Targeted delivery of therapeutic enzymes

Enzymes have great potential as therapeutic agents due to their high activity and selectivity. However, broader use of enzyme drugs in clinical practice is limited due to their poor stability, immunogenicity and potential systemic toxicity. Targeted delivery of therapeutic enzymes can in many cases provide solutions to these problems. Here we review recently developed strategies for targeted delivery of several most important classes of enzyme drugs and discuss their advantages and potential limitations. While a variety of approaches have been proposed and studied in vitro and in animal models, further investigations and clinical trials are needed to make these delivery systems suitable for clinical applications.