The promise of nanotechnology for solving clinical problems in breast cancer

Carbon nanotubes conjugated with cisplatin activate different apoptosis signaling pathways in 2D and 3D-spheroid triple-negative breast cancer cell cultures: a comparative study

The type of experimental model for the in vitro testing of drug formulations efficiency represents an important tool in cancer biology, with great attention being granted to three-dimensional (3D) cultures as these offer a closer approximation of the clinical sensitivity of drugs. In this study, the effects induced by carboxyl-functionalized single-walled carbon nanotubes complexed with cisplatin (SWCNT-COOH-CDDP) and free components (SWCNT-COOH and CDDP) were compared between conventional 2D- and 3D-spheroid cultures of human breast cancer cells. The 2D and 3D breast cancer cultures were exposed to various doses of SWCNT-COOH (0.25-2 μg/mL), CDDP (0.158-1.26 μg/mL) and the same doses of SWNCT-COOH-CDDP complex for 24 and 48 h. The anti-tumor activity, including modulation of cell viability, oxidative stress, proliferation, apoptosis, and invasion potential, was explored by spectrophotometric and fluorometric methods, immunoblotting, optical and fluorescence microscopy. The SWCNT-COOH-CDDP complex proved to have high anti-cancer efficiency on 2D and 3D cultures by inhibiting cell proliferation and activating cell death. A dose of 0.632 μg/mL complex triggered different pathways of apoptosis in 2D and 3D cultures, by intrinsic, extrinsic, and reticulum endoplasmic pathways. Overall, the 2D cultures showed higher susceptibility to the action of complex compared to 3D cultures and SWCNT-COOH-CDDP proved enhanced anti-tumoral activity compared to free CDDP.

Emerging Nanotherapeutic Approaches to Overcome Drug Resistance in Cancers with Update on Clinical Trials

A key issue with modern cancer treatments is the emergence of resistance to conventional chemotherapy and molecularly targeted medicines. Cancer nanotherapeutics were created in order to overcome the inherent limitations of traditional chemotherapeutics. Over the last few decades, cancer nanotherapeutics provided unparalleled opportunities to understand and overcome drug resistance through clinical assessment of rationally designed nanoparticulate delivery systems. In this context, various design strategies such as passive targeting, active targeting, nano-drug, and multimodal nano-drug combination therapy provided effective cancer treatment. Even though cancer nanotherapy has made great technological progress, tumor biology complexity and heterogeneity and a lack of comprehensive knowledge of nano-bio interactions remain important roadblocks to future clinical translation and commercialization. The current developments and advancements in cancer nanotherapeutics employing a wide variety of nanomaterial-based platforms to overcome cancer treatment resistance are discussed in this article. There is also a review of various nanotherapeutics-based approaches to cancer therapy, including targeting strategies for the tumor microenvironment and its components, advanced delivery systems for specific targeting of cancer stem cells (CSC), as well as exosomes for delivery strategies, and an update on clinical trials. Finally, challenges and the future perspective of the cancer nanotherapeutics to reverse cancer drug resistance are discussed.

Bioactive nanotherapeutic trends to combat triple negative breast cancer

The management of aggressive breast cancer, particularly, triple negative breast cancer (TNBC) remains a formidable challenge, despite treatment advancement. Although newer therapies such as atezolizumab, olaparib, and sacituzumab can tackle the breast cancer prognosis and/or progression, but achieved limited survival benefit(s). The current research efforts are aimed to develop and implement strategies for improved bioavailability, targetability, reduce systemic toxicity, and enhance therapeutic outcome of FDA-approved treatment regimen. This review presents various nanoparticle technology mediated delivery of chemotherapeutic agent(s) for breast cancer treatment. This article also documents novel strategies to employ cellular and cell membrane cloaked (biomimetic) nanoparticles for effective clinical translation. These technologies offer a safe and active targeting nanomedicine for effective management of breast cancer, especially TNBC.

Liposomes: Ideal drug delivery systems in breast cancer

Breast cancer (BC) has been recognized as the most common type of cancer in females across the world, accounting for 12% of each cancer case. In this sense, better diagnosis and screening have been thus far proven to contribute to higher survival rates. Moreover, traditional (or standard) chemotherapy is still known as one of the several prominent therapeutic options available, though it suffers from unsuitable cell selectivity, severe consequences, as well as resistance. In this regard, nanobased drug delivery systems (DDSs) are likely to provide promising grounds for BC treatment. Liposomes are accordingly effective nanosystems, having the benefits of multiple formulations verified to treat different diseases. Such systems possess specific features, including smaller size, biodegradability, hydrophobic/hydrophilic characteristics, biocompatibility, lower toxicity, as well as immunogenicity, which can all lead to considerable efficacy in treating various types of cancer. As chemotherapy uses drugs to target tumors, generates higher drug concentrations in tumors, which can provide for their slow release, and enhances drug stability, it can be improved via liposomes in DDSs for BC treatment. Therefore, the present study aims to review the existing issues regarding BC treatment and discuss liposome-based targeting in order to overcome barriers to conventional drug therapy.

MicroRNA-941 regulates the proliferation of breast cancer cells by altering histone H3 Ser 10 phosphorylation

Breast cancer including triple negative breast cancer (TNBC) represents an important clinical challenge, as these tumours often develop resistance to conventional chemotherapeutics. MicroRNAs play a crucial role in cell-cycle regulation, differentiation, apoptosis, and migration. Herein, we performed Affymetrix Gene Chip miRNA 4.0 microarray and observed differential regulation of miRNAs (75 upregulated and 199 downregulated) in metastatic MDA-MB-231 cells as compared to immortalized human non-tumorigenic breast epithelial (MCF-10A) cells. MicroRNA-941 was significantly upregulated in MDA-MB-231 cells (almost nine-fold increase) in comparison to MCF-10A cells. Transfection of MiRNA-941 inhibitor significantly decreased the proliferation and migration of MDA-MB-231 cells by altering the expressions of p21, Cyclin D1, PP2B-B1, E-cadherin and MMP-13. Interestingly, we provide first evidence that inhibiting miR-941 prevents cell proliferation and phosphorylation of histone H3 at Ser10 residue. Xenograft model of breast cancer was developed by subcutaneous injection of MDA-MB-231 cells into the mammary fat pad of female athymic nude mice (Crl:NU-Foxn1nu). The tumours were allowed to grow to around 60 mm³, thereafter which we divided the animals into seven groups (n = 5). Notably, intratumoral injection of miR-941 inhibitor significantly abolished the tumour growth in MDA-MB-231 xenograft model. 5-Fluorouracil (10 mg/kg, i.p.) was used as positive control in our study. To the best of our knowledge, we report for the first time that targeting miR-941 improves the sensitivity of MDA-MB-231 cells to 5-fluorouracil. This can be of profound clinical significance, as it provides novel therapeutic approach for treating variety of cancers (overexpressing miRNA-941) in general and breast cancers in particular.

Metal-shell nanocapsules for the delivery of cancer drugs

Cytotoxic drugs tend to have substantial side effects on healthy tissues leading to systemic toxicity, limited tolerated doses and reduced drug efficacy. A prominent research area focuses on encapsulating cytotoxic drugs for targeted delivery to cancer tissues. However, existing carriers suffer from low drug loading levels and high drug leaching both when circulating systemically and when accumulating in non-target organs. These challenges mean that only few encapsulation technologies for delivery of cytotoxic drugs have been adopted for clinical use. Recently, we have demonstrated efficient manufacture of impermeable metal-shell/liquid core microcapsules that permit localised delivery by triggering release with ultrasound. This method has the potential to improve on existing methods for localised drug delivery because it:We demonstrate here the further miniaturization of both the emulsion droplet template and the thickness of the surrounding metal shell to the nanoscale in an attempt to take advantage of the EPR effect and the excretion of nanoparticles by the hepatobiliary system.

Gold nanoparticles-induced cytotoxicity in triple negative breast cancer involves different epigenetic alterations depending upon the surface charge

Gold nanoparticles (AuNPs) are used enormously in different cancers but very little is known regarding their molecular mechanism and surface charge role in the process of cell death. Here, we elucidate the molecular mechanism by which differentially charged AuNPs induce cytotoxicity in triple negative breast cancer (TNBC) cells. Cytotoxicity assay revealed that both negatively charged (citrate-capped) and positively charged (cysteamine-capped) AuNPs induced cell-death in a dose-dependent manner. We provide first evidence that AuNPs-induced oxidative stress alters Wnt signalling pathway in MDA-MB-231 and MDA-MB-468 cells. Although both differentially charged AuNPs induced cell death, the rate and mechanism involved in the process of cell death were different. Negatively charged AuNPs increased the expression of MKP-1, dephosphorylated and deacetylated histone H3 at Ser10 and K9/K14 residues respectively whereas, positively charged AuNPs decreased the expression of MKP-1, phosphorylated and acetylated histone H3 at Ser 10 and K9/K14 residues respectively. High-resolution transmission electron microscopy (HRTEM) studies revealed that AuNPs were localised in cytoplasm and mitochondria of MDA-MB-231 cells. Interestingly, AuNPs treatment makes MDA-MB-231 cells sensitive to 5-fluorouracil (5-FU) by decreasing the expression of thymidylate synthetase enzyme. This study highlights the role of surface charge (independent of size) in the mechanisms of toxicity and cell death.

Detrimental impact of silica nanoparticles on the nanomechanical properties of Escherichia coli, studied by AFM

Despite great innovative and technological promises, nanoparticles (NPs) can ultimately exert an antibacterial activity by affecting the cell envelope integrity. This envelope, by conferring the cell its rigidity and protection, is intimately related to the mechanical behavior of the bacterial surface. Depending on their size, surface chemistry, shape, NPs can induce damages to the cell morphology and structure among others, and are therefore expected to alter the overall mechanical properties of bacteria. Although Atomic Force Microscopy (AFM) stands as a powerful tool to study biological systems, with high resolution and in near physiological environment, it has rarely been applied to investigate at the same time both morphological and mechanical degradations of bacteria upon NPs treatment. Consequently, this study aims at quantifying the impact of the silica NPs (SiO₂-NPs) on the mechanical properties of E. coli cells after their exposure, and relating it to their toxic activity under a critical diameter. Cell elasticity was calculated by fitting the force curves with the Hertz model, and was correlated with the morphological study. SiO₂-NPs of 100 nm diameter did not trigger any significant change in the Young modulus of E. coli, in agreement with the bacterial intact morphology and membrane structure. On the opposite, the 4 nm diameter SiO₂-NPs did induce a significant decrease in E. coli Young modulus, mainly associated with the disorganization of lipopolysaccharides in the outer membrane and the permeation of the underlying peptidoglycan layer. The subsequent toxic behavior of these NPs is finally confirmed by the presence of membrane residues, due to cell lysis, exhibiting typical adhesion features.

FTIR study of secondary structure changes in Epidermal Growth Factor by gold nanoparticle conjugation

Conformation of protein is vital to its function, but may get affected when processing to manufacture products. It is therefore important to understand structural changes during each step of production. In this study, we investigate secondary structure changes in the targeting protein Epidermal Growth Factor (EGF) during synthesis of theranostic bifunctional nanoparticle, devised for Photodynamic therapy of breast cancer. We acquired FTIR spectra of EGF; unconjugated, post treatment with α-lipoic acid, attached to gold nanoparticle, and bound to the bifunctional nanoprobe. We observed decreasing disordered structures and turns, and increasing loops, as the synthesis process progressed. There was an overall increase in β-sheets in final product compared to pure EGF, but this increase was not linear and fluctuated. Previous crystal structure studies on EGF-EGFR complex have shown loops and β-sheets to be important in the binding interaction. Since our study found increase in these structures in the final product, no adverse effect on binding function of EGF was expected. This was confirmed by functional assays. Such studies may help modify synthesis procedures, and thus secondary structures of proteins, enabling increased functionality and optimum results.

Nanomaterials as nanocarriers: a critical assessment why these are multi-chore vanquisher in breast cancer treatment

Breast cancer is a group of diseases with various subtypes and leads to high mortality throughout the globe. Various conventional techniques are in practice to cure breast cancer but these techniques are linked with various shortcomings. Mostly these treatments are not site directed and cause toxicity towards normal cells. In order to overcome these issues, we need smart system that can deliver anticancer drugs to specific sites. Targeted drug delivery can be achieved via passive or active drug delivery using nanocarriers. This mode of drug delivery is more effective against breast cancer and may help in the reduction of mortality rate. Potentially used nanocarriers for targeted drug delivery belong to organic and inorganic molecules. Various FDA approved nano products are in use to cure breast cancer. However, body's defense system is main limitation for potential use of nano systems. However, this can be overcome by surface modification of nanocarriers. In this review, breast cancer and its types, targeted drug delivery and nanocarriers used to cure breast cancer are discussed. By progressing nanotechnology, we will be able to fight against this life threatening issue and serve the humanity, which is the basic aim of scientific knowledge.

Triple Negative Breast Cancer: Nanosolutions for a Big Challenge

Triple negative breast cancer (TNBC) is a particular immunopathological subtype of breast cancer that lacks expression of estrogen and progesterone receptors (ER/PR) and amplification of the human epidermal growth factor receptor 2 (HER2) gene. Characterized by aggressive and metastatic phenotypes and high rates of relapse, TNBC is the only breast cancer subgroup still lacking effective therapeutic options, thus presenting the worst prognosis. The development of targeted therapies, as well as early diagnosis methods, is vital to ensure an adequate and timely therapeutic intervention in patients with TNBC. This review intends to discuss potentially emerging approaches for the diagnosis and treatment of TNBC patients, with a special focus on nano-based solutions that actively target these particular tumors.

Efficiency of calcium phosphate composite nanoparticles in targeting Ehrlich carcinoma cells transplanted in mice

The present study aimed to investigate the mode of action of nano-CaPs in vivo as a therapy for solid tumor in mice. To achieve this goal, Ehrlich Ascites Carcinoma (EAC) was transplanted into 85 Swiss male albino mice. After nine days, the mice were divided into 9 groups. Groups 1 and 2 were allocated as the EAC control. Groups 3 and 4 were injected once intratumorally (IT) by nano-calcium phosphate (nano-CaP). Groups 5 and 6 received once intraperitoneal injection (IP) of nano-CaP. Groups 7, 8, and 9 received nano-CaP (IP) weekly. Blood samples and thigh skeletal muscle were collected after three weeks from groups 1, 3, 5, and 7 and after four weeks from groups 2, 4, 6, and 8. On the other hand, group 9 received nano-CaP (IP) for four weeks and lasted for three months to follow up the recurrence of tumor and to ensure the safety of muscle by histopathological analysis. Tumor growth was monitored twice a week throughout the experiment. DNA fragmentation of tumor cells was evaluated. In thigh tissue, noradrenaline, dopamine, serotonin (5HT), and gamma-aminobutyric acid (GABA) were measured. In serum, 8-Hydroxy-deoxyguanosine (8-OHDG), adenosine triphosphate (ATP), and vascular endothelial growth factor (VEGF) were analyzed. Histopathological and biochemical results showed a significant therapeutic effect of nano-CaP on implanted solid tumor and this effect was more pronounced in the animals treated IP for four weeks. This improvement was evident from the repair of fragmented DNA, the significant decrease of caspase-3, 8-OHDG, myosin, and VEGF, and the significant increase of neurotransmitters (NA, DA, 5HT, and GABA). Additionally, histopathological examination showed complete recovery of cancer cells in the thigh muscle after three months.

Real-Time Nanoparticle-Cell Interactions in Physiological Media by Atomic Force Microscopy

Particle-cell interactions in physiological media are important in determining the fate and transport of nanoparticles and biological responses to them. In this work, these interactions are assessed in real time using a novel atomic force microscopy (AFM) based platform. Industry-relevant CeO2 and Fe2O3 engineered nanoparticles (ENPs) of two primary particle sizes were synthesized by the flame spray pyrolysis (FSP) based Harvard Versatile Engineering Nanomaterials Generation System (Harvard VENGES) and used in this study. The ENPs were attached on AFM tips, and the atomic force between the tip and lung epithelia cells (A549), adhered on a substrate, was measured in biological media, with and without the presence of serum proteins. Two metrics were used to assess the nanoparticle cell: the detachment force required to separate the ENP from the cell and the number of bonds formed between the cell and the ENPs. The results indicate that these atomic level ENP-cell interaction forces strongly depend on the physiological media. The presence of serum proteins reduced both the detachment force and the number of bonds by approximately 50% indicating the important role of the protein corona on the particle cell interactions. Additionally, it was shown that particle to cell interactions were size and material dependent.

Near-infrared quantum dots for HER2 localization and imaging of cancer cells

Background

Quantum dots are fluorescent nanoparticles with unique photophysical properties that allow them to be used as diagnostic, therapeutic, and theranostic agents, particularly in medical and surgical oncology. Near-infrared-emitting quantum dots can be visualized in deep tissues because the biological window is transparent to these wavelengths. Their small sizes and free surface reactive groups that can be conjugated to biomolecules make them ideal probes for in vivo cancer localization, targeted chemotherapy, and image-guided cancer surgery. The human epidermal growth factor receptor 2 gene (HER2/neu) is overexpressed in 25%–30% of breast cancers. The current methods of detection for HER2 status, including immunohistochemistry and fluorescence in situ hybridization, are used ex vivo and cannot be used in vivo. In this paper, we demonstrate the application of near-infrared-emitting quantum dots for HER2 localization in fixed and live cancer cells as a first step prior to their in vivo application.

Methods

Near-infrared-emitting quantum dots were characterized and their in vitro toxicity was established using three cancer cell lines, ie, HepG2, SK-BR-3 (HER2-overexpressing), and MCF7 (HER2-underexpressing). Mouse antihuman anti-HER2 monoclonal antibody was conjugated to the near-infrared-emitting quantum dots.

Results

In vitro toxicity studies showed biocompatibility of SK-BR-3 and MCF7 cell lines with near-infrared-emitting quantum dots at a concentration of 60 μg/mL after one hour and 24 hours of exposure. Near-infrared-emitting quantum dot antiHER2-antibody bioconjugates successfully localized HER2 receptors on SK-BR-3 cells.

Conclusion

Near-infrared-emitting quantum dot bioconjugates can be used for rapid localization of HER2 receptors and can potentially be used for targeted therapy as well as image-guided surgery.

Nanobiosensors: role in cancer detection and diagnosis

The ability to detect many cancers at an early stage in its clinical course has the potential to improve patient outcomes in terms of morbidity and mortality. Nanosized components incorporated into existing clinical diagnostic and detection systems as well as novel nanobiosensors have demonstrated improved sensitivity and specificity compared with traditional cancer testing approaches. Nanoparticles, nanowires, nanotubes, and nanocantilevers are examples of four nanobiosensor systems that have been used experimentally in the context of detection and diagnosis of prostate, breast, pancreatic, lung, and brain cancers over the past few years. Nanobiosensors will begin to transition into clinically validated tests as experimental and engineering techniques advance. This paper presents examples of some such nanobiosensors for cancer diagnosis and detection.

Nanoparticle-nanoparticle interactions in biological media by atomic force microscopy

Particle-particle interactions in physiological media are important determinants for nanoparticle fate and transport. Herein, such interactions are assessed by a novel atomic force microscopy (AFM)-based platform. Industry-relevant CeO2, Fe2O3, and SiO2 nanoparticles of various diameters were made by the flame spray pyrolysis (FSP)-based Harvard Versatile Engineering Nanomaterials Generation System (Harvard VENGES). The nanoparticles were fully characterized structurally and morphologically, and their properties in water and biological media were also assessed. The nanoparticles were attached on AFM tips and deposited on Si substrates to measure particle-particle interactions. The corresponding force was measured in air, water, and biological media that are widely used in toxicological studies. The presented AFM-based approach can be used to assess the agglomeration potential of nanoparticles in physiological fluids. The agglomeration potential of CeO2 nanoparticles in water and RPMI 1640 (Roswell Park Memorial Institute formulation 1640) was inversely proportional to their primary particle (PP) diameter, but for Fe2O3 nanoparticles, that potential is independent of PP diameter in these media. Moreover, in RPMI+10% Fetal Bovine Serum (FBS), the corona thickness and dispersibility of the CeO2 are independent of PP diameter, while for Fe2O3, the corona thickness and dispersibility were inversely proportional to PP diameter. The present method can be combined with dynamic light scattering (DLS), proteomics, and computer simulations to understand the nanobio interactions, with emphasis on the agglomeration potential of nanoparticles and their transport in physiological media.