Mimicking secreted extracellular matrix-like hydrocolloid of SF/CS/CMC biological macromolecules for compounded...

ECM-mimicking hydrocolloid was developed from biological macromolecules and integrated with calcium carbonate (CaCO₃); an inorganic compound for bone mineralization to form compounded injectable plaster-like material for bone void filling. The hydrocolloid was composed of silk fibroin (SF), chitosan (CS), and carboxymethyl cellulose (CMC), prepared in various CS/CMC weight ratios (100/0 to 0/100) and labeled as Mimic-ECM-1 to Mimic-ECM-5. These were processed via LiBr and subsequent dialysis to induce self-organization and gelation. Their behavior and viscosity development were evaluated by UV-vis spectroscopy and viscometer. CaCO₃ was then combined with Mimic-ECM hydrocolloids at a 2:1 w/w ratio to fabricate the injectable plaster-like materials. Physicochemical characterization, including morphology, molecular organization as intermolecular interactions, and thermal behavior, was performed by SEM, FTIR, and DSC. Dimensional stability and mechanical properties were assessed during drying and compression, and the adsorb Mg²⁺ and Zn²⁺ ions was investigated through a kinetic model. All formulations demonstrated non-linear gelation and viscosity development, with Mimic-ECM-2 exhibiting the optimal balance among viscosity, morphology, and self-organization. SEM images confirmed CaCO₃-rich clusters and varying pore sizes. FTIR and DSC validated strong intermolecular interactions between the organic and inorganic phases. Mechanical assessment revealed that Mimic-ECM-4 and Mimic-ECM-1 exhibited the greatest strength, whereas Mimic-ECM-2 demonstrated appropriate softness, toughness, and Young's modulus suitable for surgical application. Ion adsorption investigations indicated that CS-rich plaster enhanced Mg²⁺ absorption, whereas CMC-rich plasters improved Zn²⁺. Overall, Mimic-ECM-2 exhibited the most balanced physicochemical and mechanical performance, confirming its potential as an injectable bone void filler for oral maxillofacial and orthopedic applications.