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21.
Functionalized graphene oxide-modified poly(ε-caprolactone) composites ((graphene oxide)GO/PCL) were successfully synthesized by Steglich esterification for drug applications of controlled release. Lomefloxacin (LMF) was selected as a model drug to investigate its controlled release properties. The controlled release effect of the LMF-contained pills of the GO/PCL and polylactic acid blend was evaluated. In contrast to the pure PCL, GO/PCL could effectively adjust the time of drug release and release the drug at a constant rate, achieving the controlled release requirements. Furthermore, different additive amounts of graphene oxide have different effects on adjusting the time of controlled release, while the best result obtained under the ratio is 4% GO/PCL as carrier of drug. Thus, high-quality drug carrier materials are obtained which are more suitable for clinical use. Exploring the optimum addition of graphene oxide is very significant for the development of GO/PCL carrier material. 相似文献
22.
本文是在地质灾害监测预警项目的实践基础上,结合移动运营商对手机信令数据的侦测应用,提出了基于手机信令数据的地质灾害预警发布的解决方案。该方案可实现地质灾害隐患点威胁区域的人员实时统计、预警信息发布、预警效果判断等功能,弥补了现有基于短信和大喇叭预警发布解决方案的不足。它能有效降低地质灾害发生时造成的人员伤亡,并且适用于我国所有的地质灾害影响区域。 相似文献
23.
In order to improve the utilization rate of avermectin (AVM), a complex was prepared by electrostatic self-assembly using isolated soy protein (ISP) and carboxymethyl chitosan (CMCS) for loading AVM to obtain ISP/CMCS@AVM microspheres. The encapsulation efficiency (EE), sustained release property, ultraviolet (UV) protective ability, and toxicity of the microspheres were evaluated, and the release kinetics of AVM from the microsphere at different pHs were investigated. The results demonstrated that the average particle size of ISP/CMCS@AVM was 283.95 nm, and the EE reached 88.42% for AVM after denaturation. After 70 h of exposure to UV light, the residual rate of AVM in ISP/CMCS@AVM was 78.12%, which was significantly higher than 35.18% in the AVM emulsion. Moreover, the formulation imparted pH sensitivity and sustained-release property to AVM and was consistent with the Korsmeyer–Peppas model, controlled by Fick diffusion. Finally, the insecticidal toxicity of ISP/CMCS@AVM did not differ significantly from that of unmodified AVM. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48358. 相似文献
24.
Elahe Sharifisamani Fatemeh Mousazadegan Roohollah Bagherzadeh Masoud Latifi 《Polymer Engineering and Science》2020,60(7):1520-1529
This work presents an interesting method using an electrospinning process to fabricate suture yarns loaded with curcumin to achieve reasonable mechanical properties as well as tunable drug release behavior. Different structures including different yarn counts and twists as well as core-sheath structures were used to adjust drug release properties along with improving the yarn's mechanical properties. The core parts were made of polycaprolactone and the sheath parts were made of polyethylene glycol, polylactic acid, and polycaprolactone. Drugs can be incorporated in both parts based on the required condition and application. Electrospun yarns were compared using both structural properties and their drug release profiles as metrics. The results of comparing drug release profiles of six electrospun yarns with different yarn counts and twists showed that yarns with finer fiber diameters in the core part have more drug release as well as more initial release. Overall evaluations showed that core-sheath drugloaded yarn with appropriate physical and mechanical properties can be a useful material as a drug delivery system to the site of damaged tissue. It can also be concluded that the amount and duration of drug release can be controlled using the structural parameters of electrospun yarns as an engineering tool for designing suture yarns with required properties. 相似文献
25.
Temperature-sensitive hydrogels are attracting increasing attention for controlled drug delivery. However, achieving high drug loadings and sustained drug release remains challenging. Herein, we describe the successful synthesis of a series of novel temperature-sensitive poly(N-isopropylacrylamide) (PNIPA)/mesoporous silica nanoparticles (MSN) hydrogels by physical crosslinking of NIPA with MSN. The external and internal structures, temperature sensitivity, drug-loading capacity, and blood compatibility of the PNIPA/MSN composite hydrogels are studied. Results show that MSN addition improved the network structure and adjusted the size of the hole, MSN could also act as drug carrier, thereby enhancing the drug loading capacity. The composite hydrogels underwent a phase transition at 33.7 °C (at the lower critical solution temperature). The hemolysis rate of the composite hydrogels was less than 1%, thus they can be classified as a nonhemolytic materials with good biocompatibility. The composite hydrogels reported here thus have great potential in drug transport and temperature-activated drug release. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48391. 相似文献
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27.
This work describes the functionalization of a natural and a man-made textile substrate, namely cotton and polyamide 6.6, with inclusion agents, β-cyclodextrins (β-CDs) that are able to release gradually to the user active ingredients. In this study we used aescin (aesculus hippocastanum extract), which is a natural agent with benefits for the treatment of varicose veins.1H NMR and UV–vis data supported the role of β-CDs as an aescin complexing agent, and the covalent nature of the linkage between β-cyclodextrins and the textile substrates, which showed a wash fastness to more than 45 washing cycles. 相似文献
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29.
Sandeep Kumar Singh Venkatesh Teja Banala Girish K. Gupta Ashwni Verma Rahul Shukla Vivek K. Pawar 《Drug development and industrial pharmacy》2015,41(11):1759-1768
The aim of this study was to fabricate docetaxel loaded nanocapsules (DTX-NCs) with a high payload using Layer-by-Layer (LbL) technique by successive coating with alternate layers of oppositely charged polyelectrolytes. Developed nanocapsules (NCs) were characterized in terms of morphology, particle size distribution, zeta potential (ζ-potential), entrapment efficiency and in vitro release. The morphological characteristics of the NCs were assessed using transmission electron microscopy (TEM) that revealed coating of polyelectrolytes around the surface of particles. The developed NCs successfully attained a submicron particle size while the ζ-potential of optimized NCs alternated between (+) 34.64?±?1.5 mV to (?) 33.25?±?2.1 mV with each coating step. The non-hemolytic potential of the NCs indicated the suitability of the developed formulation for intravenous administration. A comparative study indicated that the cytotoxicity of positively charged NCs (F4) was significant higher (p?0.05) rather than negative charged NCs (F3), plain drug (DTX) and marketed preparation (Taxotere®) when evaluated in vitro on MCF-7 cells. Furthermore, cell uptake studies evidenced a higher uptake of positive NCs (≥1.2 fold) in comparison to negative NCs. In conclusion, formulated NCs are an ideal vehicle for passive targeting of drugs to tumor cells that may result in improved efficacy and reduced toxicity of encapsulated drug moiety. 相似文献
30.
Control of self-assembling systems at the micro- and nano-scale provides new opportunities for the engineering of novel materials in a bottom-up fashion. These systems have several challenges associated with control including high-dimensional and stochastic nonlinear dynamics, limited sensors for real-time measurements, limited actuation for control, and kinetic trapping of the system in undesirable configurations. Three main strategies for addressing these challenges are described, which include particle design (active self-assembly), open-loop control, and closed-loop (feedback) control. The strategies are illustrated using a variety of examples such as the design of patchy and Janus particles, the toggling of magnetic fields to induce the crystallization of paramagnetic colloids, and high-throughput crystallization of organic compounds in nanoliter droplets. An outlook of the future research directions and the necessary technological advancements for control of micro- and nano-scale self-assembly is provided. 相似文献