Food-grade fish oil supplementation promotes membrane and redox stability during cryopreservation of aquatic biomaterials

The development of food-compatible strategies represents a critical advancement for the cryopreservation of aquatic biomaterials. This study evaluated the efficacy of food-grade fish oil (FO) as a synergistic adjunct within a standard DMSO-based cryomedium. Supplementation with 0.1% FO significantly increased the post-thaw viability of fish ovarian cells from 63.52% to 78.25% compared to the control (n = 6 biological replicates). Ultrastructural and functional analyses confirmed that FO treatment effectively maintained mitochondrial integrity (n = 3) and membrane potential (n = 6). Furthermore, FO supplementation mitigated oxidative stress by lowering MDA levels and modulating the expression of stress-response genes, specifically downregulating HSP70 and lamp3 (n = 6). Crucially, functional recovery was demonstrated by a shortened population doubling time (206.71 h, n = 6) and a 36.67% engraftment efficiency in a xenotransplantation model (n = 3). These findings establish FO as a potent, food-compatible supplement for optimizing conventional cryopreservation protocols in biotechnology.