Drug targeting by surface cationization.

Cationization of drug products and carriers involves a direct modification or attachment of conveying or accompanying components, either of which cause a charge modification. Cationization of macromolecules such as proteins and nucleotides and particulate drug carriers generally enhances their cellular uptake by endocytosis. The most common use of cationization today is in gene delivery. This is undertaken by either employing cationic polymers or entraping nucleotides in cationic carriers such as cationic liposomes. Cationized delivery systems are also used to overcome biological barriers and are suggested for drug targeting, in a nonspecific manner, to a variety of body organs, including brain, eyes, nose, and inflamed intestinal epithelium. Protein cationization is also suggested both for tumor immunotherapy and as a diagnostic tool in cancer therapy. Cationization has proven itself to be a straightforward tool for targeting to cells, tissues, and selected organs. This article reviews the extensive range of applications of cationization for improving drug and gene delivery and summarizes major technologies employed for that purpose.