Coating of spirulina and phycocyanin extracts with Fe3O4 magnetic nanoparticles by green synthesis, characterization, investigation of their antimicrobial and antioxidant effects

Phycocyanin is a natural pigment derived from cyanobacteria such as Spirulina, known for its strong antioxidant, anti-inflammatory, and immunomodulatory properties. Due to its high free radical scavenging capacity, it holds significant potential for medical and biotechnological applications. Spirulina, in addition to being recognized as a superfood rich in proteins, vitamins, and minerals, contains bioactive compounds that make it a promising biocompatible coating material in nanotechnological applications. In this study, the potential biomedical applications of Fe₃O₄ magnetic nanoparticles modified with phycocyanin and Spirulina were investigated. Fe₃O₄ nanoparticles were synthesized via a two-step co-precipitation method and coated with phycocyanin or Spirulina at different concentrations using an adsorption technique. The structural and morphological properties of the synthesized Fe₃O₄ nanocomposites were characterized using XRD, FTIR, and SEM techniques. Additionally, their antimicrobial activities against pneumonia-associated pathogenic bacteria (Agar well diffusion test, MIC test) and biochemical properties (total phenolic-flavonoid content and antioxidant activities: DPPH, CUPRAC, and FRAP tests) were evaluated. The results demonstrated that modifying Fe₃O₄ nanoparticles with natural biomolecules such as phycocyanin and Spirulina enhances their biocompatibility, reduces toxicity, and improves their functional properties. This study presents an innovative approach to promoting the use of natural biomolecules in nanotechnology, contributing to the development of a safe and effective platform for biomedical applications