查找使用阿拉丁产品的科研文献

A one-step surface modification technique improved the nutrient release characteristics of controlled-release fertilizers and reduced the use of coating materials

Hongyu Tian,Lina Zhang,Jingjing Dong,Liang Wu,Fuli Fang,Yanfeng Wang,Hao Li,Chenshuo Xie,Wenjing Li,Zhanbo Wei,Zhiguang Liu,Min Zhang

Controlled-release fertilizers (CRFs) are a valid solution to agriculture's nonpoint source pollution problem. Due to surface structural defects in the fertilizer core, however, a large amount of coating material was wasted. A simple, fertilizer surface modification technique (SMT) that is based on abrasives was created in this study to modify the micro/nanostructure of the core surface, thereby considerably minimizing the amount of coating material and ensuring precise and long-term nutrient release. The effects of the SMT on the surface structure, roughness, and roundness of fertilizer cores were investigated, and a finite, element-based, interface polishing removal kinetic model and a discrete element, simulation-based, two-phase, fluid dynamics model were developed. The effect of core surface structural defects on the coating formation of CRFs and the controlled-release behavior of nutrients was observed at the micro- and nanoscale . The SMT improved the formed weak interfacial layer structure by urea crystals adsorbing water vapor, by reducing surface roughness by 64.43%, by improving overall particle fluidity, by increasing the proportion of urea with high roundness (0.950–0.975) by 8.72%, and by lessening the surface area of a single particle by 2.18%. At high temperatures, the surface was softened and deformed, allowing for the reconstruction of the surface microstructure and for a considerable improvement in interfacial bonding performance. The CRF nutrient release characteristics showed that the SMT enhanced the tightness and consistency of the coating, improved the precision of nutrient release, and reduced the use of coating material by up to 28.6% during the same release period. This novel technology has the potential to significantly optimize the production of CRF by reducing coating materials and residues in soil generated after nutrient release.

Millettia speciosa Champ cellulose-based hydrogel as a novel delivery system for Lactobacillus paracasei: Its relationship to structure, encapsulation and controlled release

Meng-Fan Li,Hua-Ling Cui,Wen-Yong Lou

We report for the first time the usage of Millettia speciosa Champ cellulose (MSCC) and carboxymethylcellulose (MSCCMC) for the fabrication of 3D-network hydrogel as delivery system for probiotics. The structural features, swelling behavior and pH-responsiveness of MSCC-MSCCMC hydrogels and their encapsulation and controlled-release behavior for Lactobacillus paracasei BY2 ( L. paracasei BY2) were mainly studied. Structural analyses demonstrated that MSCC-MSCCMC hydrogels with porous and network structures were successfully synthesized through the crosslinking of –OH groups between MSCC and MSCCMC molecules. An increasing concentration of MSCCMC significantly improved the pH-responsiveness and swelling ability of the MSCC-MSCCMC hydrogel toward neutral solvent. Besides, the encapsulation efficiency (50.38–88.91 %) and release (42.88–92.86 %) of L. paracasei BY2 were positively correlated with the concentration of MSCCMC. The higher the encapsulation efficiency was, the higher the release in the target intestine. However, due to the existence of bile salts , controlled-release behavior decreased the survivor rate and physiological state (degrading cholesterol) of encapsulating L. paracasei BY2. Even so, the number of viable cells encapsulated by hydrogels still reached the minimum effective concentration in the target intestine. This study provides an available reference for the practical application of hydrogels fabricated from the cellulose of the Millettia speciosa Champ plant for probiotic delivery.

Phase Change Material-Embedded Multifunctional Janus Nanofiber Dressing with Directional Moisture Transport, Controlled Release of Anti-Inflammatory Drugs, and Synergistic Antibacterial Properties

Yurong Liu,Shunfen Huang,Shiyi Liang,Peiran Lin,Xiangjie Lai,Xingzi Lan,Han Wang,Yadong Tang,Botao Gao

Wound healing is a systematic and complex process that involves various intrinsic and extrinsic factors affecting different stages of wound repair. Therefore, multifunctional wound dressings that can modulate these factors to promote wound healing are in high demand. In this work, a multifunctional Janus electrospinning nanofiber dressing with antibacterial and anti-inflammatory properties, controlled release of drugs, and unidirectional water transport was prepared by depositing coaxial nanofibers on a hydrophilic poly(ε-caprolactone)@polydopamine-ε-polyl-lysine (PCL@PDA-ε-PL) nanofiber membrane. The coaxial nanofiber was loaded with the phase change material lauric acid (LA) in the shell layer and anti-inflammatory ibuprofen (IBU) in the core layer. Among them, LA with a melting point of 43 °C served as a phase change material to control the release of IBU. The phase transition of LA was induced by near-infrared (NIR) irradiation that triggered the photothermal properties of PDA. Moreover, the Janus nanofiber dressing exhibited synergistic antimicrobial properties for Escherichia coli and Staphylococcus aureus due to the photothermal properties of PDA and antibacterial ε-PL. The prepared Janus nanofiber dressing also exhibited anti-inflammatory activity and biocompatibility. In addition, the Janus nanofiber dressing had asymmetric wettability that enabled directional water transport, thereby draining excessive wound exudate. The water vapor transmission test indicated that the Janus nanofiber dressing had good air permeability. Finally, skin wound healing evaluation in rats confirmed its efficacy in promoting wound healing. Therefore, this strategy of designing and manufacturing a multifunctional Janus nanofiber dressing had great potential in wound healing applications.

In vitro plasma hydrolysis of phenolic esters and their absorption kinetics in rats: Controlled release of phenolic compounds and enhanced health benefits

Xinmiao Wang,Qian Wang,Dong Cai,Jinghan Yu,Xiaoyang Liu,Fawen Yin,Dayong Zhou

Phenolic esters are considered as promising functional food ingredients. However, their digestion, absorption and metabolism are still unclear. Tyrosol acyl esters (TYr-Es), hydroxytyrosol acyl esters (HTy-Es) and alkyl gallates (A-GAs) were hydrolyzed by carboxylesterase in plasma and exhibited slow release of polyphenols (phenolic acids). In vitro hydrolysis degrees initially increased and then decreased with the increasing carbon chain length (C2-C16). TYr-Es exhibited higher hydrolysis degrees compared to HTy-Es, and hydrolysis degrees of TYr-Es and HTy-Es were markedly higher than those of A-GAs. Due to the fast hydrolysis rates of TYr-Es and HTy-Es, they were undetectable in all rat plasma samples collected at several times within 24 h after administration. Whereas, A-GAs could be detected in rat plasmas and three absorption peaks were found in the pharmacokinetic profiles. Importantly, the T 1/2 , MRT, AUC 0-∞ , AUC 0-t in octyl gallate group were longer (or stronger) than those in propyl gallate and dodecyl gallate groups.

Novel antimicrobial packaging film based on porous poly(lactic acid) nanofiber and polymeric coating for humidity-controlled release of thyme essential oil

Tiantian Min,Xiaoli Sun,Zhipeng Yuan,Liping Zhou,Xiangyu Jiao,Junwei Zha,Zhu Zhu,Yongqiang Wen

The objective of this work is to explore a new pathway to develop active packaging materials. Currently, controlled release materials have attracted considerable attention in food packaging applications. In this study, the thyme essential oil (TEO) was loaded in electrospinning porous poly(lactic acid) (PLA) nanofibers and coated with poly(vinyl alcohol)/poly(ethylene glycol) (PVA/PEG) blends for humidity-controlled TEO release. The images of scanning electron microscope displayed uniform pores distributed on the surface of PLA nanofibers. Water contact angle measurement indicated that PVA/PEG coating provided the packaging film with excellent hydrophilicity. ATR-FTIR spectral analysis supported the chemical composition of the films. The antibacterial activities of PLA/TEO/PVA/PEG films against Escherichia coli and Staphylococcus aureus reached ＞99%. Furthermore, the weight loss and firmness of strawberries packaged with this novel film were evaluated. Finally, the in vitro release behaviors of TEO were evaluated and the results demonstrated that the release rate could be controlled by adjusting the humidity (20% RH to 80% RH).

Enhanced the entrapment and controlled release of Syzygium cumini seeds polyphenols by modifying the surface and internal organization of Alginate-based microcapsules

Mohamed Abdin,Mohamed Abdelbaset Salama,Asad Riaz,Hafiz Muhammad Saleem Akhtar,Samir Youssef Elsanat

The main objective of this study is using calcium alginate to encapsulate Syzygium cumini seed polyphenolic extract to maintain its stability and functionality. Calcium chloride was exploited as a cross-linking agent to get the final form as calcium alginate capsules. Two different methods for drying of capsules were conducted; freeze-dried (FD.C) and vacuum dried (D.C). Encapsulation efficiency for FD.C and D.C was 75.96 ± 0.68% and 70.20 ± 0.59%, respectively. The scanning electron microscopy ( SEM ) photographs and the mechanical properties indicated that the polysaccharide networks of D.C were strongly firm to prevent the release of total phenolic content (TPC) in gastric phase. FD.C showed fragile polysaccharide networks however, prevented the release of TPC in gastric phase and exhibited more release of TPC than D.C in intestinal phase. The microencapsulation process improved the thermal stability of the extract with 171.97°C and 180.36°C for FD.C and D.C, respectively. Novelty Impact Statement Sodium alginate in combination with calcium chloride was exploited to fabricate controlled release microcapsules. The fabricated microcapsules physically interacted with Syzygium cumin seeds polyphenols. The polyphenolic microcapsules were characterized with high ability to preserve polyphenols in gastric conditions and admitted with release of polyphenols in intestinal conditions. Moreover, the resulted microcapsules increased the thermal stability of grafted polyphenols. Thus, the obtained results would pave a new technique for medical purposes as controlled release systems or more stable capsules for food additive.

Synthesis and characterization of dopamine-modified Ca-alginate/poly(N-isopropylacrylamide) microspheres for water retention and multi-responsive controlled release of agrochemicals

Dan Zheng,Bo Bai,Yunhua He,Na Hu,Honglun Wang

The multi-responsive controlled-release system could enhance crop yield while improving utilization efficiency of agrochemicals, and minimize environmental pollution caused by agrochemicals overuse. This work reports a novel Ca-alginate/Poly( N -isopropylacrylamide)@polydopamine (Ca-alginate/PNIPAm@PDA) microsphere to control the agrochemicals release. Microsphere with a semi-interpenetrating network, which contained pH-sensitive Ca-alginate, temperature-sensitive poly( N -isopropylacrylamide) (PNIPAm), and sunlight-sensitive polydopamine (PDA), was characterized by thermogravimetric analysis , zeta potential , Fourier transform infrared spectroscopy , and scanning electron microscopy to prove the successful synthesis. Moreover, the comprehensive performances, including photothermal conversion, water absorbency, water retention, and controlled-release agrochemicals behaviors, were systematically investigated. The results indicated that the composite microsphere was a prosperous water and agrochemicals manager to effectively retain water and control the release of agrochemicals by external stimulation. Consequently, the Ca-alginate/PNIPAm@PDA microsphere with outstanding water-retention and controlled-release capacities is economical and eco-friendly and thus is promising for utilization as water and agrochemicals controlled-release carrier material in agriculture applications.

Mechanistic insights into the degradation of trichloroethylene by controlled release nano calcium peroxide activated by iron species coupled with nano iron sulfide

Meesam Ali,Muhammad Danish,Muhammad Tariq,Ayyaz Ahmad,Khurram Shahzad Ayub,Shuguang Lyu

This study demonstrated a novel approach for prolonged benefits in groundwater remediation schemes utilizing PVA coated nano calcium peroxide (PVA@nCP) activated by Fe(II)/nFeS or Fe(III)/nFeS. Various techniques (SEM, TEM, XRD, EDS, FTIR, and BET) were used to characterize the synthesized nFeS and the prepared PVA@nCP. Trichloroethylene (TCE) was chosen as the target pollutant and its degradation performance was assessed in both Fe(II)/nFeS and Fe(III)/nFeS activated PVA@nCP systems, and the second-order reaction kinetics were determined. The effect of nFeS dose revealed its dominant role in Fe(III)/nFeS system by providing a surface platform, and at the same time, it also enhanced TCE removal in Fe(II)/nFeS system·H 2 O 2 release behavior, the participation of Fe(II) in both solution and surface, and the generated (free and surface-bound) active species (HO , O 2 − & 1 O 2 ) determined the insights of synergistic mechanisms. Electron spin resonance (ESR) identified the active species initially, which correspondingly confirmed by quenching tests. Moreover, X-ray photoelectron spectroscopy (XPS) investigated the surface reaction mechanism, showing the dominant role of S(-II) as an efficient converter of iron species as Fe(II) increased from 35% to 45% and 45.5% and Fe(III) decreased from 65% to 55% and 54.5% in Fe(II)/nFeS and Fe(III)/nFeS systems respectively. The effects of initial solution pH and common anions (Cl − , HCO 3 − , NO 3 − , & SO 4 2− ) on TCE removal were further examined, and recycling use of nFeS was investigated for its reusability in both systems. The findings of this work suggest that both systems, i.e., PVA@nCP/Fe(II)/nFeS and PVA@nCP/Fe(III)/nFeS, are novel processes and possessing potential applicability in TCE contaminated groundwater remediation.

Redox-Sensitive Polymer Micelles Based on CD44 and Folic Acid Receptor for Intracellular Drug Delivery and Drug Controlled Release in Cancer Therapy

Beibei Lu,Zhourui Xiao,Zhenyuan Wang,Binshen Wang,Weiwei Zhao,Xing Ma,Jiaheng Zhang

Redox-responsive ferrocene (Fc)-grafted supramolecular block copolymers functionalized with hyaluronic acid (HA-g-β-CD/Fc-polymers or HAP) or folic acid (FA-g-β-CD/Fc-polymers or FAP) were synthesized by host–guest interaction. The copolymer structures were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance, and gel permeation chromatography. The block copolymers self-assemble into spherical micellar aggregates in aqueous solution, and exhibit reversible redox characteristics in the presence of an oxidant and reductant. The tunable redox response was evaluated by transmission electron microscopy, ultraviolet–visible spectroscopy, cyclic voltammetry and dynamic light scattering. The micelles rapidly release DOX under oxidative and acidic condition in vitro. Furthermore, presence of HA and FA on the micelles enabled effective uptake by the CD44 and FA receptor-overexpressing cancer cells. Taken together, the redox responsive Fc-block copolymer micelles have good biocompatibility, biodegradability, low toxicity, and high selectivity, and are a highly promising drug delivery system for cancer therapy.

Preparation of glucose-sensitive and fluorescence micelles via a combination of photoinitiated polymerization and chemoenzymatic transesterification for the controlled release of insulin

Xiangxiang Du,Guohua Jiang,Lei Li,Wentong Yang,Hua Chen,Yongkun Liu,Qin Huang

Glucose-sensitive and fluorescence copolymer micelles were designed and prepared via a combination of photoinitiated polymerization and enzymatic transesterification. The water-soluble photoinitiator and emulsifier 2-oxooctanoic acid self-polymerized dimer molecules under UV irradiation were characterized by mass spectrometry. The fluorescence dye (9-anthracene alcohol) and biocompatible hydrophilic chains [poly(ethylene glycol)] were introduced to the polymer chains during the photopolymerization and enzymatic transesterification processes. The as-prepared copolymers were confirmed by 1 H-NMR spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, and dynamic light scattering. The resulting copolymers exhibited excellent glucose sensitivity and stability against protein. The optical fluorescence properties of the copolymer micelles were investigated with fluorescence spectrophotometry, fluorescence microscopy, and confocal laser scanning microscopy. Because of the amphiphilic feature, the micelles could be self-assembled and used to load insulin. The controlled release of insulin was evaluated and was triggered by glucose in vitro . This study provided a new strategy for fabricating functional carriers as self-regulated insulin-release systems. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133 , 43026.

High mechanical strength chitosan-based hydrogels cross-linked with poly(ethylene glycol)/polycaprolactone micelles for the controlled release of drugs/growth factors

Yan Wen,Fan Li,Chunge Li,Yuji Yin,Junjie Li

High mechanical strength hydrogels without burst release are known to be beneficial to deliver bioactive molecules including drugs and growth factors. Herein, chitosan-based hydrogels are fabricated by the covalent attachment of poly(ethylene glycol) diacrylate (PEGDA) to thiol groups of thiolated natural polymers via Michael addition reaction under physiological conditions. Poly(ethylene glycol-b-caprolactone-b-ethylene glycol) (PECL) micelles bearing double bonds act as both fillers and chemical cross-linkers to mechanically reinforce chitosan-based hydrogels, which is confirmed by the results of rheological behavior and compressive strength measurements. Indomethacin (IMC) and/or basic fibroblast growth factor (bFGF) are/is entrapped into the PECL micelle cross-linked hydrogel network primarily through hydrophobic interaction and specific affinity to thiolated heparin, respectively. After a relatively quick initial release, rather than an initial burst commonly occurring in conventional hydrogels based on drug delivery systems, IMC and/or bFGF are/is released from these PECL micelle cross-linked hydrogels at a slower rate until a steady state is reached. The release rate of IMC and/or bFGF could be readily tuned by varying the micelle amount and the thiolated heparin content in a polymer matrix.

Preparation of intravenous injection nanoformulation via co-assemble between cholesterylated gemcitabine and cholesterylated mPEG: enhanced cellular uptake and intracellular drug controlled release

Yanyun Xu,Xin Zhong,Xiongwen Zhang,Wei Lv,Jiahui Yu,Yi Xiao,Shiyuan Liu,Jin Huang