Metal organic framework-loaded polyethersulfone/polyacrylonitrile photocatalytic nanofibrous membranes under visible light irradiation for the removal of Cr(vi) and phenol from water.

In this work, various amounts of the UiO-66-NH2 and UiO-66-NH2/TiO2 MOFs have been loaded into polyacrylonitrile (PAN) nanofibers supported on polyethersulfone (PES). The visible light irradiation was used to investigate the influence of pH (2-10), initial concentration (10-500 mg L-1), and time (5-240 min) on the removal efficiency of phenol and Cr(vi) in the presence of MOFs. The reaction time: 120 min, catalyst dosage: 0.5 g L-1, pH: 2 for Cr(vi) ions and pH: 3 for phenol molecules were optimum to degrade phenol and to reduce Cr(vi) ions. The characterization of the produced samples was performed using X-ray diffraction, ultraviolet-visible diffuse reflectance spectroscopy, scanning electron microscopy, and Brunauer-Emmett-Teller analysis. The capability of synthesized photocatalytic membranes was investigated for the removal of phenol and Cr(vi) ions from water. The water flux, Cr(vi) and phenol solutions fluxes and their rejection percentages were evaluated under pressure of 2 bar in the presence of visible light irradiation and in the dark. The best performance of the synthesized nanofibers was obtained for UiO-66-NH2/TiO2 MOF 5 wt% loaded-PES/PAN nanofibrous membranes at temperature of 25 °C and pH of 3. Results demonstrated the high capability of MOFs-loaded nanofibrous membranes for the removal of various contaminants such as Cr(vi) ions and phenol molecules from water.

Paclitaxel-loaded liposome-incorporated chitosan (core)/poly(ε-caprolactone)/chitosan (shell) nanofibers for the treatment of breast cancer.

Liposomes and nanofibers have been introduced as effective drug delivery systems of anticancer drugs. The performance of chitosan (core)/poly(ε-caprolactone) (PCL)/paclitaxel simple nanofibers, chitosan/paclitaxel (core)/PCL/chitosan (shell) nanofibers and paclitaxel-loaded liposome-incorporated chitosan (core)/PCL-chitosan (shell) nanofibers was investigated for the controlled release of paclitaxel and the treatment of breast cancer. The synthesized formulations were characterized using polydispersity index, dynamic light scattering, zeta potential, scanning electron microscopy, transmission electron microscopy, and Fourier transform infrared analysis. The sustained release of paclitaxel from liposome-loaded nanofibers was achieved within 30 days. The release data was best described using Korsmeyer-Peppas pharmacokinetic model. The cell viabilities of synthesized nanofibrous samples were higher than 98 % ± 1 % toward L929 normal cells after 168 h. The maximum cytotoxicity against MCF-7 breast cancer cells was 85 % ± 2.5 % using liposome-loaded core-shell nanofibers. The in vivo results indicated the reduction of tumor weight from 1.35 ± 0.15 g to 0.65 ± 0.05 g using liposome-loaded core-shell nanofibers and its increasing from 1.35 ± 0.15 g to 3.2 ± 0.2 g using pure core-shell nanofibers. The three-stage drug release behavior of paclitaxel-loaded liposome-incorporated core-shell nanofibers and the high in vivo tumor efficiency suggested the development of these formulations for cancer treatment in the future.

Adsorption, and controlled release of doxorubicin from cellulose acetate/polyurethane/multi-walled carbon nanotubes composite nanofibers.

The cellulose acetate (CA)/poly (ε-caprolactone diol)/poly (tetramethylene ether) glycol-polyurethane (PCL-Diol/PTMG-PU)/multi-walled carbon nanotubes (MWCNTs) composite nanofibers were prepared via two-nozzle electrospinning on both counter sides of the collector. The performance of synthesized composite nanofibers was investigated as an environmental application and anticancer delivery system for the adsorption/release of doxorubicin (DOX). The synergic effect of MWCNTs and DOX incorporated into the nanofibers was investigated against LNCaP prostate cancer cells. The status of MWCNTs and DOX in composite nanofibers was demonstrated by SEM, FTIR and UV-vis determinations. The adsorption tests using nanofibrous adsorbent toward DOX sorption was evaluated under various DOX initial concentrations (100-2000 mg l-1), adsorption times (5-120 min), and pH values (pH:2-9). Due to the fitting of isotherm and kinetic data with Redlich-Peterson and pseudo-second order models, both chemisorption and surface adsorption of DOX molecules mechanisms have been predicted. The drug release from both nanofibers and MWCNTs-loaded nanofibers was compared. The better drug sustained release profiles verified in the presence of composite nanofibers. LNCaP prostate cancer and L929 normal cells were treated to investigate the cytotoxicity and compatibility of synthesized composite nanofibers. The apoptosis/necrosis of hybrid nanofibers and MWCNTs loaded-nanofibers was investigated. The obtained results demonstrated the synergic effects of MWCNTs and DOX loaded-nanofibers on the LNCaP prostate cancer cells death.

Ag+-promoted zinc oxide [Zn(O):Ag]: A novel structure for safe protection of human skin against UVA radiation.

Different sunscreens are employed to prevent photo damage (cancer, inflammation, etc.), including ZnO. ZnO is safe when applied as micro-size particle. To overcome some visual problems of ZnO micro-size particles, this sunscreen has been introduced as nano-size particles. Unfortunately, ZnO nanoparticles have raised some health concerns, due to Zn+2 release. On the other hand, it has been shown that ZnO metallic lattice change by metal doping decreases its solubility and toxicity. Therefore, we have decided here to develop new ZnO metallic lattice to reduce its cytotoxicity. In this study, Ag+1-promoted Zn-based nanocompounds [Zn(O):Ag] were synthesized as a novel compound and were characterized. XRD analysis showed that Ag+1 ion percolates into ZnO crystalline lattice and changes its lattice properties (strength bond, vacancies, and etc.). Cell culture studies and MTT assay on human skin (HFF-1) cells exposed to UVA radiation showed that [Zn(O):Ag] was increased cells viability in the presence of UVA radiation compared to ZnO. Actually, Ag+1 ion has catalyzed photoactivity of ZnO compound. UV-blocking tests showed that UVA-absorbance of [Zn(O):Ag] has increased compared to ZnO. Dichlorofluoroscein diacetate-ROS assay and Zn+2 release experiments in the presence of cells showed that [Zn(O):Ag] has reduced Zn+2 ions release into culture medium and its toxicity. Our study shows that doped ZnO nanostructure has the potential to be applied as a safe and effective nanoparticulate sunscreen.