Farmed yellow croaker swim bladder was supplied by Gao Shun Hang Co., Ltd. (Guangzhou, China). Microcrystalline cellulose (MCC) (α-Cellulose (C6H10O5) n, CAS 9004-34-6) and glutaraldehyde (C5H8O2, purity≥99.8 %) were provided by Macklin Biochemical Co., Ltd. (Shanghai, China). Concentrated sulfuric acid (H2SO4, AR) and phosphate buffer solution (PBS, pH 7.5) were procured from Tianjin Kemiou Chemical Reagent Co., Ltd. (Tianjin, China). Anhydrous sodium carbonate (Na2CO3) with 99.0 % purity was