the synthesis of peptide staples.     

人工种植牙失败原因分析

目的分析人工种植牙失败原因,探讨其预防对策。方法回顾性分析240例种植牙患者,统计其失败发生率。分析失败与性别、年龄、糖尿病、吸烟、种植部位及牙周炎的关系。结果种植牙失败主要原因为年龄、糖尿病、吸烟及牙周炎,失败率为8.75%。种植牙失败者,≥60岁的患者失败率明显高于〈60岁的患者（P〈0.05）;糖尿病与吸烟因素具有显著性差异（P〈0.01）,有糖尿病与吸烟的患者种植牙失败率分别为24.1%与16.7%;牙周炎的患者失败率明显高于无牙周炎的患者。结论年龄、糖尿病、吸烟及牙周炎与种植牙成功率密切相关,临床上应针对性加以防治。     

钛及钛合金表面羟基磷灰石涂层结合强度及稳定性

钛(Ti)及其合金凭借优异的机械性能和良好的生物相容性,一直是骨和牙种植体的主要临床应用材料。由于钛及其合金自身的生物惰性,不易与周围骨组织进行快速的骨整合,因此其表面的生物活性有待进一步提高。羟基磷灰石(HA)是人体骨和牙齿的主要无机成分,具有良好的生物活性和生物相容性,受其力学性能的制约,常被作为涂层材料覆盖在钛基体表面,用以提高植入体的生物活性。但一直存在涂层与基体界面结合强度低和涂层力学稳定性差的问题,成为限制其临床广泛应用的主要因素。本文从涂层结构设计、成分设计及制备方法等方面,就国内外改善钛基底与HA涂层界面结合性能的研究现状和发展动态作一综述,为高性能钛植入体的制备和应用提供参考。     

磷酸胆碱基细胞膜仿生药物缓释涂层材料的研究

随着现代医学的飞速发展 ,各种微创介入医疗装置如医用导管 (Catheter)、手术导引线(Guidewires)、金属支架 (Stents)等已广泛地应用到各种医疗技术中 ,极大地丰富了现代医学诊疗手段 .然而在临床应用中 ,现有的装置依然不同程度地存在感染、凝血和术后组织增生等问题[1 ] .设计生物相容性聚合物基载药涂层和实现药物在预定部位的定向释放 ,为解决这些问题提供了有效途径 [2～ 5] .血红细胞膜具有由磷脂分子自组装形成的双层膜 .细胞生物学研究表明 ,细胞膜外层带有等量正电荷和负电荷的卵磷脂不会激活内源性凝血途径 .因此人们设计了磷酸…     

Afterglow Implant for Arterial Embolization and Intraoperative Imaging

Transcatheter arterial embolization (TAE) is wildly used in clinical treatments. However, the online monitoring of the thrombosis formation is limited due to the challenges of the direct visualization of embolic agents and the real-time monitoring of dynamic blood flow. Thus, we developed a photochemical afterglow implant with strong afterglow intensity and a long lifetime for embolization and imaging. The liquid pre-implant injected into the abdominal aorta of mice was rapidly transformed into a hydrogel in situ to embolize the blood vessel. The vascular embolism position can be observed by the enhanced afterglow of the fixed implant, and the long lifetime of afterglow can also be used to monitor the effect of embolization. This provides an excellent candidate in bio-imaging to avoid the autofluorescence interference from continuous light excitation. The study suggests the potential usefulness of the implant as an embolic agent in TAE and artery imaging during a surgical procedure.     

Ultrathin Coating of Confined Pt Nanocatalysts by Atomic Layer Deposition for Enhanced Catalytic Performance in Hydrogenation Reactions

Metal‐support interfaces play a prominent role in heterogeneous catalysis. However, tailoring the metal‐support interfaces to realize full utilization remains a major challenge. In this work, we propose a graceful strategy to maximize the metal‐oxide interfaces by coating confined nanoparticles with an ultrathin oxide layer. This is achieved by sequential deposition of ultrathin Al₂O₃ coats, Pt, and a thick Al₂O₃ layer on carbon nanocoils templates by atomic layer deposition (ALD), followed by removal of the templates. Compared with the Pt catalysts confined in Al₂O₃ nanotubes without the ultrathin coats, the ultrathin coated samples have larger Pt–Al₂O₃ interfaces. The maximized interfaces significantly improve the activity and the protecting Al₂O₃ nanotubes retain the stability for hydrogenation reactions of 4‐nitrophenol. We believe that applying ALD ultrathin coats on confined catalysts is a promising way to achieve enhanced performance for other catalysts.     

IntelliDrug Implant for Medicine Delivery in Alzheimer's Disease Treatment

Summary : IntelliDrug it is a denture implant containing a reservoir with drug and making enable a galantamine transport via buccal mucosa by means of iontophoresis. The in vitro experimental studies on drug passive and iontophoretic transport through porcine buccal mucosa were carrying out in horizontal two-chamber permeation cell with silver electrodes. The drug mass flux was investigated. The influences of initial drug concentration and current density for transport velocity were defined.     

αvβ3‐ or α5β1‐Integrin‐Selective Peptidomimetics for Surface Coating

Engineering biomaterials with integrin‐binding activity is a very powerful approach to promote cell adhesion, modulate cell behavior, and induce specific biological responses at the surface level. The aim of this Review is to illustrate the evolution of surface‐coating molecules in this field: from peptides and proteins with relatively low integrin‐binding activity and receptor selectivity to highly active and selective peptidomimetic ligands. In particular, we will bring into focus the difficult challenge of achieving selectivity between the two closely related integrin subtypes αvβ3 and α5β1. The functionalization of surfaces with such peptidomimetics opens the way for a new generation of highly specific cell‐instructive surfaces to dissect the biological role of integrin subtypes and for application in tissue engineering and regenerative medicine.     

Development of Anti-Reflection (AR) Coating on Plastic Panels for Display Applications

Traditionally, various vacuum-based processes have been used for producing interference-type anti-reflection (AR) coatings on large area substrates for different commercial applications. In this paper, the development of sol-gel derived AR coating on large plastic substrates for display application is presented. The sol-gel dip coating process was used to deposit thin films on large size plastic panels. By developing sols with different refractive indices, multi-layer thin-film AR coating stacks were designed and fabricated. These coatings possess good uniformity and meet stringent automotive specifications. This technology has been commercialized successfully for dashboard instrument panel application in Toyota's new hybrid engine car, named Prius.In this paper, AR coatings prepared by the sol-gel process are reviewed. The basic design concept for an AR coating, the coating preparation procedure, and important parameters of the solution coating process are discussed. Optical constants of the coating materials were characterized by using spectroscopic ellipsometry. Optical, mechanical and environmental tests were performed on the sol-gel derived AR coating stack. The sol-gel derived AR coating possesses equivalent or superior properties when compared to the major commercially available AR coating products.     

Bioinspired Photocatalytic NADH Regeneration by Covalently Metalated Carbon Nitride for Enhanced CO2 Reduction

Natural photosynthesis is a highly unified biocatalytic system, which coupled cofactor (NAD(P)H) regeneration and enzymatic CO₂ reduction efficiently for solar energy conversion. Mimicking nature, a novel system with Rh complex covalently grafted onto NH₂-functionalized polymeric carbon nitride (NH₂-PCN) was constructed. The integrated connection of the light-harvesting and electron mediation modules as Rh_m3-N-PCN could promote the efficient NAD⁺ reduction to NADH. As a result, the integrated system exhibited a conversion of ∼66 % within 20 minutes. By further coupling in situ generated NADH with formate dehydrogenase (FDH), a photoenzymatic production of formic acid (HCOOH) from CO₂ was accomplished. Moreover, by immobilizing FDH onto a hydrophobic membrane, an enhanced HCOOH production of ∼5.0 mM can be obtained due to the concentrated CO₂ on the gas-liquid-solid three-phase interface. Our work herein provides an integrated strategy for coupling the anchored electron mediator with immobilized enzyme for enhanced artificial photosynthesis.     

铝酸锶荧光粉的表面包覆

用Na2SiO3对铝酸锶进行二氧化硅包膜以改善其耐水性。检测结果表明,产品被二氧化硅完整紧密包覆,表现出优良的耐水性能。在纯水中,原样6h内即完全水解,而产品在48h后无水解。同时,包膜对颜料的发光性能影响很小,发射光和激发光强度损失在1%左右。     

Coating of Sol Particles for Membrane Applications

For improving chemical and thermal stability of γ-Al₂O₃ membranes boehmite (AlOOH) sol-particles are coated with Zr⁴⁺-species with two techniques. These techniques are heterogeneous precipitation (HP-method) and “surface-reaction-followed-by-polycondensation” (SRPC-method). A continuous coating layer is formed at relative low Zr⁴⁺-concentration, about one monolayer coverage of boehmite particles, and with the HP-method. For large concentrations and for the SRPC-method small particles (order 1 nm) of Zr⁴⁺-species are formed on the surface of the boehmite particles. After drying and calcination up to 1000°C no continuous layer of a zirconia phase could be detected for all samples. However the thermal stability of the porous structure is improved. Phase transitions of alumina occur at temperatures of 1100°C and the porous structure of the membrane material is then destabilized.     

紫外光固化自修复剂的微胶囊化及智能防腐蚀涂层的制备

利用在水相中原位生成的聚脲甲醛沉淀吸附在可见紫外光固化组份构成的油相表面,制备了包覆自修复剂的脲醛树脂（PUF）微胶囊. 光学显微镜及SEM表明,PUF微胶囊尺寸为118-663 μm,与PUF 形成过程中的搅拌速度有关. 在中等搅拌速度（600 r/min）时,可以得到最高的包覆率（97.52wt%）和产率（65.23wt%）. 将此微胶囊掺入水性聚氨酯乳胶中制成的涂层表面受损后,在紫外光照射下可以进行自修复,具有优异的金属防腐蚀性能.     

Design of Sol-Gel Coating Media for Ink-Jet Printing

Image transfer and storage is rapidly becoming one of the most important technologies in the communication age. Ink-jet printing by which multicolor images are transferred onto paper and transparencies is a major branch of this technology. In this technology electronic image transfer capabilities are often limited by the shortcomings in the materials used. The coating designed to receive the ink determines the ink-dry time, edge acuity or patterns, color fidelity, as well as light and water fastness of the print. These in turn govern the speed, resolution and quality of the image transferred. Chemical, structural and process parameters involved in the design of a transparent, single layer sol-gel coating media for ink-jet printing are discussed. Design goals include quick drying of the print, water resistance, edge acuity without bleeding, UV protection of color dyes, and being printer nonspecific.     

光刻胶用底部抗反射涂层研究进展

随着微电子工业的蓬勃发展,光刻技术向着更高分辨率的方向迈进,运用底部抗反射涂层有效消除光刻技术中的驻波效应、凹缺效应,提高关键尺寸均一性和图案分辨率,引起了广大研究者的关注。本文简要介绍了光刻胶和光刻技术,底部抗反射涂层的分类、基本原理、刻蚀工艺以及其发展状况。重点对底部抗反射涂层的最新研究进展进行了总结,尤其是碱溶型底部抗反射涂层在光刻胶中的应用研究,最后对底部抗反射涂层的发展前景和方向进行了展望。     

聚氨酯漆包线漆料的研究

研制的三—(羟乙基)异氰脲酸酯(SHEIC)改性聚氨酯漆包线漆料,将杂环结构引入聚氨酯漆膜,使漆包线具有优良的电绝缘性能和较高的软化击穿温度,同时保留了聚氨酯漆膜直焊性好的特点。对异氰酸酯的封闭反应和解封反应,以及SHEIC改性聚氨酯漆膜的热性能作了研究。     

复合镀膜在陶瓷颗粒透射电镜分析中的应用

本文介绍了一种对陶瓷颗粒进行透射电镜分析的样品制备方法。采用复合电沉积方法,将陶瓷颗粒均匀分散包埋在金属铜镀层中,得到复合镀层薄膜,再通过电解双喷将薄膜减薄,获得透射电镜样品,从而可以对陶瓷颗粒进行透射电镜观察分析,讨论了获得此种复合镀层薄膜所需的电流密度、镀液pH值、搅拌措施和电镀时间。透射电镜观察分析的结果显示此方法效果良好。