A CMC-g-poly(AA-co-AMPS)/Fe3O4 hydrogel nanocomposite as a novel biopolymer-based catalyst in the synthesis of 1,4-dihydropyridines

Synthesis and characterization of self-healable supramolecular hydrogel based on carboxymethyl cellulose for biomedical applications

Hydrogels have been widely used in biomedical fields including tissue engineering, drug delivery and cell delivery and 3D cell delivery due to abundant water content in their hydrophilic three-dimensional networks and having soft tissue similar to the human body. In recent years, supramolecular hydrogels (SHG) formed by the inclusion complex between polyethylene glycol (PEG) and macrocycles such as cyclodextrin (CD) have attracted much interest due to their excellent biocompatibility and great potential in biomedical. In this research, a carboxymethyl cellulose (CMC)-based graft copolymer was prepared by using acrylic acid (AA) and maleic anhydride functionalized β-CD (β-CD-MA) as comonomers and ammonium persulfate (APS) as initiator. Then, a self-healable supramolecular hydrogel was synthesized by formation of a host-guest inclusion complex between CMC-g-poly (AA-co-β-CD-MA) as host molecule and cytosine- and guanine-modified PEG as guest molecules. The prepared hydrogel was characterized by Scanning Electron Microscope (SEM), X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Nuclear magnetic resonance spectroscopy (1H NMR). The thermal stability of hydrogel was also determined by thermal gravimetric (TGA) and differential scanning calorimetry (DSC) methods. In addition, the loading and release profiles of metformin hydrochloride (MH) drug as a model on hydrogel was investigated. The results indicated that the drug release from the hydrogel peaks around 360 min and aligns with the Ritger-Peppas model. The hydrogel's self-healing property was examined at ambient temperature and 37 °C. It showed 70 % healing in 1.5 h and completed recovery after 9 h.

A versatile magnetic nanocomposite based on cellulose-cyclodextrin hydrogel embedded with graphene oxide and Cu2O nanoparticles for catalytic application

The study focused on creating a novel and environmentally friendly nanocatalyst using cellulose (Cell), β-Cyclodextrin (BCD), graphene oxide (GO), Cu2O, and Fe3O4.The nanocatalyst was prepared by embedding GO and Cu2O into Cell-BCD hydrogel, followed by the in-situ preparation of Fe3O4 magnetic nanoparticles to magnetize the nanocomposite. The effectiveness of this nanocatalyst was evaluated in the one-pot, three-component symmetric Hantzsch reaction for synthesizing 1,4-dihydropyridine derivatives with high yield under mild conditions. This novel nanocatalyst has the potential for broad application in various organic transformations due to its effective catalytic activity, eco-friendly nature, and ease of recovery.