Electrospun tetracycline hydrochloride loaded zein/gum tragacanth/poly lactic acid nanofibers for biomedical application.

Newly, fabrication of scaffolds along with the therapeutic agent of tetracycline hydrochloride for application in wound healing and anti-inflammatory effect could interest consideration. In this work, we developed a novel drug delivery mat composed of gum tragacanth (GT), zein, poly lactic acid (PLA) and tetracycline hydrochloride (TCH) (zein/GT/PLA/TCH) in different blending ratios of zein/GT. Scanning electron microscope (SEM) images of mats showed interconnected pores with beadles nanofibers. The results of SEM showed that by increasing the ratio of zein/GT, the average diameter of nanofibers increased from 253.22 ± 15.36 to 547.78 ± 56.48 nm for the ratios of 80:20 and 90:10, respectively. Moreover, the successful loading of TCH and was approved by Fourier transform infrared (FTIR) spectroscopy and thermal gravimetric analysis (TGA). By addition of TCH and increasing the GT content to the developed nanofibrous mats, the tensile strength, swelling degree and porosity of zein/GT/PLA/TCH nanofibers increased. Furthermore, this scaffold also displayed appropriate antibacterial properties and suitable degradability for skin tissue engineering. The results of cytocompatibility and SEM micrographs proved that zein/GT/PLA/TCH scaffold had promising proliferation and adhesion against NIH-3 T3 fibroblast cell.

Silver sulfadiazine-loaded electrospun ethyl cellulose/polylactic acid/collagen nanofibrous mats with antibacterial properties for wound healing.

Recently, the electrospun nanofiber mats with appropriate properties for applications in the biomedical area has been more considered. In this regard, we successfully fabricated a novel antibacterial nanofiber mat (ethyl cellulose/poly lactic acid/collagen) (EC/PLA/collagen) incorporated with silver sulfadiazine (AgSD) and then analyzed with the required tests. AgSD was loaded in the developed mats with different contents (0.25%, 0.5% and 0.75%) and then electrospun to prepare nanofiber mats. To check the chemical structure of the developed mat, Fourier transform infrared spectroscopy (FTIR) was assessed. Surface morphological studies were performed by Scanning Electron Microscopy (SEM), which displayed uniform nanofiber mats without any bead formation. When the hydrophilicity was enhanced by decreasing the blending ratios of EC/PLA, the thermal stability of the nanofibers was reduced. The water contact angle (WCA) of NFs enhanced by decreasing the blending ratios of EC/PLA. The antibacterial properties showed the inhibition activity against Bacillus (9.71 ± 1.15 mm) and E. coli (12.46 ± 1.31 mm) bacteria. Besides, nanofibers have improved cell proliferation and adhesion with any cytotoxic effect on NIH 3T3 fibroblast cells. According these results, it seems that the developed mats would be effective scaffold for application in wound dressings.

Development of reinforced aldehyde-modified kappa-carrageenan/gelatin film by incorporation of halloysite nanotubes for biomedical applications.

Recently, with the progression in tissue engineering, the importance of biocompatible nanocomposite film with suitable properties for potential applications in the biomedical area has been more developed. In this work, nanocomposite films of aldehyde-modified Carrageenan/Gelatin/halloysite nanotubes (AD-Carr/Gel/HNTs) nanocomposite films were successfully fabricated by the solution casting process. Halloysite nanotubes (HNTs) with different concentrations (0.5, 1.0, and 1.5 wt%) loaded into the aldehyde-modified Carrageenan/Gelatin (AD-Carr/Gel). Meanwhile, the developed AD-Carr/Gel/HNTs nanocomposite films were characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), mechanical property, water adsorption as well as in vitro degradation. The feasibility and capability of the nanocomposite films were further evaluated by hemocompatibility study, which showed that these nanocomposite films are hemocompatible. Besides, MTT assay revealed that the nanocomposite films are non-toxic, presenting the films as a good candidate to be used for tissue engineering purposes.

Fluorescence Intensity Enhancement of Green Carbon Dots: Synthesis, Characterization and Cell Imaging.

The hydrothermal treatment of green carbon dots (CDs) is an appropriate fluorescent probe synthesis method. CDs are exploited as biological staining agents, especially for cellular detection and imaging. The nitrogen-doped green carbon dots (N-CDs) formation can improve the fluorescence intensity property in a one-step process. Here, we report two N-CDs from lemon and tomato extraction in the presence of hydroxylamine. Lemon and tomato N-CDs showed the blue fluorescence under ultraviolet radiation of about 360 nm. The characterization of CDs and N-CDs showed the presence of N-H and C-N bonds which enhanced the fluorescence efficiency. The mean size of lemon and tomato N-CDs were about 2 and 3 nm with an increased quantum yield (QY) of 5% and 3.38%, respectively. The CDs and N-CDs cytotoxicity assay exhibited high cell viability approximately 85% and 73%, respectively. N-CDs show superior fluorescent intensity in different solvents and significant stability under long-time UV irradiation, different PH and high ionic strength. Our results indicated that the use of N-CDs in cell imaging can lead to fluorescence intensity enhancement as well as proper biocompatibility. Therefore, the safe and high fluorescence intensity of green N-CDs can be utilized for fluorescent probes in biolabeling and bioimaging applications.

Chemotherapy of Breast Cancer Cells Using Novel pH-Responsive Cellulose-Based Nanocomposites.

Purpose: The objective of the current study was to compare the anticancer efficacy of doxorubicin-loaded cellulose based magnetic (Fe3O4), zinc oxide (ZnO) nanoparticles on and free doxorubicin (DOX) on MCF-7 breast cancer cells. Methods: Novel pH-sensitive cellulose-graft poly acrylic acid based Fe3O4 (Cellulose-g-PAAg- PAcMNPs) and ZnO (Cellulose-g-PAA-g-PAcZnO) nanocomposites were synthesized via polymerization of acrylic acid and modified 3-(trimethoxysilyl) propyl methacrylate onto the cellulosic backbone via reversible addition-fragmentation chain transfer (RAFT) method. Results : Cellulose-g-PAA-g-PAcMNPs and Cellulose-g-PAA-g-PAcZnO nanocarriers with mean diameter of 15 and 38 nm were prepared successfully. DOX was loaded effectively to the ZnO and Fe3O4 nanocarriers via complexing and electrostatic force with great encapsulation efficiency of 99.07% and 98.92%, respectively. DOX-loaded nanocarriers showed obvious pHdependent tumor specific drug release pattern. MTT assay results indicated that IC50 of the DOX loaded Cellulose-g-PAA-g-PAcZnO, DOX loaded Cellulose-g-PAA-g-PAcMNPs and free DOX after 48 hours treatment with MCF7 cell lines were about 24.03, 49.27 and 99.76 µg mL-1, respectively. Therefore both DOX nanoformulations significantly increase antitumor ability compared to free DOX (P < 0.05). The results of MTT assay and DAPI staining revealed that DOX-loaded Cellulose-g-PAA-g-PAcZnO NPs show higher chemotherapy efficiency in MCF7 breast cancer cell line compare to the DOX-loaded Cellulose-g-PAA-g-PAcMNPs due to high interaction of ZnO with DOX. Conclusion: The formation of the complexes between the DOX and ZnO nanoparticles at the chelating sites of the quinone and the phenolic oxygen molecules of DOX, lead to more sustained drug release and enhanced chemotherapy effectiveness by increasing the intracellular concentration of DOX.

Chitosan-based nanomicelle as a novel platform for targeted delivery of methotrexate.

Conventional chemotherapy suffers lack of bioavailability, selectivity and multidrug resistance (MDR). Nano-sized drug delivery systems (DDS) is developing aimed to solve several limitations of conventional drug delivery systems. These systems have been offered for targeting tumor tissue due to their long circulation time and improved drug solubility, retention (EPR) effect, and enhanced permeability. So, the aim of this research was the development and design of a novel targeted nanocarrier for cancer chemotherapy. For this reason, chitosan (CS) was first modified with a chain transfer agent (CTA) to create CS-CTA macroinitiator. Then, the controlled grafting polymerization of itaconic acid (IA) and dimethylaminoethyl methacrylate quaternary ammonium alkyl halide (DMAEMAQ) monomers were occurred using reversible addition-fragmentation chain transfer (RAFT) polymerization to generate CS-g-(PIA-co-PDMAEMAQ) nanomicelles. To follow the cancer cells, fluorescein dye was entrapped into the core of nanomicelles and methotrexate (MTX) anticancer drug as a target ligand was incorporated into the cationic segment of nanomicelles. The chemical structures, biocompatibility, MTX loading capacity, in-vitro cytotoxicity effects and drug targeting ability of the developed nanomicelles were also investigated. Finally, it is expected that the nanomicelles can be used as a novel platform for targeted delivery.

A novel gold-based stimuli-responsive theranostic nanomedicine for chemo-photothermal therapy of solid tumors.

The chemo-photothermal therapy performance of a novel theranostic nanoparticles that fabricated through the conjugation of HS-poly(ε-caprolactone)-block-poly(N-isopropylacrylamide)-block-poly(acrylic acid) (HS-PCL-b-PNIPAAm-b-PAA) and gold nanoparticles (GNPs) was extensively investigated. The GNPs@polymer conjugate theranostic NPs was loaded with doxorubicin hydrochloride (DOX) as an anticancer drug through electrostatic interactions to afford GNPs@polymer-DOX theranostic nanomedicine. Temperature and pH-triggered in vitro drug release behavior of the developed theranostic nanomedicine were also examined. The biocompatibility of the synthesized GNPs@polymer theranostic NPs was confirmed through the assessing survival rate of breast cancer cell line (MCF7) using MTT assay. In vitro cytotoxic effects of the GNPs@polymer-DOX theranostic nanomedicine was also evaluated against MCF7 cells in both with or without laser irradiation (532 nm, 145 mJ per pulse, 5 min) conditions, and the results obtained were compared with free DOX as the reference. As the results, the developed GNPs@polymer-DOX can be considered as theranostic nanomedicine for chemo-photothermal therapy of solid tumors.

Chitosan-grafted-poly(methacrylic acid)/graphene oxide nanocomposite as a pH-responsive de novo cancer chemotherapy nanosystem.

The aim of this study was the design and development of a novel de novo drug delivery system for cancer chemotherapy. For this purpose, chitosan (CS) functionalized using phthalic anhydride followed by 4-cyano, 4-[(phenylcarbothioyl) sulfanyl] pentanoic acid as a chain transfer agent (CTA) to afford CS-CTA macroinitiator. The synthesized CS-CTA macroinitiator was then copolymerized with methacrylic acid (MAA) monomer using reversible addition-fragmentation chain transfer (RAFT) polymerization technique to produce chitosan-graft-poly(methacrylic acid) (CS-g-PMAA) graft copolymer. Afterward, graphene oxide (GO) nanosheets were incorporated into the synthesized copolymer through the physical interactions. The CS-g-PMAA/GO nanocomposite was loaded with doxorubicin hydrochloride (DOX) as a universal anticancer drug. The biocompatibility, DOX-loading capacity, and pH dependent drug release behavior of the developed nanocomposite were also investigated. As the experimental results, as well as superior biological and physicochemical features of CS and GO, we envision that the developed CS-g-PMAA/GO nanocomposite may be applied as de novo drug delivery nanosystem for cancer chemotherapy.