| Abstract [eng] |
This study focused on the development of physically crosslinked molecularly imprinted conducting hydrogel composites for tetracycline delivery. The work aimed to fabricate PVAMCC hydrogels containing molecularly imprinted PPy and to evaluate their drug loading, swelling behaviour, pH-responsive release, and potential for electrically stimulated release. PPy molecularly imprinted polymer powder was synthesized using tetracycline hydrate as the template molecule, followed by solvent extraction to create selective recognition cavities. The PPy–MIP powder was incorporated into PVA–MCC hydrogel matrices at different concentrations and crosslinked using freeze–thaw cycles. The resulting hydrogels were characterized using UV–Vis spectroscopy, swelling studies, drug loading experiments, release studies, kinetic modelling, and FTIR analysis–Vis analysis confirmed that tetracycline hydrate exhibited absorption maxima at approximately 275 nm and 360 nm, with 360 nm selected for quantitative analysis due to better specificity and sensitivity. The calibration curve showed excellent linearity, supporting reliable quantification of tetracycline in loading and release studies. Swelling studies showed that increasing PPy–MIP content reduced hydrogel swelling, indicating that PPy incorporation restricted water uptake and network expansion. Drug loading was highest in the 0.2% PPy–MIP formulation, suggesting an optimal balance between available binding sites and hydrogel permeability. Drug release studies demonstrated clear pHdependent behaviour, with the highest tetracycline release observed under acidic conditions, followed by physiological pH, and the lowest release under alkaline conditions. Kinetic modelling indicated that the release mechanism was mainly diffusion-controlled, with the Higuchi and Korsmeyer–Peppas models showing the best fit. In contrast, electrical stimulation at −1 V did not significantly enhance tetracycline release compared with passive release. This limited electro-responsive behaviour was likely due to poor PPy dispersion, insufficient conductive pathways, masking of PPy by the PVA–MCC matrix, and weak electrode–hydrogel contact. Overall, the developed PPy–MIP/PVA–MCC hydrogel system demonstrated potential as a pH-responsive tetracycline delivery platform. However, further optimisation of PPy dispersion, electrode interface design, hydrogel conductivity, and formulat ion composition is required to achieve reliable electrically triggered drug release. |
