Recent advances of nanocellulose in drug delivery systems

Background: Nanocellulose, which possesses great physical, chemical, and biological properties, is a natural polymer derived from widely available native cellulose. It has outstanding properties such as high mechanical strength, stiffness, low weight, biocompatibility, and renewability, which are beneficial for the design of advanced drug delivery systems, as either an excipient or a carrier. Area covered: This review introduces three types of nanocellulose: cellulose nanocrystals, cellulose nanofibers, and bacterial cellulose. Their physical and chemical properties along with their methods of preparation are also compared. Recent studies of nanocellulose for various drug delivery applications are summarized and discussed. Selected nanocellulose studies with significant findings for oral, ocular, intratumoral, topical, and transdermal delivery are also emphasized. Expert opinion: Nanocellulose has potential for drug delivery applications due to its high surface area-to-volume ratio and high polymerization, which provide nanocellulose with a high loading and binding capacity for active pharmaceutical ingredients, enabling the control of the drug release.