顺铂温敏载药粒子的制备表征

制备了顺铂温敏载药纳米粒子，表征其相关性质并考察不同温度下对体外肿瘤细胞的生长抑制作用。制备的两亲嵌段聚合物在水溶液中自发形成胶束结构并包裹顺铂，测定顺铂载药粒子的结构、形态、粒径及包封率、载药量、晶体状态等特性，并对顺铂的体外释放以及不同细胞系体外毒性也做了研究。载药粒子粒径为83.3 ± 4.3 nm，载药量为37.8%，包封率为77.8%。血清中相变温度39.3 ℃。载药颗粒在单纯化疗时细胞抑制率较小，加热后抑制作用明显增加(P<0.01)，与游离药物相近(P>0.5)。顺铂载药纳米粒子具有较好的温控特性，为顺铂在肿瘤热靶向治疗中的应用提供了一条新的途径。     

合成高分子基温敏水凝胶在眼病治疗中的研究进展

由于眼部存在角膜/结膜屏障、血-房水屏障和血-视网膜屏障等,有效的眼部给药依然面临巨大挑战.近年来,温敏水凝胶在眼部给药领域受到了广泛关注.在室温下,温敏水凝胶材料呈液态,便于以局部滴加或玻璃体内注射的方式给药;当与眼部接触升温并超过其临界成胶温度时,能以物理交联的方式快速凝胶化,从而实现原位缓释给药,提高药物生物利用度.在众多温敏水凝胶材料中,合成高分子具有材料和功能多样化等优势,其中较常见的为泊洛沙姆、聚乙二醇/聚酯和聚(N-异丙基丙烯酰胺).本综述首先介绍了以上3类合成高分子基温敏水凝胶材料的制备方法和成胶特性.然后,围绕眼部给药存在的难点,探讨这些温敏水凝胶在治疗角膜病、干眼症、青光眼和眼部炎症等各种眼病中的相关研究进展.最后,我们比较了这3种水凝胶在使用性能上的优缺点,并对未来眼科温敏水凝胶的材料设计提出了设想和展望.     

聚乙二醇相对分子质量及用量对温敏型PCL-PEG-PCL水凝胶的制备及释药性研究

采用开环聚合法制备PCL-PEG-PCL共聚物,并将其制成温敏性水凝胶,探究了PEG(聚乙二醇)相对分子质量及质量浓度对水凝胶温敏性的影响.水凝胶的相变温度由翻转小瓶法测定.通过FTIR、热分析仪和SEM等技术对其组成及结构进行表征.以疏水性姜黄素(Cur)为模型药物,制备出载Cur PCL-PEG-PCL水凝胶,并研究其体外释药行为.FTIR结果表明:实验制备的共聚物中含有PCL和PEG的链段.热分析结果表明:在25℃~65℃内水凝胶存在相变过程.SEM结果表明:水凝胶剖面具有疏松多孔.体外释药结果表明:PCL-PEG-PCL水凝胶对Cur具有缓释作用,释药机理符合Higuchi骨架溶蚀模型.     

温敏性水凝胶在抗菌领域应用的研究进展

智能水凝胶是一种能在水中溶胀而不溶于水的高分子聚合物,且能对外界刺激而作出应答的一类凝胶体系。温敏水凝胶是智能水凝胶的一种,它能根据环境温度的变化而产生体积相转变现象,与抗菌剂复合可使其具有抗菌活性。温敏水凝胶可以根据环境温度的变化间断式地释放抗菌剂,提高抗菌剂的效用时间,可应用于生物、医药、纺织等领域。本文介绍了温敏水凝胶的温敏机理,重点综述了近年来与抗菌剂相结合的丙烯酰胺、泊洛沙姆、壳聚糖及聚乙二醇-b-聚酯类共聚物等温敏性复合水凝胶在抗菌应用方面的研究进展,并探讨了近年来抗菌复合水凝胶研究存在的问题及未来的研究方向。     

聚乙二醇-聚乳酸共聚物胶束溶液的冷冻干燥及胶束体外释药动力学研究

合成了一系列亲水、疏水链段质量比例不同的聚乙二醇-聚乳酸(PEG-PLA)嵌段共聚物胶束, 并以两性霉素B为模型药物制备了载药胶束. 为获得稳定性良好的、可长期储存的载药胶束剂型, 对胶束进行了冷冻干燥. 使用不同浓度的糖类(包括甘露糖、海藻糖、葡萄糖)、泊洛沙姆188 (Pluronic F68)、聚乙二醇作为冻干保护剂, 以冻干产品的重分散性、冻干前后胶束的粒径及多分散性为指标评价各种保护剂的保护效果. 结果发现, 当嵌段聚合物中聚乳酸链段的质量百分比小于或等于聚乙二醇时, 糖类、Pluronic F68和PEG均可以起到有效的冻干保护作用; 而对于聚乳酸链段质量比例较大的共聚物胶束, 只有PEG和Pluronic F68能够起到较好的冻干保护作用. 对载药胶束体外释放研究表明, 聚合物胶束的体外释放缓慢, 符合一级动力学特征.     

海洋珍珠生物提取液单独与顺铂联合对人宫颈癌Siha细胞的生长抑制作用

为探讨海洋珍珠生物提取液对人宫颈癌Siha细胞体外生长的抑制作用,以及海洋珍珠生物提取液增加Siha细胞对顺铂的敏感性,以期对治疗宫颈癌及其它肿瘤寻找新的治疗药物,体外培养人宫颈癌Siha细胞,分别用海洋珍珠生物提取液、顺铂、海洋珍珠生物提取液加顺铂处理24、48、72 h,采用四甲基偶氮唑蓝(MTT)比色法检测海洋珍珠生物提取液和顺铂及两者联合应用Siha细胞的存活率。结果表明,海洋珍珠生物提取液对Siha细胞的增殖有明显的抑制作用(P0.01),其处理,24、48、72 h的IC50分别为56.26、51.92、48.92μg/mL,顺铂对Siha细胞的24、48、72 h的IC50分别为16.74、4.68、6.69μg/mL;两者合用可大大提高对Siha细胞的抑制作用,比单用海洋珍珠生物提取液或单用顺铂均有明显的提高(P0.01)。提示海洋珍珠生物提取液能抑制Siha细胞的生长,同时能增加Siha细胞对顺铂的敏感性。     

载万古霉素PLGA-PEG-PLGA温度敏感水凝胶的体外抗菌性能

利用聚乙二醇（PEG 1500）引发乙交酯和D,L-丙交酯开环共聚合制备聚丙交酯乙交酯（PLGA）三嵌段共聚物（PLGA-PEG-PLGA）温敏水凝胶材料,并通过核磁共振氢谱（¹H NMR）确定产物的结构及组成.应用倒置小瓶法测量得到不同浓度下PLGA-PEG-PLGA水凝胶的溶胶-凝胶相变温度为27~32℃.此外,体外降解实验及细胞毒性实验结果表明,质量分数为25%的水凝胶有满意的降解速度及良好的生物相容性.同时,利用紫外-可见光谱分析了载万古霉素水凝胶的体外药物释放行为,结果表明,万古霉素可以持续释放12 d.抗菌实验结果表明,载万古霉素水凝胶具有良好的抗菌效果.表明PLGA-PEG-PLGA三嵌段温敏水凝胶是一种较理想的万古霉素缓释载体,具有良好的临床应用前景.     

温敏性抗菌水凝胶的制备与控释技术研究进展

温敏水凝胶是一类通过感知温度变化使自身发生相变的智能型聚合物凝胶,通过负载抗菌剂或抗菌性单体制备抗菌水凝胶是近年来药物控制释放、组织工程以及生物免疫等领域关注的热点。本文概述了负载抗菌剂型温敏性抗菌水凝胶的物理交联和化学交联制备技术的研究概况,着重阐述了温敏性抗菌水凝胶的孔径调控、制备材料调控、载药模式调控等技术的研究进展,并对温敏性抗菌水凝胶的控释技术应用前景,特别是在生物质材料领域的应用前景进行了展望。     

PVP-semi-IPN-PCL/PLA水凝胶制备及负载卡马西平药物共晶体外释放

通过N-乙烯基吡咯烷酮(N-vinyl pyrrolidone, NVP)在聚己内酯(polycaprolactone, PCL)、聚乳酸(poly(lactic acid),PLA)乙酸乙酯溶液中自由基聚合,制得聚乙烯吡咯烷酮(Polyvinylpyrrolidone, PVP)/聚己内酯、聚乳酸半互穿网络(semi-interpenetrating network, semi-IPN)水凝胶(PVP-semi-IPN-PCL/PLA)。实验制得疏水/亲水比例分别为1∶9、3∶7、5∶5的三种水凝胶。采用溶剂挥发法制备卡马西平-丁二酸药物共晶(carbamazepine-succinic acid, CBZ-SUC)。使用PVP-semi-IPN-PCL/PLA负载CBZ-SUC共晶,考察上述三种凝胶药物载体的载药能力及体外释放行为。使用1∶9、3∶7、5∶5比例凝胶制备了载药量分别为17%、19%、21%,包封率分别为71%、83%、89%的载药凝胶,其在37℃,pH=6.8 PBS溶液中体外释放效果均优于未使用凝胶载体的CBZ-SUC共晶。其中,3∶7组载药凝胶的累积释放量最高,...     

负载紫杉醇的聚乳酸纳米纤维对宫颈癌的抑制作用

从细胞水平和动物模型两个层次上研究了负载紫杉醇的聚乳酸纤维毡诱导U14宫颈癌细胞凋亡和抑制小鼠U14皮下移植瘤生长的能力.将U14细胞在纤维毡存在下孵育48 h,经Annexin V-FITC及PI双染后行流式细胞分析.结果表明,载药纤维(折合紫杉醇浓度40)g/mL)组总凋亡细胞比例(25.6%)明显高于对照组(1.0%)和未载药纤维组(1.5%).建立U14宫颈癌皮下移植瘤小鼠模型,将其随机分为3组.A组为对照组,不做任何处理.B、C组小鼠以纳米纤维毡覆盖于肿瘤表面,覆盖率约为70%～75%.其中B组纤维毡为纳米聚乳酸电纺丝纤维,不载药,C组为同种材料纤维毡,载有33 wt%紫杉醇.经处理后第7、14天每组各处死动物5～7只,剥离肿瘤,照相,称重,计算抑瘤率.结果表明,载药纤维对U14宫颈癌皮下移植瘤有明显抑制作用(48%～56%).用未载药聚乳酸纤维包裹肿瘤表面,肿瘤质量与对照组无显著差别,说明聚乳酸纤维本身对肿瘤没有抑制作用,载药纤维组所观察到的抑瘤效果为紫杉醇从纤维毡中释放所致.     

Camptothecin@HMSNs/thermosensitive hydrogel composite for applications in preventing local breast cancer recurrence

The CPT was loaded into the HMSNs with the high loading capacity. Then the CPT@HMSNs were loaded into the PLEL thermosensitive hydrogels for local therapy to prevent the recurrence of breast cancer after the tumor was resected.     

一种新型的可生物降解的热敏凝胶微粒的制备

聚合物水凝胶是由高分子组成的三维空间交联网络与水的混合体系,有望在药物控制释放等领域获得广泛应用,某些水凝胶还具有显著的环境响应性,构成了一类主流的智能材料,在生物医用材料领域,对于材料的可降解性有严格要求,而单一的可降解药物缓释载体材料和单一的智能型水凝胶材料已有较多报道,但能够将这两种特性结合在同一种材料中的报道则很少,其中智能响应范围合适、降解速率易于大范围调节的合成水凝胶则更少。     

Enhanced antitumor chemo-immunotherapy by local co-delivery of chemotherapeutics,immune checkpoint blocking antibody and IDO inhibitor using an injectable polypeptide hydrogel

The efficiency of antitumor immunotherapy is usually limited by the immunosuppressive tumor microenvironment (TME). In this study, we developed a chemo-immunotherapy strategy that is able to improve the immunosuppressive TME for enhancing the antitumor efficacy. The chemo-immunotherapy was achieved by the topical co-delivery of a chemotherapeutic drug, Doxorubicin (DOX), an immune checkpoint blocking antibody targeting programmed cell death protein 1 (aPD-1), and an indoleamine-2,3-dioxygenase (IDO) inhibitor, 1-methyl-d -tryptophan (d -1MT) by using a thermosensitive polypeptide hydrogel. It was revealed that the sustained DOX release from the hydrogel caused the immunogenic cell death (ICD) of B16F10 cells in vitro, and the tumor cell lysates subsequently promoted the activation of dendritic cells (DCs). After intratumoral injection into B16F10 melanoma-bearing mice, the DOX/aPD-1/D-1MT co-loaded hydrogel exhibited enhanced tumor inhibition efficacy and prolonged animal survival time, compared to the DOX/aPD-1/D-1MT mixed solution, DOX-loaded hydrogel or DOX/aPD-1 co-loaded hydrogel. The improvement of immunosuppressive TME and enhancement of antitumor immune response after the local chemo-immunotherapy were demonstrated by the augmented activation of DCs and increased infiltration of CD8⁺ and CD4⁺ T cells, as well as enhanced secretion of pro-inflammatory cytokines. Therefore, the hydrogel-based local chemo-immunotherapy system holds great potential for effective antitumor treatment.     

Optimization and physicochemical characterization of thermosensitive poloxamer gel containing puerarin for ophthalmic use

The purpose of this study was to systematically optimize an ophthalmic thermosensitive poloxamer analogs gel containing puerarin that was a free flowing liquid below the room temperature and could shift to a gel with an eligible gel strength and bioadhesive force in physiological condition (dilution by the simulated tear fluid and at 35.0 degrees C). A two-factor, five-level central composite design (CCD) was employed to the optimization procedure. The effect of formulation variables (the w/v concentration of poloxamer 407 (X1) and poloxamer 188 (X2)) on a number of response variables (the gelation temperature before (Y1) and after (Y2) the simulated tear fluid diluted, the difference between them (Y3)) was systemically investigated. A second order polynomial equation was fitted to the data. The resulting equation and response surface plots were used to predict the responses in the optimal region. Finally, 21.0% (w/v) poloxamer 407 and 5.0% (w/v) poloxamer188 were chosen as the optimal poloxamer gel matrix. The influence of the other ingredients on the physicochemical properties of the formulation was also investigated. Hydroxypropyl-beta-cyclodextrin (HPCD) enhanced the gelation temperature and reduced the gel strength and the bioadhesive force, while puerarin and benzalkonium chloride (BC) had a comparatively smaller influence. All the isotonicity agents studied had the gelation temperatures lowered, and the gel strengths and the bioadhesive forces enhanced. But only sodium chloride appears to be a promising isotonicity agent for the poloxamer gel containing puerarin, HPCD and BC.     

Injectable poloxamer/graphene oxide hydrogels with well‐controlled mechanical and rheological properties

Although significant progress has been made in the design and application of injectable hydrogels for biomedical applications, concurrent control of rheological and mechanical properties of injectable hydrogels has remained as an open challenge to the researchers. In this work, we introduce and put into practice a photo‐curable poloxamer (also known as Pluronic)/graphene oxide (Plu/GO) injectable hydrogel with well‐controlled rheological and mechanical properties. Acrylate group was anchored to hydrogel structure to endow photo‐crosslinking ability through decelerating degradation rate of poloxamer hydrogels after injection. It was found that the modified Plu remains stable in biological media for a long‐term period without significant weight loss. Rheological properties of hydrogels were also carried out as essential prerequisite for an ideal injectability via frequency sweep, flow curve, recovery, and yield stress before and after modification, signifying shear‐thinning behavior of Plu/GO hydrogels with high recoverability. The viscosity of shear‐thinning‐like hydrogels dropped at higher shear stress, which facilitated injection process. Moreover, mechanical behavior of Plu was optimized by manipulating the content of Plu, degree of modification with reactive precursor, curing, and particularly incorporation of GO without deteriorating effects on rheological behavior of Plu.     

Swelling Kinetics of Microgels Embedded in a Polyacrylamide Hydrogel Matrix

Composite hydrogels—macroscopic hydrogels with embedded microgel particles—are expected to respond to external stimuli quickly because microgels swell much faster than bulky gels. In this work, the kinetics of the pH‐induced swelling of a composite hydrogel are studied using turbidity measurements. The embedded microgel is a pH‐ and thermosensitive poly(N‐isopropylacrylamide‐co‐acrylic acid) microgel and the hydrogel matrix is polyacrylamide. A rapid pH‐induced swelling of the embedded microgel particles is observed, confirming that composite hydrogels respond faster than ordinary hydrogels. However, compared with the free microgels, the swelling of the embedded microgel is much slower. Diffusion of OH^? into the composite hydrogel film is identified as the main reason for the slow swelling of the embedded microgel particles, as the time of the pH‐induced swelling of this film is comparable to that of OH^? diffusion into the film. The composition of the hydrogel matrix does not significantly change the characteristic swelling time of the composite hydrogel film. However, the swelling pattern of the film changes with composition of the hydrogel matrix.     

Modeling the nonlinear large deformation kinetics of volume phase transition for the neutral thermosensitive hydrogels

By regarding the neutral thermosensitive hydrogel as a biphasic mixture media, an incompressible deformable porous solid skeleton, and an incompressible interstitial fluid phase saturating the interconnected space, a novel biphasic mixture theory for modeling the nonlinear large deformation kinetics of the volume phase transition was developed from the first law of thermodynamics and the continuum mixture theory. The governing equations consist of the saturated continuity equation, the momentum equations of the fluid, and the momentum equations of the bulk hydrogel. The explicit expressions of the constitutive relationships, which are capable of characterizing the nonlinear large deformation kinetics of the volume phase transition of the N-isopropylacrylamide thermosensitive hydrogels, were derived from the Helmholtz free energy formed by the elastic and mixing contributions. Both the governing equations and the constitutive relationships are in the Lagrangian framework, and special attention was paid to the deformable porous solid skeleton.     

A green chemistry approach towards synthesizing hydrogel for sustained ocular delivery of brinzolamide: In vitro and ex vivo evaluation

Brinzolamide is a carbonic anhydrase inhibitor used in the eye drop form for the treatment of glaucoma. It requires frequent dosing to attain therapeutic concentration. Therefore, this study aimed to prepare sustained ocular drug delivery of brinzolamide. The objective of the study was to prepare a hydrogel loaded with a nanostructured lipid carrier (NLC) of brinzolamide. The hydrogel was prepared by a green synthesis approach using genipin as a natural crosslinking agent and polymers such as carboxymethyl chitosan and poloxamer 407. The melt emulsification-ultra sonication method was used to prepare a nanostructured lipid carrier of brinzolamide, which was loaded into a hydrogel using a swelling and loading method. The NLC formulation has shown small particle sizes of 111.20 ?± ?2.15 ?nm, polydispersity index of 0.280 ?± ?0.005 and % entrapment efficiency of 82.16% ?± ?0.14%. The NLC-loaded hydrogels of brinzolamide formulations were studied for swelling properties and showed temperature and pH-responsive swelling behavior. The optimized hydrogel formulation has been studied for in vitro drug release and showed drug release for a longer duration (24 ?h) than marketed eye drops (8 ?h). In an ex vivo study, hydrogel formulations showed transcorneal permeability 4.54 times greater than marketed eye drops. The hydrogel formulation of brinzolamide produced by the green synthesis method has shown sustained-release properties with no sign of ocular irritation. Hence, the hydrogel of brinzolamide-loaded NLC would be the potential drug delivery approach in the near future for sustained ocular drug delivery in glaucoma management.     

载银离子PLGA-PEG-PLGA温度敏感水凝胶的制备及体外抗菌性能

利用聚乙二醇(PEG 1000)引发乙交酯和 D,L-丙交酯开环共聚合, 制备了聚丙交酯乙交酯(PLGA)三嵌段共聚物(PLGA-PEG-PLGA)温敏水凝胶材料; 利用核磁共振氢谱( ¹H NMR)确定了产物的结构及组成. 通过还原硝酸银的方法制备银纳米粒子(AgNPs), 并将其与PLGA-PEG-PLGA三嵌段共聚物水凝胶混合, 制得新型AgNPs/PLGA-PEG-PLGA复合水凝胶; 对该复合水凝胶的相关性能进行了表征. AgNPs/PLGA-PEG-PLGA复合水凝胶仍然具有温敏性能, 随着温度升高可发生溶胶-凝胶的相转变; 还可以持续释放银纳米粒子, 从而发挥抗菌性能. 体外细胞实验结果表明, AgNPs/PLGA-PEG-PLGA复合水凝胶具有良好的生物相容性, 未见明显细胞毒性, 是具有应用前景的新型复合水凝胶.