聚多巴胺修饰的介孔二氧化硅微球的合成及其用于负载左旋薄荷醇凉味剂

介孔二氧化硅材料具有巨大的孔隙率、开放的孔道结构、易于改性的孔道表面以及良好的生物相容性, 广泛用于药物传递、吸附分离以及催化等领域。本研究通过非极性溶剂辅助共组装法合成了具有较大孔径(6.9 nm)和比表面积(615 m²/g)的介孔二氧化硅微球。采用纳米浇铸的方法, 成功地将左旋-薄荷醇负载到该材料的孔内。进一步通过界面聚合的方法, 在所得微球的表面涂覆一层聚多巴胺(PDA)涂层, 从而将薄荷醇封装在微球的孔道内。利用PDA作为半透膜, 研究了复合微球在不同温度的空气吹扫下释放薄荷醇的行为, 发现在相对适宜的温度下PDA涂层有利于薄荷醇的可控缓慢释放。这些研究结果表明基于聚多巴胺修饰的介孔二氧化硅材料有望用于开发食品和医药等领域的缓释制剂。     

磁性核壳Ag/PDA@SiO2@CoFe2O4复合纳米材料的制备、表征及其抑菌性能研究

采用溶剂热法制备单分散的CoFe₂O₄亚微米球, 分别用正硅酸乙酯(TEOS)和多巴胺(DA)为前体通过溶胶-凝胶法和自聚合法对CoFe₂O₄核表面进行修饰形成具有多层核壳结构的PDA@SiO₂@CoFe₂O₄, 最外层为聚多巴胺(PDA)。采用原位还原法在PDA表面沉积均匀的银纳米粒子, 合成Ag/PDA@SiO₂@CoFe₂O₄磁性复合粒子。采用透射电子显微镜(TEM)、X射线粉末衍射(XRD)、X射线光电子能谱分析(XPS)、振动探针式磁强计(VSM)和电感耦合等离子发射光谱仪(ICP-OES)对样品的形貌、结构等进行表征, 并研究其对大肠杆菌(E.Coli)和金黄色葡萄球菌(S.Aureas)的抑菌性能。结果表明, 当Ag浓度在0.6 mg/mL时, Ag/PDA@SiO₂@CoFe₂O₄对E.Coli和S.Aureas的抑菌率均在92%以上。除了优异的抑菌性能, 它具有很强的磁性, 可以通过外加磁场回收利用。     

UV‐Triggered Polydopamine Secondary Modification: Fast Deposition and Removal of Metal Nanoparticles

Since the first report in 2007, polydopamine (PDA) coating has shown great potential as a general and versatile method to create functional nanocoatings on arbitrary substrates. Slow kinetics and poor controllability of the coating and secondary modification processes, however, have limited the further development of this attractive method. In this work, it is demonstrated that UV irradiation at 365 nm significantly accelerates the process of secondary modification of a PDA‐coated surface. The kinetics of both thiol and amine modifications of PDA are increased 12‐fold via UV irradiation, while the kinetics of metal ion reduction at the PDA interface is increased more than 550 times. Moreover, it is demonstrated that irradiating a PDA/metal nanoparticle composite surface with UV light at 254 nm leads to dissolution of the deposited metal nanoparticles (MNPs). Finally, grayscale metallic patterns, dynamic deposition, and removal of MNPs on PDA surface are realized with the proposed method.     

新型聚多巴胺纳米颗粒光热蒸发性能评价

聚多巴胺具有与黑色素相似的吸光性能,是一种被广泛关注的高分子近红外吸收材料,在光热转化方面有良好前景。但由于其本身聚合机理多样,内部结构复杂,目前对聚多巴胺功能性设计的研究较少。本文通过设计Fe³⁺和硅烷偶联剂与多巴胺反应,提高了聚多巴胺的吸光特性和亲水性;通过X射线光电子能谱(XPS)、傅里叶变换红外光谱(FTIR)等表征证明,成功合成了高吸光度亲水聚多巴胺纳米颗粒,吸光度达到90%。同时将合成的纳米颗粒真空抽滤,堆叠构建亲水输运通道。实验表明：在太阳光蒸发环境,一个太阳光强下,使用本文设计的光热膜进行纯水蒸发实验,纯水蒸发速率可以达到1.1 kg/(m²·h),光热转化效率为80%,比普通聚多巴胺提高15%,证明该材料有很好的光热转化性能,在海水淡化领域有着良好的应用前景。     

仿生聚多巴胺对HMX、TATB和铝粉的界面性能改性

为了研究表面改性方法及表面包覆均匀性、浸润性等性状对含能材料的机械感度、界面力学性能以及工艺性能的影响,仿生贻贝黏附蛋白的作用原理,以多巴胺为前驱体,采用一步法使其在含能材料表面聚合形成一层致密牢固的包覆薄膜聚多巴胺(PDA),制备了改性单质炸药(HMX@PDA、TATB@PDA)和改性铝粉(Al@PDA)。通过扫描电子显微镜、X射线光电子能谱和接触角测试仪对改性含能材料的表面形貌、药柱断裂处微观形貌、元素含量以及表面浸润性能进行了表征,采用国军标(GJB-772A-1997)、巴西实验等标准测试方法对改性含能材料的机械感度、拉伸应力-应变曲线等进行了测试,并将实测性能与未改性含能材料进行了对比分析。结果表明,与HMX晶体比较,HMX@PDA晶体的摩擦感度下降30%,特性落高数值增加一倍;与TATB基药柱比较,TATB@PDA基药柱的拉伸强度提高约15%;与Al粉比较,Al@PDA在HTPB液相中24h后可有效减缓沉降。聚多巴胺对晶体完整致密的包覆性能以及含有丰富活性基团的特性,对含能材料的包覆降感、界面力学性能提升和工艺稳定性提升等方面具有显著的界面改性作用。     

非晶光子晶体结构色织物的制备及其数值模拟

为深入研究非晶光子晶体结构,实现对结构色的有效调控,将经快速氧化制备的壳核结构聚苯乙烯/聚多巴胺(PS/PDA)微球在棉织物上构建三维非晶光子晶体结构,采用Rsoft软件建立数值模型对其光学性质进行计算。探究晶体微球粒径、光线入射角度对光子晶体反射率的影响,并通过CIE标准色度系统得到色品坐标,在CIE色度图中直观地反映光子晶体结构色变化。研究表明:计算结果与实验测试结果较为吻合,粒径为195、222、267、287 nm的PS/PDA纳米微球构建的非晶光子晶体结构,依次对应蓝色、绿色、黄绿色和红色,且随着入射角的不同,结构色不会发生改变。通过数值模拟计算,可控制纳米微球粒径、调节非晶光子晶体的光子赝带隙,从而对产生的结构色进行有效调控。     

3D Manufacture of Gold Nanocomposite Channels Facilitates Neural Differentiation and Regeneration

Conductive nerve guidance channels are promising alternative therapies in peripheral nerve tissue engineering because they have excellent biocompatibility, biodegradation, and electrical conductivity. Gold, a kind of conductive material, is investigated widely concerning its potential roles in promoting peripheral nerve repair. In the present study, a polydopamine‐coated gold/polycaprolactone nanoscaffold is fabricated via a multilayer molding method and its proliferative, adhesive, and neural differentiation potential for bone marrow mesenchymal stem cells (BMSCs) and Schwann cells (SCs) in vitro is evaluated. Functional, electrophysiological evaluation, and morphological assessment all exhibit satisfactory recovery of sciatic nerves with increased thickness and number of myelinated fibers in vivo. In addition, increased microvessels are confirmed in gold nanocomposite channels, indicating their potential benefits in angiogenesis. Functional regeneration is further enhanced by neurotrophic growth factors released from BMSC and SC loading. The gold nanocomposite channel will have great potential in peripheral nerve restoration.     

TiNb2O7 microsphere anchored by polydopamine-modified graphene oxide as a superior anode material in lithium-ion batteries

TiNb₂O₇ (TNO) is considered a promising anode material for lithium-ion batteries. High contact and homogeneity of the composite fabricated by TNO powder and conductive materials with different density are significant to improve the poor electric conductivity of TNO microspheres. In this study, we introduce graphene oxide (GO) to synthesize a composite material with TNO microspheres. Moreover, a polydopamine (PDA) coating technique is applied to achieve uniform distribution and high contact between TNO and GO materials. The -OH catechol groups in the PDA have a strong adhesion ability to inorganic surfaces. After a simple sonication process, the hybrid material is well-fabricated, where TNO microspheres are attached along the surface of the PDA-coated GO (PGO). The TNO/PGO composite shows remarkably enhanced performances such as cycling stability (202.7 mAh g⁻¹ over 300 cycles at 1C) and rate capability (136.5 mAh g⁻¹ over 1000 cycles at 5C). The formation of a high conductive network among TNO microspheres mainly enhances those electrochemical performances, and the PDA layer is a key factor in obtaining a homogeneous GO composite through its high adhesive ability and hydrophilicity.     

Injectable Ovalbumin-Based Composite Implant for Photothermal Tumor Therapy

Polymeric hydrogels with three-dimensional network structures have found tremendous applications in biomedicine. Herein, we report the synthesis of a multifunctional implant based on ovalbumin (OVA) as a carrier capable of synergistically delivering a photothermal transducing agent (polydopamine, PDA) to tumors. The formation of PDA was achieved by utilizing the basicity of OVA, whereas the formation of the hydrogel implant was achieved through the in vitro/in vivo near-infrared (NIR) laser-induced hyperthermia of PDA. The as-prepared PDA@OVA implant exhibits high photothermal conversion efficiency (38.7 %). Once implanted in vivo, the OVA-based implant shows great versatility in the treatment of malignant tumors. Furthermore, a chemotherapeutic (doxorubicin, DOX) and a contrast agent (iohexol), dispersed in the OVA solution in advance, can also be firmly entrapped in the hydrogel along with the hydrogel formation. It is anticipated that the multifunctional OVA-based implant, not showing any obvious toxicity to healthy tissue, could be a promising system for synergistic cancer treatment.