Pullulan based derivatives: synthesis, enhanced physicochemical properties, and applications

Drug distribution relies heavily on polymers, which also offer a variety of benefits like controlled release, targeted release, prolonged release, etc. Due to their low toxicity and great safety, biodegradable polymers are highly preferred. The exopolysaccharide known as pullulan is generated from a fungus known as Aureobasidium pullulan. It has many different qualities, including biodegradability, appropriate adhesion, antioxidant, film-forming capacity, blood compatibility, mucosal adhesion, etc. However, its application in the pharmaceutical industry is restricted by its insolubility in organic solvents, mechanical characteristics, and lack of macromolecule-carrying ability groups. This review provides an overview of the modifications made to pullulan, including periodate oxidation, etherification, esterification, sulfation, urethane derivatization, PEG incorporation, and cationization, to enhance its solubility in organic solvents, mechanical properties, pH sensitivity, drug delivery, anticoagulant, and antimicrobial properties. Pullulan has nine active hydroxyl groups in its structure that react chemically that can be used for physicochemical modification to produce pullulan derivatives. A key area of pullulan research has been pullulan modification, which has demonstrated enhanced solubility, pH-sensitive targeting, broadened horizons for delivery systems, anticoagulation, and antibacterial properties.