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Warming Hansson posted an update 7 days ago
Conductive electrospun nanofiber scaffold containing conductive polypyrrole (PPy) polymer was fabricated to accelerate healing of damaged tissues. In order to prepare these scaffolds, various weight percentages of polypyrrole (5, 10, 15, 20, 25%) relative to the polymers combination (chitosan, collagen, and polyethylene oxide) were used. The fabricated composite scaffolds were characterized using chemical, morphological, physio-mechanical, and biological analyses including; FTIR spectroscopy, SEM, electrical conductivity, tensile test, in vitro degradation, MTT Assay and cell culture. The polypyrrole particles were perfectly dispersed inside the nanofibers, and the fibers average diameter were reducing by increasing the polypyrrole content in the composites. The presence of polypyrrole in fibers enhanced their conductivity up to 164.274 × 10-3 s/m which is in the range of semi-conductive and conductive polymers. MTT and SEM analyses displayed that nanofibers composing 10% polypyrrole possess better cell adhesion, growth and proliferation properties comparing to other compositions. Furthermore, the suitable mechanical properties of scaffolds ideally fitted them for different kinds of tissue applications including skin, nerve, heart muscle, etc. Therefore, these fabricated conductive nanofiber scaffolds are particularly appropriate for employing in body parts with electrical signals such as cardiovascular, heart muscles, or nerves.The polysaccharide-based pH-responsive compounds, namely, N,N,N-trimethyl chitosan (TMC), polyethylene glycolated hyaluronic acid (PEG-HA), and polysaccharide-based nano-conjugate of hyaluronic acid, chitosan oligosaccharide and alanine [HA-Ala-Chito(oligo)] were chemically synthesized using biopolymers chitosan and hyaluronic acid, and applied here to observe the changes in morphology, pH-stability, mechanical and drug-release behavior, and cytotoxicity of thermo-responsive polymer Poloxamer 407 (PF127)-based drug delivery systems for traditional Chinese medicine Cortex Moutan (CM). The thermo-responsive hydrogel of PF127 loaded with CM (GelC) was used as control. The dual-responsive (pH/temperature) hydrogels PF127/TMC/PEG-HA (Gel1) and PF127/HA-Ala-Chito(oligo) (Gel2) showed improved mechanical behavior as obtained by rheology and mechanical agitation study, and pH-stability under various external pH conditions, and those improvements occurred due to the addition of polysaccharide-based pH-responsive compoμg/ml for Gel2. The formulations without loaded drug namely, Gel1-CM and Gel2-CM exhibited strong anti-bacterial action against gram positive bacteria Staphylococcus aureus.Wide dissemination of pesticides for protecting plants against pests has resulted in high production of un-infected crops but higher environmental pollution. High percentages of pesticides are released to the environment and finally use water as the final destination. The current study is concerning by removal of Imidacloprid pesticide from water using pressure-free passage through polymeric membrane integrated design. Both of chitosan and chitosan functionalized silver nanoparticles (AgNPs @chitosan) membranes were prepared, characterized and applied as adsorbent matrix for Imidacloprid. SEM, TEM and PSA analysis revealed the biosynthesis of AgNPs in the range of 25-50 nm. However, SEM and FTIR analysis revealed the proper formation of chitosan membrane and its proper functionalization with silver nanoparticles. Both of chitosan and AgNPs @chitosan membranes succeeded to remove 40 and 85% of Imidacloprid at slightly acidic pH, respectively. read more Moreover, the amount of removed Imidacloprid was proportional with the amount of its initial concentration indicating the successful removal of Imidacloprid by AgNPs @chitosan membrane even at higher pesticide concentrations. The obtained results indicate the promising use of AgNPs @chitosan membranes for removal of Imidacloprid pesticide from contaminated water depending on the pressure-free design that lacks external energy support.A chitosan-based (CS) film was developed with nanosized TiO2 and red apple pomace extract (APE). The intermolecular interactions of CS, TiO2 and APE were evaluated by Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction. TiO2 nanoparticles remarkably improved the water vapor and UV-Vis light barrier properties, mechanical strength and thermal stability of CS-APE films. The strong antioxidant abilities of CS-APE and CS-TiO2-APE films were characterized. Nano-TiO2 and APE showed a synergistic enhancement of the antimicrobial activity in CS matrix. The addition of TiO2 nano-particles into CS-APE films resulted the sensitive color variations, which applied successfully as an indicator to monitor the freshness of salmon fillets. Consequently, the development of CS-APE-TiO2 film provides a new solution to convert rad apple pomace to an active and multifunctional food packaging material with considerable mechanical, antibacterial, antioxidant and pH-responsive color-changing properties.
EMR and endoscopic submucosal dissection (ESD) are treatment modalities for Barrett’s esophagus involving high-grade dysplasia or early cancer. Injectional corticosteroid therapy decreases the risk of procedure-related esophageal stricture (ES) formation. Our aim was to assess the efficacy of topical budesonide on the rate of ES formation after EMR or ESD.
Patients included prospectively from 3 tertiary endoscopy centers received 3 mg budesonide orally twice a day for 8 weeks after esophageal EMR or ESD of 50% or more of the esophageal circumference between January 1, 2014 and June 30, 2018. These patients were matched (13 ratio) retrospectively with a consecutive patient cohort who underwent EMR or ESD of 50% or more of the esophageal circumference without concomitant corticosteroid therapy. The primary endpoint was the presence of ES at the 12-week follow-up.
Twenty-five patients (budesonide) were matched with 75 patients (no budesonide). Most underwent EMR for Barrett’s esophagus with biopsy-proven high-grade dysplasia or suspected T1a cancer. Although most baseline characteristics did not differ significantly, patients in the budesonide cohort tended to have a higher proportion of circumferential EMR. The proportion of patients with ES was not significantly lower in the budesonide cohort (16% vs 28%). On logistic regression analysis, budesonide remained associated with a lower incidence of ES (P= .023); however, when controlling for baseline characteristics with a propensity score weighted logistic regression model, there was no significant effect on ES formation (P= .176).
Topical budesonide might be associated with a reduction of ES after EMR or ESD; however, further studies are needed to verify our results.
Topical budesonide might be associated with a reduction of ES after EMR or ESD; however, further studies are needed to verify our results.