Triple-negative breast cancer (TNBC) treatment is challenging and frequently characterized by an aggressive phenotype and low prognosis in comparison to other subtypes. This paper presents fabricated implantable drug-loaded microporous poly-di-methyl-siloxane (PDMS) devices for the delivery of targeted therapeutic agents [Luteinizing Hormone-Releasing Hormone conjugated paclitaxel (PTX-LHRH) and Luteinizing Hormone-Releasing Hormone conjugated prodigiosin (PG-LHRH)] for the treatment and possible prevention of triple-negative cancer recurrence. In vitro assessment using the Alamar blue assay demonstrated a significant reduction (p < 0.05) in percentage of cell growth in a time-dependent manner in the groups treated with PG, PG-LHRH, PTX, and PTX-LHRH. Subcutaneous triple-negative xenograft breast tumors were then induced in athymic female nude mice that were four weeks old. Two weeks later, the tumors were surgically but partially removed, and the device implanted. Mice were observed for tumor regrowth and organ toxicity. The animal study revealed that there was no tumor regrowth, six weeks post-treatment, when the LHRH targeted drugs (LHRH-PTX and LHRH-PGS) were used for the treatment. The possible cytotoxic effects of the released drugs on the liver, kidney, and lung are assessed using quantitative biochemical assay from blood samples of the treatment groups. Ex vivo histopathological results from organ tissues showed that the targeted cancer drugs released from the implantable drug-loaded device did not induce any adverse effect on the liver, kidneys, or lungs, based on the results of qualitative toxicity studies. The implications of the results are discussed for the targeted and localized treatment of triple negative breast cancer.

This paper presents the results of an experimental study on the effects of magnetite nanoparticle (MNP) shape on magnetic resonance imaging (MRI) of triple-negative breast cancer (TNBC) xenograft tissues. T₂-weighted MRI scans using spherical shaped MNPs as contrast agents are compared to MRI scans done with nanorod-shaped MNPs as contrast agents. The MNPs were first coated with polyethylene glycol (PEG) and subsequently conjugated to luteinizing hormone-releasing hormone (LHRH) to specifically target LHRH receptors, which are present at high levels on the surfaces of xenograft TNBC cells/tissues. After 3 weeks of tumor growth in nude immunocompromised mice, LHRH-conjugated (functionalized) and unconjugated (non-functionalized) MNPs were injected into the immunocompromised mice. Four types of MNPs were used: non-functionalized nanorod-shaped MNPs (BMNR); LHRH-conjugated nanorod-shaped MNPs (LCMNR); non-functionalized spherical-shaped MNPs (BSSMNP); and LHRH-conjugated spherical-shaped MNPs (LCSSMNP). T₂-weighted magnetic resonance imaging (MRI) scans were obtained from the mice before the injection of the MNPs and two hours after the injection of the MNPs. The results show that using nanorod-shaped LHRH-conjugate MNPs as contrast agents yielded higher-resolution T₂-weighted MRI scans of TNBC tumors compared to those from spherical-shaped MNPs. The implications of the results are discussed in relation to potential applications of functionalized MNPs in MRI for TNBC diagnosis.