Marine collagen nanoparticles synthesized using Colpomenia sinuosa: Optimization, characterization, wound-healing...

In recent years, green-synthesized collagen nanoparticles have attracted growing attention for their exceptional physicochemical and biological characteristics. These characteristics highlight their importance in biomedical applications, including drug delivery, wound healing, cancer therapy, tissue engineering, and advanced diagnostics. This study presents a unique sustainable approach for producing collagen nanoparticles using an algal extract obtained from the brown macroalga, Colpomenia sinuosa. Biochemical analysis of the extract indicated a carbohydrate content of 5.33 mg g^-1 dry weight. Gas chromatography analysis showed that saturated fatty acids were predominant, mainly methyl palmitate, methyl stearate, and methyl myristate, which contributed 46.77%, 15.01%, and 11.24% of the total fatty acid methyl esters (FAMEs) peak area, respectively. UV-vis analysis showed a distinctive peak at 250 nm, while transmission electron microscopy examination revealed spherical particles with an average size of 15.8 ± 7.3 nm. The surfaces of collagen nanoparticles were negatively charged (-11.1 mV). Additionally, X-ray diffraction and selected area electron diffraction investigations confirmed their crystallinity. A rotatable central composite design was employed to optimize the collagen nanoparticles biosynthesis across 20 experiments, yielding a maximum of 20.1 mg/mL at 18.2 mg/mL collagen concentration, 4.5 days incubation, and pH 9.8. Their wound-healing activity reached 89%, compared to collagen (75.6%) and untreated human fibroblasts (54%). Collagen nanoparticles showed cytotoxic activity with an IC₅₀ value of 40.45 ± 0.75 μg/mL against colorectal adenocarcinoma cells in vitro, demonstrating strong anticancer potential. Computational analyses revealed that collagen nanoparticles disrupt extracellular matrix interactions, modulate immune responses, inhibit proliferative signaling, and reprogram cancer metabolism. These insights support their promising potential as anti-colorectal nanotherapeutics.