Delivery of Natural Products Using Polymeric Particles for Cancer Chemotherapeutics

Abstract

Cancer is a major cause of deaths throughout the world. According to World Health Organization, cancer lead to the loss of about 9.6 million lives in the year 2018 with low and middle income countries accounting for 70% of these deaths. With its ability to grow in an uncontrolled manner and spreading out to different sites in the body, cancer is seen as that dreaded disease with no cure or treatment. Several promising cancer chemotherapeutic advancements have emerged but these came along with unavoidable limitations like toxicity, limits on the administered dosage as well as affordability for the people who most need them. Natural products with anticancer potential have also emerged as an immensely attractive option to treat cancer. The use of natural products has been credited to doubling of human life span in twentieth century. Furthermore, of all the anti-cancer agents approved and pre-new drug application candidates till date, more than 60% are of natural origin or a derivative thereof. However, an estimated 4 in 10 of the new chemical entity proposed against cancer turns out to be lipophilic. Problems of low aqueous solubility, low bioavailability and non-specific action still pose as major stumbling blocks in their advancement. Recently, polymeric nanocarriers have been used to deliver cancer chemotherapeutics to circumvent the associated limitations and improve their efficacy. Polymers like polylactic acid/poly lactic-co-glycolic acid are have a long history of use in medical field. These are safe and biodegradable with about 20 products approved by the Food and Drug Administration and European Medicine Agency for use in humans. The polymeric nanocarriers with their versatility offer solution to many of the hurdles of natural product delivery for cancer chemotherapy.In this chapter, we briefly discuss about the characteristics acquired by a cell progressing towards carcinogenesis. We then explore some of the conventional chemotherapeutic strategies that have been in use for the treatment of cancer. Moving further we discuss about the emergence of natural products in the cancer chemotherapy field. We examine how their non-toxic nature and ability to target multiple mechanisms has garnered attention. We conclude by reviewing about the use of polymeric nanocarriers to deliver natural products. We discuss some of the advantages offered by them and how they can be used to circumvent the limitations associated with the delivery of natural products for cancer chemotherapy. With this chapter we hope to shed light on how delivering anticancer natural products via polymeric nanocarriers can offer a safe and patient compliant strategy for the treatment of cancer.