The present invention generally relates to particles, including nanoparticles, for example, for
drug delivery or other applications. Certain aspects of the present invention are generally
directed to particles, such as nanoparticles, comprising an inner portion and a coating. The
inner portion may contain insulin or other therapeutic molecules for delivery to a living
organism. In some cases, the molecules may be electrostatically complexed with an
oppositely-charged peptide, such as an oligoarginine, or other species. The therapeutic …