Injectable carboxymethylcellulose hydrogels for soft tissue filler applications

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Polymer Chemistry

Background:

• Soft tissue deficits due to disease, trauma, or aging necessitate effective restorative materials.
• Current gold standards like autogenous fat have limitations, and hyaluronic acid (HA) fillers can cause adverse reactions due to their origin.
• A need exists for safer, affordable, and plant-derived alternatives for soft tissue augmentation.

Purpose of the Study:

• To characterize a novel plant-derived carboxymethylcellulose (CMC) hydrogel as an injectable soft tissue filler.
• To evaluate the influence of macromer concentration on the physical, mechanical, and degradation properties of the CMC hydrogel.
• To assess the cytocompatibility of the developed CMC hydrogel with human dermal fibroblasts.

Main Methods:

• Methacrylated CMC was synthesized and crosslinked into hydrogels using a redox initiation system (ammonium persulfate/ascorbic acid) at varying concentrations (2-4% w/v).
• Equilibrium Young's modulus, swelling properties, rheological behavior (gelation kinetics), and hydrolytic/enzymatic degradation were analyzed.
• Cytocompatibility was assessed through co-culture with human dermal fibroblasts.

Main Results:

• Hydrogel properties, including Young's modulus (∼2–9.25 kPa), swelling, crosslinking density, and mesh size, were tunable with macromer concentration.
• Rheological analysis confirmed gelation within ISO standards for injectable materials.
• Degradation profiles were sensitive to macromer concentration, and enzymatic degradation was demonstrated. The hydrogels showed favorable cytocompatibility.

Conclusions:

• Redox-crosslinked CMC hydrogels offer tunable properties by adjusting fabrication parameters, presenting a versatile platform for soft tissue filler applications.
• The plant-derived nature and demonstrated biocompatibility suggest potential for a safer and more affordable soft tissue filler alternative.
• Further development of these CMC-based hydrogels could address the limitations of existing soft tissue augmentation materials.