Common treatment approaches for triple-negative breast cancer (TNBC) are associated with severe side effects due to the unfavorable biodistribution profile of potent chemotherapeutics. Here, we explored the potential of TNBC-targeting aptamer-decorated porous silicon nanoparticles (pSiNPs) as targeted nanocarriers for TNBC. A "salt-aging" strategy was employed to fabricate a TNBC-targeting aptamer functionalized pSiNP that was highly colloidally stable. Doxorubicin (Dox) was efficiently loaded into nanoparticles (179 ± 5 μg/mg of pSiNP) and experienced pH-dependent release kinetics. Further experiments highlighted that clathrin-mediated endocytosis was the primary route that aptamer-pSiNP conjugates take to enter the endolysosomal compartment of the MCF10Ca1h TNBC cells. A time-interval colocalization study shows the accumulation of an aptamer-decorated pSiNP conjugate in the lysosomes of TNBC cells, unlike for antibody-decorated pSiNPs, leading to particle-induced lysosomal swelling and membrane destabilization. Dox-loaded aptamer-pSiNPs efficiently reduced the viability of the TNBC cells (11.8 ± 1.5%) compared to nontargeted nanoparticles (58.2 ± 8.8%) while the developed system showed a low level of toxicity in healthy cells, both in vitro and in vivo. These findings have laid the foundation for further investigating the potential of aptamer-pSiNP conjugates as a targeted treatment strategy in preclinical TNBC models.
Keywords: aptamer; nanoparticles; porous silicon; targeted drug delivery; triple-negative breast cancer.