Nanoradiopharmaceuticals for breast cancer imaging: development, characterization, and imaging in inducted animals

Exploring the Potential of Montmorillonite as an Antiproliferative Nanoagent against MDA-MB-231 and MCF-7 Human Breast Cancer Cells

Unlike MCF-7 cells, MDA-MB-231 cells are unresponsive to hormone therapy and often show resistance to chemotherapy and radiotherapy. Here, the antiproliferative effect of biocompatible montmorillonite (Mt) nanosheets on MDA-MB-231 and MCF-7 human breast cancer cells was evaluated by MTT assay, flow cytometry, and qRT-PCR. The results showed that the Mt IC50 for MDA-MB-231 and MCF-7 cells in a fetal bovine serum (FBS)-free medium was ~50 and ~200 µg/mL, and in 10% FBS medium ~400 and ~2000 µg/mL, respectively. Mt caused apoptosis in both cells by regulating related genes including Cas-3, P53, and P62 in MDA-MB-231 cells and Bcl-2, Cas-8, Cas-9, P53, and P62 in MCF-7 cells. Also, Mt arrested MCF-7 cells in the G0/G1 phase by altering Cyclin-D1 and P21 expression, and caused sub-G1 arrest and necrosis in both cells, possibly through damaging the mitochondria. However, fewer gene expression changes and more sub-G1 arrest and necrosis were observed in MDA-MB-231 cells, confirming the higher vulnerability of MDA-MB-231 cells to Mt. Furthermore, MDA-MB-231 cells appeared to be much more vulnerable to Mt compared to other cell types, including normal lung fibroblast (MRC-5), colon cancer (HT-29), and liver cancer (HepG2) cells. The higher vulnerability of MDA-MB-231 cells to Mt was inferred to be due to their higher proliferation rate. Notably, Mt cytotoxicity was highly dependent on both the Mt concentration and serum level, which favors Mt for the local treatment of MDA-MB-231 cells. Based on these results, Mt can be considered as an antiproliferative nanoagent against MDA-MB-231 cells and may be useful in the development of local nanoparticle-based therapies.

Radiolabeled Human Serum Albumin Nanoparticles Co-Loaded with Methotrexate and Decorated with Trastuzumab for Breast Cancer Diagnosis

Breast cancer is a leading cause of cancer-related mortality among women worldwide, with millions of new cases diagnosed yearly. Addressing the burden of breast cancer mortality requires a comprehensive approach involving early detection, accurate diagnosis, effective treatment, and equitable access to healthcare services. In this direction, nano-radiopharmaceuticals have shown potential for enhancing breast cancer diagnosis by combining the benefits of nanoparticles and radiopharmaceutical agents. These nanoscale formulations can provide improved imaging capabilities, increased targeting specificity, and enhanced sensitivity for detecting breast cancer lesions. In this study, we developed and evaluated a novel nano-radio radiopharmaceutical, technetium-99m ([99mTc]Tc)-labeled trastuzumab (TRZ)-decorated methotrexate (MTX)-loaded human serum albumin (HSA) nanoparticles ([99mTc]-TRZ-MTX-HSA), for the diagnosis of breast cancer. In this context, HSA and MTX-HSA nanoparticles were prepared. Conjugation of MTX-HSA nanoparticles with TRZ was performed using adsorption and covalent bonding methods. The prepared formulations were evaluated for particle size, PDI value, zeta (ζ) potential, scanning electron microscopy analysis, encapsulation efficiency, and loading capacity and cytotoxicity on MCF-7, 4T1, and MCF-10A cells. Finally, the nanoparticles were radiolabeled with [99mTc]Tc using the direct radiolabeling method, and cellular uptake was performed with the nano-radiopharmaceutical. The results showed the formation of spherical nanoparticles, with a particle size of 224.1 ± 2.46 nm, a PDI value of 0.09 ± 0.07, and a ζ potential value of -16.4 ± 0.53 mV. The encapsulation efficiency of MTX was found to be 32.46 ± 1.12%, and the amount of TRZ was 80.26 ± 1.96%. The labeling with [99mTc]Tc showed a high labeling efficiency (>99%). The cytotoxicity studies showed no effect, and the cellular uptake studies showed 97.54 ± 2.16% uptake in MCF-7 cells at the 120th min and were found to have a 3-fold higher uptake in cancer cells than in healthy cells. In conclusion, [99mTc]Tc-TRZ-MTX-HSA nanoparticles are promising for diagnosing breast cancer and evaluating the response to treatment in breast cancer patients.

Triple-negative breast cancer treatment in xenograft models by bifunctional nanoprobes combined to photodynamic therapy

Triple-negative breast cancer (TNBC) overexpresses the Epidermal Growth Factor Receptor (EGFR), a characteristic of different types of tumors, linked to worse disease prognosis and risk of recurrence. Conventional treatments are aggressive and, on several occasions, have a poor prognosis, which may be related to the clinical heterogeneity of tumors, among other factors. Therefore, the improvement and development of new methods are notorious. Photodynamic Therapy (PDT) is an effective method for treating different types of cancer by using radiation to activate a photosensitizing agent (drug) in molecular oxygen presence, promoting cell death. Aiming to urge new treatments against breast cancer, drug uptake in target cells could contribute to PDT efficiency. This association is less invasive and has fewer side effects, increasing quality of life and survival rate. Accordingly, we developed a bifunctional nanoprobe (BN), used in PDT as an alternative treatment method in vivo against breast cancer. The BN uses gold nanoparticles with active targeting through the Epidermal Growth Factor (EGF) protein and Chlorine e6 (Ce6) carriers. We evaluated the therapeutic efficacy of in vivo xenograft in 4 groups: Saline, BN, Ce6+PDT, and BN+PDT. As a result, we observed that the BN+PDT group exhibited an excellent effect with greater selectivity to tumor tissue and tissue damage when compared to the Saline, BN, and Ce6+PDT groups. The results indicate a potential impact on breast cancer treatment in vivo, promising therapeutic benefits against cancer. In conclusion, our data propose that the BN developed heightened PDT efficacy through cellular DNA repair effects and tumor microenvironment.

Disturbance of cellular homeostasis as a molecular risk evaluation of human endothelial cells exposed to nanoparticles

Even though application of nanoparticles in medicine seems to provide unique solutions for drug delivery and diagnosis diseases, understanding interactions between nanoscale materials and biological systems is imperative. Therefore, this study determined the effect of different types of nanoparticles (NPs) on human endothelial cells and examined the types of toxicity responses they can induce. Four different types of NPs were tested (PLA/MMT/TRASTUZUMAB, PLA/EDTMP, PLGA/MDP, and Pluronic F127 MICELLES), representing three putative areas of application: anticancer therapy, scintigraphy, and cosmetology. The experiments were performed on immortalized human umbilical vein endothelial cells (HUVEC-STs). Light contrast phase microscopy as well as cell viability assays showed that only Pluronic F127 MICELLES decreased the number of HUVEC-STs in contrast to PLA/MMT/TRASTUZUMAB, PLA/EDTMP, and PLGA/MDP NPs, which altered cell morphology, but not their confluency. The tested NPs induced not only DNA strand-breaks and alkali-labile sites, but also internucleosomal DNA fragmentation, visualized as a DNA ladder pattern typical of apoptosis. Moreover, generation of free radicals and subsequent mitochondrial membrane potential collapse showed the significance of free radical production during interactions between NPs and endothelial cells. High concentrations of NPs had different degrees of toxicity in human endothelial cells and affected cell proliferation, redox homeostasis, and triggered mitochondrial dysfunction.

Technetium-99 m-PEGylated dendrimer-G2-(Dabcyle-Lys6,Phe7)-pHBSP: A novel Nano-Radiotracer for molecular and early detecting of cardiac ischemic region

In cardiac ischemic disorder, pyroglutamate helix B surface peptide (pHBSP) which derived from erythropoietin causes to increase cell stability. To improve the serum stability of pHBSP, two lipophilic amino acids Arg⁶, Ala⁷ were replaced with Fmoc-(Dabcyle)-Lys-OH and Fmoc-Phe-OH during the peptide synthesis. This peptide was subsequently conjugated to PEGylated dendrimer-G₂ and labeled with ^99mTcO₄^- to detect cardiac ischemic region. Radiochemical purity (RCP) of ^99mTc-PEGylated dendrimer-G₂-(Dabcyle-Lys⁶,Phe⁷)-pHBSP was evaluated by ITLC method. In addition, the radiopeptide was investigated for stability in human serum and binding affinity to hypoxic cells in myocardium H9c2 cell lines. Biodistribution and SPECT/CT scintigraphy were assessed in cardiac ischemic rats. Radiochemical yield indicated that the anionic dendrimer has a very high potential to complex formation with ^99mTcO^-₄ (RCP > 94%) which was stable in human serum with RCP 89% up to 6 h. The binding of ^99mTc- nanoconjugate to hypoxic cells was significantly more than normoxic cells (3-fold higher compared to normoxic cells at 1 h). In biodistribution studies, erythropoietin receptor-Beta common receptor (EPO-BcR)-positive uptake in the cardiac ischemic region was 3.62 ± 0.44% ID/g 30 min post injection. SPECT imaging showed a prominent uptake of ^99mTc-nanoconjugate in EPO-BcR expressing ischemic heart.

Nanoparticle interactions with immune cells dominate tumor retention and induce T cell-mediated tumor suppression in models of breast cancer

The factors that influence nanoparticle fate in vivo following systemic delivery remain an area of intense interest. Of particular interest is whether labeling with a cancer-specific antibody ligand ("active targeting") is superior to its unlabeled counterpart ("passive targeting"). Using models of breast cancer in three immune variants of mice, we demonstrate that intratumor retention of antibody-labeled nanoparticles was determined by tumor-associated dendritic cells, neutrophils, monocytes, and macrophages and not by antibody-antigen interactions. Systemic exposure to either nanoparticle type induced an immune response leading to CD8+ T cell infiltration and tumor growth delay that was independent of antibody therapeutic activity. These results suggest that antitumor immune responses can be induced by systemic exposure to nanoparticles without requiring a therapeutic payload. We conclude that immune status of the host and microenvironment of solid tumors are critical variables for studies in cancer nanomedicine and that nanoparticle technology may harbor potential for cancer immunotherapy.

Molecular and Cellular Risk Assessment of Healthy Human Cells and Cancer Human Cells Exposed to Nanoparticles

Nanodrugs have in recent years been a subject of great debate. In 2017 alone, almost 50 nanodrugs were approved for clinical use worldwide. Despite the advantages related to nanodrugs/nanomedicine, there is still a lack of information regarding the biological safety, as the real behavior of these nanodrugs in the body. In order to better understand these aspects, in this study, we evaluated the effect of polylactic acid (PLA) nanoparticles (NPs) and magnetic core mesoporous silica nanoparticles (MMSN), of 1000 nm and 50 nm, respectively, on human cells. In this direction we evaluated the cell cycle, cytochemistry, proliferation and tubulogenesis on tumor cells lines: from melanoma (MV3), breast cancer (MCF-7, MDA-MB-213), glioma (U373MG), prostate (PC3), gastric (AGS) and colon adenocarcinoma (HT-29) and non-tumor cell lines: from human melanocyte (NGM), fibroblast (FGH) and endothelial (HUVEC), respectively. The data showed that an acute exposure to both, polymeric nanoparticles or MMSN, did not show any relevant toxic effects on neither tumor cells nor non-tumor cells, suggesting that although nanodrugs may present unrevealed aspects, under acute exposition to human cells they are harmless.

Decorated Superparamagnetic Iron Oxide Nanoparticles with Monoclonal Antibody and Diethylene-Triamine-Pentaacetic Acid Labeled with Thechnetium-99m and Galium-68 for Breast Cancer Imaging

PURPOSE

In this study we developed and tested an iron oxide nanoparticle conjugated with DTPA and Trastuzumab, which can efficiently be radiolabeled with 99m-Tc and Ga-68, generating a nanoradiopharmaceutical agent to be used for SPECT and PET imaging.

METHODS

The production of iron oxide nanoparticle conjugated with DTPA and Trastuzumab was made using phosphorylethanolamine (PEA) surface modification. Both radiolabeling process was made by the direct radiolabeling of the nanoparticles. The in vivo assay was done in female Balb/c nude mice xenografted with breast cancer. Also a planar imaging using the radiolabeled nanoparticle was performed.

RESULTS

No thrombus and immune response leading to unwanted interaction and incorporation of nanoparticles by endothelium and organs, except filtration by the kidneys, was observed. In fact, more than 80% of ^99mTc-DTPA-TZMB@Fe₃O₄ nanoparticles seems to be cleared by the renal pathway but the implanted tumor whose seems to increase the expression of HER2 receptors enhancing the uptake by all other organs.

CONCLUSION

However, even in this unfavorable situation the tumor bioconcentrated much larger amounts of the nano-agent than normal tissues giving clear enough contrast for breast cancer imaging for diagnostics purpose by both SPECT and PET technique. Graphical Abstract ᅟ.

MUC1 aptamer-capped mesoporous silica nanoparticles for controlled drug delivery and radio-imaging applications

Mucin 1 (MUC1) is a cell surface protein overexpressed in breast cancer. Mesoporous silica nanoparticles (MSNs) loaded with safranin O, functionalized with aminopropyl groups and gated with the negatively charged MUC1 aptamer have been prepared (S1-apMUC1) for specific targeting and cargo release in tumoral versus non-tumoral cells. Confocal microscopy studies showed that the S1-apMUC1 nanoparticles were internalized in MDA-MB-231 breast cancer cells that overexpress MUC1 receptor with subsequent pore opening and cargo release. Interestingly, the MCF-10-A non-tumorigenic breast epithelial cell line that do not overexpress MUC1, showed reduced (S1-apMUC1) internalization. Negligible internalization was also found for S1-ap nanoparticles that contained a scrambled DNA sequence as gatekeeper. S2-apMUC1 nanoparticles (similar to S1-apMUC1 but loaded with doxorubicin) internalized in MDA-MB-231 cells and induced a remarkable reduction in cell viability. Moreover, S1-apMUC1 nanoparticles radio-labeled with ^99mTc (S1-apMUC1-Tc) showed a remarkable tumor targeting in in vivo studies with MDA-MB-231 tumor-bearing Balb/c mice.

Diagnosing lung cancer using etoposide microparticles labeled with 99mTc

The diagnosis of lung cancer mostly occurs when the cancer is already in an advanced stage. In this situation, there are few options for the treatment and most of them have few chances of success. In this study, we developed and tested etoposide microparticles as a diagnostic agent for imaging lung cancer at early stages of development. We tested etoposide microparticles labeled with technetium 99m in inducted mice. The results demonstrated that over 10% of the total dose used was uptake by the tumor site. Also, the results showed that the microparticles had a good renal clearance and low uptake by liver and spleen. The data suggest that these micro-radiopharmaceuticals may be used for lung cancer imaging exam, especially single-photo emission computed tomography (SPECT).[Formula: see text].