Advancing breast cancer drug delivery with polymeric layer-by-layer core-shell particles.

INTRODUCTION: Breast cancer is one of the most common forms of malignant neoplasms worldwide. Systemic and selective therapies exist but the heterogeneity of the tumor microenvironment (TME) hinders their efficiency and contributes to the development of drug resistance. AREAS COVERED: We discuss the opportunities offered by layer-by-layer (LbL) assembly toward engineering carriers for breast cancer therapy. The deposition of sequential molecular layers on nano- and micro- particles enables the development of systems with core-shell architecture. Such compartmentalized structure allows precise control of loading and distribution of drugs and targeting molecules within the carrier, thus permitting to tune the release profile and enhance targeting. The incorporation of materials that interact with TME components can further enhance the release at the tumor. Information was searched on PubMed, Web of Science, Google Scholar, Food and Drug Administration, European Medicines Agency and ClinicalTrials websites, focusing on breakthroughs achieved in the last 15 years. EXPERT OPINION: LbL core-shell systems are currently placed at preclinical stage. Concerns about therapeutic reproducibility in vivo and scalable manufacture should be addressed to advance into regulatory translation. In the long term, LbL carriers could progress beyond mainstream treatments against breast cancer by tackling less developed therapeutic paradigms, such as TME-associated immune therapy.