Isolation of cellulose microfibers from banana plant residues and their conversion into sustainable and biocompatible 3D printable hydrogels for drug delivery

Abstract

Cellulose microfibers extracted from banana plant residues were used to develop sustainable hydrogels by dissolving them in a sodium hydroxide-urea solvent and cross-linking with epichlorohydrin. Three formulations (2 %, 3 %, and 4 % w/v cellulose microfiber content, designated as 2CH, 3CH, and 4CH) were synthesized and evaluated for their structural, mechanical, and biological properties. The lyophilized hydrogels exhibited highly macroporous structures (>90 % porosity). Increasing microfiber concentration led to greater chain entanglement, reducing the equilibrium swelling ratio by approximately 1.5-fold per 1 % increase in microfiber content. The hydrogels showed soft yet flexible mechanical behavior, with compressive moduli of 100 ± 42 Pa (2CH) and 625 ± 91 Pa (4CH), and exhibited viscoelastic properties, including shear-thinning and thixotropic recovery. Enzymatic biodegradation studies over 28 days revealed higher degradation for 2CH (93.47 ± 2.63 %) compared to 3CH (77.04 ± 2.17 %) and 4CH (66.44 ± 3.47 %), indicating that increased microfiber content enhanced the stability. The hydrogels demonstrated excellent cytocompatibility with HaCaT (keratinocyte), McCoy (fibroblast), and THP-1 (monocyte) cells. Additionally, hydrogel facilitated the cell attachment and proliferation of McCoy and THP-1 cells. Immunocompatibility of developed hydrogel was confirmed through the retention of mononuclear morphology of THP-1 cells cultured on hydrogel and CD14 immunostaining assay. Beyond this, the hydrogels significantly promoted fibroblast migration when checked by transwell co-culture. Notably, the 3CH hydrogel exhibited superior 3D printability and controlled drug release potential, making it a promising candidate for skin-related biomedical applications. Overall, this study highlights the potential of cellulose microfiber-based hydrogels as sustainable, biocompatible materials with tunable properties for implantable medicines and soft tissue engineering.