Natural biopolymers combined with metallic nanoparticles: a view of biocompatibility and cytotoxicity

Combining polymers with various nanomaterials has resulted in considerable advances in applying polymer science to nanomedicine in medical approaches. However, most of these applications ultimately seek to perfectly mimic different tissues and organs within the treatment host to avoid potential disruptions in their functionality and viability. Despite a wide array of available polymers, only those from natural sources, known as natural biopolymers, can trigger properties similar to those in biological tissue. Combining natural biopolymers with nanomaterials can improve mechanobiological properties, speed healing, and enhance integration within the host tissue. Metal-based nanomaterials have been employed in recent decades as suitable agents in composites with natural biopolymers. Nevertheless, they often suffer from a lack of biocompatibility and cytotoxicity, hindering some potential biomedical applications for these composites. Despite these shortcomings, extensive research has been done to find the perfect balance in the composition or ratio of both components—natural biopolymers and metal-based nanoparticles—to trigger the most desirable outcome. This chapter reviews and discusses the most recent advances in this field, with a special focus on how combining metal nanoparticles with natural biopolymers from bacterial, plant, and animal sources can improve the biomedical applications of these novel nanobiological composites.