The Effect of Citric Acid on Crosslinking Behavior, Hemostasis, Calcium Ion Release, Swelling, and Cytotoxicity of Gelatin/Monetite Sponge for Dental Hemostatic Applications

ABSTRACT The hemostatic gelatin sponge is widely used in dental applications to control bleeding. This study investigates the effect of citric acid (CA) as a crosslinking agent for the gelatin sponges incorporated with monetite (CaHPO 4 ), offering a less toxic alternative to glutaraldehyde. Sponges were prepared using 10% w/v gelatin and 10% w/v monetite in distilled water, with CA added at varying concentrations (5%–30% w/w relative to gelatin content), followed by freeze‐drying and thermal treatment. FTIR analysis confirms that increasing CA enhances ester bond formation (1730–1715 cm −1 ), indicating higher crosslinking density with rising CA concentration. The swelling degree decreases markedly from ~2900% to 450% as CA content increases, while calcium ion release rises, reaching a maximum of 47.73 mg/L. MTT assay results indicate non‐toxic behavior and support cell viability for all samples as it exceeds the control's OD value at 0.145. Hemolytic activity of monetite‐gelatin sponges containing 5% CA remained within the acceptable 5% limit, indicating that the material is still relatively hemocompatible. However, higher citric concentration tended to increase the hemolysis rate. Overall, CA effectively enhanced crosslinking, biocompatibility, and calcium ion release for improved hemostatic performance, but its concentration must be carefully optimized to maintain balance between functionality and hemocompatibility.