Additive-manufactured PLA scaffolds reinforced with agro-waste cellulose and microfiber: Toward high-performance bone regeneration biomaterials

This study addresses the need for sustainable, high-performance biomaterials for bone-regeneration applications by investigating additive-manufactured PLA scaffolds reinforced with 20 vol % silane-treated sorghum husk microfiber and varying amounts of silane-treated bagasse pith cellulose. Such agro-waste–derived fillers offer renewable, low-cost alternatives to conventional synthetic reinforcements while improving scaffold performance. Mechanical testing showed significant improvements over neat PLA, with PSC2 (3 vol% silane-treated cellulose) achieving the best overall performance: tensile strength of 135.3 MPa, flexural strength of 150.7 MPa, impact energy of 3.586 J, and hardness of 94.6 Shore D, attributed to enhanced interfacial bonding and uniform filler dispersion. Swelling and degradation tests confirmed PSC2 as the most hydrolytically stable composition, while PSC3 (5 vol % cellulose) exhibited superior fire resistance due to dense char formation. SEM analysis supported these findings, revealing fiber pull-out in PSC0, uniform dispersion in PSC2, and filler agglomeration in PSC3. Overall, the study demonstrates that controlled hybrid reinforcement using silane-treated agro-waste fibers and fillers can sustainably enhance mechanical, thermal, and hydrolytic properties, providing a balanced and eco-friendly solution for bone scaffold applications.