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排序方式: 共有896条查询结果,搜索用时 15 毫秒
1.
Core-Shell Arginine-Containing Chitosan Microparticles for Enhanced Transcorneal Permeation of Drugs
Nicolò Mauro Giulia Di Prima Paola Varvarà Mariano Licciardi Gennara Cavallaro Gaetano Giammona 《Journal of pharmaceutical sciences》2019,108(2):960-969
Chitosan oligosaccharide (C) was functionalized with l-arginine (A) and short hydrocarbon chains (C8) to design an amphiphilic copolymer, henceforth CAC8, leading to microparticles (MPs) consisting of an arginine-decorated hydrophilic shell and inner hydrophobic domains allowing the encapsulation of high amount hydrophobic drugs such as sorafenib tosylate (>10% w/w). l-arginine side chains were selected in order to impart the final MPs enhanced transcorneal penetration properties, thus overcoming the typical biological barriers which hamper the absorption of drugs upon topical ocular administration. The mucoadhesive properties and drug release profile of the CAC8 MPs (CAC8-MPs) were studied, showing that CAC8-MPs can strongly interact with mucin, and thus gradually release their payload in situ to potentially improve the bioavailability of the drug after topical administration. In vitro transcorneal studies also showed that CAC8-MPs are endowed with effective permeation enhancer ability combined with negligible toxicity. 相似文献
2.
Xin Shen Yuandou Wang Laishun Xi Feng Su Suming Li 《Saudi Pharmaceutical Journal》2019,27(7):1025-1035
Nanotubes were prepared by self-assembly of the copolymer using co-solvent evaporation method. The biocompatibility of the nanotubes was assessed in comparison with spherical micelles and filomicelles prepared from poly(ethylene glycol)-poly(L-lactide-co-glycolide) (PEG-PLGA) and poly(ethylene glycol)-poly(L-lactide) (PEG-PLA), respectively. Several aspects of biocompatibility of the aggregates were considered, including agar diffusion and MTT assay, release of cytokines, hemolysis, protein adsorption, dynamic clotting in vitro, and Zebrafish embryonic compatibility in vivo. The nanotubes present good cell compatibility and blood compatibility in vitro, and almost no toxicity towards Zebrafish embryos development in vivo. Furthermore, dual-loading of hydrophilic cisplatin and hydrophobic paclitaxel was achieved in the nanotubes with high loading content and loading efficiency. The release of both drugs was slower from dual-loaded nanotubes than from single-loaded ones, but the total amount of released drugs in higher for dual-loaded nanotubes than from single-loaded ones. Cellular uptake and inhibition tests showed that the nanotubes were successfully taken up by tumor cells and effectively inhibited cell growth. It is thus concluded that PEG-PLA-PEG nanotubes with outstanding biocompatibility could be promising for co-delivery of hydrophilic and hydrophobic agents in combination cancer therapy. 相似文献
3.
In this study, a novel poly (SMIm)-Tris-Fe3O4 nanocomposite was prepared for selective extraction of Cu+ and Cu2+ ions by ultrasound assisted-cloud point extraction (UA-CPE). The nanocomposite was characterized by analysis of ATR-FT-IR, 1H NMR and XRD. After optimization of the extraction conditions, the copper ions were independently detected against sample blank at 347 nm by micro-volume UV–vis spectrophotometer. Under the optimal conditions, good linear relationship was obtained in the ranges of 0.3−150 and 10−350 μg L−1 for each ion at pH 7.0 and pH 5.0, respectively, with a better regression coefficient than 0.992. The method detection limits, accuracy and precision were 0.095 and 3.03 μg L−1, 91.5−96.0 % and 93.0−98.5 %, and 2.5–4.5 and 3.8–7.1 % (n:5, 25 and 100 μg L−1) for Cu+ and Cu2+ ions, respectively. A preconcentration of 70-fold was obtained from 35-mL of sample. After validation, the method was successfully applied to determination of total Cu levels in lichen and mushroom samples after pre-reduction at pH 7.0, and the recoveries in the range of 90−96 % were obtained by two calibration approaches after spiking with 10 μg L−1. The results were also statistically compared with those obtained by FAAS analysis to ensure accuracy and precision. 相似文献
4.
通过缩聚反应制备聚乙二醇-柠檬酸共聚物(PEGCA),通过密炼制备了PEGCA与聚乳酸(PLA)的共混物,研究了PEGCA对共混物的形貌结构、热性能和力学性能的影响。结果表明,PEGCA与PLA部分相容,PEGCA呈球状颗粒分散在PLA基体中。PEGCA对PLA有良好的增韧效果,当PEGCA质量分数为15%时,材料的断裂伸长率提高到327.9%,冲击强度提高到63.0 J/m。同时利用空穴化理论解释PEGCA增韧PLA的机理,用临界韧带厚度理论和J积分定量描述增韧的效果。 相似文献
5.
《Journal of vascular and interventional radiology : JVIR》2020,31(6):986-992
PurposeTo assess the feasibility, safety, and efficacy of balloon-assisted delivery of ethylene vinyl alcohol copolymer (EVOH) for a range of peripheral arterial applications.Materials and MethodsSix academic medical centers entered retrospective data on 46 consecutive patients (27 men, 19 women; ages, 11–94 y; mean age, 50.3 y) who underwent 60 balloon-assisted EVOH procedures. The cohort was restricted to procedures involving peripheral, nonneural arteries 1–5.5 mm in diameter. Clinical indications included a wide range of vascular pathologic conditions (most commonly arteriovenous malformations [n = 20], renal angiomyolipomas [n = 8], and acute hemorrhage [n = 9]) and targeted visceral and musculoskeletal peripheral arteries. Data collected included sex, age, clinical indication, arterial pathology, arteries embolized, type of occlusion balloon microcatheter, type and concentration of EVOH agent, effectiveness as an embolic backstop, vessels protected, adequacy of EVOH cast penetration, catheter extraction, nontarget embolization, and complications.ResultsBalloon occlusion prevented EVOH reflux in 59 of 60 procedures (98.3%). Nontarget EVOH embolization occurred in 2 procedures (3.3%). Adequate EVOH cast penetration and complete filling of the target pathologic structure were seen in 57 of 60 procedures (95%). Balloon deflation and uneventful extraction occurred in all procedures; small EVOH fragments detached into target arteries in 2 cases. One major (1.7%) and 2 minor (3.3%) complications occurred.ConclusionsBalloon-assisted EVOH embolization of peripheral arteries is feasible, safe, effective, and versatile. The primary advantage of balloon-assisted EVOH embolization is the ability to apply more injection pressure to advance the EVOH cast assertively into the pathologic structure(s). 相似文献
6.
本文制备了人工外泌体,共传递蛋白和核酸,实现多组分药物高效安全共传递。采用阳离子脂质赋形剂二油酰基三甲基铵丙烷(dioleyl trimethylammonium propane, DOTAP)修饰聚乳酸-羟基乙酸共聚物(polylactic acidglycolic acid copolymer, PLGA)基质来设计优化的制剂,双乳化法制备包裹蛋白和核酸的PLGA/DOTAP纳米粒,再用逆相蒸发法制备最外层的膜结构,此膜结构由二棕榈酰磷脂酰胆碱(1, 2-dipalmitoyl-sn-glycero-3-phosphocholine,DPPC)、二油酰磷脂酰胆碱(1,2-dioleoyl-sn-glycero-3-phosphocholine, DOPC)、二硬脂酰磷脂酰胆碱(1,2-distearoylsn-glycero-3-phosphocholine, DSPC)、胆固醇及膜蛋白组成,通过超声分散和挤出的方式形成人工外泌体结构,并分析其物理特性和传递效果性质。结果表明,人工外泌体粒径约为156.13 nm,带负电荷(-18.23±0.57 mV),能高效共传递蛋白和siRNA,且siRNA能高效抑制目标基因Trim 28的表达。这说明人工外泌体模拟了外泌体结构,实现了多组分药物安全高效的共递送。 相似文献
7.
目的 采用HPLC测定卡波姆共聚物中残留的丙烯酸含量。方法 使用Sepax GP-C18柱(4.6 mm×250 mm,5 μm)分离,流动相为磷酸二氢钾-甲醇(8∶2),流速为1.0 mL·min-1,检测波长200 nm,柱温为30 ℃。结果 卡波姆共聚物中的残留丙烯酸可达到满意的分离,丙烯酸浓度在0.327 5~32.75 μg·mL-1内有良好的线性关系(r=0.999 6),方法平均回收率为93.02%。结论 本方法准确,可靠,重现性好,可作为卡波姆共聚物中丙烯酸残留的控制方法。 相似文献
8.
《Biomaterials》2015
The aim of this paper is to present a method to produce macroporous thin membranes made of poly (ethyl acrylate-co-hydroxyethyl acrylate) copolymer network with varying cross-linking density for cell transplantation and prosthesis fabrication. The manufacture process is based on template techniques and anisotropic pore collapse. Pore collapse was produced by swelling the membrane in acetone and subsequently drying and changing the solvent by water to produce 100 microns thick porous membranes. These very thin membranes are porous enough to hold cells to be transplanted to the organism or to be colonized by ingrowth from neighboring tissues in the organism, and they present sufficient tearing stress to be sutured with surgical thread. The obtained pore morphology was observed by Scanning Electron Microscope, and confocal laser microscopy. Mechanical properties were characterized by stress–strain experiments in tension and tearing strength measurements. Morphology and mechanical properties were related to the different initial thickness of the scaffold and the cross-linking density of the polymer network. Seeding efficiency and proliferation of mesenchymal stem cells inside the pore structure were determined at 2 h, 1, 7, 14 and 21 days from seeding. 相似文献
9.
Nagendra Kalva Vinod K. Aswal Ashootosh V. Ambade 《Macromolecular chemistry and physics.》2014,215(15):1456-1465
Hydrophobic dendrons based on different branching patterns, viz. 3,5‐di‐ and 3,4,5‐trisubstituted phenyl rings, consist of the same backbone but exhibit different sizes, shapes, and hydrophobic densities. These dendrons are attached to poly(ethylene glycol) and the core properties of the copolymer micelles are investigated in tetrahydrofuran (THF)/water mixtures by neutron scattering. Two polymers with intermediate hydrophobicity are studied further with variations in the solvent composition and the temperature. The aggregation numbers for 3,4,5‐based dendron copolymers are lower, with more THF molecules of solvation compared with the 3,5‐based dendron copolymer, the difference being greater at higher generations due to different molecular shapes. The micellar core size increases in small steps with dendron size so that dye encapsulation is tuned.
10.
Currently an effective strategy in nanomedicine for cancer therapy is the combination of photothermal therapy with chemotherapy. Because combination cancer therapy improve the therapy efficiency by synergistic effects and overcoming drug resistance as compared to monotherapy possesses. According to these facts, gold nanorods-cored biodegradable micelles were prepared by coating gold nanorods (AuNRs) with synthesized pH-sensitive thiol-ended amphiphilic triblock copolymer (PAA-b-PDMAEMAQ-b-PCL-SH). The synthesized AuNRs@polymer was loaded with methotrexate (MTX) as an anticancer drug through electrostatic interactions to afford AuNRs@polymer-MTX. The success of the coating was investigated by means of atomic force microscopy (AFM), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible (UV-vis) spectroscopy, as well as dynamic light scattering (DLS), and zeta potential measurements. MTX-loading capacity, and pH triggered in vitro drug release behavior of the synthesized nanocomposites were also investigated. In vitro cytotoxic effects was comprehensively evaluated among free MTX, AuNRs@polymer, and AuNRs@polymer–MTX, with or without NIR light irradiation (1064?nm, 125?mJ/pulse, and 4?min) to improve curative effect of AuNRs@polymer–MTX led by the combination of photothermal therapy and chemotherapy. 相似文献