Green synthesis of chitosan/polyacrylic acid/graphitic carbon nitride nanocarrier as a potential pH-sensitive system for curcumin delivery to MCF-7 breast cancer cells.

A novel pH-sensitive nanocarrier containing chitosan (CS), polyacrylic acid (PAA), and graphitic carbon nitride (g-C3N4) was designed via water/oil/water (W/O/W) emulsification to administer curcumin (CUR) drug. g-C3N4 nanosheets with a high surface area and porous structure were produced via simple one-step pyrolysis process using thiourea as precursor, and incorporated into CS/PAA hydrogel. X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) were used to assess the crystalline structure of the nanocarrier and the interactions between its components, respectively. Scanning electron microscopy (SEM) images revealed a spherical structure and confirmed the g-C3N4 impregnation into the CS/PAA matrix. Zeta potential and dynamic light scattering (DLS) provided information about the surface charge and average size distribution. High CUR loading and entrapment efficiencies were obtained, which were further improved upon addition of g-C3N4. The release kinetics of drug-loaded CS/PAA/g-C3N4 nanocomposites were investigated at pH = 5.4 and pH = 7.4, and the results showed an excellent controlled pH-sensitive release profile. Cell apoptosis and in vitro cytotoxicity were investigated using flow cytometry and MTT analyses. CS/PAA/g-C3N4/CUR resulted in the highest rate of apoptosis in MCF-7 breast cancer cells, demonstrating the excellent nanocomposite efficacy in eliminating cancerous cells. CS/PAA hydrogel coated with g-C3N4 shows great potential for pH-sensitive controlled drug release.

Development of an antibacterial and antioxidative nanofibrous membrane using curcumin-loaded halloysite nanotubes for smart wound healing: In vitro and in vivo studies.

Endowing wound dressings with drug delivery capability is a suitable strategy to transfer medicinal compounds locally to damaged skin layers. These dressings are especially useful for accelerating the healing rate in the cases of long-term treatment, and adding more functionalities to the platform. In this study, a wound dressing composed of polyamide 6, hyaluronic acid, and curcumin-loaded halloysite nanotubes (PA6/HA/HNT@Cur) was designed and fabricated for wound healing applications. The physicochemical properties of this platform were investigated through Fourier-transform infrared spectroscopy and field-emission scanning electron microscopy. Moreover, wettability, tensile strength, swelling, and in vitro degradation were assessed. The HNT@Cur was incorporated in the fibers in three concentrations and 1 wt% was found as the optimum concentration yielding desirable structural and mechanical properties. The loading efficiency of Cur on HNT was calculated to be 43 ± 1.8%, and the release profiles and kinetics of nanocomposite were investigated at physiological and acidic pH. In vitro antibacterial and antioxidation studies showed that the PA6/HA/HNT@Cur mat had strong antibacterial and antioxidation activities against gram-positive and -negative pathogens and reactive oxygen species, respectively. Desirable cell compatibility of the mat was found through MTT assay against L292 cells up to 72 h. Finally, the efficacy of the designed wound dressing was evaluated in vivo; after 14 days, the results indicated that the wound size treated with the nanocomposite mat significantly decreased compared to the control sample. This study proposed a swift and straightforward method for developing materials that might be utilized as wound dressings in clinical settings.

Synthesis and characterization of a novel molecularly imprinted polymer for the controlled release of rivastigmine tartrate.

To develop novel imprinted poly (methacrylic acid) nanoparticles for the controlled release of Rivastigmine Tartrate (RVS), the amalgamation of molecular imprinting techniques and polymerization of precipitates were applied in this work. By permuting different concentrations of pentaerythritol triacrylate (PETA) or trimethylolpropane triacrylate (TMPTA) as cross-linkers, ten different samples were synthesized, and their abilities assessed for RVS absorption. Among them, uniform mono-disperse nanoparticles were synthesized in an RVS/PMAA/PETA mole ratio of 1:6:12, named molecularly imprinted polymers 2 (MIP2), which showed the highest RVS absorption. Analytical procedures involving the Fourier transform infrared (FT-IR), Thermogeometric analysis (TGA), Field emission scanning electron microscopy (FE-SEM), Dynamic light scattering (DLS), and absorption/desorption porosimetry (BET) measurements were applied to characterize the morphology and physicochemical properties of the MIP2. In addition, the cytotoxicity of the MIP2 sample was measured by MTT assay on an L929 cell line. Studies pertaining to the in-vitro release of RVS from MIP2 samples showed that the prepared sample had a controlled and sustained release compared, which differed from the results obtained from the non-imprinted polymer (NIP) with the same formulization. Results obtained further reinforced the feasibility of prepared MIPs as a prime candidature for RVS drug delivery to alleviate Alzheimer's and other diseases.

The Effect of Poly (Ethylene glycol) Emulation on the Degradation of PLA/Starch Composites.

As a hydrophilic renewable polymer, starch has been widely used in biocompatible plastics as a filler for more than two decades. The present study aimed at investigating the effects of polyethylene glycol (PEG), as a plasticizer, on the physicochemical properties of a hybrid composite-polylactic acid (PLA) and thermoplastic starch (TPS). A solvent evaporation process was adopted to gelatinize the starch and disparate PEG contents ranging from 3 to 15 wt.% (with respect to the sample weight) were examined. It was revealed that the increase in the PEG content was accompanied by an increment in the starch gelatinization degree. Referring to the microstructural analyses, the TPS/PLA mixture yielded a ductile hybrid composite with a fine morphology and a uniform phase. Nevertheless, two different solvents, including acetone and ethanol, were used to assess if they had any effect on the hybrid's morphology, tensile strength and thermal properties. It was found that ethanol culminated in a porous hybrid composite with a finer morphology and better starch distribution in the PLA structure than acetone. As the result of PEG addition to the composite, the crystallinity and tensile strength were decreased, whereas the elongation increased. The hydrolytic degradation of samples was assessed under different pH and thermal conditions. Moreover, the microbial degradation of the PLA/TPS hybrid composite containing different PEG molar fractions was investigated in the soil for 45 days. The rate of degradation in both hydrolytic and biodegradation increased in the samples with a higher amount of PEG with ethanol solvent.