pH敏感型交联微球的制备

采用铈盐-羟基氧化还原引发体系,以对苯乙烯磺酸钠(SSS)和葡聚糖(Dex)为原料,通过自由基接枝聚合将聚对苯乙烯磺酸钠(PSSS)接枝到Dex上,得到接枝共聚物Dex-g-PSSS,再通过交联反应合成C(Dex-g-PSSS)微球。利用FTIR、光学显微镜、Zeta电位仪表征了试样的结构和形态,研究了反应条件对PSSS接枝度的影响,考察了C(Dex-g-PSSS)微球在模拟胃液和结肠液中的溶胀率。表征结果显示,C(Dex-g-PSSS)微球为交联微球,其Zeta电位为绝对值较大的负值。实验结果表明,在适宜的反应条件(硫酸铈铵浓度12 mmol/L、H+浓度0.08 mol/L、Dex 5 g、SSS 5 g、50℃,6 h)下,可得到接枝度为11.86 g(基于100 g Dex-g-PSSS)的PSSS。C(Dex-g-PSSS)微球有较明显的p H敏感性,它在模拟胃液中的溶胀率仅有134%,在模拟结肠液中的溶胀率可达到678%,是潜在的口服结肠定位给药系统基质材料。     

如何提高内部质量体系审核工作有效性的探讨

针对目前质量体系运行和内部质量体系审核工作的现状 ,提出抓好内部质量体系工作的措施 ,促进文件化的质量体系持续有效地运行 ,实现质量方针和质量目标 ,确保产品实物质量的稳定可靠     

特殊通信网网络管理系统效能评估

针对特殊通信网网络管理系统的效能评估,提出了一种评估算法,该方法适用于受到多个因素影响和制约的系统的评估,确定了特殊通信网网络管理系统效能指标体系,指标体系包括:管理功能、管理对象、实时性、动态性、可扩展性、智能化、可靠性、抗毁性、安全性以及操作使用性等。利用模糊综合评判法进行建模,采用层次分析法确定权重系数。最后通过实例说明了特殊通信网管系统的效能评估流程。     

Modular Self‐Assembling Peptide Platform with a Tunable Thermoresponsiveness via a Single Amino Acid Substitution

The introduction of a stimulus‐responsive property is an effective way to increase the applicability of functional materials in the field of nanobiotechnology. Herein, a peptide platform is devised for constructing elastin‐like peptide amphiphiles (ELPAs) that exhibit a temperature‐responsiveness that can be easily tuned via a single N‐terminal amino acid substitution at the final step of peptide synthesis. Due to the modular property of peptides, the platform based on a miniaturized elastin‐like peptide (MELP) can be conjugated with various bioactive peptide sequences in diverse macromolecular topologies. First, the MELP platform is coupled with a short linear RGD peptide. The ELPAs of the peptide conjugates exhibit rapid aggregation (coacervation) and retard disaggregation in response to heating and cooling, respectively. Second, the platform is grafted with an α‐helical guest peptide in a lariat‐type structure, which forms ELPAs that undergo faster disassembly than the ELPAs without the guest peptide in response to temperature increases. Interestingly, the critical temperatures for the thermoresponsive behaviors are commonly dependent on the hydrophobic and aromatic properties of the N‐terminal amino acid residues. These results suggest that this peptide platform possesses great potential for use in the development of smart materials in wide‐ranging applications related to temperature change.     

光动力疗法在头颈部恶性肿瘤治疗中的研究进展

头颈部恶性肿瘤严重影响患者的生存质量,且长期生存率较低。光动力疗法是近年来兴起的一种诊断和治疗肿瘤的新型方法,本文对光动力的原理及其在头颈部恶性肿瘤治疗方面的应用进展作一综述。     

肿瘤光动力学疗法的生物学机制

光动力学疗法是新兴出现的治疗肿瘤的有效方法,但其机制有待阐明。本文从细胞性损伤、血管性损伤、细胞凋亡以及免疫功能等方面对其生物学机制进行了综述和探讨。     

Site‐Selectively Coated,Densely‐Packed Microprojection Array Patches for Targeted Delivery of Vaccines to Skin

Densely packed dry‐coated microprojections are shown to deliver vaccines to targeted locations within the skin that are rich in immune cells, thus inducing protective immune responses against a lethal virus challenge. Selectively limiting the antigen coating to the tips of the projections, which penetrate the skin, would significantly reduce the amount of vaccine required in immunization. In this paper a simple technique, dip‐coating the microprojections, is introduced to meet this goal. By increasing the coating solution viscosity, an otherwise strong capillary action is mitigated and the desired controlled coating length on projections is achieved. Following application to the skin, most of the coated vaccine material is rapidly released from the projections (82.6% in mass within 2 min) to the target locations within the skin strata and a potent immune response is induced when a conventional influenza vaccine (Fluvax) is tested in a mouse model. The utility of this coating approach to a variety of molecules representative of vaccines (e.g., chicken egg ovalbumin (OVA) protein, DNA, and fluorescent dyes) is demonstrated. These collective attributes, together with the simplicity of the approach, position the dip‐coating method for practical utility in large vaccination campaigns.     

Boosting H2O2‐Guided Chemodynamic Therapy of Cancer by Enhancing Reaction Kinetics through Versatile Biomimetic Fenton Nanocatalysts and the Second Near‐Infrared Light Irradiation

Fenton reaction–based chemodynamic therapy (CDT) has attracted considerable attention for tumor treatment, because the Fenton reaction can degrade endogenous H₂O₂ within the tumor to form reactive oxygen species (ROS) to kill cancer cells. The kinetics of the Fenton reaction has significantly influenced its treatment efficacy. It is crucial to enhance the reaction kinetics at the maximum H₂O₂ concentration to quickly produce vast amounts of ROS to achieve treatment efficacy, which to date, has not been realized. Herein, reported is an efficacious CDT treatment of breast cancer using biomimetic CS‐GOD@CM nanocatalysts, which are rationally designed to significantly boost the Fenton reaction through improvement of H₂O₂ concentration within tumors, and application of the second near‐infrared (NIR‐II) light irradiation at the maximum concentration, which is monitored by photoacoustic imaging. The biomimetic nanocatalysts are composed of ultra‐small Cu_2?xSe (CS) nanoparticles, glucose oxidase (GOD), and tumor cell membrane (CM). The nanocatalysts can be retained in tumor for more than two days to oxidize glucose and produce an approximately 2.6‐fold increase in H₂O₂ to enhance the Fenton reaction under the NIR‐II irradiation. This work demonstrates for the first time the CDT treatment of cancer enhanced by the NIR‐II light.     

A Visible‐ and NIR‐Light Responsive Photothermal Therapy Agent by Chirality‐Dependent MoO3−x Nanoparticles

Chirality‐based semiconducting nanocrystals, as an emerging area, are envisioned to have great potential in chiral sensing, biomedicine, and chiroptical devices. Herein, chiral substoichiometric molybdenum oxide (l /d ‐Cys‐MoO_3?x) nanoparticles are synthesized via step‐by‐step reduction treatment with chiral cysteine molecules. The obtained nanoparticles are used as visible‐ and near‐infrared‐light dual responsive photothermal therapy agent for tumor cell ablation. Notably, the chiral nanoparticles show chiral selectivity for incident light, i.e., when irradiated by left‐circularly polarized light, l ‐Cys‐MoO_3?x is the most sensitive agent giving the highest mortality for HeLa cell ablation in vitro, and vice versa for right‐circularly polarized light with d ‐Cys‐MoO_3?x. In comparison to traditional photothermal therapy with near‐field light source, the investigations with chiral visible light at 532 nm indicate the possibility of chiral Cys‐MoO_3?x nanoparticles for visible light‐based phototherapy via metal–ligand charge transfer chirality, which provides insights for new methods in nanotechnology supported photothermal treatments.