Phyco-synthesized inorganic nanoparticles and their biomedical applications

Marine macroalgae have long been utilized commercially and industrially in food, pharmaceutical, and cosmetic industries. The current trend is to synthesize nanoparticles (NPs) utilizing marine macroalgae as they are a rich source of bioactive compounds. Utilization of marine macroalgae and algal-based polysaccharides is becoming a trendsetter as a simple, cost-effective, sustainable method to synthesize metallic and metallic oxide NPs, thus opening up a new field known as phyco-nanotechnology. Due to safe and biocompatible nature, macroalgae based NPs are investigated for their biological activities such as antibacterial, antifungal, antiviral, anti-inflammatory, anticancer and antioxidant activities. This review focuses on metallic and metallic oxide NPs synthesized from marine macroalgae and their biological activities, with a detailed comparison of how various types of NPs differ in their mechanisms to highlight their distinct effects and potential biomedical applications. Furthermore, current innovations of marine macroalgal polysaccharides such as alginate, fucoidan, and ulvan based NPs as well as their promising opportunities in biomedical applications and therapeutics are also reviewed.