ABSTRACT
Owing to their high activity and specificity of binding to their targets, enzymes have important advantages as potential therapeutic agents [1]. Moreover, enzymes convert target substances by acting as catalytic agents. These features distinguish enzymes from all other types of drugs. Development of enzyme drugs for the treatm ent of various disorders is a growing field in pharmaceutical research [2]. Although there is a range of approved drugs for enzyme therapy, there are still a lot of challenges for broader application of enzymebased drugs. Limitations include low storage stability and limited shelf life, poor penetration of physiological barriers due to large molecular weight, and potential immunogenicity [3]. Moreover, many, if not all, enzymatic drugs act at a certain location in the human body-organ, tissue, or cell compartment. By the time these drugs reach the targeted site, their therapeutic efficacy could be limited by either inhibitors or proteolytic degradation [4]. This usually
leads to requirement of high doses of enzymatic drugs; in some cases such high doses can result in systemic toxicity [5]. Because of these reasons, a large number of newly developed enzymatic drugs are eventually rejected by researchers and will never benefit patients. Therefore, improving enzyme delivery systems remains an extremely important subject of scientific inquiry.
