Water Uptake as a Crucial Factor on the Properties of Cryogels of Gelatine Cross-Linked by Dextran Dialdehyde

Abstract

We investigated the water sorption properties of macroporous cryogels of gelatine (Gel) and dextran dialdehyde (DDA) prepared via cryogelation at 260 K and following the freeze drying processes. Water vapour sorption isotherms for aerogels were studied at 293 K by two independent methods: static-gravimetric and dynamic vapour sorption (DVS) over a water activity range of 0.11–1.0. Experimental data were fitted by use of the Brunauer–Emmett–Teller (BET) and Guggenheim–Anderson–de Boer (GAB) models. The BET model (for a water activity range of 0.1 ≤ p/po ≤ 0.5) was used to calculate the sorption parameters of the studied cryogels (the monolayer capacity, surface area and energy of interaction). In comparison with BET, the GAB model can be applied for the whole range of water activities (0.1 ≤ p/po ≤ 0.95). This model gave an almost perfect correlation between the experimental and calculated sorption isotherms using nonlinear least squares fitting (NLSF). Confocal Laser Scanning Microscopy (CLSM) was used to confirm the structural differences between various DDA:Gel cryogel compositions. Thermogravimetric analysis and DSC data for aerogels DDA:Gel provided information regarding the bonded water loss, relative remaining water content of the material and the temperature of decomposition. Estimation of the amount of bound water in the cryogels after the freeze drying process as well as after the cycle of treatment of cryogels with high humidity and drying was performed using DSC. The results of the DSC determinations showed that cryogels with higher gelatin content had higher levels of bonded water.

Preparation and Characterization of Biodegradable Sponge-like Cryogel Particles of Chitosan via the Inverse Leidenfrost (iLF) Effect

“…Furthermore, acetic acid was used as a solvent to dissolve chitosan. The nature of the cross-linking agent, polymer, solvent, and the reaction conditions (i.e., temperature, concentration, and duration) affect the structure and the chemical characteristics of the resulting chemically cross-linked network . As a solvent, acetic acid might significantly impact the interaction between chitosan and glutaraldehyde.…”

“…The nature of the cross-linking agent, polymer, solvent, and the reaction conditions (i.e., temperature, concentration, and duration) affect the structure and the chemical characteristics of the resulting chemically cross-linked network. 28 As a solvent, acetic acid might significantly impact the interaction between chitosan and glutaraldehyde. Moreover, due to the viscosity of the solution, the solvent could affect the characteristics and physical form of the cryogels.…”

Formulation of Polymers-Based Methotrexate Patches and Investigation of the Effect of Various Penetration Enhancers: In Vitro, Ex Vivo and In Vivo Characterization

“…This might be due to the presence of maximum amount of hydrophilic polymer (HPMC). The formulation F9 exhibited low rate of water vapor transmission, due to presence of maximum concentration of hydrophobic polymer [ 32 ]. The formulated patches depicted good folding endurance value.…”

Impact of Hydroxyapatite on Gelatin/Oxidized Alginate 3D-Printed Cryogel Scaffolds

“…The impact of HAp particles on viscosity and the resulting printing accuracy of hydrogels has been previously report [33,34] for Gel/Alg/HAp hydrogels, which is in line with our observations. The physical characteristics of the scaffold, including its capacity to absorb bodily fluids, define vital parameters for tissue growth, such as cell proliferation, nutrient/waste transport, degradation, and ECM deposition rates [35]. The duration of bone tissue formation greatly depends on the cell type, scaffold characteristics, and conditions provided, and can last from a few weeks to several months to achieve full maturation [36,37].…”