Bioinspired collagen–hydroxyethyl cellulose hydrogels for sustainable agriculture: Water management and plant growth stimulation

The design of biodegradable hydrogels that enhance plant development while improving water management is gaining importance in sustainable agriculture. In this study, semi-interpenetrating polymer network (semi-IPN) hydrogels based on collagen and hydroxyethyl cellulose (HEC) were synthesized and evaluated for their physicochemical performance and plant cell interaction. Varying the HEC content (0–60 wt.%) modulated scaffold morphology, producing fibrillar-granular architectures with tunable gelation (3 min), superabsorbent capacity (>2800%), and thermal resistance. Increased HEC levels reduced chemical crosslinking (~27%) but improved mechanical stiffness (complex modulus up to 140 Pa), indicating strong physical interactions through hydrogen bonding. Biodegradability assays revealed rapid enzymatic degradation under collagenase exposure and slower hydrolytic and plant enzymatic breakdown, supporting scaffold stability during early plant development. When embedded in horticultural substrate, the hydrogels retained up to 92% of absorbed water and enabled gradual release over 15 days. Biological assays using tomato-derived plant cells (Solanum lycopersicum and Physalis philadelphica) confirmed that scaffolds with 20–40 wt.% HEC significantly enhanced cell adhesion, migration, metabolic activity, and proliferation. Seed germination studies in horticultural substrate further demonstrated that scaffolds containing 20 wt.% HEC promoted greater foliage development, while in vitro assays with MS-supplemented media revealed that C–HEC40% scaffolds effectively supported tomato growth through controlled sucrose delivery. These findings highlight collagen–HEC hydrogels as biodegradable, bioactive platforms with potential for moisture regulation, nutrient transport, and seedling support in environmentally responsible agricultural systems.