Conjugation strategies for colonic delivery and its application in colorectal cancer therapy

BACKGROUND: Efficient colon-specific drug delivery has been demonstrated recently in the treatment of various diseases, including Crohn's disease, ulcerative colitis (inflammatory bowel disease), and colorectal cancer. METHODS: Of all strategies, the conjugation of a model drug to a carrier (with or without spacers) has been recognized as promising for targeting the colon. RESULTS: This is because the conjugation method releases large amounts of the drug while reducing the amount of the drug released in the stomach and small intestine. CONCLUSION: This review focuses on the design of linkage conjugates that carry out specific delivery to the colon. The types of conjugation for application in colorectal cancer therapy will be discussed as well.