Dual-Functional PTX@Fe₃O₄ Nanobubbles: A Novel Theranostic Platform for Enhanced Ultrasound Imaging and Controlled Drug Delivery in Breast Cancer.

Background: In recent years, there has been great interest in developing drugs that modify epigenetic changes as new therapies for breast cancer (BC). There is evidence that aberrant epigenetic inactivation of genes, essential for normal cell growth, is involved in cancer. These modifications are potentially reversible therefore re-activation of genes in response to epigenetic drugs can result in inhibition of tumour growth or sensitisation to other anti-cancer therapies. Epigenetic drugs are in clinical trials for BC but have some drawbacks: while some can be highly effective in vitro, their poor stability could compromise their clinical use. Also, high doses required to induce an effect in patients could increase off-site toxicity. As a result there is an urgent need to develop novel systems for the delivery and release of these drugs. Objectives: Our aim is to develop targeted microbubbles (MBs) to enhance therapeutic effects in vitro and in vivo. Ultrasound (US)-mediated drug delivery using MBs is proposed as a non-invasive approach for localised drug administration. Methods: We developed assays using low doses of a DNA methyltransferase inhibitor, called decitabine (DAC), for determining its delivery and effect in vitro and in vivo. VEGFR2 was assessed as a targeting molecule for therapeutic delivery to tumour vasculature in vitro and in a human BC xenograft model. We have generated therapeutic MBs with DAC using a flow-focussing microfluidic platform and conducted in vitro and currently performing in vivo studies to observe tumour and tissue responses. Results: Treatment of triple-negative BC (TNBC) cells with low DAC doses revealed restoration of epigenetically dysregulated tumour suppressor genes. These genes were used as biomarkers for the assessment of DAC effects in a human TNBC mouse model. To evaluate the use of a targeting molecule for drug delivery, specific binding of VEGFR2-targeted MBs on VEGFR2+ve mouse endothelial cells was verified by a flow assay. VEGFR2 expression was assessed longitudinally in xenograft tissue and demonstrated significantly higher VEGFR2 expression in the vasculature of smaller size tumours, indicating the time that delivery of targeted MBs would be most effective. DAC-loaded liposomes or co-administration of DAC and MBs in combination with US using a specifically designed US transducer, were tested in vitro. Currently, investigation of the potential of US-triggered drug delivery enhancing efficacy of DAC in vivo is being carried out. In addition, combination treatments have been performed in vitro, showing increased sensitisation of cells to anthracycline treatment after priming with DAC. Conclusions: It may be feasible to combine US, MBs and epigenetic therapy in a pre-clinical setting to improve drug efficacy, particularly for drugs that are rapidly degraded within the body. MB delivery may have the potential to reduce the dosage required, thus reducing off-site side effects in patients. Citation Format: Alataki A, Abou-Saleh R, McLaughlan JR, Markham AF, Evans SD, Coletta PL, Valleley EM. Developing targeted therapeutic microbubbles for enhanced epigenetic drug delivery for breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-04-04.

Breast cancer is a global health challenge with staggering statistics underscoring its pervasive impact. The burden of this disease is measured in terms of its prevalence and the challenges it poses to healthcare systems, necessitating a closer look at its epidemiology and impact. Current breast cancer treatments, including surgery, chemotherapy, radiation therapy, and targeted therapies, have made significant strides in improving patient outcomes. However, they are not without limitations, often leading to adverse effects and the development of drug resistance. This comprehensive review delves into the complex landscape of breast cancer, including its incidence, current treatment modalities, and the inherent limitations of existing therapeutic approaches. It also sheds light on the promising role of nanotechnology, encompassing both inorganic and organic nanoparticles equipped with the ability to selectively deliver therapeutic agents to tumor sites, in the battle against breast cancer. The review also addresses the emerging therapies, their associated challenges, and the future prospects of targeted drug delivery in breast cancer management.

Introduction: A tumor's blood supply and interstitial flow play an essential role in tumor growth, invasion, and treatment response. We have developed a methodology that employs quantitative MRI data to constrain a patient-specific, computational fluid dynamics (CFD) model of blood flow and interstitial transport within breast tumors. The dynamics of solute transport are characterized based on steady state flow fields, so that delivery of oxygen, nutrients, or therapies through the circulation can be estimated. It is a fundamentally new way to characterize breast tumor hemodynamics using MRI. Method: Eleven malignant and five benign lesions from 12 patients were included in this study. Vessel segmentation and tracking were performed to reconstruct the whole breast vasculature and to identify vessels feeding or draining tumors. Ultrafast dynamic contrast-enhanced MRI and diffusion-weighted imaging data were analyzed to estimate the bolus arrival time, Ktrans (volume transfer coefficient), and ADC (apparent diffusion coefficient); these data were used to spatially assign flow direction, local vascular permeability, and tissue density, respectively. The model of steady state flow was described by three components: 1) blood flow following Poiseuille's law, 2) interstitial flow following Darcy's law, and 3) flux transmitted across the vascular walls following Starling's law. The behavior of drug delivery was described by an advection-diffusion equation in the interstitial tissue, with the profile of the vascular bolus as a source term. The whole system was solved with a 1D-3D coupled implementation. At the end of analysis, the tracer's propagation through the tissue-of-interest was visualized and hemodynamic characteristics are derived to compare the malignant and benign lesions. Result: Visualization of the time-resolved distribution and propagation of solute demonstrated the intratumoral heterogeneity of accessibility to drugs. Furthermore, we are currently calculating the spatially-resolved accumulation, wash-in rate, and infiltration duration of different drugs for each lesion, so that a quantitative comparison can be performed between malignant and benign lesions. Conclusion: We have developed a computational model, informed by patient-specific MRI data, to simulate the blood supply, interstitial fluid environment, and intratumorally heterogeneous access to therapies for breast tumors. It represents the first methodology of integrating CFD with patient specific MRI data for quantifying the spatiotemporally resolved drug propagation as well as the entire pressure and flow fields within the breast. NCI U01CA142565, U01CA CA174706, and R01 CA218700. CPRIT RR160005. Citation Format: Chengyue Wu, David A. Hormuth, Federico Pineda, Gregory S. Karczmar, Robert D. Moser, Thomas E. Yankeelov. Characterization of patient-specific drug delivery for breast cancer using image-guided computational fluid dynamics [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4263.

WITHDRAWN: Folic acid Grafted, cell-penetrating peptide conjugated pH-sensitive hydrophobically modified Glycol chitosan nanoparticles for drug delivery in breast cancer

Exploiting novel placental homing peptides for targeted drug delivery in breast cancer.

Magnetic iron oxide nanoparticles as drug delivery system in breast cancer

Different strategies have been investigated for a more satisfactory treatment of advanced breast cancer, including the adjuvant use of omega-3 polyunsaturated fatty acids (PUFAs). These nutritional compounds have been shown to possess potent anti-inflammatory and antiangiogenic activities, the capacity to affect transduction pathways/receptors involved in cell growth and to reprogram tumor microenvironment. Omega-3 PUFA-containing nanoformulations designed for drug delivery in breast cancer were shown to potentiate the effects of enclosed drugs, enhance drug delivery to target sites, and minimize drug-induced side effects. We have critically analyzed here the results of the most recent studies investigating the effects of omega-3 PUFA-containing nanoformulations in breast cancer. The anti-neoplastic efficacy of omega-3 PUFAs has also been convincingly demonstrated by using preclinical in vivo models of ovarian cancer. The results obtained are critically analyzed here and seem to provide a sufficient rationale to move to still lacking interventional clinical trials, as well as to evaluate possible advantages of enclosing omega-3 PUFAs to drug-delivery nanosystems for ovarian cancer. Future perspectives in this area are also provided.

Formulation and evaluation of targeted nanoparticles for breast cancer theranostic system

To construct aptamer AS1411-functionalized targeted lipid nanobubbles that could simultaneously target abnormally highly expressed nucleolin (NCL) on tumor tissue and neovasculature. Additionally, the study of their contrast-enhanced ultrasound molecular imaging capabilities in vitro and in vivo to explore new methods and approaches for the early and accurate diagnosis of triple-negative breast cancer (TNBC). First, the targeted lipid-nucleic acid molecules were constructed by an amide reaction. Then, the targeted lipid nanobubbles (AS1411-NBs) and nontargeted lipid nanobubbles (NBs) were prepared by membrane hydration, mechanical vibration and centrifugal floatation. The physicochemical characteristics and contrast-enhanced ultrasound imaging capabilities of AS1411-NBs and NBs were compared and analyzed in vitro and in vivo. There were no significant differences between the AS1411-NBs and NBs in their concentration, average particle size or ultrasound imaging capabilities in vitro (P > 0.05). However, AS1411-NBs could simultaneously target NCL in tumor tissue and neovasculature to effectively prolong the duration of contrast-enhanced ultrasound imaging compared to NBs in vivo. The area under the time-intensity curve was significantly different between AS1411-NBs and NBs (P < 0.001), and the drug loading capacity of the AS1411-NBs was also significantly higher than that of the NBs (P < 0.05). Aptamer AS1411-functionalized targeted lipid nanobubbles could significantly prolong the duration of contrast-enhanced ultrasound imaging to achieve dual-targeted ultrasound molecular imaging of tumor tissue and neovasculature. AS1411-NBs also have higher drug loading and targeted drug delivery capabilities compared with NBs, which can provide new methods and approaches for the early accurate diagnosis and effective treatment of TNBC.

CNTs mediated CD44 targeting; a paradigm shift in drug delivery for breast cancer

Methotrexate (MTX), a frequently used chemotherapeutic agent, has limited water solubility, leading to rapid clearance even in local injections. In the present study, we developed folic acid-conjugated BSA-stabilized selenium-ZIF-8 core/shell nanoparticles for targeted delivery of MTX to combat breast cancer. FT-IR, XRD, SEM, TEM, and elemental mapping analysis confirmed the successful formation of FA-BSA@MTX@Se@ZIF-8. The developed nano-DDS had a mean diameter, polydispersity index, and zeta potential of 254.8nm, 0.17, and - 16.5 mV, respectively. The release behavior of MTX from the nanocarriers was pH-dependent, where the cumulative release percentage at pH 5.4 was higher than at pH 7.4. BSA significantly improved the blood compatibility of nanoparticles so that after modifying their surface with BSA, the percentage of hemolysis decreased from 12.67 to 5.12%. The loading of methotrexate in BSA@Se@ZIF-8 nanoparticles reduced its IC50 on 4T1 cells from 40.29µg/mL to 16.54µg/mL, and by conjugating folic acid on the surface, this value even decreased to 12.27µg/mL. In vivo evaluation of the inhibitory effect in tumor-bearing mice showed that FA-BSA@MTX@Se@ZIF-8 caused a 2.8-fold reduction in tumor volume compared to the free MTX, which is due to the anticancer effect of selenium nanoparticles, the pH sensitivity of ZIF-8, and the presence of folic acid on the surface as a targeting agent. More importantly, histological studies and animal body weight monitoring confirmed that developed nano-DDS does not have significant organ toxicity. Taking together, the incorporation of chemotherapeutics in folic acid-conjugated BSA-stabilized selenium-ZIF-8 nanoparticles may hold a significant impact in the field of future tumor management.

Breast cancer remains one of the most challenging malignancies worldwide due to its heterogeneity, which affects tumor behavior, progression, and treatment response. The complexity of breast cancer necessitates innovative therapeutic strategies to improve treatment outcomes. This review explores the potential of vesicular nanocarriers, including liposomes, niosomes, ethosomes, polymerosomes, phytosomes, and transferosomes, in enhancing breast cancer treatment efficacy through targeted drug delivery. A detailed analysis of recent progress in the functionalization and application of vesicular nanocarriers is discussed, highlighting their contribution to enhancing pharmacokinetics, drug solubility, and targeted delivery. Both passive and active targeting strategies were assessed for their ability to enhance tumor-specific drug accumulation. Vesicular nanocarriers offer significant advantages, including reduced systemic toxicity, improved drug bioavailability, and precise delivery to cancer cells. Passive targeting utilizes the enhanced permeation and retention effect for tumor accumulation, while active targeting employs surface modifications with antibodies, aptamers, or peptides to enhance specificity. The integration of vesicular nanocarriers in breast cancer therapy presents a promising strategy for more effective and personalized treatment approaches. Their ability to optimize drug delivery and minimize off-target effects highlights their potential to revolutionize breast cancer treatment.

Breast cancer remains a significant global health challenge, necessitating innovative approaches to improve treatment efficacy while minimizing side effects. This review explores the promising advancements in breast cancer drug delivery driven by the transformative potential of bioinformatics and Artificial Intelligence (AI). Bioinformatics plays a pivotal role in unraveling the intricate genomic landscape of breast cancer, enabling the identification of potential drug targets and biomarkers. The integration of multi-omics data facilitates a comprehensive understanding of the disease, guiding personalized treatment strategies. Moreover, bioinformatics-driven approaches aid in biomarker discovery and prediction, offering novel tools for prognosis and treatment response assessment. AI, particularly machine learning and deep learning, has revolutionized breast cancer research. Machine learning models empower accurate diagnosis through image analysis, improve survival prediction, and enhance risk assessment. Deep learning algorithms, such as convolutional neural networks, enable precise tumor detection and classification from medical imaging data, notably mammograms and MRI scans. Additionally, natural language processing techniques facilitate the mining of vast scientific literature, uncovering hidden insights and identifying potential drug targets. Network-based approaches integrated with AI algorithms facilitate the identification of central proteins as promising drug targets within complex biological networks. This review also examines AIoptimized nanoformulations designed to enhance targeted drug delivery. AI-guided design of drugloaded nanoparticles improves drug encapsulation efficiency, release kinetics, and site-specific delivery, offering promising solutions to overcome the challenges of conventional drug delivery.

Asparagine endopeptidase-targeted Ultrasound-responsive Nanobubbles Alleviate Tau Cleavage and Amyloid-β Deposition in an Alzheimer's Disease Model

We explored the role of microRNAs (miRNAs) in acquiring resistance to tamoxifen, a drug successfully used to treat women with estrogen receptor-positive breast cancer. miRNA microarray analysis of MCF-7 cell lines that are either sensitive (parental) or resistant (4-hydroxytamoxifen-resistant (OHT(R))) to tamoxifen showed significant (>1.8-fold) up-regulation of eight miRNAs and marked down-regulation (>50%) of seven miRNAs in OHT(R) cells compared with parental MCF-7 cells. Increased expression of three of the most promising up-regulated (miR-221, miR-222, and miR-181) and down-regulated (miR-21, miR-342, and miR-489) miRNAs was validated by real-time reverse transcription-PCR. The expression of miR-221 and miR-222 was also significantly (2-fold) elevated in HER2/neu-positive primary human breast cancer tissues that are known to be resistant to endocrine therapy compared with HER2/neu-negative tissue samples. Ectopic expression of miR-221/222 rendered the parental MCF-7 cells resistant to tamoxifen. The protein level of the cell cycle inhibitor p27(Kip1), a known target of miR-221/222, was reduced by 50% in OHT(R) cells and by 28-50% in miR-221/222-overexpressing MCF-7 cells. Furthermore, overexpression of p27(Kip1) in the resistant OHT(R) cells caused enhanced cell death when exposed to tamoxifen. This is the first study demonstrating a relationship between miR-221/222 expression and HER2/neu overexpression in primary breast tumors that are generally resistant to tamoxifen therapy. This finding also provides the rationale for the application of altered expression of specific miRNAs as a predictive tamoxifen-resistant breast cancer marker.