Colloidal nanoparticles as pharmaceutical agents

Colloidal nanoparticles can be designed and utilized as pharmaceutical agents due to their unique physicochemical properties, which are beneficial for therapeutic purposes. While traditional applications use nanoparticles as inert carriers for drug transport, this chapter presents their application as active therapeutic agents that enable modulation of pharmacokinetic and pharmacodynamic characteristics. Such therapeutically active nanoparticles include nanoparticles that allow autonomous activity based on the integration of drugs as an essential part of the nanomaterial, induction of reactive oxygen species, ferroptosis, or autophagy. Another form of therapeutically active nanoparticles translates exogenous energy into therapeutic effects: they serve as antennas for external light, magnetic fields, X-rays, or ultrasound used to generate heat or reactive oxygen species, sensitize the target tissue to radiation and localize tissue exposure. Finally, therapeutically active nanoparticles may serve in immunotherapy by stimulating, modulating, or enhancing immune responses. This review summarizes different principles and mechanisms of therapeutic nanoparticles.