<p>Olaparib, a poly(adenosine diphosphate-ribose) polymerase inhibitor, has demonstrated therapeutic potential particularly in BRCA-mutated triple-negative breast cancers (TNBCs). However, its effectiveness has yet to be established in BRCA wild-type TNBCs, where its use remains unapproved. Poor aqueous solubility and limited tumor distribution pose additional challenges to its broader clinical application. To address these limitations, this study employed the nanoparticle albumin-bound (Nab^™) technology to enhance the tumor accumulation and subcellular delivery of olaparib. Utilizing the standard Nab^™ technology, we successfully produced olaparib-loaded human serum albumin nanoparticles. Physicochemical characterization confirmed their nanoscale dimensions (under 110&#xa0;nm) and minimal polydispersity (below 0.15), suggesting the stable inclusion of olaparib into these albumin-based formulations. These nanoparticles exhibited improved cellular internalization, leading to enhanced cytotoxic effects in breast cancer cells. Specifically, treatment with olaparib-loaded human serum albumin nanoparticles significantly increased cytotoxicity against MDA-MB-231 cancer cells compared to free olaparib. These findings support the potential of human serum albumin nanoparticles to enhance the potency of olaparib, thus providing a more effective treatment option for BRCA wild-type TNBCs.</p> Graphical abstract <p>Albumin-bound nanoparticles helped enhance intracellular delivery of olaparib and induce apoptosis in BRCA wild-type triple-negative breast cancer (TNBC) cells, leading to the greater anticancer activity than the free drug.</p>