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The aim of this study was to prepare cellulose nanowhiskers (CNWs) from wastepaper powder (WPP), as an environmentally friendly approach for obtaining the source material, which is a highly available and low-cost precursor for cellulose nanomaterial processing. Acid hydrolysis and calcification treatments were employed for extraction of CNWs and preparation of novel phospho-calcified cellulose nanowhiskers (PCCNWs). CNWs and PCCNWs were analyzed through optical microscopy (OM), scanning electron microscopy (SEM), Fourier-transformed infrared spectra (FTIR) and X-ray diffraction analysis (XRD). Cell behaviors in the presence of CNWs and PCCNWs were studied by MTT assay and live-dead staining. Finally, the effect of these particles on osteogenic differentiation of stem cells was evaluated based on alkaline phosphatase activity (ALP), calcium mineralization as well as von Kossa and alizarin red staining. Based on the results, PCCNWs had a positive effect on osteogenic differentiation of human mesenchymal stem cells (hMSCs) and can be used for developing new approaches for bone tissue engineering., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

All of the cells' interactions are done through their surfaces. Evaluation of surface physicochemical scaffolds along with other factors is important and determines the fate of stem cells. In this work, biodegradable and biocompatible polyester/polyether based polyurethanes (PUs) were synthesized by polycaprolactone diol (PCL) and poly (tetra methylene ether) glycol (PTMEG) as the soft segment. To assess better the impact of surface parameters such as stiffness and roughness effects on osteogenic differentiation of the human mesenchymal stem cell (hMSC), the dimension effect of substrates was eliminated and two-dimensional membranes were produced by synthesized polyurethane. Surface and bulk properties of prepared 2D membranes such as surface chemistry, roughness, stiffness and tensile behavior were evaluated by Attenuated total reflectance Fourier transform infrared (ATR-FTIR), atomic force microscopy (AFM) and tensile behavior. The prepared 2D PU films had suitable hydrophilicity, biodegradability, water absorption, surface roughness and bulk strength. The hMSCs showed greater osteogenesis expression in PU substrates with more roughness and stiffness than others. The results demonstrated that surface parameters along with other differentiation cues have a synergistic effect on stem cells fates., (Copyright © 2017 Elsevier B.V. All rights reserved.)

In the present study, the PCL-Diol-b-PU/Au nanocompsite nanofibers were fabricated via electrospinning process during two different stages to load an anticancer temozolomide (TMZ) drug into the nanofibers. The first stage was the incorporation of Au nanoparticles into the nanofibers and the second stage was coating the gold nanoparticles on the surface of PCL-Diol-b-PU/Au composite nanofibers. The prepared nanofibrous formulations were characterized using FTIR, SEM and TEM analysis. Box-Behnken-design was used to investigate the influence of electrospinning parameters including solution concentration, applied voltage to tip-collector distance ratio and collector speed on the morphology and fiber diameter of PCL-Diol-b-PU/Au nanofibers. Drug loading efficiency, in vitro release profiles of TMZ from PCL-Diol-b-PU/Au and gold-coated PCL-Diol-b-PU/Au composite nanofibers as well as in vitro antitumor efficacy against U-87 MG human glioblastoma cells were carried out. The TMZ release data were well described using Korsmayer-Peppas kinetic model in which results indicated Fickian diffusion of TMZ from nanofibers. The obtained results revealed the higher efficiency of PCL-Diol-b-PU/Au@TMZ nanofibrous implants for treatment of glioblastoma tumors., (Copyright © 2017 Elsevier B.V. All rights reserved.)