Targeted nanoparticles for image-guided treatment of triple-negative breast cancer: clinical significance and technological advances

Efficient Sequential Co-Delivery Nanosystem for Inhibition of Tumor and Tumor-Associated Fibroblast-Induced Resistance and Metastasis

Purpose

Triple-negative breast cancer (TNBC) is the most lethal subtype of breast cancer. However, the effect of current treatment strategies by inducing tumor cell apoptosis alone is not satisfactory. The growth, metastasis and treatment sensitivity of tumors can be strongly influenced by cancer-associated fibroblasts (CAFs) in the microenvironment. Effective cancer therapies may need to target not only the tumor cells directly but also the CAFs that protect them.

Methods

Celastrol and small-sized micelles containing betulinic acid were co-encapsulated into liposomes using the thin-film hydration method (CL@BM). Folic acid was further introduced to modify liposomes as the targeting moiety (F/CL@BM). We established a novel NIH3T3+4T1 co-culture model to mimic the tumor microenvironment and assessed the nanocarrier's inhibitory effects on CAFs-induced drug resistance and migration in the co-culture model. The in vivo biological distribution, fluorescence imaging, biological safety evaluation, and combined therapeutic effect evaluation of the nanocarrier were carried out based on a triple-negative breast cancer model.

Results

In the present study, a novel multifunctional nano-formulation was designed by combining the advantages of sequential release, co-loading of tretinoin and betulinic acid, and folic acid-mediated active targeting. As expected, the nano-formulation exhibited enhanced cytotoxicity in different cellular models and effectively increased drug accumulation at the tumor site by disrupting the cellular barrier composed of CAFs by tretinoin. Notably, the co-loaded nano-formulations proved to be more potent in inhibiting tumor growth in mice and also showed better anti-metastatic effects in lung metastasis models compared to the formulations with either drug alone. This novel drug delivery system has the potential to be used to develop more effective cancer therapies.

Conclusion

Targeting CAFs with celastrol sensitizes tumor cells to chemotherapy, increasing the efficacy of betulinic acid. The combination of drugs targeting tumor cells and CAFs may lead to more effective therapies against various cancers.

Nanotechnology-mediated delivery of resveratrol as promising strategy to improve therapeutic efficacy in triple negative breast cancer (TNBC): progress and promises

INTRODUCTION

Triple-negative breast cancer (TNBC) presents unique challenges in diagnosis and treatment. Resveratrol exhibits potential as a therapeutic intervention against TNBC by regulating various pathways such as the PI3K/AKT, RAS/RAF/ERK, PKCδ, and AMPK, leading to apoptosis through ROS-mediated CHOP activationand the expression of DR4 and DR5. However, the clinical efficacy of resveratrol is limited due to its poor biopharmaceutical characteristics and low bioavailability at the tumor site. Nanotechnology offers a promising approach to improving the biopharmaceutical characteristics of resveratrol to achieve clinical efficacy in different cancers. The small dimension (<200 nm) of nanotechnology-mediated drug delivery system is helpful to improve the bioavailability, internalization into the TNBC cell, ligand-specific targeted delivery of loaded resveratrol to tumor site including reversal of MDR (multi-drug resistance) condition.

AREAS COVERED

This manuscript provides a comprehensive discussion on the structure-activity relationship (SAR), underlying anticancer mechanism, evidence of anticancer activity in in-vitro/in-vivo investigations, and the significance of nanotechnology-mediated delivery of resveratrol in TNBC.

EXPERT OPINION

Advanced nano-formulations of resveratrol such as oxidized mesoporous carbon nanoparticles, macrophage-derived vesicular system, functionalized gold nanoparticles, etc. have increased the accumulation of loaded therapeutics at the tumor-site, and avoid off-target drug release. In conclusion, nano-resveratrol as a strategy may provide improved tumor-specific image-guided treatment options for TNBC utilizing theranostic approach.

Recent Advances of Multifunctional PLGA Nanocarriers in the Management of Triple-Negative Breast Cancer

Even though chemotherapy stands as a standard option in the therapy of TNBC, problems associated with it such as anemia, bone marrow suppression, immune suppression, toxic effects on healthy cells, and multi-drug resistance (MDR) can compromise their effects. Nanoparticles gained paramount importance in overcoming the limitations of conventional chemotherapy. Among the various options, nanotechnology has appeared as a promising path in preclinical and clinical studies for early diagnosis of primary tumors and metastases and destroying tumor cells. PLGA has been extensively studied amongst various materials used for the preparation of nanocarriers for anticancer drug delivery and adjuvant therapy because of their capability of higher encapsulation, easy surface functionalization, increased stability, protection of drugs from degradation versatility, biocompatibility, and biodegradability. Furthermore, this review also provides an overview of PLGA-based nanoparticles including hybrid nanoparticles such as the inorganic PLGA nanoparticles, lipid-coated PLGA nanoparticles, cell membrane-coated PLGA nanoparticles, hydrogels, exosomes, and nanofibers. The effects of all these systems in various in vitro and in vivo models of TNBC were explained thus pointing PLGA-based NPs as a strategy for the management of TNBC.

Emerging targeted therapeutic strategies for the treatment of triple-negative breast cancer

Triple-negative breast cancer (TNBC), a subtype of breast cancer that lacks expression of oestrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER-2), has clinical features including a high degree of invasiveness, an elevated risk of metastasis, tendency to relapse, and poor prognosis. It constitutes around 10-15% of all breast cancer, and having heredity of BRCA1 mutated breast cancer could be a reason for the occurrence of TNBC in women. Overexpression of cellular and molecular targets, i.e. CD44 receptor, EGFR receptor, Folate receptor, Transferrin receptor, VEGF receptor, and Androgen receptor, have emerged as promising targets for treating TNBC. Signalling pathways such as Notch signalling and PI3K/AKT/mTOR also play a significant role in carrying out and managing crucial pro-survival and pro-growth cellular processes that can be utilised for targeted therapy against triple-negative breast cancer. This review sheds light on various targeting strategies, including cellular and molecular targets, signalling pathways, poly (ADP-ribose) polymerase inhibitors, antibody-drug conjugates, and immune checkpoint inhibitors PARP, immunotherapy, ADCs have all found a place in the current TNBC therapeutic paradigm. The role of photothermal therapy (PTT) and photodynamic therapy (PDT) has also been explored briefly.

Triple Negative Breast Cancer Treatment Options and Limitations: Future Outlook

Triple negative breast cancer (TNBC) has a negative expression of estrogen receptors (ER), progesterone receptors (PR), and human epidermal growth factor receptors (HER2). The survival rate for TNBC is generally worse than other breast cancer subtypes. TNBC treatment has made significant advances, but certain limitations remain. Treatment for TNBC can be challenging since the disease has various molecular subtypes. A variety of treatment options are available, such as chemotherapy, immunotherapy, radiotherapy, and surgery. Chemotherapy is the most common of these options. TNBC is generally treated with systemic chemotherapy using drugs such as anthracyclines and taxanes in neoadjuvant or adjuvant settings. Developing resistance to anticancer drugs and off-target toxicity are the primary hindrances to chemotherapeutic solutions for cancer. It is imperative that researchers, clinicians, and pharmaceutical companies work together to develop effective treatment options for TNBC. Several studies have suggested nanotechnology as a potential solution to the problem of suboptimal TNBC treatment. In this review, we summarized possible treatment options for TNBC, including chemotherapy, immunotherapy, targeted therapy, combination therapy, and nanoparticle-based therapy, and some solutions for the treatment of TNBC in the future. Moreover, we gave general information about TNBC in terms of its characteristics and aggressiveness.

Synthesis, Characterization, and In Vitro Cytotoxicity Evaluation of Doxorubicin-Loaded Magnetite Nanoparticles on Triple-Negative Breast Cancer Cell Lines

In this study, we investigated the cytotoxicity of doxorubicin (DOX)-loaded magnetic nanofluids on 4T1 mouse tumor epithelial cells and MDA-MB-468 human triple-negative breast cancer (TNBC) cells. Superparamagnetic iron oxide nanoparticles were synthesized using sonochemical coprecipitation by applying electrohydraulic discharge treatment (EHD) in an automated chemical reactor, modified with citric acid and loaded with DOX. The resulting magnetic nanofluids exhibited strong magnetic properties and maintained sedimentation stability in physiological pH conditions. The obtained samples were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy, UV-spectrophotometry, dynamic light scattering (DLS), electrophoretic light scattering (ELS), vibrating sample magnetometry (VSM), and transmission electron microscopy (TEM). In vitro studies using the MTT method revealed a synergistic effect of the DOX-loaded citric-acid-modified magnetic nanoparticles on the inhibition of cancer cell growth and proliferation compared to treatment with pure DOX. The combination of the drug and magnetic nanosystem showed promising potential for targeted drug delivery, with the possibility of optimizing the dosage to reduce side-effects and enhance the cytotoxic effect on cancer cells. The nanoparticles' cytotoxic effects were attributed to the generation of reactive oxygen species and the enhancement of DOX-induced apoptosis. The findings suggest a novel approach for enhancing the therapeutic efficacy of anticancer drugs and reducing their associated side-effects. Overall, the results demonstrate the potential of DOX-loaded citric-acid-modified magnetic nanoparticles as a promising strategy in tumor therapy, and provide insights into their synergistic effects.

Insulin‑like growth factor axis: A potential nanotherapy target for resistant cervical cancer tumors (Review)

Cervical cancer is among the most frequently occurring neoplasms worldwide, and it particularly affects individuals in developing countries. Factors such as the low quality of screening tests, the high incidence of locally advanced cancer stages and the intrinsic resistance of certain tumors are the main causes of failure in the treatment of this neoplasm. Due to advances in the understanding of carcinogenic mechanisms and bioengineering research, advanced biological nanomaterials have been manufactured. The insulin-like growth factor (IGF) system comprises multiple growth factor receptors, including IGF receptor 1. These receptors are activated by binding to their respective growth factor ligands, IGF-1 and IGF-2, and insulin, and play an important role in the development, maintenance, progression, survival and treatment resistance of cervical cancer. In the present review, the role of the IGF system in cervical cancer and three nanotechnological applications that use elements of this system are described, namely Trap decoys, magnetic iron oxide nanoparticles and protein nanotubes. Their use in the treatment of resistant cervical cancer tumors is also discussed.

Unveiling Role of MicroRNAs in Metastasizing Triple Negative Breast Cancer: From Therapeutics to Delivery

Triple negative breast cancers are malignant, heterogeneous tumors with high histological grades, increased reoccurrence, and cancer-related death rates. TNBC metastasis to the brain, lungs, liver, and lymph nodes is a complex process regulated by epithelial to mesenchymal transition, intravasation, extravasation, stem cell niche, and migration. Aberrant expression of miRNAs, also known as a transcriptional regulators of genes, may function as oncogenes or tumor suppressors. In this review, we systematically elucidated the biogenesis and tumor suppressor role of miRNA in targeting distant metastasis of TNBC cells and the above-mentioned underlying mechanisms involved in complicating the disease. Apart from their therapeutic implications, the emerging roles of miRNAs as prognostic markers have also been discussed. To overcome delivery bottlenecks, RNA nanoparticles, nano-diamonds, exosomes, and mesoporous silica nanoparticle-mediated delivery of miRNAs have been contemplated. Altogether, the present review article uncovers the potential role of miRNA in antagonizing distant metastasis of TNBC cells, and highlights their clinical significance as prognostic markers and possible drug delivery strategies to enhance the likely outcome of miRNA-based therapy against the disease.

Novel Implications of Nanoparticle-Enhanced Radiotherapy and Brachytherapy: Z-Effect and Tumor Hypoxia

Radiotherapy and internal radioisotope therapy (brachytherapy) induce tumor cell death through different molecular signaling pathways. However, these therapies in cancer patients are constrained by dose-related adverse effects and local discomfort due to the prolonged exposure to the surrounding tissues. Technological advancements in nanotechnology have resulted in synthesis of high atomic elements such as nanomaterials, which can be used as radiosensitizers due to their photoelectric characteristics. The aim of this review is to elucidate the effects of novel nanomaterials in the field of radiation oncology to ameliorate dose-related toxicity through the application of ideal nanoparticle-based radiosensitizers such as Au (gold), Bi (bismuth), and Lu (Lutetium-177) for enhancing cytotoxic effects of radiotherapy via the high-Z effect. In addition, we discuss the role of nanoparticle-enhanced radiotherapy in alleviating tumor hypoxia through the nanodelivery of genes/drugs and other functional anticancer molecules. The implications of engineered nanoparticles in preclinical and clinical studies still need to be studied in order to explore potential mechanisms for radiosensitization by minimizing tumor hypoxia, operational/logistic complications and by overcoming tumor heterogeneity in radiotherapy/brachytherapy.

Self-assembled hydrogel nanocube for stimuli responsive drug delivery and tumor ablation by phototherapy against breast cancer

The shape and responsiveness of nanoengineered delivery carriers are crucial characteristics for the rapid and efficient delivery of therapeutics. We report on a novel type of micrometer-sized hydrogel particles of controlled shape with dual pH and redox sensitivity for intracellular delivery of anticancer drugs and phototherapy. The cubical HA-DOP-CS-PEG networks with disulfide links are obtained by cross-linking HA-DOP-CS-PEG with cystamine. The pH-triggered hydrogel swelling/shrinkage was not only affords effective doxorubicin release. It also actively provides the endosomal/lysosomal escape, redox-triggered drug release. The hydrogels degrade rapidly to low molecular weight chains in the presence of the typical intracellular concentration of glutathione. Drug-loaded cube particles found to be 12% more cytotoxic. ICG and DOX-loaded hydrogel cubes demonstrate 90% cytotoxicity when incubated with MCF-7 cancer cells for 24 and 48 h, respectively. This approach integrates the advantages of pH sensitivity, enzymatic degradation, and shape-regulated internalization for novel types of "intelligent" three-dimensional networks with programmable behavior for controlled delivery of therapeutics.

Ozonated Olive Oil: Enhanced Cutaneous Delivery via Niosomal Nanovesicles for Melanoma Treatment

Ozonated olive oil (OL) combines the therapeutic effects of both ozone and olive oil. However, it suffers from limited water solubility and poor transdermal permeation, which hinder its application in melanoma treatment. Nanocarrier host molecules, such as niosomes, were used to improve the water solubility, transdermal permeation, and anticancer effect of hydrophobic compounds. This study aims to design and optimize a niosomal vesicular nanoplatform loaded with OL (OL/NSs) to improve OL’s skin permeation and anti-melanoma effect. In this regard, OL was prepared and characterized by evaluating its chemical properties (acid, peroxide, and iodine values) and fatty acid composition using gas chromatography. Then, OL/NSs were developed using the thin film hydration method employing cholesterol, Span 60, and Tween 60 at five different molar ratios. The optimized niosomes had an average diameter of 125.34 ± 13.29 nm, a surface charge of −11.34 ± 4.71 mV, and a spherical shape. They could entrap 87.30 ± 4.95% of the OL. OL/NSs showed a 75% sustained oil release over 24 h. The skin permeation percentage of OL/NSs was 36.78 ± 3.31 and 53.44 ± 6.41% at 12 and 24 h, respectively, three times higher than that of the free OL (11.50 ± 1.3 and 17.24 ± 2.06%, at 12 and 24 h, respectively). Additionally, the anticancer activity of the developed niosmal formulation, when tested on human melanoma cells (A375), was double that of the free OL; the IC50 of the OL/NSs was 8.63 ± 2.8 μg/mL, and that of the free OL was 17.4 ± 3.7 μg/mL. In conclusion, the encapsulation of ozonated olive oil in niosomes enhanced its water solubility, skin permeation, and anticancer activity and thus may represent potent natural chemotherapy in treating melanoma.

Breast Cancer Cell Membrane Camouflaged Lipid Nanoparticles for Tumor-Targeted NIR-II Phototheranostics

Photoacoustic imaging and photothermal therapy that employ organic dye in the second near-infrared window (NIR-II) became an attractive theranostical strategy for eliminating solid tumors, in which IR1048 was previously reported to be a good candidate. However, the further biomedical application of IR1048 was blocked by its poor water-solubility and lack of tumor-targeting. To solve this problem, liposome camouflaged with 4T1 cell membrane fragments was employed to encapsulate IR1048 (thereafter called MLI), and its application for photoacoustic and thermo-imaging and photothermal therapy were explored in vitro and in vivo. The results showed that MLI exhibited spherical morphology around 92.55 ± 5.41 nm coated by monolayer adventitial fragments, and uniformly dispersed in PBS with high loading efficiency and encapsulation efficiency to IR1048. In addition, both free IR1048 and MLI presented strong absorption in NIR-II, and upon 1064 nm laser irradiation the MLI showed awesome photothermal performance that could rapidly elevate the temperature to 50.9 °C in 6 min. Simultaneously, phantom assay proved that MLI could dramatically enhance the photoacoustic amplitudes by a linear concentration-dependent way. Moreover, either flow cytometry or confocal analysis evidenced that MLI was the most uptaked by 4T1 cells among other melanoma B16 cells and Hek293 cells and coexist of IR1048 and 1064 nm laser irradiation were indispensable for the photothermal cytotoxicity of MLI that specifically killed 96.16% of 4T1 cells far outweigh the B16 cells while hardly toxic to the Hek293 normal cells. Furthermore, PA imaging figured out that 4 h post tail-vein injection of MLI was the best time to give 1064 nm irradiation to conduct the photothermal therapy when the average tumor-accumulation of MLI achieved the highest. In the NIR-II photothermal therapy, MLI could significantly inhibit the tumor growth and almost ablated the tumors with slight body weight variation and the highest average life span over the therapy episode and caused no damage to the normal organs. Hence, MLI could pave the way for further biomedical applications of IR-1048 by homologous tumor-targeting and dual-modal imaging directed NIR-II accurate photothermal therapy with high efficacy and fine biosafety.

New Achievements for the Treatment of Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) constitutes a heterogeneous group of malignancies that are often aggressive and associated with a poor prognosis. The development of new TNBC treatment strategies has become an urgent clinical need. Diagnosis and subtyping of TNBC are essential to establish alternative treatments and targeted therapies for every TNBC patient. Chemotherapy, particularly with anthracycline and taxanes, remains the backbone for medical management for both early and metastatic TNBC. More recently, immune checkpoint inhibitors and targeted therapy have revolutionized cancer treatment. Included in the different strategies studied for TNBC treatment is drug repurposing. Despite the numerous medications available, numerous studies in medicinal chemistry are still aimed at the synthesis of new compounds in order to find new antiproliferative agents capable of treating TNBC. Additionally, some supplemental micronutrients, nutraceuticals and functional foods can potentially reduce the risk of developing cancer or can retard the rate of growth and metastases of established malignant diseases. Finally, nanotechnology in medicine, termed nanomedicines, introduces nanoparticles of variable chemistry and architecture for cancer treatment. This review highlights the most recent studies in search of new therapies for the treatment of TNBC, along with nutraceuticals and repositioning of drugs.

Engineered Cell-Derived Vesicles Displaying Targeting Peptide and Functionalized with Nanocarriers for Therapeutic microRNA Delivery to Triple-Negative Breast Cancer in Mice

Polymeric nanocarriers (PNCs) can be used to deliver therapeutic microRNAs (miRNAs) to solid cancers. However, the ability of these nanocarriers to specifically target tumors remains a challenge. Alternatively, extracellular vesicles (EVs) derived from tumor cells show homotypic affinity to parent cells, but loading sufficient amounts of miRNAs into EVs is difficult. Here, it is investigated whether uPAR-targeted delivery of nanococktails containing PNCs loaded with therapeutic antimiRNAs, and coated with uPA engineered extracellular vesicles (uPA-eEVs) can elicit synergistic antitumor responses. The uPA-eEVs coating on PNCs increases natural tumor targeting affinities, thereby enhancing the antitumor activity of antimiRNA nanococktails. The systemic administration of uPA-eEV-PNCs nanococktail shows a robust tumor tropism, which significantly enhances the combinational antitumor effects of antimiRNA-21 and antimiRNA-10b, and leads to significant tumor regression and extension of progression free survival for syngeneic 4T1 tumor-bearing mice. In addition, the uPA-eEV-PNCs-antimiRNAs nanococktail plus low dose doxorubicin results in a synergistic antitumor effect as evidenced by inhibition of tumor growth, reduction of lung metastases, and extension of survival of 4T1 tumor-bearing mice. The targeted combinational nanococktail strategy could be readily translated to the clinical setting by using autologous cancer cells that have flexibility for ex vivo expansion and genetic engineering.

Applications of Extracellular Vesicles in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is the most aggressive and refractory subtype of breast cancer, often occurring in younger patients with poor clinical prognosis. Given the current lack of specific targets for effective intervention, the development of better treatment strategies remains an unmet medical need. Over the last decade, the field of extracellular vesicles (EVs) has grown tremendously, offering immense potential for clinical diagnosis/prognosis and therapeutic applications. While TNBC-EVs have been shown to play an important role in tumorigenesis, chemoresistance and metastasis, they could be repurposed as potential biomarkers for TNBC diagnosis and prognosis. Furthermore, EVs from various cell types can be utilized as nanoscale drug delivery systems (NDDS) for TNBC treatment. Remarkably, EVs generated from specific immune cell subsets have been shown to delay solid tumour growth and reduce tumour burden, suggesting a new immunotherapy approach for TNBC. Intrinsically, EVs can cross the blood-brain barrier (BBB), which holds great potential to treat the brain metastases diagnosed in one third of TNBC patients that remains a substantial clinical challenge. In this review, we present the most recent applications of EVs in TNBC as diagnostic/prognostic biomarkers, nanoscale drug delivery systems and immunotherapeutic agents, as well as discuss the associated challenges and future directions of EVs in cancer immunotherapy.

Stem Cell Mimicking Nanoencapsulation for Targeting Arthritis

Mesenchymal stem cells (MSCs) are considered a promising regenerative therapy due to their ability to migrate toward damaged tissues. The homing ability of MSCs is unique compared with that of non-migrating cells and MSCs are considered promising therapeutic vectors for targeting major cells in many pathophysiological sites. MSCs have many advantages in the treatment of malignant diseases, particularly rheumatoid arthritis (RA). RA is a representative autoimmune disease that primarily affects joints, and secreted chemokines in the joints are well recognized by MSCs following their migration to the joints. Furthermore, MSCs can regulate the inflammatory process and repair damaged cells in the joints. However, the functionality and migration ability of MSCs injected in vivo still show insufficient. The targeting ability and migration efficiency of MSCs can be enhanced by genetic engineering or modification, eg, overexpressing chemokine receptors or migration-related genes, thus maximizing their therapeutic effect. However, there are concerns about genetic changes due to the increased probability of oncogenesis resulting from genome integration of the viral vector, and thus, clinical application is limited. Furthermore, it is suspected that administering MSCs can promote tumor growth and metastasis in xenograft and orthotopic models. For this reason, MSC mimicking nanoencapsulations are an alternative strategy that does not involve using MSCs or bioengineered MSCs. MSC mimicking nanoencapsulations consist of MSC membrane-coated nanoparticles, MSC-derived exosomes and artificial ectosomes, and MSC membrane-fused liposomes with natural or genetically engineered MSC membranes. MSC mimicking nanoencapsulations not only retain the targeting ability of MSCs but also have many advantages in terms of targeted drug delivery. Specifically, MSC mimicking nanoencapsulations are capable of encapsulating drugs with various components, including chemotherapeutic agents, nucleic acids, and proteins. Furthermore, there are fewer concerns over safety issues on MSC mimicking nanoencapsulations associated with mutagenesis even when using genetically engineered MSCs, because MSC mimicking nanoencapsulations use only the membrane fraction of MSCs. Genetic engineering is a promising route in clinical settings, where nano-encapsulated technology strategies are combined. In this review, the mechanism underlying MSC homing and the advantages of MSC mimicking nanoencapsulations are discussed. In addition, genetic engineering of MSCs and MSC mimicking nanoencapsulation is described as a promising strategy for the treatment of immune-related diseases.

Current Photoactive Molecules for Targeted Therapy of Triple-Negative Breast Cancer

Cancer is the second leading cause of death worldwide; therefore, there is an urgent need to find safe and effective therapies. Triple-negative breast cancer (TNBC) is diagnosed in ca. 15-20% of BC and is extremely aggressive resulting in reduced survival rate, which is mainly due to the low therapeutic efficacy of available treatments. Photodynamic therapy (PDT) is an interesting therapeutic approach in the treatment of cancer; the photosensitizers with good absorption in the therapeutic window, combined with their specific targeting of cancer cells, have received particular interest. This review aims to revisit the latest developments on chlorin-based photoactive molecules for targeted therapy in TNBC. Photodynamic therapy, alone or combined with other therapies (such as chemotherapy or photothermal therapy), has potential to be a safe and a promising approach against TNBC.

Nanotechnology-based siRNA delivery strategies for treatment of triple negative breast cancer

Triple negative breast cancer (TNBC) is a subtype of breast cancer characterized by absence of estrogen (ER) receptor, progesterone (PR) receptor, and human epidermal growth factor-2 (HER-2) receptor. TNBC is an aggressive disease that develops early Chemoresistance. The major pitfall associated is its poor prognosis, low overall survival, high relapse, and mortality as compared to other types of breast cancer. Chemotherapy could be helpful but do not contribute to an increase in survival of patient. To overcome such obstacles, in our article we explored advanced therapy using genes and nanocarrier along with its conjugation to achieve high therapeutic profile with reduced side effect. siRNAs are one of the class of RNA associated with gene silencing. They also regulate the expression of certain proteins that are involved in development of tumor cells. But they are highly unstable. So, for efficient delivery of siRNA, very intelligent, efficient delivery systems are required. Several nanotechnologies based non-viral vectors such as liposome, micelles, nanoparticles, dendrimers, exosomes, nanorods and nanobubbles etc. offers enormous unique properties such as nanometric size range, targeting potential with the capability to link with several targeting moieties for the gene delivery. These non-viral vectors are much safer, effective and efficient system for the delivery of genes along with chemotherapeutics. This review provides an overview of TNBC, conventional and advanced treatment approach of TNBC along with understanding of current status of several nanocarriers used for the delivery of siRNA for the treatment of TNBC.

Drug Resistance in Metastatic Breast Cancer: Tumor Targeted Nanomedicine to the Rescue

Breast cancer, specifically metastatic breast, is a leading cause of morbidity and mortality in women. This is mainly due to relapse and reoccurrence of tumor. The primary reason for cancer relapse is the development of multidrug resistance (MDR) hampering the treatment and prognosis. MDR can occur due to a multitude of molecular events, including increased expression of efflux transporters such as P-gp, BCRP, or MRP1; epithelial to mesenchymal transition; and resistance development in breast cancer stem cells. Excessive dose dumping in chemotherapy can cause intrinsic anti-cancer MDR to appear prior to chemotherapy and after the treatment. Hence, novel targeted nanomedicines encapsulating chemotherapeutics and gene therapy products may assist to overcome cancer drug resistance. Targeted nanomedicines offer innovative strategies to overcome the limitations of conventional chemotherapy while permitting enhanced selectivity to cancer cells. Targeted nanotheranostics permit targeted drug release, precise breast cancer diagnosis, and importantly, the ability to overcome MDR. The article discusses various nanomedicines designed to selectively target breast cancer, triple negative breast cancer, and breast cancer stem cells. In addition, the review discusses recent approaches, including combination nanoparticles (NPs), theranostic NPs, and stimuli sensitive or “smart” NPs. Recent innovations in microRNA NPs and personalized medicine NPs are also discussed. Future perspective research for complex targeted and multi-stage responsive nanomedicines for metastatic breast cancer is discussed.

Preclinical Advances in Theranostics for the Different Molecular Subtypes of Breast Cancer

Breast cancer is the most common cancer in women worldwide. The heterogeneity of breast cancer and drug resistance to therapies make the diagnosis and treatment difficult. Molecular imaging methods with positron emission tomography (PET) and single-photon emission tomography (SPECT) provide useful tools to diagnose, predict, and monitor the response of therapy, contributing to precision medicine for breast cancer patients. Recently, many efforts have been made to find new targets for breast cancer therapy to overcome resistance to standard of care treatments, giving rise to new therapeutic agents to offer more options for patients with breast cancer. The combination of diagnostic and therapeutic strategies forms the foundation of theranostics. Some of these theranostic agents exhibit high potential to be translated to clinic. In this review, we highlight the most recent advances in theranostics of the different molecular subtypes of breast cancer in preclinical studies.

Image-guided thermosensitive liposomes for focused ultrasound enhanced co-delivery of carboplatin and SN-38 against triple negative breast cancer in mice

Triggerable nanocarriers have the potential to significantly improve the therapeutic index of existing anticancer agents. They allow for highly localised delivery and release of therapeutic cargos, reducing off-target toxicity and increasing anti-tumour activity. Liposomes may be engineered to respond to an externally applied stimulus such as focused ultrasound (FUS). Here, we report the first co-delivery of SN-38 (irinotecan's super-active metabolite) and carboplatin, using an MRI-visible thermosensitive liposome (iTSL). MR contrast enhancement was achieved by the incorporation of a gadolinium lipid conjugate in the liposome bilayer along with a dye-labelled lipid for near infrared fluorescence bioimaging. The resulting iTSL were successfully loaded with SN-38 in the lipid bilayer and carboplatin in the aqueous core - allowing co-delivery of both. The iTSL demonstrated both thermosensitivity and MR-imageability. In addition, they showed effective local targeted co-delivery of carboplatin and SN-38 after triggered release with brief FUS treatments. A single dosage induced significant improvement of anti-tumour activity (over either the free drugs or the iTSL without FUS-activation) in triple negative breast cancer xenografts tumours in mice.

Role of inflammatory microenvironment: potential implications for improved breast cancer nano-targeted therapy

Tumor cells, inflammatory cells and chemical factors work together to mediate complex signaling networks, which forms inflammatory tumor microenvironment (TME). The development of breast cancer is closely related to the functional activities of TME. This review introduces the origins of cancer-related chronic inflammation and the main constituents of inflammatory microenvironment. Inflammatory microenvironment plays an important role in breast cancer growth, metastasis, drug resistance and angiogenesis through multifactorial mechanisms. It is suggested that inflammatory microenvironment contributes to providing possible mechanisms of drug action and modes of drug transport for anti-cancer treatment. Nano-drug delivery system (NDDS) becomes a popular topic for optimizing the design of tumor targeting drugs. It is seen that with the development of therapeutic approaches, NDDS can be used to achieve drug-targeted delivery well across the biological barriers and into cells, resulting in superior bioavailability, drug dose reduction as well as off-target side effect elimination. This paper focuses on the review of modulation mechanisms of inflammatory microenvironment and combination with nano-targeted therapeutic strategies, providing a comprehensive basis for further research on breast cancer prevention and control.

Understanding Patterns of Brain Metastasis in Triple-Negative Breast Cancer and Exploring Potential Therapeutic Targets

Triple-negative breast cancer (TNBC) is a highly malignant subtype of breast cancer. High invasiveness and heterogeneity, as well as a lack of drug targets, are the main factors leading to poor prognosis. Brain metastasis (BM) is a serious event threatening the life of breast cancer patients, especially those with TNBC. Compared with that for hormone receptor-positive and HER2-positive breast cancers, TNBC-derived BM (TNBCBM) occurs earlier and more frequently, and has a worse prognosis. There is no standard treatment for BM to date, and one is urgently required. In this review, we discuss the current knowledge regarding the developmental patterns of TNBCBM, focusing on the key events in BM formation. Specifically, we consider (i) the nature and function of TNBC cells; (ii) how TNBC cells cross the blood–brain barrier and form a fenestrated, more permeable blood–tumor barrier; (iii) the biological characteristics of TNBCBM; and (iv) the infiltration and colonization of the central nervous system (CNS) by TNBC cells, including the establishment of premetastatic niches, immunosurveillance escape, and metabolic adaptations. We also discuss putative therapeutic targets and precision therapy with the greatest potential to treat TNBCBM, and summarize the relevant completed and ongoing clinical trials. These findings may provide new insights into the prevention and treatment of BM in TNBC patients.

Targeted polymeric nanoparticles for drug delivery to hypoxic, triple-negative breast tumors

High recurrence and metastasis to vital organs are the major characteristics of triple-negative breast cancer (TNBC). Low vascular oxygen tension promotes resistance to chemo- and radiation therapy. Neuropilin-1 (NRP-1) receptor is highly expressed on TNBC cells. The tumor-penetrating iRGD peptide interacts with the NRP-1 receptor, triggers endocytosis and transcytosis, and facilitates penetration. Herein, we synthesized a hypoxia-responsive diblock PLA-diazobenzene-PEG copolymer and prepared self-assembled hypoxia-responsive polymersomes (Ps) in an aqueous buffer. The iRGD peptide was incorporated into the polymersome structure to make hypoxia-responsive iRGD-conjugated polymersomes (iPs). Doxorubicin (DOX) was encapsulated in the polymersomes to prepare both targeted and non-targeted hypoxia-responsive polymersomes (DOX-iPs and DOX-Ps, respectively). The polymeric nanoparticles released less than 30% of their encapsulated DOX within 12 hours under normoxic conditions (21% oxygen), whereas under hypoxia (2% Oxygen), doxorubicin release remarkably increased to over 95%. The targeted polymersomes significantly decreased TNBC cells' viability in monolayer and spheroid cultures under hypoxia compared to normoxia. Animal studies displayed that targeted polymersomes significantly diminished tumor growth in xenograft nude mice. Overall, the targeted polymersomes exhibited potent anti-tumor activity in monolayer, spheroid, and animal models of TNBC. With further developments, the targeted nanocarriers discussed here might have the translational potential as drug carriers for the treatment of TNBC.

Chondroitin sulfate-hybridized zein nanoparticles for tumor-targeted delivery of docetaxel

Chondroitin sulfate-hybridized zein nanoparticles (zein/CS NPs) were developed for targeted delivery of docetaxel, which exhibited mean diameters of 157.8 ± 3.6 nm and docetaxel encapsulation efficiency of 64.2 ± 1.9 %. Docetaxel was released from the NPs in a sustained manner (∼72 h), following first-order kinetics. The zein/CS NPs showed improved colloidal stability, maintaining the initial size in serum for 12 h. The pre-treatment of CS reduced the uptake efficiency of the NPs by 23 % in PC-3 cells, suggesting the involvement of CD44-mediated uptake mechanism. The NPs showed 2.79-fold lower IC₅₀ values than free docetaxel. Enhanced tumor accumulation of the NPs was confirmed in PC-3 xenograft mice by near-infrared fluorescence imaging (35.3-fold, versus free Cy5.5). The NPs exhibited improved pharmacokinetic properties (9.5-fold longer terminal half-life, versus free docetaxel) and anti-tumor efficacy comparable to Taxotere with negligible systemic toxicity, suggesting zein/CS NPs could be a promising nanoplatform for targeted cancer therapy.

Triple-Negative Breast Cancer: A Review of Conventional and Advanced Therapeutic Strategies

Triple-negative breast cancer (TNBC) cells are deficient in estrogen, progesterone and ERBB2 receptor expression, presenting a particularly challenging therapeutic target due to their highly invasive nature and relatively low response to therapeutics. There is an absence of specific treatment strategies for this tumor subgroup, and hence TNBC is managed with conventional therapeutics, often leading to systemic relapse. In terms of histology and transcription profile these cancers have similarities to BRCA-1-linked breast cancers, and it is hypothesized that BRCA1 pathway is non-functional in this type of breast cancer. In this review article, we discuss the different receptors expressed by TNBC as well as the diversity of different signaling pathways targeted by TNBC therapeutics, for example, Notch, Hedgehog, Wnt/b-Catenin as well as TGF-beta signaling pathways. Additionally, many epidermal growth factor receptor (EGFR), poly (ADP-ribose) polymerase (PARP) and mammalian target of rapamycin (mTOR) inhibitors effectively inhibit the TNBCs, but they face challenges of either resistance to drugs or relapse. The resistance of TNBC to conventional therapeutic agents has helped in the advancement of advanced TNBC therapeutic approaches including hyperthermia, photodynamic therapy, as well as nanomedicine-based targeted therapeutics of drugs, miRNA, siRNA, and aptamers, which will also be discussed. Artificial intelligence is another tool that is presented to enhance the diagnosis of TNBC.

Combined Magnetoliposome Formation and Drug Loading in One Step for Efficient Alternating Current-Magnetic Field Remote-Controlled Drug Release

We have developed a reproducible and facile one step strategy for the synthesis of doxorubicin loaded magnetoliposomes by using a thin-layer evaporation method. Liposomes of around 200 nm were made of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and iron oxide nanoparticles (NPs) with negative, positive, and hydrophobic surfaces that were incorporated outside, inside, or between the lipid bilayers, respectively. To characterize how NPs are incorporated in liposomes, advanced cryoTEM and atomic force microscope (AFM) techniques have been used. It was observed that only when the NPs are attached outside the liposomes, the membrane integrity is preserved (lipid melt transition shifts to 38.7 °C with high enthalpy 34.8 J/g) avoiding the leakage of the encapsulated drug while having good colloidal properties and the best heating efficiency under an alternating magnetic field (AMF). These magnetoliposomes were tested with two cancer cell lines, MDA-MB-231 and HeLa cells. First, 100% of cellular uptake was achieved with a high cell survival (above 80%), which is preserved (83%) for doxorubicin-loaded magnetoliposomes. Then, we demonstrate that doxorubicin release can be triggered by remote control, using a noninvasive external AMF for 1 h, leading to a cell survival reduction of 20%. Magnetic field conditions of 202 kHz and 30 mT seem to be enough to produce an effective heating to avoid drug degradation. In conclusion, these drug-loaded magnetoliposomes prepared in one step could be used for drug release on demand at a specific time and place, efficiently using an external AMF to reduce or even eliminate side effects.

An ATF24 peptide-functionalized β-elemene-nanostructured lipid carrier combined with cisplatin for bladder cancer treatment

Objective: In this study, we aimed to develop an amino-terminal fragment (ATF) peptide-targeted liposome carrying β-elemene (ATF₂₄-PEG-Lipo-β-E) for targeted delivery into urokinase plasminogen activator receptor-overexpressing bladder cancer cells combined with cisplatin (DDP) for bladder cancer treatment.

Methods: The liposomes were prepared by ethanol injection and high-pressure microjet homogenization. The liposomes were characterized, and the drug content, entrapment efficiency, and in vitro release were studied. The targeting efficiency was investigated using confocal microscopy, ultra-fast liquid chromatography, and an orthotopic bladder cancer model. The effects of ATF₂₄-PEG-Lipo-β-E combined with DDP on cell viability and proliferation were evaluated by a Cell Counting Kit-8 (CCK-8) assay, a colony formation assay, and cell apoptosis and cell cycle analyses. The anticancer effects were evaluated in a KU-19-19 bladder cancer xenograft model.

Results: ATF₂₄-PEG-Lipo-β-E had small and uniform sizes (˜79 nm), high drug loading capacity (˜5.24 mg/mL), high entrapment efficiency (98.37 ± 0.95%), and exhibited sustained drug release behavior. ATF₂₄-PEG-Lipo-β-E had better targeting efficiency and higher cytotoxicity than polyethylene glycol (PEG)ylated β-elemene liposomes (PEG-Lipo-β-E). DDP, combined with ATF₂₄-PEG-Lipo-β-E, exerted a synergistic effect on cellular apoptosis and cell arrest at the G2/M phase, and these effects were dependent on the caspase-dependent pathway and Cdc25C/Cdc2/cyclin B1 pathways. Furthermore, the in vivo antitumor activity showed that the targeted liposomes effectively inhibited the growth of tumors, using the combined strategy.

Conclusions: The present study provided an effective strategy for the targeted delivery of β-elemene (β-E) to bladder cancer, and a combined strategy for bladder cancer treatment.

Affibody-Indocyanine Green Based Contrast Agent for Photoacoustic and Fluorescence Molecular Imaging of B7-H3 Expression in Breast Cancer

Spectroscopic photoacoustic (sPA) molecular imaging has high potential for identification of exogenous contrast agents targeted to specific markers. Antibody-dye conjugates have recently been used extensively for preclinical sPA and other optical imaging modalities for highly specific molecular imaging of breast cancer. However, antibody-based agents suffer from long circulation times that limit image specificity. Here, the efficacy of a small protein scaffold, the affibody (ABY), conjugated to indocyanine green (ICG), a near-infrared fluorescence dye, as a targeted molecular imaging probe is demonstrated. In particular, B7-H3 (CD276), a cellular receptor expressed in breast cancer, was imaged via sPA and fluorescence molecular imaging to differentiate invasive tumors from normal glands in mice. Administration of ICG conjugated to an ABY specific to B7-H3 (ABYB7-H3-ICG) showed significantly higher signal in mammary tumors compared to normal glands of mice. ABYB7-H3-ICG is a compelling scaffold for molecular sPA imaging for breast cancer detection.

Assessment of Copper Nanoclusters for Accurate in Vivo Tumor Imaging and Potential for Translation

Nanoparticles have been widely used for preclinical cancer imaging. However, their successful clinical translation is largely hampered by potential toxicity, unsatisfactory detection of malignancy at early stages, inaccurate diagnosis of tumor biomarkers, and histology for imaging-guided treatment. Herein, a targeted copper nanocluster (CuNC) is reported with high potential to address these challenges for future translation. Its ultrasmall structure enables efficient renal/bowel clearance, minimized off-target effects in nontargeted organs, and low nonspecific tumor retention. The pH-dependent in vivo dissolution of CuNCs affords minimal toxicity and potentially selective drug delivery to tumors. The intrinsic radiolabeling through the direct addition of ⁶⁴Cu to CuNC (⁶⁴Cu-CuNCs-FC131) synthesis offers high specific activity for sensitive and accurate detection of CXCR4 via FC131-directed targeting in novel triple negative breast cancer (TNBC) patient-derived xenograft mouse models and human TNBC tissues. In summary, this study not only reveals the potential of CXCR4-targeted ⁶⁴Cu-CuNCs for TNBC imaging in clinical settings, but also provides a useful strategy to design and assess the translational potential of nanoparticles for cancer theranostics.

Delivery of Anti-miRNA for Triple-Negative Breast Cancer Therapy Using RNA Nanoparticles Targeting Stem Cell Marker CD133

Triple-negative breast cancer (TNBC) is an aggressive disease with a short median time from relapse to death. The increased aggressiveness, drug resistance, disease relapse, and metastasis are associated with the presence of stem cells within tumors. Several stem cell markers, such as CD24, CD44, CD133, ALDH1, and ABCG2, have been reported, but their roles in breast cancer tumorigenesis remain unclear. Herein, we apply RNA nanotechnology to deliver anti-microRNA (miRNA) for TNBC therapy. The thermodynamically and chemically stable three-way junction (3WJ) motif was utilized as the scaffold to carry an RNA aptamer binding to CD133 receptor and a locked nuclei acid (LNA) sequence for miRNA21 inhibition. Binding assays revealed the specific uptake of the nanoparticles to breast cancer stem cells (BCSCs) and TNBC cells. Functional assays showed that cancer cell migration was reduced, miR21 expression was inhibited, and downstream tumor suppressor PTEN and PDCD4 expressions were upregulated. In vitro and in vivo studies revealed that these therapeutic RNA nanoparticles did not induce cytokine secretion. Systemic injection of these RNA nanoparticles in animal trial demonstrated high specificity in TNBC tumor targeting and high efficacy for tumor growth inhibition. These results revealed the clinical translation potential of these RNA nanoparticles for TNBC therapy.

Evaluation of a novel monoclonal antibody against tumor-associated MUC1 for diagnosis and prognosis of breast cancer

There is still a great unmet medical need concerning diagnosis and treatment of breast cancer which could be addressed by utilizing specific molecular targets. Tumor-associated MUC1 is expressed on over 90 % of all breast cancer entities and differs strongly from its physiological form on epithelial cells, therefore presenting a unique target for breast cancer diagnosis and antibody-mediated immune therapy. Utilizing an anti-tumor vaccine based on a synthetically prepared glycopeptide, we generated a monoclonal antibody (mAb) GGSK-1/30, selectively recognizing human tumor-associated MUC1. This antibody targets exclusively tumor-associated MUC1 in the absence of any binding to MUC1 on healthy epithelial cells thus enabling the generation of breast tumor-specific radiolabeled immune therapeutic tools. Methods: MAb GGSK-1/30 was used for immunohistochemical analysis of human breast cancer tissue. Its desferrioxamine (Df')-conjugate was synthesized and labelled with ⁸⁹Zr. [⁸⁹Zr]Zr-Df'-GGSK-1/30 was evaluated as a potential PET tracer. Binding and pharmacokinetic properties of [⁸⁹Zr]Zr-Df'-GGSK-1/30 were analyzed in vitro using human and murine cell lines that express tumor-associated MUC1. Self-generated primary murine breast cancer cells expressing human tumor-associated MUC1 were transplanted subcutaneously in wild type and human MUC1-transgenic mice. The pharmacology of [⁸⁹Zr]Zr-Df'-GGSK-1/30 was investigated using breast tumor-bearing mice in vivo by PET/MRT imaging as well as by ex vivo organ biodistribution analysis. Results: The mAb GGSK-1/30 stained specifically human breast tumor tissue and can be possibly used to predict the severity of disease progression based on the expression of the tumor-associated MUC1. For in vivo imaging, the Df'-conjugated mAb was radiolabeled with a radiochemical yield of 60 %, a radiochemical purity of 95 % and an apparent specific activity of 6.1 GBq/µmol. After 7 d, stabilities of 84 % in human serum and of 93 % in saline were observed. In vitro cell studies showed strong binding to human tumor-associated MUC1 expressing breast cancer cells. The breast tumor-bearing mice showed an in vivo tumor uptake of >50 %ID/g and clearly visible specific enrichment of the radioconjugate via PET/MRT. Principal conclusions: Tumor-associated MUC1 is a very important biomarker for breast cancer next to the traditional markers estrogen receptor (ER), progesterone receptor (PR) and HER/2-neu. The mAb GGSK-1/30 can be used for the diagnosis of over 90% of breast cancers, including triple negative breast cancer based on biopsy staining. Its radioimmunoconjugate represents a promising PET-tracer for breast cancer imaging selectively targeting breast cancer cells.

Reduced Breast Tumor Growth after Immunization with a Tumor-Restricted MUC1 Glycopeptide Conjugated to Tetanus Toxoid

Preventive vaccination against tumor-associated endogenous antigens is considered to be an attractive strategy for the induction of a curative immune response concomitant with a long-lasting immunologic memory. The mucin MUC1 is a promising tumor antigen, as its tumor-associated form differs from the glycoprotein form expressed on healthy cells. Due to aberrant glycosylation in tumor cells, the specific peptide epitopes in its backbone are accessible and can be bound by antibodies induced by vaccination. Breast cancer patients develop per se only low levels of T cells and antibodies recognizing tumor-associated MUC1, and clinical trials with tumor-associated MUC1 yielded unsatisfactory therapeutic effects, indicating an urgent need to improve humoral immunity against this tumor entity. Herein, we demonstrate that preventive vaccination against tumor-associated human MUC1 results in a specific humoral immune response, a slowdown of tumor progression and an increase in survival of breast tumor-bearing mice. For preventive vaccination, we used a synthetic vaccine containing a tumor-associated glycopeptide structure of human MUC1 coupled to Tetanus Toxoid. The glycopeptide consists of a 22mer huMUC1 peptide with two immune dominant regions (PDTR and GSTA), glycosylated with the sialylated carbohydrate ST_N on serine-17. PyMT (polyomavirus middle T-antigen) and human MUC1 double-transgenic mice expressing human tumor-associated MUC1 on breast tumor tissue served as a preclinical breast cancer model.

Drug delivery systems for elemene, its main active ingredient β-elemene, and its derivatives in cancer therapy

β-elemene is a noncytotoxic Class II antitumor drug extracted from the traditional Chinese medicine Curcuma wenyujin Y. H. Chen et C. Ling. β-elemene exerts its effects by inhibiting cell proliferation, arresting the cell cycle, inducing cell apoptosis, exerting antiangiogenesis and antimetastasis effects, reversing multiple-drug resistance (MDR), and enhancing the immune system. Elemene injection and oral emulsion have been used to treat various tumors, including cancer of the lung, liver, brain, breast, ovary, gastric, prostate, and other tissues, for >20 years. The safety of both elemene injection and oral emulsion in the clinic has been discussed. Recently, the secondary development of β-elemene has attracted the attention of researchers and made great progress. On the one hand, studies have been carried out on liposome-based systems (including solid lipid nanoparticles [SLNs], nanostructured lipid carriers [NLCs], long-circulating liposomes, active targeting liposomes, and multidrug-loaded liposomes) and emulsion systems (including microemulsions, self-emulsion drug delivery systems [SEDDSs], and active targeting microemulsion) to solve the issues of poor solubility in water, low bioavailability, and severe phlebitis, as well as to improve antitumor efficacy. The pharmacokinetics of different drug delivery systems of β-elemene are also summarized. On the other hand, a number of highly active anticancer β-elemene derivatives have been obtained through modification of the structure of β-elemene. This review focuses on the two drug delivery systems and derivatives of β-elemene for cancer therapy.

Global trends in nanomedicine research on triple negative breast cancer: a bibliometric analysis

Nanotechnology has emerged as a promising tool in the clinic to combat several difficult-to-manage diseases, such as cancer, which is the second leading cause of death worldwide. Chemotherapeutic drugs present several limitations such as undesired side effects, low specificity, resistance, and high relapse rates. Triple negative breast cancer (TNBC) is caused by cells that lack specific receptors in their membrane, such as estrogen (ER+) and progesterone (PR+) receptors, or by cells that do not express the amplification of human epidermal growth factor receptor-2 (HER-2+). This cancer type has poor prognosis, high relapse rates, and no targeted therapies. Thus, this study aimed to investigate the trends of nanotechnology research in TNBC and compare the contribution of research from different regions, institutions, and authors. A search of the studies published between 2012 and 2017, related to nanotechnology and TNBC, with different keyword combinations, was performed in the Scopus database. The keywords found in this search were grouped into four clusters, in which "breast cancer" was the most mentioned (1,133 times) and the word "MCF-7 cell line" is one of the latest hotspots that appeared in the year 2016. A total of 1,932 articles, which were cited 26,450 times, were identified. The USA accounted for 28.36% of the articles and 27.61% of the citations; however, none of its centers appeared in the list of 10 most productive ones in terms of publications. The journals Biomaterials and International Journal of Nanomedicine had the highest number of publications. The USA and China had the highest number of articles produced and cited; however, the highest average citation per article was from Singapore. The studies focused on the research of antineoplastic agents in animal models and cell culture, and these were the most used topics in research with nanotechnology and TNBC.

Anti-Trop2 antibody-conjugated bioreducible nanoparticles for targeted triple negative breast cancer therapy

Trop2, a transmembrane glycoprotein, has emerged as a biomarker for targeted cancer therapy since it is overexpressed in 80% of triple negative breast cancer (TNBC) patients. For the site-specific delivery of the anticancer drug into TNBC, anti-Trop2 antibody-conjugated nanoparticles (ST-NPs) were prepared as the potential nanocarrier, composed of carboxymethyl dextran (CMD) derivatives with bioreducible disulfide bonds. Owing to its amphiphilicity, the CMD derivatives were self-assembled into nano-sized particles in an aqueous condition. Doxorubicin (DOX), chosen as a model anticancer drug, was effectively encapsulated into the nanoparticles. DOX-loaded ST-NPs (DOX-ST-NPs) rapidly released DOX in the presence of 10mM glutathione (GSH), whereas the DOX release is significantly retarded in the physiological condition (PBS, pH 7.4). Confocal microscopic images and flow cytometry analysis demonstrated that DOX-ST-NPs were selectively taken up by MDA-MB-231 as the representative Trop2-expressing TNBC cells. Consequently, DOX-ST-NPs exhibited higher toxicity to Trop2-positive MDA-MB-231 cancer cells, compared to DOX-loaded control nanoparticles without the disulfide bond or anti-Trop2 antibody. Overall, ST-NPs might be a promising carrier of DOX for targeted TNBC therapy.

Nanoparticles as Theranostic Vehicles in Experimental and Clinical Applications-Focus on Prostate and Breast Cancer

Prostate and breast cancer are the second most and most commonly diagnosed cancer in men and women worldwide, respectively. The American Cancer Society estimates that during 2016 in the USA around 430,000 individuals were diagnosed with one of these two types of cancers, and approximately 15% of them will die from the disease. In Europe, the rate of incidences and deaths are similar to those in the USA. Several different more or less successful diagnostic and therapeutic approaches have been developed and evaluated in order to tackle this issue and thereby decrease the death rates. By using nanoparticles as vehicles carrying both diagnostic and therapeutic molecular entities, individualized targeted theranostic nanomedicine has emerged as a promising option to increase the sensitivity and the specificity during diagnosis, as well as the likelihood of survival or prolonged survival after therapy. This article presents and discusses important and promising different kinds of nanoparticles, as well as imaging and therapy options, suitable for theranostic applications. The presentation of different nanoparticles and theranostic applications is quite general, but there is a special focus on prostate cancer. Some references and aspects regarding breast cancer are however also presented and discussed. Finally, the prostate cancer case is presented in more detail regarding diagnosis, staging, recurrence, metastases, and treatment options available today, followed by possible ways to move forward applying theranostics for both prostate and breast cancer based on promising experiments performed until today.

Nanoparticles for imaging and treatment of metastatic breast cancer

INTRODUCTION

Metastatic breast cancer is one of the most devastating cancers that have no cure. Many therapeutic and diagnostic strategies have been extensively studied in the past decade. Among these strategies, cancer nanotechnology has emerged as a promising strategy in preclinical studies by enabling early identification of primary tumors and metastases, and by effective killing of cancer cells. Areas covered: This review covers the recent progress made in targeting and imaging of metastatic breast cancer with nanoparticles, and treatment using nanoparticle-enabled chemo-, gene, photothermal- and radio-therapies. This review also discusses recent developments of nanoparticle-enabled stem cell therapy and immunotherapy. Expert opinion: Nanotechnology is expected to play important roles in modern therapy for cancers, including metastatic breast cancer. Nanoparticles are able to target and visualize metastasis in various organs, and deliver therapeutic agents. Through targeting cancer stem cells, nanoparticles are able to treat resistant tumors with minimal toxicity to healthy tissues/organs. Nanoparticles are also able to activate immune cells to eliminate tumors. Owing to their multifunctional, controllable and trackable features, nanotechnology-based imaging and therapy could be a highly potent approach for future cancer research and treatment.

Multi-functionality Redefined with Colloidal Carotene Carbon Nanoparticles for Synchronized Chemical Imaging, Enriched Cellular Uptake and Therapy

Typically, multiplexing high nanoparticle uptake, imaging, and therapy requires careful integration of three different functions of a multiscale molecular-particle assembly. Here, we present a simpler approach to multiplexing by utilizing one component of the system for multiple functions. Specifically, we successfully synthesized and characterized colloidal carotene carbon nanoparticle (C(3)-NP), in which a single functional molecule served a threefold purpose. First, the presence of carotene moieties promoted the passage of the particle through the cell membrane and into the cells. Second, the ligand acted as a potent detrimental moiety for cancer cells and, finally, the ligands produced optical contrast for robust microscopic detection in complex cellular environments. In comparative tests, C(3)-NP were found to provide effective intracellular delivery that enables both robust detection at cellular and tissue level and presents significant therapeutic potential without altering the mechanism of intracellular action of β-carotene. Surface coating of C(3) with phospholipid was used to generate C(3)-Lipocoat nanoparticles with further improved function and biocompatibility, paving the path to eventual in vivo studies.