Formulation of Carnosic-Acid-Loaded Polymeric Nanoparticles: An Attempt to Endorse the Bioavailability and Anticancer Efficacy of Carnosic Acid against Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) is considered to be one of the most difficult subtypes of breast cancer (BC) to treat. The sheer absence of certain receptors makes it very tough to target, leaving high-dose chemotherapy as probably the sole therapeutic option at the cost of nonspecific toxic effects. Carnosic acid (CA) has been established as a potential chemotherapeutic agent against a range of cancer cells. However, its in vivo chemotherapeutic potential is significantly challenged due to its poor pharmacokinetic attributes. In this study, poly(lactic--glycolic) acid (PLGA) nanoparticles (NPs) were formulated to circumvent the biopharmaceutical limitations of CA. CA-loaded polymeric NPs (CA-PLGA NPs) have been evaluated as a potential therapeutic option in the treatment of TNBC. Different in vitro studies exhibited that CA-PLGA NPs significantly provoked oxidative-stress-mediated apoptotic death in MDA-MB-231 cells. The improved anticancer potential of CA-PLGA NPs over CA was found to be associated with improved cellular uptake of the nanoformulation by TNBC cells. In vivo studies also established the improvement in the chemotherapeutic efficacy of CA-nanoformulation over that of free CA without showing any sign of systemic toxicity. Thus, CA-PLGA NPs emerge as a promising candidate to fix two bugs with a single code, resolving biopharmaceutical attributes of CA as well as introducing a treatment option for TNBC.