Crystallinity, antimicrobial activity and dyeing properties of chitosan-g-poly(N-acryloyl morpholine) copolymer

Evaluation of drug release efficiency and antibacterial property of a pH-responsive dextran-based silver nanocomposite hydrogel

The bioavailability of curcumin (CUR), a highly lipophilic and commonly used anticancer drug, is mainly affected by its poor solubility in aqueous environment and quick metabolism. These challenges can be met by employing delivery systems. Nanocomposite materials have been used as delivery systems to enhance the solubility and dissolution rate of the drug. This study aims to develop dextran-graft-poly(4-acryloylmorpholine) silver nanocomposite using a microwave-assisted method to evaluate its drug-release efficiency and antimicrobial activity. The materials were characterized by FT-IR, FE-SEM, EDS, XRD, HR-TEM, TGA, and BET techniques. Drug loading and release efficiency were evaluated using CUR as the model drug. The swelling and drug release studies were conducted in buffer solutions of pH 1.2 and 7.4. Staphylococcus aureus and Escherichia coli were employed to evaluate the antibacterial activity. The cytotoxicity was assessed by MTT assay against the breast MCF-10. Higher swelling and drug release were observed at pH 1.2 than 7.4. Nanocomposite hydrogel exhibited antibacterial activity against the tested bacterial strains. Cytotoxicity study proved the safety of the developed matrix. The results suggest the developed nanocomposite hydrogel to be a promising polymer matrix for the sustained release of CUR for cancer treatment that requires infectious control.

Utilization of marine and agro-waste materials as an economical and active food packaging: Antimicrobial, mechanical and biodegradation studies of O-Carboxymethyl chitosan/pectin/neem composite films

The present work deals with the eco-friendly preparation of highly degradable food packaging films consisting of O-CMC (O-Carboxymethyl Chitosan) and pectin, incorporated with neem (Azadirachta indica) leaves powder and extract. This study aimed to investigate the tensile properties, antimicrobial activity, biodegradability, and thermal behavior of the composite films. The results of tensile strength and elongation at break, showed that the incorporation of neem leaves powder improved the tensile properties (7.11 MPa) of the composite films compared to the neat O-CMC and pectin films (3.02 MPa). The antimicrobial activity of the films was evaluated against a panel of microorganisms including both gram-positive and gram-negative bacteria as well as fungi. The composite films exhibited excellent antimicrobial activity with a zone of inhibition (12-17.6 mm) against the tested microorganisms. The opacity of the composite films ranges from 1.14 to 4.40 mm-1 and the addition of fiber causes a decrease in opacity value. Biodegradability studies were conducted by Soil burial method and the films demonstrated complete biodegradability within 75 days. The results of thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) of composite films show that they are thermally stable and might be used in food packaging.

Cobalt oxide-chitosan based nanocomposites: Synthesis, characterization and their potential pharmaceutical applications

This research aimed to prepare, characterize, and investigate the biological efficacy of chitosan‑cobalt (II) oxide hybrid nanocomposites against a variety of micrograms. Analytical methods, FTIR, SEM, XRD, and EDX, were utilized to thoroughly characterize the produced CS-CoO nanocomposite. In FTIR spectra, the presence of the chitosan peaks in addition to that of CoO at 681 and 558 cm-1 confirmed that CoO molecules interact with the chitosan backbone. Moreover, in the XRD measurements, significantly less chitosan crystallinity was observed. Due to the incorporation of a larger amount of cobalt oxide within the polymer matrix. Applying the Debye-Sherrer calculation, the crystallite size was obviously reduced from 48.24 nm (5 wt %) to 19.27 nm (20 wt %) for the obtained nanocomposites. Furthermore, SEM measurements showed a transformation in the chitosan surface with the physical adsorption of CoO molecules on the surface active sites of chitosan that were visible in SEM graphs. Additionally, EDX determined the amount of Co element within the chitosan, with the sample of 20 wt % weight being found to be 19.26 wt %. The variable dose well-diffusion method was utilized to assess the efficacy of the CS-Co nanocomposite against a wide range of bacteria and fungi. CS - CoO nanocomposite is more effective than chitosan alone as an antibacterial agent against both Gram-positive and Gram-negative bacteria. Moreover, the MTT approach was employed to measure the cytotoxicity based on the cell viability of different cancer cell lines under different UV expositions. The proportion of the destroyed cells elevated due to the easy diffusion of CS - CoO nanocomposite into cancer cells as UV-free anticancer activity. UV exposition has stimulated the anticancer activity, which was attributed to an increase in ROS generation caused by the increased dose of the chitosan and its CS - CoO nanocomposites. Furthermore, the antioxidant capacities of the prepared nano-composites thin films were validated using the DPPH free radical scavenging method and showed good antioxidant activities with the DPPH radical compared with standard vitamin C. It has been noticed that by increasing the content of CoO nanoparticles from 5 to 20 wt %, the biological activity of the prepared nanocomposites was enhanced.

Fabrication of Bilayer Coating of Poly(3,4-ethylenedioxythiophene)-Halloysite/Chitosan and Mg2+/Sr2+-Doped HAP on Titanium Alloy for Biomedical Implant Applications: Physicochemical and In Vitro Biological Performances Studies

The prime objective of the present work is to develop biocompatible overlayer-deposited titanium alloys to replace already available titanium alloy-based biomaterials for implantation applications. Here, we prefer to use a bilayer coating on titanium alloys instead of single coating. The adhesion and biocompatibility of titanium alloy is improved by coating with a bilayer, for example, PEDOT-HNT/CS-MHA composite using the electrochemical deposition method. Corrosion behavior of the PEDOT-HNT/CS-MHA bilayer composite coating was investigated in the PBS medium by polarization studies. The functional groups, phase purity, surface morphology, and wettability of the PEDOT-HNT/CS-MHA were characterized by various instrumental techniques like FTIR, XRD, SEM, and contact angle techniques. From the above studies, it is proved that PEDOT-HNT/CS-MHA-coated Ti alloy showing a better biocompatibility and corrosion resistance than the PEDOT-HNT-deposited Ti alloy. In addition, the in vitro bactericidal and cell viability studies were also carried out to further confirm the biocompatibility of the protective coating. Hence, the bilayer deposition has shown excellent stability and biocompatibility and can be used for the potential biomaterials for orthopedics applications.

Synthesis of novel morpholine conjugated benzophenone analogues and evaluation of antagonistic role against neoplastic development

A series of novel 4-benzyl-morpholine-2-carboxylic acid N'-[2-(4-benzoyl-phenoxy)-acetyl]-hydrazide derivatives 8a-j has been synthesized from (4-hydroxy-aryl)-aryl methanones through a multi-step reaction sequence and then evaluated for anti-proliferative activity in vitro against various types of neoplastic cells of mouse and human such as DLA, EAC, MCF-7 and A549 cells. From the cytotoxic studies and structural activity relationship of compounds 8a-j, it is clear that methyl group on the B ring of benzophenone is essential for antiproliferative activity and bromo at ortho position (compound 8b) and methyl at para position (compound 8f) on A ring of benzophenone are significant for extensive anti-mitogenic activity. Investigation on clonogenesis and Fluorescence-activated cell sorting suggests that compounds 8b and 8f have the potency to exhibit the prolonged activity with cell cycle arrest on G2/M phase against cancer progression. Further, the compounds 8b and 8f inhibit murine ascites lymphoma through caspase activated DNase mediated apoptosis.

Utilization of a pyrrole derivative based antimicrobial functionality impregnated onto CaO/g-C3N4 for dyes adsorption

A novel functionalization of CaO/g-C₃N₄ based nanocomposite using 4,5-diphenyl-2-thioxo-2,5-dihydro-1H-pyrrole-3-cabonitrile (P3C@CaO–HCN) was fabricated for wastewater remediation from organic dyes and microbial pollutants.