Methylene Blue Release from Chitosan/Pectin and Chitosan/DNA Blend Hydrogels

Abstract

Chitosan/DNA blend hydrogel (CDB) and chitosan/pectin blend hydrogel (CPB) were synthesized using an emulsion (oil-in-water) technique for the release of methylene blue (model molecule). Both hydrogels were characterized by swelling assays, Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM), before and after the methylene blue (MB) loading. Higher swelling degrees were determined for both hydrogels in simulated gastric fluid. FT-IR spectra inferred absorption peak changes and shifts after MB loading. The TGA results confirmed changes in the polymer network degradation. The SEM images indicated low porosities on the hydrogel surfaces, with deformed structure of the CPB. Smoother and more uniform surfaces were noticed on the CDB chain after MB loading. Higher MB adsorption capacities were determined at lower initial hydrogel masses and higher initial dye concentrations. The MB adsorption mechanisms on the hydrogel networks were described by the monolayer and multilayer formation. The MB release from hydrogels was studied in simulated gastric and intestinal fluids, at 25 °C and 37 °C, with each process taking place at roughly 6 h. Higher release rates were determined in simulated gastric fluid at 25 °C. The release kinetics of MB in chitosan/DNA and chitosan/pectin matrices follows a pseudo-second-order kinetic mechanism.

3D Printed Chitosan-Pectin Hydrogels: From Rheological Characterization to Scaffold Development and Assessment

“…Thereafter, swelling continued increasing more slowly up to 1830% at day 7. Since pectin moieties were negatively charged with -COO- groups at pH 7.4, electrostatic repulsions were promoted and, thus, the swelling ability increased [ 55 , 56 ]. In this context, having a high swelling capacity is desirable in order to absorb wound exudates that could slow the wound healing and macerate the nearby skin [ 57 ].…”

An efficient pH‐responsive kappa‐carrageenan/tamarind kernel powder hydrogel for the removal of brilliant green and rose bengal from aqueous solution

“…By combining KCG with additional polymers through chemical crosslinking, a novel adsorbent with tremendous improved adsorption capabilities and enhanced properties might be developed. [46][47][48][49] For enhancing thermal stability, mechanical properties, and high adsorbent capacity, KCG was blended with natural polysaccharides like tamarind kernel powder (TKP) via chemical crosslinking. 50 TKP is a biodegradable and biocompatible galactoxyloglucan produced from Tamarindus indica kernels.…”

“…As a result, dealing with the improvement of physicochemical properties is a difficult issue in the formation of this bio‐adsorbent. By combining KCG with additional polymers through chemical crosslinking, a novel adsorbent with tremendous improved adsorption capabilities and enhanced properties might be developed 46–49 . For enhancing thermal stability, mechanical properties, and high adsorbent capacity, KCG was blended with natural polysaccharides like tamarind kernel powder (TKP) via chemical crosslinking 50 .…”

Direct visualization of the drug loading of single DNA origami nanostructures by AFM-IR nanospectroscopy

“…32 It should be noted that while the absolute position of this particular absorption band depends on the environment and the binding state of MB, it is almost always observed with similar intensities in the wavenumber range from about 1600 to 1700 cm −1 and may thus serve as a MB-specific marker band also in the case of intercalative DNA binding. 32,35–38 The observed increases in the intensities of the MB-specific absorption bands at the positions of the adsorbed DNA origami can be explained by local variations in the surface density of MB molecules due to their specific binding to the DNA origami triangles. The MB-specific bands between 1000 and 1250 cm −1 and between 1600 and 1700 cm −1 can also be resolved in the IR reflection absorption spectrum of the same sample investigated in Fig.…”