Preparation of crystalline nanocellulose/hydroxypropyl β cyclodextrin/carboxymethyl cellulose polyelectrolyte complexes and their controlled release of neohesperidin-copper (II) in vitro.

A natural hydrogel film was prepared using carboxymethyl cellulose (CMC), cellulose nanocrystals (CNC), and hydroxypropyl β cyclodextrin (HP-β-CD) as reactants and citric acid as the cross-linking agent and used for the controlled release of neohesperidin-copper(II)(NH-Cu (II)). The hydrogel film was characterized by ATR-FTIR, XRD, TGA and DSC. The film showed controlled swelling behavior; the release behavior of NH-Cu(II) from the hydrogel film was also investigated in different solutions including distilled water, various salt solutions including 0.9% NaCl, and solutions having different pH values. Thiazolyl blue tetrazolium bromide assay and relative growth rates were adopted to evaluate the biocompatibility and cytotoxicity of the prepared hydrogel films. The results indicated that the expansion kinetics followed Fickian diffusion and Schott's second-order kinetics model. The hydrogel film exhibited enhanced mechanical properties and improved thermal stability at high temperatures due to the addition of CNC, with the amount of added CNC affecting the swelling ratio, salt sensitivity, and pH sensitivity of the hydrogel film in different solutions. Additionally, the CNC largely improved the loading and encapsulation efficiency of the hydrogel films, with the optimal CNC addition amount being 4% which yielded a loading amount of 753.75 mg/g and an accumulated release rate of 85.08%. The hydrogel film with proven cell compatibility and non-cytotoxicity can potentially be used as a drug delivery and controlled release material.