Streptomyces細胞無細胞システムを介して合成されたコラーゲンナノ粒子の生体製造、統計的最適化、および特性評価：がん治療への応用

Collagen nanoparticles (CollNPs) exhibit low antigenicity, high surface area, non-toxicity, and excellent biocompatibility, making them promising for diverse biomedical applications. This study reports, for the first time, an eco-friendly, sustainable microbial-mediated biosynthesis of CollNPs using the cell-free system of Streptomyces viridochromogenes. UV-Vis spectroscopy showed a distinct absorption peak at 240 nm. A synergistic modeling approach combining Central Composite Rotatable Design (CCRD) and Artificial Neural Networks (ANN) were used to optimize biosynthesis parameters. The ANN identified the predicted optimal conditions at pH 7, collagen concentration 20 mg/mL, incubation time 115 h, and temperature 32 °C, with a theoretical maximum yield of 19.87 mg/mL. Experimental validation confirmed the model's accuracy, yielding 19.1 mg/mL Sv-CollNPs, closely matched the theoretical prediction ANN exhibited higher predictive accuracy than CCRD, confirming its robustness for process optimization. TEM revealed hollow, spherical Sv-CollNPs with an average diameter of 30.41 nm. FTIR analysis identified NH, CH, C = O, and OH functional groups contributing to nanoparticles formation and stabilization. The ζ-potential was - 19.4 mV, indicating good colloidal stability. The Sv-CollNPs displayed strong antioxidant and anti-hemolytic activities, alongside notable anticancer activity . The IC₅₀ values were 7.94 ± 0.6 µg/mL (MCF-7), 13.89 ± 1.0 µg/mL (HepG2), and 22.06 ± 1.6 µg/mL (HCT116). In vivo experiments were conducted on six groups (n = 8 per group). Treatment with native collagen, Sv-CollNPs, and DOX reduced EAC tumor growth by  65.66%, 83.84%, and 85.86%, respectively. The combined treatment of Sv-CollNPs and DOX achieved the highest tumor inhibition (97.98%), exceeding the effects of the individual treatments. In conclusion, this study introduces S. viridochromogenes as a novel microbial source for collagen nanoparticles biosynthesis and demonstrates the superior predictive performance of ANN-based modeling. The findings reveal that biosynthesized Sv-CollNPs, especially when combined with DOX, exhibit strong therapeutic potential and represent an eco-friendly, innovative strategy for anticancer nanomedicine development.