Abstract
INTRODUCTION/OBJECTIVE: The spread of tumors (48% in men and 51% in women), as well as the protection of malignant tumors by stromal cells and complex blood vessels, pose significant challenges to drug delivery to tumors. Modern chemotherapy, on the other hand, addresses tumor growth suppression by at least 60% through versatile formulation systems and numerous modifications to drug delivery systems. The renewable and naturally occurring polymers present invariably in all living cells form the fundamental foundation for most anticancer drug development. The review aims to discuss in detail the preparations of polysaccharide, lipid, and protein-based drug-loading vehicles for the targeted delivery of prominent anticancer drugs. It also provides an explanation of drug distribution in blood (cumulative releases of nearly 80% drug) and drug accumulation at tumor sites (1-5 mg/kg) due to enhanced permeability and retention (EPR). METHODS: Specific delivery examples for treating colorectal and breast carcinomas have been presented to distinguish the varied drug administration, bioavailability, and tumor internalization mechanisms between sugar, fatty acid, and amino acid polymers. Current therapy possibilities based on cutting-edge literature are provided, along with drug delivery systems tailored to tumor location and invasive properties. RESULTS: The unique combinations of the three natural polymers provide unparalleled solutions to minimize the toxicity (<20% drug release) of the chemotherapeutic drugs on normal tissues. Moreover, the development of a consolidated drug delivery system has contributed to a substantial reduction (dose reduction from 10.43 μM to 1.9 μM) in the undesirable consequences of higher dosages of chemotherapeutic drugs. CONCLUSION: The review extensively covers safe chemotherapeutic systems with significant advantages (tumor volume shrinkage of 4T1 cells from 1000 mm3 to 200 mm(3)) in clinical applications of carcinoma treatments using natural polymers.