Sustainable Carboxymethyl Cellulose-Based Foams via Deep Eutectic Solvent Processing for pH-Responsive Drug Delivery

Area of Science:

• Materials Science
• Polymer Chemistry
• Sustainable Chemistry

Background:

• Carboxymethyl cellulose (CMC) materials are valuable for functional applications but often require unsustainable methods for stability.
• Conventional crosslinking methods for CMC-based materials involve energy-intensive thermal curing or toxic chemicals.
• There is a need for sustainable and eco-friendly approaches to produce stable CMC-based porous materials.

Purpose of the Study:

• To develop a sustainable method for preparing carboxymethyl cellulose (CMC)-based foams.
• To investigate the use of deep eutectic solvents (DES) as multifunctional structuring agents in CMC foam synthesis.
• To characterize the physicochemical properties and stimuli-responsive behavior of the resulting CMC-DES foams.

Main Methods:

• Preparation of CMC hydrogels using various DES at room temperature.
• Freeze-drying of hydrogels to form porous foam structures.
• Characterization of foam properties including water uptake, stability, morphology (SEM), mechanical strength (compression tests), and chemical interactions (FTIR).
• Evaluation of pH-dependent resveratrol release kinetics from the CMC-DES foams.

Main Results:

• CMC foams were successfully prepared using DES at room temperature, offering a sustainable alternative.
• Choline chloride:oxalic acid (1:1) with glycerol yielded foams with high water uptake (288.24%) and excellent 28-day water stability.
• Foams exhibited a homogeneous, interconnected porous network (32.2 µm) and good mechanical recovery (93.29% over 10 cycles).
• pH-dependent resveratrol release was observed, with limited release at acidic pH and significant release at neutral and alkaline pH.
• Drug release mechanisms varied from diffusion-controlled at acidic pH to anomalous transport at higher pH.

Conclusions:

• Deep eutectic solvents (DES) provide a sustainable and effective route for fabricating stable, porous carboxymethyl cellulose (CMC)-based foams.
• The developed CMC-DES foams demonstrate tunable, stimuli-responsive drug release capabilities, particularly pH-dependent release.
• These materials offer a promising physicochemical basis for developing advanced, eco-friendly porous matrices for functional and potential therapeutic applications, pending further biological validation.