Effect of surfactant on the swelling and mechanical behavior of NIPAM-based terpolymer

Preparation of interpenetrating networks from chitosan and poly(hydroxypropyl methacrylate) or p(hydroxyethyl methacrylate) for controlled release of doxorubicin and curcumin: Investigation of potential use in wound dressing

The IPNs hydrogel films based on chitosan (CS), 2-hydroxyethyl methacrylate (HEMA), and 2-hydroxypropyl methacrylate (HPMA) were prepared, and their potential for drug delivery and wound dressing was evaluated. The characterizations of the IPNs were examined through swelling tests, FTIR, DSC, SEM, mechanical properties, and BET analyses. The percent swelling of the CS/p(HEMA)1 and CS/p(HPMA)1 were obtained as 240 % and 110 %, respectively. The release behavior of prepared hydrogel formulations was investigated in two different pH values for DOX and CUR at pH 5.5 and 7.4, respectively, at varying drug concentrations. In vitro, drug release profiles revealed a time-dependent release pattern, with a maximum release observed at 48 h for all formulations. Among the IPNs, CS/p(HEMA)1 formulation containing CS/HEMA in a 1:1 ratio showed the highest drug release rates of 76.0 % for doxorubicin and 75.5 % for curcumin. MTT assays revealed that the IPNs formulations exhibit enhanced interaction with drugs, leading to an improved drug release rate. A marked decrease in cell viability was observed as the concentration of both drugs increased for testing the ATCC-CRL 2451 leukemia cell line in the prepared formulations. These findings highlight the potential of these composite hydrogels as efficient drug delivery systems for wound dressing applications.

Multi-responsive PNIPAM-PEGDA hydrogel composite

Hydrogels are widely used in applications such as soft robots and flexible sensors due to their sensitivity to environmental stimuli. It is highly demanded to develop multiple-responsive hydrogel structures. In this work, we employ the 3D printing technique to fabricate a PNIPAM-PEGDA hydrogel bilayer that can change shape through controlling the temperature, solvent mixture and magnetic field. The PNIPAM gel is a typical thermo-responsive gel, showing a decrease in swelling ratio with increasing temperature. Meanwhile, the PNIPAM gels also exhibit the cononsolvency effect in ethanol-water mixtures with a smaller swelling ratio in the mixture compared with that in each pure solvent. In comparison, the swelling ratio of PEGDA gels is insensitive to changes in both the temperature and solvent composition. Thus, the bilayer structure of PNIPAM-PEGDA can bend in different directions and with different angles with changing the temperature and solvent composition. Finally, Fe₃O₄ nanoparticles are incorporated into the matrix of PEGDA gels, endowing the whole structure with deformation and motion in response to an external magnetic field.