Peptide- and Protein-Based Nanoparticles

The fundamental objective of research and development in nanomedicine is to develop more sensitive diagnostics and more effective therapeutics. The basic structure of a nanoparticle (NP) consists of a core, in which a therapeutic or imaging agent can be loaded, and surface components, which modify the nanoparticle by improving its stability, enhancing its solubility, aiding in its transport across the blood–brain barrier (BBB), or promoting its binding to a target at the site of interest. The surface of a nanoparticle can be tagged with various structures to improve its efficacy. Modification of the surface of the nanoparticle can add multivalent affinity that produces more robust anchoring, homing to multiple receptors, and activation of cell signaling pathways. Vault nanoparticles are natural ribonucleoproteins whose structure consists of several polypeptides and are universally present in all cell types across all species. Several peptides have been conjugated with polymeric nanoparticles and show that they increase drug accumulation and improve drug transportation. Nanoparticle conjugates are being developed to improve the transit of certain medications that otherwise could not cross the BBB or enter the central nervous system (CNS). Targeting a nanoparticle to a tumor cell can be made more specific by tagging the nanoparticle with an antibody that binds to a receptor on the tumor cell. Nanotechnology-based anticancer medicine is a developing field that seeks to design novel agents that selectively target cancer cells, improve cancer imaging and efficacy, and reduce the target effects of cancer treatment on normal structures. Basic, translational, and clinical researchers will continue to develop and test diagnostic agents and therapeutics that use nanoparticles, which may improve the treatment of presently disabling and incurable diseases.