Nano-conjugated drug delivery systems for enhanced tumour-specific targeting

Cancer remains among the major causes of death in the world, yet the treatment has been hampered and hindered by the issue of nonspecific drug toxicity, lack of selectivity and resistance. Drug delivery systems based on nanocarriers have become one of the promising platforms to enhance the precision and efficacy of therapeutic options. Of particular interest among them are glycan-functionalized nanocarriers since they can utilize cancer-related glycosylation patterns to achieve better tumor-specific targeting, greater biocompatibility, and lesser systemic toxicity. Precision nanomedicine is based on specific molecular markers, which are obtained through aberrant glycosylation in cancer including tumor-associated carbohydrate antigens (TACAs) including truncated O-linked glycans, abnormal N-glycan branching, and increased sialylation. This review discusses the importance of glycosylation in cancer biology, design and functionalization of nanocarriers; such as polymeric nanoparticles, liposomes, gold nanoparticles, dendrimers, and quantum dots, application of the nanocarriers in overcoming biological barriers and improving therapeutic outcomes. Progress in glycoengineering, such as protein engineering and cell line engineering, is also described. Lastly, the opportunities and challenges regarding translating glycan-conjugated nanomedicines to clinical use are discussed in the review with emphasis on regulatory barriers, mass-produced manufacturing, and safety issues. Glycan-conjugated nanomedicine by combining the understanding of tumor-selective glycosylation with novel nanocarrier design has the capacity to revolutionize cancer therapy to achieve a more targeted, personalized, and clinical viable approach to cancer therapy.