Injectable hydrogel scaffolds composed of Nanocellulose derived from sugarcane bagasse and combined with calcium for Bone regeneration

Injectable in-situ forming hydrogel scaffolds (IHS) were prepared using TEMPO-oxidized nanofibrillated cellulose (TONFC) originating from sugarcane bagasse. TONFC (0.5%w/w) was prepared and characterized, then various concentrations of poloxamer 407 (P407) were added to prepare the thermo-responsive hydrogels. Two sources of calcium; Fujicalin® (DCP) or Hydroxyapatite (TCP), were utilized to prepare the calcium-enriched HIS loaded with the antiresorptive drug raloxifene hydrochloride. Physicochemical evaluation comprising the gelation temperature, drug content, injectability and in-vitro drug release were performed in addition to the examination of the morphological characters. The chosen formulation ‘Ca-IHS4’ consisted of TONFC, 15% P407 and 10% TCP displayed the most extended release pattern (for 12 days) with the smallest burst effect. SEM images of the in-situ formed scaffolds presented a highly porous 3D structure essential for cells migration, nutrient transport and tissue infiltration. Cell biology studies were performed using Saos-2 cells and proved that “Ca-IHS4” is biocompatible and has cell regenerative effect. These findings suggest that Ca-IHS4 presents a simple, safe and non-invasive platform for bone regeneration.