ABSTRACT
Advancement in genetic engineering has led to the proliferation of an enormous diversity of proteins with high purity that are devoid of any biological contaminants. Despite their strength and specificity in physiological activities, most protein therapeutics are hard to deliver clinically. The inherent problems to parenteral protein delivery are poor patient compliance, high level of discomfort and inconsistent bioavailability. To sort out these problems, enormous research has been undertaken to develop trouble-free and noninvasive means of delivery for proteins and peptides. To accomplish this objective, attempts were made to deliver proteins by different routes such as oral, nasal and pulmonary. Noteworthy efforts are afoot on formulating proteins/peptides in nanocapsules, hydrogels, micellar sytems, microemulsions, nanoliposomes, niosomes, bioadhesive carriers and stealth nanoparticles. Later, these carriers were conjugated by specific ligand(s) in order to deliver therapeutic protein(s) into the target organs in an active form. The key task in designing nanocarriers is to manage particle size and surface properties. In fact, one of the major issues in successful protein delivery is stability of protein in the carrier system(s). Hence, the characterization of these nanocarriers is very critical to control their desired behavior in vitro as well as in vivo.
