Naturally Occurring Bioactive Compound‐Derived Nanoparticles for Biomedical Applications

Bioactive, small molecular compounds from a variety of plants and organisms have tremendous potential for use as treatments for cancer, microbial infections, inflammatory diseases, and other medical conditions. There have also been attempts to use naturally occurring bioactive compounds as delivery carriers. Such bioactive, natural compound‐derived nanocarriers are expected to have better biocompatibility than synthetic material‐derived drug‐delivery systems and also exhibit intrinsic therapeutic efficacy. Despite these expectations, however, research on the topic is limited and thus has been the subject of very few reviews. Here, the authors describe carriers derived from four typical naturally occurring bioactive compounds—curcumin, resveratrol, epigallocatechin gallate (EGCG) (an active ingredient in green tea), and bilirubin—that have been used for biomedical applications. In this review, the pros and cons of each bioactive small molecular compound and processes for synthesizing and preparing these compound‐derived delivery carriers are discussed. A number of examples that show the potential of these delivery carriers as disease treatments are considered, and their future prospects for biomedical applications are assessed. Nanoparticles that simply encapsulate or encase such bioactive compounds are outside the scope of this review and thus are not considered.