基于正电荷和光热协同效应的新型半导体聚合物纳米抗菌材料（英文）

由于抗生素的不当使用和细菌多药耐药的出现,迫切需要开发新的抗菌剂.本文制备了具有光热转换性能的正电荷半导体高分子材料及具有协同抗菌活性的半导体聚合物纳米粒子(SP-PPh₃NPs). SP-PPh₃NPs的光热转化效率为43. 8%.带正电荷的SP-PPh₃NPs可以附着在细菌上,有助于将热量有效传递给细菌.在热和正电荷的协同作用下,SP-PPh₃NPs对革兰氏阴性大肠杆菌(E. coli)和革兰氏阳性金黄色葡萄球菌(S.aureus)均具有抗菌活性,其对二者的体外抑菌率分别为99. 9%和98. 6%.此外,SP-PPh₃NPs具有良好的生物相容性,对小鼠的主要器官几乎无副作用.对细菌感染的小鼠皮肤伤口用SP-PPh₃NPs治疗12 d后,伤口可以很好地愈合.     

半导体纳米微粒在聚合物基体中的复合与组装

总结了有关半导体纳米微粒在聚合物基体中的制备，复合与组装及性能研究等工作，对半导体纳米微粒的尺寸大小，粒度分布，表面修饰，复合过程及组装维数等控制问题进行了讨论。     

纳米粒子/聚合物复合光热平台的构筑和应用

叙述了一系列增强纳米粒子光热性能的方法,包括通过自组装方法调控纳米粒子的空间排列,进而优化电子结构和光热转化性能;在纳米粒子及其组装结构外表面进一步包覆具有光热性质的聚合物等.这些手段能够有效地增强光热试剂在近红外光区的消光能力,达到增强光热性能的目的.另外,包覆聚合物壳层后,纳米粒子的胶体稳定性、光稳定性以及生物兼容性都能得到进一步提高,为后续的体外细胞实验和动物体内肿瘤模型实验提供了可能.     

电致发光聚合物/纳米半导体材料及其双功能器件

电致发光材料在大屏幕平板显示和移动通讯器件方面有着极大的优越性。Ⅱ-Ⅵ族无机半导体、金属有机化合物及共轭聚合物等都是电致发光材料。由半导体纳米晶体和电致发光聚合物组成的双发光器件中,纳米半导体的发光不仅可以通过掺杂及形成核壳结构来加以调节,而且受到其复合体系类型、纳晶含量、外加电压等因素制约;而无机半导体的高电荷输运特性也将影响聚合物发光层的效率。同时,利用无机纳米半导体的光导特性,这种复合体系也可以制成光导与电致发光双功能器件,且其发光效率可有较大幅度提高。     

抗菌聚合物纳米纤维的研究进展

静电纺丝技术是制备功能聚合物纳米纤维的一种简单而有效的方法。由电纺纳米纤维堆砌而成的无纺织物具有巨大的比表面积,赋予其广泛的应用前景。通过在电纺聚合物纳米纤维中添加各类抗菌剂或对其表面进行化学改性,制备具有优异抗菌性能的新型功能聚合物纳米材料,将进一步拓展电纺纳米纤维在生物医学、过滤、精密制造等领域的应用。本文基于抗菌纳米纤维的分类进行总结,介绍国内外抗菌聚合物纳米纤维的研究现状,并对抗菌纳米纤维的未来发展进行了探讨。     

基于氧化铁颗粒与聚合物的纳米复合材料磁电容特性研究

对由Fe3O4纳米颗粒-聚二甲基硅烷(PDMS)聚合物材料所组成纳米复合材料磁电容特性进行了研究,提出了该复合材料的制备方法,并对其进行了表征、磁化特性测试以及零磁场环境下介电特性测试;分析了该复合材料的相对介电常数随环境磁场的变化关系以及具有不同含量、粒径纳米颗粒的复合材料磁电容特性差异.实验结果显示,该复合材料的相对介电常数随环境磁场的增大而增大,其变化曲线有一定的滞后特性;复合材料的相对介电常数变化量随材料中纳米颗粒粒径以及含量的增大而增大,但含有较大颗粒复合材料的相对介电常数变化曲线具有较大的滞后性.研究表明,该复合材料在环境磁场中能够产生磁电容效应,其相对介电常数随环境磁场的变化率、饱和值以及滞后性都会受到材料中包含的纳米颗粒的含量以及磁化特性(磁导率、饱和磁化强度、矫顽力)所影响.     

基于共轭聚合物的近红外光传感器

近红外光(NIR)传感器在军事警戒、空间勘探、科研检测、医疗诊断等领域有着极为重要的应用价值。传统的NIR传感材料主要是基于半金属的无机材料,借助窄带隙来吸收低能量的NIR而改变材料自身的电导率,继而实现检测。无机传感材料由于加工繁琐、不具备柔性、成本高昂以及难降解等因素致其进一步发展受到限制。新兴的共轭聚合物材料通过光热转换或者能级可调的光电效应实现对NIR的高灵敏传感,同时能够实现快速响应。该类聚合物材料具有π电子离域的共轭结构,同样具有较窄的带隙,在NIR照射下能够通过自身电导率的改变或光热转换作用将热量传递至其他超热敏材料来实现对光的检测。借助柔性、环境友好、制备简单、便于掺杂、灵敏度高等优势,共轭聚合物材料为新一代NIR传感器的应用与普及开辟了新的前景。     

金纳米球和金纳米棒的制备及其光热催化性能

以氯金酸(HAuCl_4)为原料,硼氢化钠(NaBH_4)为还原剂,聚乙烯吡咯烷酮K30(PVP)为稳定剂制备了尺寸5 nm的金纳米球;以阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)为模板剂和油酸钠(NaOL)稳定剂,用种子生长法制备了不同长径比(R=2.5~4)的金纳米棒。在2 W·cm~(-2)的808 nm激光照射10 min条件下,C(0.4 mg·mL~(-1))浓度金纳米球溶液升温10.2℃,该溶液可催化血液中亚硝基硫醇释放NO,最大释放量可达1.42 nmol·L~(-1);相同光热及催化条件下,C(0.4 mg·mL~(-1))浓度金纳米棒(R=3.01)溶液升温41.3℃,该溶液催化血液中亚硝基硫醇释放NO最大释放量可达1.89 nmol·L~(-1)。金纳米球和金纳米棒的光热及催化性能随着浓度增加而增强,金纳米棒的光热及催化性能要优于金纳米球。     

小分子基温敏聚合物纳米粒子的制备及在近红外二区荧光成像与光热治疗中的应用

以有机小分子4,9-二(5-9H-芴-2-基-噻吩-2-基)-6',7-联苯[1,2,5]噻二唑并[3,4-g]喹喔啉(TQF)为前驱体, 通过化学方法将其修饰为可引发可逆加成-断裂链转移聚合(RAFT)反应的小分子链转移剂TQF-苯基硫代链 转移剂（CTA）. 以TQF-CTA为链转移剂, 以偶氮二异丁腈为引发剂, 引发N-异丙基丙烯酰胺(NIPAAm)和 甲基丙烯酸寡聚乙二醇酯(OEGMA)发生RAFT聚合反应, 合成了具有良好水溶性和较低临界溶解温度(LCST)的小分子基共聚物[TQF-P(NIPAAm-co-OEGMA), TPNO]. 将其直接溶于水中可制备成温敏的球形纳米粒子 TPNO NPs. 研究结果表明, TPNO NPs在温度大于LCST(35 ℃)时表现出一个明显的粒径变化和显著的荧光 增强行为(2.2倍), 并成功实现了对活体小鼠血管与肿瘤的明亮近红外二区(NIR-Ⅱ)荧光成像(FI). 同时, TPNO NPs有着良好的光热转换效率(PCE=29.8%), 通过体外细胞实验证明了其对细胞具有较好的光热治疗(PTT)效果.     

Semiconducting Polycomplex Nanoparticles for Photothermal Ferrotherapy of Cancer

This study reports the development of iron‐chelated semiconducting polycomplex nanoparticles (SPFeN) for photoacoustic (PA) imaging‐guided photothermal ferrotherapy of cancer. The hybrid polymeric nanoagent comprises a ferroptosis initiator (Fe³⁺) and an amphiphilic semiconducting polycomplex (SP_C) serving as both the photothermal nanotransducer and iron ion chelator. By virtue of poly(ethylene glycol) (PEG) grafting and its small size, SPFeN accumulates in the tumor of living mice after systemic administration, which can be monitored by PA imaging. In the acidic tumor microenvironment, SPFeN generates hydroxyl radicals, leading to ferroptosis; meanwhile, under NIR laser irradiation, it generates localized heat to not only accelerate the Fenton reaction but also implement photothermal therapy. Such a combined photothermal ferrotherapeutic effect of SPFeN leads to minimized dosage of iron compared to previous studies and effectively inhibits the tumor growth in living mice, which is not possible for the controls.     

Dual‐Mode Antibacterial Conjugated Polymer Nanoparticles for Photothermal and Photodynamic Therapy

In this work, dual‐mode antibacterial conjugated polymer nanoparticles (DMCPNs) combined with photothermal therapy (PTT) and photodynamic therapy (PDT) are designed and explored for efficient killing of ampicillin‐resistant Escherichia coli (Amp^r E. coli). The DMCPNs are self‐assembled into nanoparticles with a size of 50.4 ± 0.6 nm by co‐precipitation method using the photothermal agent poly(diketopyrrolopyrrole‐thienothiophene) (PDPPTT) and the photosensitizer poly[2‐methoxy‐5‐((2‐ethylhexyl)oxy)‐p‐phenylenevinylene] (MEH‐PPV) in the presence of poly(styrene‐co‐maleic anhydride) which makes nanoparticles disperse well in water via hydrophobic interactions. Thus, DMCPNs simultaneously possess photothermal effect and the ability of sensitizing oxygen in the surrounding to generate reactive oxygen species upon the illumination of light, which could easily damage resistant bacteria. Under combined irradiation of near‐infrared light (550 mW cm^?2, 5 min) and white light (65 mW cm^?2, 5 min), DMCPNs with a concentration of 9.6 × 10^?4 µm could reach a 93% inhibition rate against Amp^r E. coli, which is higher than the efficiency treated by PTT or PDT alone. The dual‐mode nanoparticles provide potential for treating pathogenic infections induced by resistant microorganisms in clinic.     

Development of Semiconducting Polymer Nanoparticles for Photoacoustic Imaging

Semiconducting polymer nanoparticles (SPNs) have evolved into a new class of photonic materials with great potential for biomedical applications. Depending on the polymer structures, SPNs can be developed into optical agents for fluorescence and chemiluminescence imaging, photosensitizers for photodynamic therapy, and heat converters for photothermal therapy. In this feature article, recent work is summarized on the development of SPNs for in vivo photoacoustic (PA) imaging, a state‐of‐the‐art imaging modality that converts light energy into mechanical acoustic waves to provide deep tissue penetration. The structure–property relationship and doping approaches are discussed to reveal the importance of promoting nonradiative decay in amplifying the PA brightness of SPNs. Moreover, their imaging applications, including lymph node mapping, tumor imaging, and monitoring of pathological indexes, are highlighted. These studies demonstrate that SPNs can serve as versatile PA agents for advanced molecular imaging applications.

     

温敏聚合物/纳米CuS复合微球在肿瘤光热化学联合治疗中的应用

利用湿化学法合成了具有光热效应的纳米硫化铜(Cu S)颗粒,采用沉淀聚合法,以N-异丙基丙烯酰胺(NIPAAm)和N-乙烯基吡咯烷酮(NVP)为共聚单体,锂藻土(laponite)作为交联剂,吸附纳米硫化铜,制备出兼具光热效应和温敏响应性的复合微凝胶[P(NIPAAm-co-NVP)/Cu S](NNC/Cu S),并测试其载药和药物缓释性能.实验结果表明,制备的纳米Cu S和NNC/Cu S复合微凝胶均在近红外区有很宽的光谱吸收带,在980 nm(0.51 W/cm2)激光的辐照条件下,NNC/Cu S复合微凝胶具有良好的光热效应,温度在8 min内可以升至51.9℃,对于Hela细胞杀伤效果明显,并随着激光照射时间的延长效果越好.复合微凝胶的载药量为0.15mg/mg,在p H=5.5的PBS缓冲液中累积药物释放为75%,高于p H=7.4的63%.同时光热效应对于温敏性载药微球的药物释放具有有效地调控作用,在药物释放阶段,激光照射段药物释放率明显高于未加激光照射段.另外聚合物与纳米Cu S的复合改善了纳米Cu S对于细胞的毒性,NNC/Cu S复合微凝胶细胞存活率为90.9%高于纳米Cu S的63%.     

Synchronously Manipulating Absorption and Extinction Coefficient of Semiconducting Polymers via Precise Dual-Acceptor Engineering for NIR-II Excited Photothermal Theranostics

Integrating the ultralong excitation wavelength, high extinction coefficient, and prominent photothermal conversion ability into a single photothermal agent is an appealing yet significantly challenging task. Herein, a precise dual-acceptor engineering strategy is exploited for this attempt based on donor-acceptor (D-A) type semiconductor polymers by subtly regulating the molar proportions of the two employed electron acceptor moieties featuring different electronic affinity and π-conjugation degrees, and making full use of the active intramolecular motion-induced photothermal effect. The optimal polymer SP4 synchronously shows desirable second near-infrared (NIR-II) absorption, an extremely high extinction coefficient, and satisfactory photothermal conversion behavior. Consequently, the unprecedented performance of SP4 NPs on 1064 nm laser-excited photoacoustic imaging (PAI)-guided photothermal therapy (PTT) is demonstrated by the precise tumor diagnosis and complete tumor elimination.     

Temperature‐Correlated Afterglow of a Semiconducting Polymer Nanococktail for Imaging‐Guided Photothermal Therapy

Nanoparticles for photothermal therapy: Real‐time temperature monitoring is critical to reduce the nonspecific damage during photothermal therapy (PTT); however, PTT agents that can emit temperature‐related signals are rare and limited to few inorganic nanoparticles. We herein synthesize a semiconducting polymer nanococktail (SPN_CT) that can not only convert photo‐energy to heat but also emit temperature‐correlated luminescence after cessation of light excitation. Such an afterglow luminescence of the SPN_CT detects tumors more sensitively than fluorescence as a result of the elimination of tissue autofluorescence, while its temperature‐dependent nature allows tumor temperature to be optically monitored under near‐infrared (NIR) laser irradiation. Thus, SPN_CT represents the first organic optical nanosystem that enables optical‐imaging guided PTT without real‐time light excitation.     

Near-infrared Aza-BODIPY Dyes Through Molecular Surgery for Enhanced Photothermal and Photodynamic Antibacterial Therapy

The widespread use of high-dose antibiotics will not only lead to the rapid acquisition of antibiotic resistance and increased incidence of drug-resistant bacterial infections, but also produce toxic side effects on normal tissues. Herein, two near-infrared dyes BDP-4PTZ and BDP-4DPA were synthesized, and the electron donors of diphenylamine and phenothiazine with the only difference of sulphur(S)-lock between the two phenyl rings were introduced onto the electron acceptor aza-dipyrromethene boron difluoride(aza-BODIPY) through molecular surgery. Through co-precipitation into nanoparticles(NPs), BDP-4PTZ NPs and BDP-4DPA NPs were fabricated with good biocompatibility. Upon 660 nm photoirradiation, BDP-4PTZ NPs and BDP-4DPA NPs showed excellent photothermal conversion efficiency(43% and 50%, respectively) and reactive oxygen species(ROS) production performance(ca. 3.6 and 6 times higher than that of indocyanine green, respectively). In vitro antibacterial experiments indicated that both NPs could effectively destroy the bacteria's membrane to eradicate drug-resistant bacteria. Furthermore, the bacterial abscess was effectively eliminated after treatment with BDP-4DPA NPs under 660 nm photoirradiation without adverse effects. Thus, through molecular surgery, BDP-4DPA without the S-lock demonstrates synergistic photothermal and photodynamic antimicrobial activities, which is promising for further molecular design towards effective neo-antimicrobial phototherapy.     

用高分子保护的纳米MgO的合成

本文利用高分子表面保护的化学沉淀方法成功地制备了粒径分布均匀的类球型纳米MgO。并对所制得的纳米粒子采用红外光谱（IR）、透射电镜（TEM）、差热及热重分析（TG－DTA）和X射线衍射（XRD）等现代分析测试手段进行了表面形貌、结构、晶形和组成等的表征。结果表明利用高分子的表面保护作用能够控制纳米微粒的形状和大小;由于聚乙烯醇分子中多羟基与金属离子间强的相互作用,因此获得的纳米微粒径更小,分散性更好。     

新型抗菌高分子及其抗菌策略的研究进展

抗菌高分子具有丰富的分子结构和独特的抗菌机制。同时,对微生物具有低耐药性的倾向。这些特点使新型高分子材料在抗菌领域受到人们越来越多的关注。本文首先分析了细菌产生耐药性的原因及由其带来的严峻医学和社会问题;然后系统梳理并探讨了新型抗菌高分子材料（如树状大分子、嵌段共聚物、壳聚糖及其衍生物和抗菌高分子/纳米复合材料等）的结构特点和抗菌机理;最后展望了未来新型功能高分子在抗菌领域的重点延伸及探索方向。     

Antibacterial polyethylene - Ethylene vinyl acetate polymeric blend by incorporation of zinc oxide nanoparticles

In this work, a Low-Density Polyethylene (LDPE) - Ethylene Vinyl Acetate (EVA) polymeric blend with antimicrobial activity was obtained. The main objective was to develop an antibacterial LDPE-EVA polymeric blend from the incorporation of antibacterial nanoparticles to increase the antimicrobial and sanitary safety of this polymeric blend when applied in the manufacture of medical products. The antibacterial activity was obtained from the incorporation of zinc oxide nanoparticles (ZnO-NPs) in the LDPE-EVA polymeric blends and the thermal properties were evaluated by differential scanning calorimetry and the mechanical properties by tensile stress tests for different percentages of ZnO-NPs. Scanning electron microscopy was used to study the morphological characteristics of the ZnO-NPs and also the characteristics of the distribution of nanoparticles in the polymer blends. The dispersive energy of x-ray fluorescence spectroscopy was used to study the chemical composition of the nanoparticles. Microbiological tests were performed to evaluate the antibacterial activity of the LDPE-EVA polymeric blends without and with ZnO-NPs against the bacteria Staphylococcus aureus (gram-positive) and Escherichia coli (gram-negative). The results obtained were excellent for the future application of the antibacterial LDPE-EVA polymeric blends to the manufacture of medical products. The Young's modulus values decreased and the tensile strength values showed small reductions and the thermal properties of the LDPE-EVA were not modified. However, the antibacterial activity of LDPE-EVA with 4 wt% of ZnO-NPs was excellent, eliminating the gram-positive bacteria in just 2 h and the gram-negative bacteria in just 2.5 h on their surfaces.