Self-assembled glucose-cored poly (aryl ether) dendron gel for efficient encapsulation and controlled release of guest molecules

Abstract

Event Abstract Back to Event Self-assembled glucose-cored poly (aryl ether) dendron gel for efficient encapsulation and controlled release of guest molecules Ramya Kannan1, Vignesh Muthuvijayan2 and Edamana Prasad1 1 Indian Institute of Technology Madras, Department of Chemistry, India 2 Indian Institute of Technology Madras, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, India Introduction: Dendrimers/dendrons are well-defined, monodisperse compounds with repeating subunits from a core unit. Self-assembled dendritic systems have been examined for their efficiency to carry and deliver drug molecules in a controlled fashion[1],[2]. Nonetheless, utilizing self-assembled lower generation dendritic structures for drug loading/release has rarely been reported. The proposed work involves the design, synthesis of lower generation dendron-based gel for controlled guest release kinetics under in vitro conditions. The lower generation dendron is designed with complementary chemical functional groups at the periphery so that the amphiphilic dendrons self-assemble to form robust gel with an extensive three dimensional fibrous network, making it an ideal guest release system with controlled release kinetics. Materials and Methods: The first generation (G1) poly (aryl ether) dendron containing glucose moiety, attached through an acyl hydrazone spacer unit, was synthesized based on a previous reported procedure[3]. and estimated using Nuclear magnetic resonance spectrometry (NMR) and Mass spectrometry (MS). The glucose attached poly (aryl ether) dendron self assembles in a solvent mixture (DMSO:Water) to form a stable gel with a critical gelation concentration of 0.1wt%. Structural,morphological and viscoelastic property of the gel was analysed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and rheology measurements. The dendron gel was further loaded with model hydrophilic and hydrophobic dyes and evaluated for its loading efficiency. The release was monitored in vitro in PBS medium at pH 7.4 and release kinetics was fitted with the Peppas model to find out the exponential coefficient, so that an approximate mechanism of the drug release can be elucidated. Results and Discussions: Structure and morphology of the dendron gel were analysed by NMR, Mass spectrometry, FTIR and SEM. SEM images indicate a dense fibrous network of the xerogel (dried gel). FTIR spectrum shows a distinct shift in IR bands of carbonyl groups upon gelation, indicating extensive intermolecular hydrogen-bonding. The amplitude and frequency sweep of the dendron gels exhibited larger values of G’ (storage moduli) compared to the G" (loss moduli) and also showcased a concentration dependent viscoelasticity property of the dendron gel. Maximum loading efficiency of the dendron gel was confirmed by inverted vial method[4] and found that the amount of loading is a function of gelator concentration, molar mass and solubility of the dye. The release kinetics of the dyes from 0.5wt % and 0.7 wt% dendron gels demonstrated sustained release in comparison with the experimental control and curve fitting using Peppas model shows a good fit for the first 60% of the release profile. The exponential coefficient validated non-Fickian diffusion from the dendron gel. Conclusion: In summary, we report a simple dendron based gel to efficiently encapsulate and release small guest molecules under in-vitro conditions. Structural, morphological and viscoelastic studies validated the self-assembly of the dendron. In addition, investigations of the dye release behaviour of dendron gel suggests that the molecules are promising candidates for hosting suitable drug molecules with controlled release kinetics under in vivo conditions[5],[6]. We thank Interdisciplinary program, Department of Chemistry and Department of Biotechnology , IIT Madras for their support; We thank DST-Inspire for the fellowship