负载活性组分的核壳结构纤维膜的制备及性能

采用同轴静电纺丝技术制备了用于伤口修复的核壳结构纳米纤维膜,将蛛丝蛋白(Ss)和美洲大蠊提取物(PAE)分别负载于纳米纤维的壳层与核层.采用SEM和TEM对纳米纤维膜的形貌进行了表征,结果显示,纤维具有明显的核壳结构,且随着Ss含量的增加,纤维直径从350 nm降至280 nm,核层直径由120 nm升至140 nm,壳层厚度由115 nm降至70 nm;FTIR结果证明Ss已成功负载到纤维膜中.纤维膜的物理性能测定实验表明,制备的纳米纤维膜拉伸强度可达4.3 MPa,溶胀率可达150％,水蒸气透过率可达1834 g/(m2·24 h),水接触角减小到32.7°.药物释放实验结果显示,7 d内药物释放可达77％;考察了纳米纤维膜的生物相容性,相较于未负载Ss的纳米纤维膜,Ss含量为20％的纤维膜的细胞增殖率提高了25％.     

基于静电纺丝技术的PLGA载药纳米纤维膜的制备工艺

同轴静电纺丝法制备的聚乳酸-乙醇酸(PLGA)纳米纤维具有良好的生物相容性和生物可降解性, 加之其高孔隙率和高透氧率, 使其能成为优良的药物载体。本文初步摸索了PLGA的同轴静电纺丝的工艺条件, 并通过同轴静电纺丝法制备了PLGA载氟比洛芬酯(FA)的纳米纤维膜, 应用扫描电子显微镜、红外光谱分析观察纤维的表观形貌并确定其微观结构。重点探究了不同溶剂配比的混合溶剂对载药纤维膜药物释放性能影响。研究结果表明在U⁺为+15.00kV, U^-为-2.50kV, 接受距离为15cm, 壳层推进速度为0.4mm/min, 芯层推进速度为0.1mm/min进行静电纺丝时, 所制备的PLGA(壳)/PVP+FA(核)复合载药纤维膜壳核结构良好, 且成功载了约0.5%的FA。当改变壳层混合溶剂(DCM和DMF)和芯层混合溶剂(无水乙醇和DMF)体积比时, 纤维直径会随着DMF的减少而增大。     

载木犀草素纳米纤维膜的制备与性能

采用2种pH敏感材料(Eudragit S100和Eudragit RS100),通过同轴静电纺丝技术制备了壳/核结构载木犀草素纳米纤维膜,通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)、傅里叶变换红外光谱仪(FTIR)、X射线衍射仪(XRD)等研究了壳/核结构载木犀草素纳米纤维膜的表面形貌、化学结构和药物释放性能。结果表明：壳/核结构载木犀草素纳米纤维膜表面整体较光滑,纳米纤维平均直径随木犀草素含量增加而增大。该纳米纤维膜具有良好的结肠靶向性和生物相容性。     

溶液参数对静电纺丝PAN@PS复合纳米纤维形貌及结构的影响

采用同轴静电纺丝技术,以聚丙烯腈(PAN)溶液为核层、聚苯乙烯(PS)溶液为壳层,制备了PAN@PS复合纳米纤维。研究了纺丝液浓度、溶剂种类对PAN@PS复合纳米纤维形貌和结构的影响。结果表明:PS/四氢呋喃(THF)作为壳层溶液的复合纳米纤维(PAN@PS/THF)可获得相界面清晰的同轴纤维。随PS纺丝液浓度的增加,纤维的直径先增大后有所减小,整体呈现递增的趋势,当PS/THF质量分数为20%时,纤维直径约为693 nm且表面光滑。而以质量分数为20%的PS/二甲基甲酰胺(DMF)为壳层溶液的复合纳米纤维(PAN@PS/DMF)直径有所增加且纤维表面凹凸不平,呈现双相连续的结构。因此,在静电纺丝过程中,可以通过改变纺丝液的参数来调节纤维的形貌和结构。     

胶原蛋白肽/壳寡糖复合纳米纤维的螺旋电纺制备及结构性质分析

采用螺旋式静电纺丝机,配制不同质量比例和质量分数的胶原蛋白肽/壳寡糖的水溶液,在一定的工艺条件下,进行胶原蛋白肽与壳寡糖的无针电纺。通过扫描电镜来测定纳米纤维的形貌和直径,采用红外光谱测定纳米纤维的微细结构,利用质构仪来对纤维膜的力学性能进行分析。结果表明:随着胶原蛋白肽质量配比从100%减小到70%,纳米纤维的平均直径从687nm降低到525nm;随着整体质量分数从14%增加到23%,复合纳米纤维的平均直径从306nm增加到719nm;胶原蛋白肽与壳寡糖共混,存在着较强的分子间氢键,导致其基团的特征峰都出现不同程度的红移;纳米纤维膜的拉伸强度随着胶原蛋白肽质量配比的减少而减小,随着整体质量分数的增加而增加,其中质量分数相比质量配比为主要影响因素。     

静电纺玉米醇溶蛋白纳米纤维及其药物缓释行为

利用静电纺丝法制备了玉米醇溶蛋白(Zein)、Zein/乙二醛交联纳米纤维,分别制得了负载不同质量药物的载药纳米纤维膜,并对纤维膜形态与结构进行了表征,研究了药物缓释行为。利用扫描电镜(SEM)对交联前后与负载药物后纳米纤维的形貌和直径分布进行了分析;强力测试结果表明,乙二醛交联后的Zein纳米纤维强度提高了近10倍;傅里叶变换红外光谱(FTIR)研究了Zein、乙二醛与药物之间的分子间作用力;紫外可见光(UV-Vis)光谱分析表明,乙二醛交联Zein载药纤维累积释放率比未交联的高且有一定的缓释效果。     

纤维素纳米纤维负载氧化亚铜的制备及性能研究

以木醋杆菌为菌种,在30℃下静态培养得到纤维素纳米纤维构建的网状薄膜,浸泡在硫酸铜溶液后,经葡萄糖还原产生的氧化亚铜跟纤维素纳米纤维紧密结合,制得纤维素纳米纤维负载氧化亚铜;分析了氧化亚铜和纤维素纳米纤维的微观结构、纤维素纳米纤维负载氧化亚铜的含量以及纤维素纳米纤维负载氧化亚铜对亚甲基蓝的降解效果。结果表明:纤维素纳米纤维直径为40~80nm,在70℃下,葡萄糖还原硫酸铜只产生氧化亚铜,没有其他杂质;在太阳光照射120 min后,纤维素纳米纤维负载氧化亚铜和氧化亚铜粉末对亚甲基蓝的降解率分别达到85%和76%。     

新型核壳纤维增韧聚丙烯的研究

采用同轴静电纺丝技术制备聚碳酸酯为壳层,三元乙丙橡胶为核层的直径为300～600 nm的同轴纤维.将不同份数的核壳纤维与聚丙烯经过单螺杆混合,注塑后得到PP/核壳纤维复合材料.研究发现,核壳纤维用量在3份以下时,其在PP基体中的分散均匀,界面良好;核壳纤维的加入使PP的结晶速率提高,β晶含量先增大后减少;核壳纤维的用量为3份时,冲击性能较纯PP相比提高了22.17%.     

溶液喷射纺丝制备PMIA/MWNTs纳米纤维的研究（英文）

采用溶液喷射纺丝技术制备间位芳纶/多壁碳纳米管(PMIA/MWNTs)纳米纤维,探讨了不同工艺参数下纳米纤维表观形貌和直径分布的变化,研究了MWNTs对PMIA纳米纤维膜结晶性能和力学性能的影响。结果表明:在拉伸风压为0.12 MPa、喷丝孔内径为0.4~0.5 mm时,可以制得形貌较好的PMIA/MWNTs纳米纤维;随MWNTs负载量的增加,制得纳米纤维的平均直径变粗,结晶度变大,纤维膜拉伸强度增大,断裂伸长率则下降;MWNTs的最佳负载量为0.3%,此时可制得形貌结构均匀,直径较细的PMIA/MWNTs纳米纤维,纤维平均直径为372 nm,纤维膜拉伸强度达到41.85 MPa,较纯PMIA纳米纤维膜提高了86%以上。     

生物高分子明胶纳米纤维膜的制备及其应用

利用电纺丝技术制备了明胶纳米纤维,系统考察了溶液浓度、电场强度、纺丝距离、喷丝口内径4种因素对纤维膜的形貌以及平均直径的影响;在此基础上,制备了具有较好力学性能的明胶-聚乙烯醇/溶菌酶复合纳米纤维膜,考察了其药物释放性能.结果表明,在上述几种工艺因素中,明胶的浓度对明胶纳米纤维的可纺性以及直径影响较大,当溶液浓度在7%-23%之间能获得连续纤维,并随着浓度的增大,纤维直径也随之增大.纺丝距离10cm、纺丝电压12.5kV是实验中获得连续纤维的临界工艺条件.药物释放结果发现明胶-聚乙烯醇复合纳米纤维膜对溶菌酶的释放具有一定的缓释效果.     

Fabrication of Core/Shell Nanofibers with Desirable Mechanical and Antibacterial Properties by Pickering Emulsion Electrospinning

To endow nanofibers with the desirable antibacterial and mechanical properties, a facile strategy using Pickering emulsion (PE) electrospinning is proposed to prepare functional nanofibers with core/shell structure for the first time. The water‐in‐oil (W/O) Pickering emulsion stabilized by oleic acid (OA)‐coated magnetite iron oxide nanoparticles (OA‐MIONs) is comprised of aqueous vancomycin hydrochloride (Van) solution and poly(lactic acid) (PLA) solution. The core/shell structure of the electrospun Van/OA‐MIONs‐PLA nanofibers is confirmed by scanning electron microscopy and transmission electron microscopy observation. Sustained release of Van from the PE electrospun nanofiber membrane is achieved within the time of 600 h. Compared with the neat PLA electrospun nanofiber membrane, 57% increase of tensile strength and 36% elevation of elongation at break are achieved on PE electrospun nanofiber membrane. In addition, the PE electrospun nanofiber membrane demonstrates excellent antibacterial property stemming from the combinational antibacterial activities of OA‐MIONs and Van. The Van‐loaded PE electrospinning nanofibers with sustained antibacterial performance possess potential applications in tissue engineering and drug delivery.

     

Core–shell hexadecane‐polyurethane nanofiber/net structured membrane: Evaluation of surfactant addition on morphology and performance

Coelectrospinning/netting or fabrication of well‐controlled nanofibers/net (NFN) within core–shell hexadecane (HD)–polyurethane (PU) nanofiber membranes is an effective strategy to improve nanostructure morphology, mechanical properties, and performance characteristics. Three types of surfactants were separately added to PU solutions in order to make controlled NFN layers within membrane structures. The experimental results indicated that the NFN layers composed of core–shell nanowires with a diameter of 20–40 nm increased significantly when a cationic surfactant was added. Also, the results confirmed that the NFN structure caused a significant increase in strength and a noticeable decrease in elongation of the membranes. The performance characteristics of the membranes, such as water vapor transmission rate and hydrostatic pressure, were not affected significantly by the addition of the cationic surfactant. The results confirmed that the mechanical properties and morphology of the core–shell HD‐PU nanofiber membranes could be controlled and tuned by the amount and type of surfactant. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45047.     

紫杉醇两亲性共聚物纳米胶束体外释药动力学

采用低分子量PEG-PCL-PEG、mPEG-PLLA、mPEG-PDLLA等两亲性嵌段共聚物作载体包载紫杉醇形成纳米胶束.研究了不同载药率胶束在磷酸缓冲液中释放的动力学,发现紫杉醇PEG-PCL-PEG胶束和mPEG-PLLA胶束的体外释药遵从一级释放动力学;紫杉醇mPEG-PDLLA纳米胶束的体外释放多呈现出两段零级释放动力学;低载药率胶束表现出高释药率;体外释药过程中磷酸缓冲液的更新量越大,紫杉醇的释放率越高.     

Core–shell biopolymer microspheres for sustained drug release

In this work, a core–shell biopolymer microsphere comprising a carvedilol‐loaded yeast cell wall polysaccharides core surrounded by a silk fibroin shell layer is developed to eliminate the risks of using synthetic polymers for drug encapsulation on human health and to avoid burst release and to prolong the release time. Transmission electron microscopy, Fourier‐transform infrared, confocal laser scanning microscope, and phase contrast microscopy analysis indicate that yeast treated with Tris–HCl containing cetyltrimethylammonium bromide, EDTA, and NaCl could provide much larger space for host drug as compared to plasmolyzed cells because the former can help maintain the original shape of yeast cells. In addition, its permeability barrier is significantly altered and nucleus becomes pyknotic. In contrast, plasmolyzed cells can hardly maintain the rigidity and integrity of their cell walls and will finally end up with cell fragments. SEM observation reveals that the carvedilol‐loaded cells maintain very similar shape and size before and after coating with 0.1% silk fibroin. In vitro release studies show that a drug delivery system using the carvedilol‐loaded cells can achieve a sustained drug release up to 20 days probably due to the electrostatic interaction between the positively charged carvedilol and the negatively charged yeast cells at the pH 7.4 and to the stability of the yeast cell helped by silk fibroin that provides an effective diffusion barrier. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41782.     

Encapsulation of docetaxel in oily core polyester nanocapsules intended for breast cancer therapy

ABSTRACT: This study is designed to test the hypothesis that docetaxel [Doc] containing oily core nanocapsules [NCs] could be successfully prepared with a high percentage encapsulation efficiency [EE%] and high drug loading. The oily core NCs were generated according to the emulsion solvent diffusion method using neutral Labrafac CC and poly(d, l-lactide) [PLA] as oily core and shell, respectively. The engineered NCs were characterized for particle mean diameter, zeta potential, EE%, drug release kinetics, morphology, crystallinity, and cytotoxicity on the SUM 225 breast cancer cell line by dynamic light scattering, high performance liquid chromatography, electron microscopies, powder X-ray diffraction, and lactate dehydrogenase bioassay. Typically, the formation of Doc-loaded, oily core, polyester-based NCs was evidenced by spherical nanometric particles (115 to 582 nm) with a low polydispersity index (< 0.05), high EE% (65% to 93%), high drug loading (up to 68.3%), and a smooth surface. Powder X-ray diffraction analysis revealed that Doc was not present in a crystalline state because it was dissolved within the NCs' oily core and the PLA shell. The drug/polymer interaction has been indeed thermodynamically explained using the Flory-Huggins interaction parameters. Doc release kinetic data over 144 h fitted very well with the Higuchi model (R2 > 0.93), indicating that drug release occurred mainly by controlled diffusion. At the highest drug concentration (5 μM), the Doc-loaded oily core NCs (as a reservoir nanosystem) enhanced the native drug cytotoxicity. These data suggest that the oily core NCs are promising templates for controlled delivery of poorly water soluble chemotherapeutic agents, such as Doc.     

Influence of structure on release profile of acyclovir loaded polyurethane nanofibers: Monolithic and core/shell structures

In this study, monolithic and core/shell polyurethane (PU) nanofibers were fabricated by single and coaxial electrospinning techniques, respectively. An antivirus drug, Acyclovir (ACY), was loaded on PU nanofibers. The physical condition and interaction of the loaded ACY within these nanofibers were studied by FTIR, XRD, DSC, SEM, and TEM. In vitro tests exhibited an obvious difference in the release pattern between monolithic and core/shell nanofibers and burst release in monolithic nanofibers could be controlled by core/shell structure. Release profile was found to follow Korsmeyere‐Peppas model with Fickian diffusion mechanism. Our study demonstrated that the ACY‐loaded core/shell nanofibers might serve as a device for drug delivery systems. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44073.     

Electrospun biocompatible poly (ε-caprolactonediol)-based polyurethane core/shell nanofibrous scaffold for controlled release of temozolomide

The electrospun biocompatible poly (ε-caprolactonediol)-based polyurethane (PCL-Diol-b-PU) core/shell nanofibrous scaffolds were prepared via the coaxial electrospinning process. Temozolomide (TMZ) as an anticancer drug was loaded into the core of fibers to control the release of TMZ for the treatment of glioblastoma. The properties of nanofibers were characterized using XRD, FTIR, SEM, and TEM analysis. The sustained delivery of TMZ without initial burst release was achieved from all prepared core–shell nanofibrous samples over 30 days. The cytotoxicity results revealed that the TMZ-loaded PCL-Diol-b-PU core–shell nanofibers could be used as a drug delivery implant to deliver TMZ against glioblastoma tumors.     

Preparation of new dendrimer‐like star‐shaped amphiphilic poly(ethylene glycol)–poly(ϵ‐caprolactone) copolymers for biocompatible and high‐efficiency curcumin delivery

Novel amphiphilic star‐shaped terpolymers comprised of hydrophobic poly(?‐caprolactone), pH‐sensitive polyaminoester block and hydrophilic poly(ethylene glycol) (M_n = 1100, 2000 g mol^?1) were synthesized using symmetric pentaerythritol as the core initiator for ring‐opening polymerization (ROP) reaction of ?‐caprolactone functionalized with amino ester dendrimer structure at all chain ends. Subsequently, a second ROP reaction was performed by means of four‐arm star‐shaped poly(?‐caprolactone) macromer with eight ‐OH end groups as the macro‐initiator followed by the attachment of a poly(ethylene glycol) block at the end of each chain via a macromolecular coupling reaction. The molecular structures were verified using Fourier transform infrared and ¹H NMR spectroscopies and gel permeation chromatography. The terpolymers easily formed core–shell structural nanoparticles as micelles in aqueous solution which enhanced drug solubility. The hydrodynamic diameter of these agglomerates was found to be 91–104 nm, as measured using dynamic light scattering. The hydrophobic anticancer drug curcumin was loaded effectively into the polymeric micelles. The drug‐loaded nanoparticles were characterized for drug loading content, encapsulation efficiency, drug–polymer interaction and in vitro drug release profiles. Drug release studies showed an initial burst followed by a sustained release of the entrapped drug over a period of 7days at pH = 7.4 and 5.5. The release behaviours from the obtained drug‐loaded nanoparticles indicated that the rate of drug release could be effectively controlled by pH value. Altogether, these results demonstrate that the designed nanoparticles have great potential as hydrophobic drug delivery carriers for cancer therapy. © 2015 Society of Chemical Industry     

亲水改性聚氨酯纳米纤维酶膜催化油水两相体系转糖苷反应

利用静电纺丝法制备含LiCl的聚氨酯(PU)纳米纤维,用牛血清白蛋白(BSA)对纤维亲水改性,于其上固定b-D-半乳糖苷酶,提高酶在油水两相介质中催化转糖苷反应的活力. 结果表明,以PU浓度26%(w)的电纺液制备的直径240~300 nm的PU纤维膜在LiCl辅助作用下吸附BSA高达222 mg/g,使纤维膜的水接触角由103.7o降至77.3o. 改性PU膜固定化酶比活力为1.59 U/mg,而未改性PU膜仅为其79.2%. 改性膜固定化酶55℃下的活力半衰期高达游离酶的14倍,在4℃下储存45 d活力仍保持80%,而游离酶活力仅剩余16.3%;改性膜固定化酶重复催化42次转糖苷反应活力仍能保持31%.     

Magnetic nanobeads decorated by thermo-responsive PNIPAM shell as medical platforms for the efficient delivery of doxorubicin to tumour cells

Medical nanoplatforms based on clusters of superparamagnetic nanoparticles decorated with a PNIPAM thermo-responsive shell have been synthesized and used as drug carriers for doxorubicin (DOXO), a common chemotherapeutic agent. The nanosystem here developed has a total diameter below 200 nm and exploits the temperature responsive behaviour of the PNIPAM polymeric shell for the controlled loading and release of DOXO. The system has been tested in vitro on tumour cells and it clearly demonstrates the effectiveness of drug polymer encapsulation and time-dependent cell death induced by the doxorubicin release. Comparative cellular studies of the DOXO loaded nanoplatform in the presence or absence of an external magnet (0.3 T) showed the synergic effect of accumulation and enhanced toxicity of the system, when magnetically guided, resulting in the enhanced efficacy of the system.