<span lang="EN-GB">Capecitabine Release Kinetics in Gelatin-PVA-MMT Clay Bio-Nanocomposite Hydrogels: Size and MMT Content Effects

Despite their importance and wide applications, the effectiveness of traditional cancer treatment methods is limited due to the side effects and toxicity of anti-cancer chemicals on normal tissues. To address these limitations, increasing attention has been devoted to developing controlled drug delivery systems. This study aimed to develop and characterize bio-nanocomposite hydrogels based on polyvinyl alcohol, gelatin, and montmorillonite (MMT) clay for controlled capecitabine delivery. The bio-nanocomposite hydrogels with varying MMT contents (۰, ۵, and ۱۰ wt.%) were prepared using a freeze-thaw method. The microstructural properties of the prepared hydrogels were characterized By X-Ray Diffractometry (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), and gel fraction analysis. The prepared bio-nanocomposite hydrogels were then loaded with the anti-cancer drug capecitabine to investigate the drug release behavior. XRD analysis confirmed the complete exfoliation of MMT within the polymer matrix, as evidenced by the disappearance of the characteristic MMT peak. FE-SEM observations revealed that increasing the MMT content resulted in a denser microstructure with more numerous but smaller pores. Drug release studies indicated that the release kinetics of capecitabine depend on both the hydrogel dimension and the amount of incorporated MMT. The drug transport mechanism was studied by fitting experimental data to the Korsmeyer-Peppas and Peppas-Sahlin models. Results demonstrated that in MMT-free samples, the predominant drug release mechanism was Fickian diffusion, whereas in the presence of MMT, chain relaxation played a more dominant role in drug transport. The content of incorporated MMT appeared to have a noticeable effect on the drug release mechanism. Samples with lower MMT content showed a higher relaxation-to-Fickian ratio. With a further increase in the MMT content, the contribution of polymer relaxation decreased. This change was more pronounced in low-thickness samples. Overall, the drug release mechanism was significantly affected by the MMT clay content and the shape of the samples.

کلیدواژه ها:

Hydrogel ، Bio-nanocomposite ، Drug release ، Gelatin ، Polyvinyl alcohol ، MMT