Gradient dynamic cross-linked photochromic multifunctional polyelectrolyte hydrogels for visual display and information storage application

Facile fabrication and antibacterial properties of chitosan/acrylamide/gold nanocomposite hydrogel incorporated with Chaetomium globosium extracts from Gingko biloba leaves

Microorganisms are a unique part of our ecosystem because they affect the survival of living organisms. Although pathogenic microorganisms could be detrimental to the plants, animals, and humans, beneficial microbes have provided significant improvement in the growth and development of living organisms. In this study, the fungus Chaetomium globosium was isolated from the medicinal tree Gingko biloba, and then incorporated into a polymerization system to fabricate chitosan/acrylamide/gold (CS/Am/Au) nanocomposite hydrogels. The as-prepared hydrogel displayed increased mechanical strength due to the reinforcement of Au (gold) nanocomposites within the hydrogel matrix. Also, the equilibrium pH responsive swelling rates of the hydrogels gradually increased as the pH increases due to partial acid and basic hydrolysis occurring in the hydrogel as well as formation of hydrogen bond. In addition, the hydrogel demonstrated promising antibacterial activities against selected gram-positive (Staphylococcus epidermidis and Staphylococcus aureus) and gram-negative (Pseudomonas aeruginosa) bacterial strains with an average MIC90 of 0.125 mg/mL at a dosage of 1.0 mg/L. The obtained results are quite promising towards resolving several health challenges and advancing the pharmaceutical industries.

Influence of pH on the release of an active principle from 3D printed carrageenan-k combined with alginate or xanthan gum

The use of 3D printing began to diffuse in the pharmaceutical field in recent times, since 2015, with the approval of the first 3D printed drug from the FDA. The most used materials in association with this technique in this specific scope are hydrogels, already used widely in tissue engineering to produce scaffolds used in the realization of synthetic tissues. The aim of this project was to study the influence of different pH conditions on the release of a therapeutic molecule from a Carrageenan-k combined with alginate or xanthan gum hydrogel with a high level of biocompatibility and enough mechanical resistance to be used as printing material for a 3D bioprinter. The addition of biologically active supplements without affecting the model of the 3D printing structure of the biocompatible polymers was achieved by adopting the extrusion at moderately low temperatures. This study aimed to produce the necessary percentage of hydrogels which is responsible for the release of active drugs which respect to the pH of the system. In this case, the chosen curcumin drug which exhibits active release in the pH of the small intestine is a pH value of 6.