Targeted Nanocarriers for Systemic Delivery of IRAK4 Inhibitors to Inflamed Tissues

Persistent and uncontrolled inflammation is the root cause of various debilitating diseases. Given that interleukin-1 receptor-associated kinase 4 (IRAK4) is a critical modulator of inflammation, inhibition of its activity with selective drug molecules (IRAK4 inhibitors) represents a promising therapeutic strategy for inflammatory disorders. To exploit the full potential of this treatment approach, drug carriers for efficient delivery of IRAK4 inhibitors to inflamed tissues are essential. Herein, the first nanoparticle-based platform for the targeted systemic delivery of a clinically tested IRAK4 inhibitor, PF-06650833, with limited aqueous solubility (57 µg mL-1 ) is presented. The developed nanocarriers increase the intrinsic aqueous dispersibility of this IRAK4 inhibitor by 40 times. A targeting peptide on the surface of nanocarriers significantly enhances their accumulation after intravenous injection in inflamed tissues of mice with induced paw edema and ulcerative colitis when compared to non-targeted counterparts. The delivered IRAK4 inhibitor markedly abates inflammation and dramatically suppresses paw edema, mitigates colitis symptoms, and reduces proinflammatory cytokine levels in the affected tissues. Importantly, repeated injections of IRAK4 inhibitor-loaded nanocarriers have no acute toxic effect on major organs of mice. Therefore, the developed nanocarriers have the potential to significantly improve the therapeutic efficacy of IRAK4 inhibitors for different inflammatory diseases.

From Bench to Bedside: Implications of Lipid Nanoparticle Carrier Reactogenicity for Advancing Nucleic Acid Therapeutics

In biomedical applications, nanomaterial-based delivery vehicles, such as lipid nanoparticles, have emerged as promising instruments for improving the solubility, stability, and encapsulation of various payloads. This article provides a formal review focusing on the reactogenicity of empty lipid nanoparticles used as delivery vehicles, specifically emphasizing their application in mRNA-based therapies. Reactogenicity refers to the adverse immune responses triggered by xenobiotics, including administered lipid nanoparticles, which can lead to undesirable therapeutic outcomes. The key components of lipid nanoparticles, which include ionizable lipids and PEG-lipids, have been identified as significant contributors to their reactogenicity. Therefore, understanding the relationship between lipid nanoparticles, their structural constituents, cytokine production, and resultant reactogenic outcomes is essential to ensure the safe and effective application of lipid nanoparticles in mRNA-based therapies. Although efforts have been made to minimize these adverse reactions, further research and standardization are imperative. By closely monitoring cytokine profiles and assessing reactogenic manifestations through preclinical and clinical studies, researchers can gain valuable insights into the reactogenic effects of lipid nanoparticles and develop strategies to mitigate undesirable reactions. This comprehensive review underscores the importance of investigating lipid nanoparticle reactogenicity and its implications for the development of mRNA-lipid nanoparticle therapeutics in various applications beyond vaccine development.

Development and Perspectives: Multifunctional Nucleic Acid Nanomedicines for Treatment of Gynecological Cancers

Gynecological malignancies are a significant cause of morbidity and mortality across the globe. Due to delayed presentation, gynecological cancer patients are often referred late in the disease's course, resulting in poor outcomes. A considerable number of patients ultimately succumb to chemotherapy-resistant disease, which reoccurs at advanced stages despite treatment interventions. Although efforts have been devoted to developing therapies that demonstrate reduced resistance to chemotherapy and enhanced toxicity profiles, current clinical outcomes remain unsatisfactory due to treatment resistance and unfavorable off-target effects. Consequently, innovative biological and nanotherapeutic approaches are imperative to strengthen and optimize the therapeutic arsenal for gynecological cancers. Advancements in nanotechnology-based therapies for gynecological malignancies offer significant advantages, including reduced toxicity, expanded drug circulation, and optimized therapeutic dosing, ultimately leading to enhanced treatment effectiveness. Recent advances in nucleic acid therapeutics using microRNA, small interfering RNA, and messenger RNA provide novel approaches for cancer therapeutics. Effective single-agent and combinatorial nucleic acid therapeutics for gynecological malignancies have the potential to transform cancer treatment by giving safer, more tailored approaches than conventional therapies. This review highlights current preclinical studies that effectively exploit these approaches for the treatment of gynecological malignant tumors and malignant ascites.

Nanomedicines for Improved Management of Ectopic Pregnancy: A Narrative Review

Ectopic pregnancy (EP) - the implantation of an embryo outside of the endometrial cavity, often in the fallopian tube - is a significant contributor to maternal morbidity and leading cause of maternal death due to hemorrhage in first trimester. Current diagnostic modalities including human chorionic gonadotropin (hCG) quantification and ultrasonography are effective, but may still misdiagnose EP at initial examination in many cases. Depending on the patient's hemodynamic stability and gestational duration of the pregnancy, as assessed by history, hCG measurement and ultrasonography, management strategies may include expectant management, chemotherapeutic treatment using methotrexate (MTX), or surgical intervention. While these strategies are largely successful, expectant management may result in tubal rupture if the pregnancy does not resolve spontaneously; MTX administration is not always successful and may induce significant side effects; and surgical intervention may result in loss of the already-damaged fallopian tube, further hampering the patient's subsequent attempts to conceive. Nanomaterial-based technologies offer the potential to enhance delivery of diagnostic imaging contrast and therapeutic agents to more effectively and safely manage EP. The purpose of this narrative review is to summarize the current state of nanomedicine technology dedicated to its potential to improve both the diagnosis and treatment of EP.

Glutathione-Responsive Methotrexate Polymersomes for Potential Management of Ectopic Pregnancy

The first-line treatment for ectopic pregnancy (EP), the chemotherapeutic methotrexate (MTX), has a failure rate of more than 10%, which can lead to severe complications or death. Inadequate accumulation of administered MTX at the ectopic implantation site significantly contributes to therapeutic failure. This study reports the first glutathione-responsive polymersomes for efficient delivery of MTX to the implantation site and its triggered release in placental cells. Fluorescence and photoacoustic imaging have confirmed that the developed polymersomes preferentially accumulate after systemic administration in the implantation site of pregnant mice at early gestational stages. The high concentrations of intracellular glutathione (GSH) reduce an incorporated disulfide bond within polymersomes upon internalization into placental cells, resulting in their disintegration and efficient drug release. Consequently, MTX delivered by polymersomes induces pregnancy demise in mice, as opposed to free MTX at the same dose regimen. To achieve the same therapeutic efficacy with free MTX, a sixfold increase in dosage is required. In addition, mice successfully conceive and birth healthy pups following a prior complete pregnancy demise induced by methotrexate polymersomes. Therefore, the developed MTX nanomedicine can potentially improve EP management and reduce associated mortality rates and related cost.

A Photoacoustic Contrast Nanoagent with a Distinct Spectral Signature for Ovarian Cancer Management

Photoacoustic imaging (PAI) has tremendous potential for improving ovarian cancer detection. However, the lack of effective exogenous contrast agents that can improve PAI diagnosis accuracy significantly limits this application. This study presents a novel contrast nanoagent with a specific spectral signature that can be easily distinguished from endogenous chromophores in cancer tissue, allowing for high-contrast tumor visualization. Constructed as a 40 nm biocompatible polymeric nanoparticle loaded with two naphthalocyanine dyes, this agent is capable of efficient ovarian tumor accumulation after intravenous injection. The developed nanoagent displays a spectral signature with two well-separated photoacoustic peaks of comparable PA intensities in the near-infrared (NIR) region at 770 and 860 nm, which remain unaffected in cancer tissue following systemic delivery. In vivo experiments in mice with subcutaneous and intraperitoneal ovarian cancer xenografts validate that this specific spectral signature allows for accurate spectral unmixing of the nanoagent signal from endogenous contrast in cancer tissue, allowing for sensitive noninvasive cancer diagnosis. In addition, this nanoagent can selectively eradicate ovarian cancer tissue with a single dose of photothermal therapy by elevating the intratumoral temperature to ≈49 °C upon exposure to NIR light within the 700-900 nm range.

Peptide-guided lipid nanoparticles deliver mRNA to the neural retina of rodents and nonhuman primates

Lipid nanoparticle (LNP)-based mRNA delivery holds promise for the treatment of inherited retinal degenerations. Currently, LNP-mediated mRNA delivery is restricted to the retinal pigment epithelium (RPE) and Müller glia. LNPs must overcome ocular barriers to transfect neuronal cells critical for visual phototransduction, the photoreceptors (PRs). We used a combinatorial M13 bacteriophage-based heptameric peptide phage display library for the mining of peptide ligands that target PRs. We identified the most promising peptide candidates resulting from in vivo biopanning. Dye-conjugated peptides showed rapid localization to the PRs. LNPs decorated with the top-performing peptide ligands delivered mRNA to the PRs, RPE, and Müller glia in mice. This distribution translated to the nonhuman primate eye, wherein robust protein expression was observed in the PRs, Müller glia, and RPE. Overall, we have developed peptide-conjugated LNPs that can enable mRNA delivery to the neural retina, expanding the utility of LNP-mRNA therapies for inherited blindness.

Novel Nanoparticle-Based Treatment and Imaging Modalities

Over the last twenty years, nanomaterials have been widely used in cancer research [...].

Nano-Theranostic Modality for Visualization of the Placenta and Photo-Hyperthermia for Potential Management of Ectopic Pregnancy

Ectopic pregnancy (EP) is the leading cause of maternity-related death in the first trimester of pregnancy. Approximately 98% of ectopic implantations occur in the fallopian tube, and expedient management is crucial for preventing hemorrhage and maternal death in the event of tubal rupture. Current ultrasound strategies misdiagnose EP in up to 40% of cases, and the failure rate of methotrexate treatment for confirmed EP exceeds 10%. Here the first theranostic strategy for potential management of EP is reported using a near-infrared naphthalocyanine dye encapsulated within polymeric nanoparticles. These nanoparticles preferentially accumulate in the developing murine placenta within 24 h following systemic administration, and enable visualization of implantation sites at various gestational stages via fluorescence and photoacoustic imaging. These nanoparticles do not traverse the placental barrier to the fetus or impact fetal development. However, excitation of nanoparticles localized in specific placentas with focused NIR light generates heat (>43 °C) sufficient for disruption of placental function, resulting in the demise of targeted fetuses with no effect on adjacent fetuses. This novel approach would enable diagnostic confirmation of EP when current imaging strategies are unsuccessful, and elimination of EP could subsequently be achieved using the same nano-agent to generate localized hyperthermia resulting in targeted placental impairment.

Poly(aspartic acid)-Based Polymeric Nanoparticle for Local and Systemic mRNA Delivery

Recently, therapeutics based on mRNA (mRNA) have attracted significant interest for vaccines, cancer immunotherapy, and gene editing. However, the lack of biocompatible vehicles capable of delivering mRNA to the target tissue and efficiently expressing the encoded proteins impedes the development of mRNA-based therapies for a variety of diseases. Herein, we report mRNA-loaded polymeric nanoparticles based on diethylenetriamine-substituted poly(aspartic acid) that induce protein expression in the lungs and muscles following intravenous and intramuscular injections, respectively. Animal studies revealed that the amount of polyethylene glycol (PEG) on the nanoparticle surface affects the translation of the delivered mRNA into the encoded protein in the target tissue. After systemic administration, only mRNA-loaded nanoparticles modified with PEG at a molar ratio of 1:1 (PEG/polymer) induce protein expression in the lungs. In contrast, protein expression was detected only following intramuscular injection of mRNA-loaded nanoparticles with a PEG/polymer ratio of 10:1. These findings suggest that the PEG density on the surface of poly(aspartic acid)-based nanoparticles should be optimized for different delivery routes depending on the purpose of the mRNA treatment.

An Advanced Thermal Decomposition Method to Produce Magnetic Nanoparticles with Ultrahigh Heating Efficiency for Systemic Magnetic Hyperthermia

Due to the limited heating efficiency of available magnetic nanoparticles, it is difficult to achieve therapeutic temperatures above 44 °C in relatively inaccessible tumors during magnetic hyperthermia following systemic administration of nanoparticles at clinical dosage (≤10 mg kg-1 ). To address this, a method for the preparation of magnetic nanoparticles with ultrahigh heating capacity in the presence of an alternating magnetic field (AMF) is presented. The low nitrogen flow rate of 10 mL min-1 during the thermal decomposition reaction results in cobalt-doped nanoparticles with a magnetite (Fe3 O4 ) core and a maghemite (γ-Fe2 O3 ) shell that exhibit the highest intrinsic loss power reported to date of 47.5 nH m2 kg-1 . The heating efficiency of these nanoparticles correlates positively with increasing shell thickness, which can be controlled by the flow rate of nitrogen. Intravenous injection of nanoparticles at a low dose of 4 mg kg-1 elevates intratumoral temperatures to 50 °C in mice-bearing subcutaneous and metastatic cancer grafts during exposure to AMF. This approach can also be applied to the synthesis of other metal-doped nanoparticles with core-shell structures. Consequently, this method can potentially be used for the development of novel nanoparticles with high heating performance, further advancing systemic magnetic hyperthermia for cancer treatment.

Nanoparticle-Based Follistatin Messenger RNA Therapy for Reprogramming Metastatic Ovarian Cancer and Ameliorating Cancer-Associated Cachexia

This study presents the first messenger RNA (mRNA) therapy for metastatic ovarian cancer and cachexia-induced muscle wasting based on lipid nanoparticles that deliver follistatin (FST) mRNA predominantly to cancer clusters following intraperitoneal administration. The secreted FST protein, endogenously synthesized from delivered mRNA, efficiently reduces elevated activin A levels associated with aggressive ovarian cancer and associated cachexia. By altering the cancer cell phenotype, mRNA treatment prevents malignant ascites, delays cancer progression, induces the formation of solid tumors, and preserves muscle mass in cancer-bearing mice by inhibiting negative regulators of muscle mass. Finally, mRNA therapy provides synergistic effects in combination with cisplatin, increasing the survival of mice and counteracting muscle atrophy induced by chemotherapy and cancer-associated cachexia. The treated mice develop few nonadherent tumors that are easily resected from the peritoneum. Clinically, this nanomedicine-based mRNA therapy can facilitate complete cytoreduction, target resistance, improve resilience during aggressive chemotherapy, and improve survival in advanced ovarian cancer.

Targeted Nanoparticles with High Heating Efficiency for the Treatment of Endometriosis with Systemically Delivered Magnetic Hyperthermia

Endometriosis is a devastating disease in which endometrial-like tissue forms lesions outside the uterus. It causes infertility and severe pelvic pain in ≈176 million women worldwide, and there is currently no cure for this disease. Magnetic hyperthermia could potentially eliminate widespread endometriotic lesions but has not previously been considered for treatment because conventional magnetic nanoparticles have relatively low heating efficiency and can only provide ablation temperatures (>46 °C) following direct intralesional injection. This study is the first to describe nanoparticles that enable systemically delivered magnetic hyperthermia for endometriosis treatment. When subjected to an alternating magnetic field (AMF), these hexagonal iron-oxide nanoparticles exhibit extraordinary heating efficiency that is 6.4× greater than their spherical counterparts. Modifying nanoparticles with a peptide targeted to vascular endothelial growth factor receptor 2 (VEGFR-2) enhances their endometriosis specificity. Studies in mice bearing transplants of macaque endometriotic tissue reveal that, following intravenous injection at a low dose (3 mg per kg), these nanoparticles efficiently accumulate in endometriotic lesions, selectively elevate intralesional temperature above 50 °C upon exposure to external AMF, and completely eradicate them with a single treatment. These nanoparticles also demonstrate promising potential as magnetic resonance imaging (MRI) contrast agents for precise detection of endometriotic tissue before AMF application.

Targeting Estrogen Receptor-Positive Breast Microtumors with Endoxifen-Conjugated, Hypoxia-Sensitive Polymersomes

Endoxifen is the primary active metabolite of tamoxifen, a nonsteroidal-selective estrogen receptor modulator (SERM) and widely used medication to treat estrogen receptor-positive (ER+) breast cancer. In this study, endoxifen was conjugated to the surface of polymeric nanoparticles (polymersomes) for targeted delivery of doxorubicin (DOX) to estrogen receptor-positive breast cancer cells (MCF7). Rapid cell growth and insufficient blood supply result in low oxygen concentration (hypoxia) within the solid breast tumors. The polymersomes developed here are prepared from amphiphilic copolymers of polylactic acid (PLA) and poly(ethylene glycol) (PEG) containing diazobenzene as the hypoxia-responsive linker. We prepared two nanoparticle formulations: DOX-encapsulated hypoxia-responsive polymersomes (DOX-HRPs) and endoxifen-conjugated, DOX-encapsulated hypoxia-responsive polymersomes (END-DOX-HRPs). Cellular internalization studies demonstrated eight times higher cytosolic and nuclear localization after incubating breast cancer cells with END-DOX-HRPs (targeted polymersomes) in contrast to DOX-HRPs (nontargeted polymersomes). Cytotoxicity studies on monolayer cell cultures exhibited that END-DOX-HRPs were three times more toxic to ER+ MCF7 cells than DOX-HRPs and free DOX in hypoxia. The cell viability studies on three-dimensional hypoxic cultures also demonstrated twice as much toxicity when the spheroids were treated with targeted polymersomes instead of nontargeted counterparts. This is the first report of surface-decorated polymeric nanoparticles with endoxifen ligands for targeted drug delivery to ER+ breast cancer microtumors. The newly designed endoxifen-conjugated, hypoxia-responsive polymersomes might have translational potential for ER+ breast cancer treatment.

A targeted combinatorial therapy for Ewing's sarcoma

Ewing's sarcoma (EwS) is the second most common bone cancer in children and adolescents. Current chemotherapy regimens are mainly ineffective in patients with relapsed disease and cause long-term effects in survivors. Therefore, we have developed a combinatorial therapy based on a novel drug candidate named ML111 that exhibits selective activity against EwS cells and synergizes with vincristine. To increase the aqueous solubility of hydrophobic ML111, polymeric nanoparticles (ML111-NP) were developed. In vitro data revealed that ML111-NP compromise viability of EwS cells without affecting non-malignant cells. Furthermore, ML111-NP exhibit strong synergistic effects in a combination with vincristine on EwS cells, while this drug pair exhibits antagonistic effects towards normal cells. Finally, animal studies validated that ML111-NP efficiently accumulate in orthotopic EwS xenografts after intravenous injection and provide superior therapeutic outcomes in a combination with vincristine without evident toxicity. These results support the potential of the ML111-based combinatorial therapy for EwS.

Discovery and Validation of a Compound to Target Ewing's Sarcoma

Ewing’s sarcoma, characterized by pathognomonic t (11; 22) (q24; q12) and related chromosomal ETS family translocations, is a rare aggressive cancer of bone and soft tissue. Current protocols that include cytotoxic chemotherapeutic agents effectively treat localized disease; however, these aggressive therapies may result in treatment-related morbidities including second-site cancers in survivors. Moreover, the five-year survival rate in patients with relapsed, recurrent, or metastatic disease is less than 30%, despite intensive therapy with these cytotoxic agents. By using high-throughput phenotypic screening of small molecule libraries, we identified a previously uncharacterized compound (ML111) that inhibited in vitro proliferation of six established Ewing’s sarcoma cell lines with nanomolar potency. Proteomic studies show that ML111 treatment induced prometaphase arrest followed by rapid caspase-dependent apoptotic cell death in Ewing’s sarcoma cell lines. ML111, delivered via methoxypoly(ethylene glycol)-polycaprolactone copolymer nanoparticles, induced dose-dependent inhibition of Ewing’s sarcoma tumor growth in a murine xenograft model and invoked prometaphase arrest in vivo, consistent with in vitro data. These results suggest that ML111 represents a promising new drug lead for further preclinical studies and is a potential clinical development for the treatment of Ewing’s sarcoma.

Near-Infrared Heptamethine Cyanine Dyes for Nanoparticle-Based Photoacoustic Imaging and Photothermal Therapy

We have synthesized and characterized a library of near-infrared (NIR) heptamethine cyanine dyes for biomedical application as photoacoustic imaging and photothermal agents. These hydrophobic dyes were incorporated into a polymer-based nanoparticle system to provide aqueous solubility and protection of the photophysical properties of each dye scaffold. Among those heptamethine cyanine dyes analyzed, 13 compounds within the nontoxic polymeric nanoparticles have been selected to exemplify structural relationships in terms of photostability, photoacoustic imaging, and photothermal behavior within the NIR (∼650-850 nm) spectral region. The most contributing structural features observed in our dye design include hydrophobicity, rotatable bonds, heavy atom effects, and stability of the central cyclohexene ring within the dye core. The NIR agents developed within this project serve to elicit a structure-function relationship with emphasis on their photoacoustic and photothermal characteristics aiming at producing customizable NIR photoacoustic and photothermal tools for clinical use.

Nanomedicines for Endometriosis: Lessons Learned from Cancer Research

Endometriosis is an incurable gynecological disease characterized by the abnormal growth of endometrium-like tissue, characteristic of the uterine lining, outside of the uterine cavity. Millions of people with endometriosis suffer from pelvic pain and infertility. This review aims to discuss whether nanomedicines that are promising therapeutic approaches for various diseases have the potential to create a paradigm shift in endometriosis management. For the first time, the available reports and achievements in the field of endometriosis nanomedicine are critically evaluated, and a summary of how nanoparticle-based systems can improve endometriosis treatment and diagnosis is provided. Parallels between cancer and endometriosis are also drawn to understand whether some fundamental principles of the well-established cancer nanomedicine field can be adopted for the development of novel nanoparticle-based strategies for endometriosis. This review provides the state of the art of endometriosis nanomedicine and perspective for researchers aiming to realize and exploit the full potential of nanoparticles for treatment and imaging of the disorder.

A novel multimodal nanoplatform for targeting tumor necrosis

Peri-necrotic tumor regions have been found to be a source of cancer stem cells (CSC), important in tumor recurrence. Necrotic and peri-necrotic tumor zones have poor vascular supply, limiting effective exposure to systemically administered therapeutics. Therefore, there is a critical need to develop agents that can effectively target these relatively protected tumor areas. We have developed a multi-property nanoplatform with necrosis avidity, fluorescence imaging and X-ray tracking capabilities to evaluate its feasibility for therapeutic drug delivery. The developed nanoparticle consists of three elements: poly(ethylene glycol)-block-poly(ε-caprolactone) as the biodegradable carrier; hypericin as a natural compound with fluorescence and necrosis avidity; and gold nanoparticles for X-ray tracking. This reproducible nanoparticle has a hydrodynamic size of 103.9 ± 1.7 nm with a uniform spherical morphology (polydispersity index = 0.12). The nanoparticle shows safety with systemic administration and a stable 30 day profile. Intravenous nanoparticle injection into a subcutaneous tumor-bearing mouse and intra-arterial nanoparticle injection into rabbits bearing VX2 orthotopic liver tumors resulted in fluorescence and X-ray attenuation within the tumors. In addition, ex vivo and histological analysis confirmed the accumulation of hypericin and gold in areas of necrosis and peri-necrosis. This nanoplatform, therefore, has the potential to enhance putative therapeutic drug delivery to necrotic and peri-necrotic areas, and may also have an application for monitoring early response to anti-tumor therapies.

Au-Hyp-NP developed by encapsulation of gold and hypericin into PEG-PCL nanoplatform for fluorescence and X-ray tracking with tumor necrosis targeting.

Abstract 2875: Intravascular delivery of nanoclusters for treatment of prostate cancer with magnetic hyperthermia

Prostate cancer is the leading cause of cancer death in American men. The high mortality rate is attributable to current treatments not providing a cure for hormone-refractory prostate cancer. The main goal of this project is to provide a novel therapeutic approach based on nanoparticle-mediated magnetic hyperthermia for efficient treatment of this cancer. Magnetic hyperthermia is a form of thermal therapy where magnetic nanoparticles delivered to cancer sites generate heat after exposure to an external alternating magnetic field (AMF). Many studies suggest that it has significant potential to kill cancer cells directly or enhance their susceptibility to radiation, chemotherapy and immunotherapy. Magnetic hyperthermia, however, is restricted to the treatment of localized and accessible tumors because therapeutic temperatures above 40 Celsius have only been achieved by intratumoral injection of magnetic nanoparticles. This is due to the low heating efficiency of conventional iron oxide nanoparticles combined with low tumor accumulation of these nanoparticles following systemic delivery. To employ this therapy for primary and metastatic prostate cancer tumors that are difficult to access for intratumoral injection, we have designed novel biocompatible nanoclusters with high heating efficiency that efficiently accumulate in prostate cancer tumors after intravenous injection at clinically relevant doses and generate the desirable intratumoral temperatures upon exposure to AMF. Our nanoclusters are built on hydrophobic iron oxide nanoparticles doped with zinc and manganese. To overcome challenges associated with poor water solubility of the synthesized nanoparticles, the solvent evaporation approach was employed to encapsulate and cluster them within the hydrophobic core of PEG-PCL-based polymeric nanoparticles. The amphiphilic PEG-PCL (methoxy poly(ethylene glycol)-b-poly(ϵ-caprolactone)) molecules, composed of hydrophobic 10 kDa PCL and hydrophilic 5 kDa PEG blocks, self-assemble in aqueous solution upon evaporation of the organic solvent to form nanoparticles with a hydrophilic PEG outer shell and hydrophobic PCL core. The transmission electron microscope images reveal that iron oxide nanoparticles form clusters within a single PEG-PCL nanoparticle. It is validated that the clustering of iron oxide nanoparticles enhances their heating efficiency. Animal studies demonstrate that following intravenous injection into mice bearing prostate cancer grafts the nanoclusters efficiently accumulate in cancer tumors and increase the intratumoral temperature up to 42 Celsius upon exposure to AMF. Finally, the systemically delivered magnetic hyperthermia significantly inhibits prostate cancer growth and does not exhibit any sign of toxicity. In summary, this discovery will allow to realize the true therapeutic potential of magnetic hyperthermia alone and in combination with other therapies for inaccessible primary and metastatic prostate cancer tumors.

Citation Format: Oleh Taratula, Olena Taratula. Intravascular delivery of nanoclusters for treatment of prostate cancer with magnetic hyperthermia [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 2875.

DNA Photocleavage in the Near-Infrared Wavelength Range by 2-Quinolinium Dicarbocyanine Dyes

Here, we report the syntheses of two pentamethine cyanine dyes containing quinolinium rings and substituted with either hydrogen (3) or bromine (4) at the meso carbon. The electron withdrawing bromine atom stabilizes dye 4 in aqueous buffer, allowing complex formation to occur between the dye and double-helical DNA. UV–visible, CD, and fluorescence spectra recorded at low DNA concentrations suggest that dye 4 initially binds to the DNA as a high-order aggregate. As the ratio of DNA to dye is increased, the aggregate is converted to monomeric and other low-order dye forms that interact with DNA in a non-intercalative fashion. The brominated dye 4 is relatively unreactive in the dark, but, under 707–759 nm illumination, generates hydroxyl radicals that cleave DNA in high yield (pH 7.0, 22 °C). Dye 4 is also taken up by ES2 ovarian carcinoma cells, where it is non-toxic under dark conditions. Upon irradiation of the ES2 cells at 694 nm, the brominated cyanine reduces cell viability from 100 ± 10% to 14 ± 1%. Our results suggest that 2-quinolinium-based carbocyanine dyes equipped with stabilizing electron withdrawing groups may have the potential to serve as sensitizing agents in long-wavelength phototherapeutic applications.

Nanoparticle-Based Platform for Activatable Fluorescence Imaging and Photothermal Ablation of Endometriosis

Endometriosis is a painful disorder where endometrium-like tissue forms lesions outside of the uterine cavity. Intraoperative identification and removal of these lesions are difficult. This study presents a nanoplatform that concurrently delineates and ablates endometriosis tissues using real-time near-infrared (NIR) fluorescence and photothermal therapy (PTT). The nanoplatform consists of a dye, silicon naphthalocyanine (SiNc), capable of both NIR fluorescence imaging and PTT, and a polymeric nanoparticle as a SiNc carrier to endometriosis tissue following systemic administration. To achieve high contrast during fluorescence imaging of endometriotic lesions, nanoparticles are constructed to be non-fluorescent prior to internalization by endometriosis cells. In vitro studies confirm that these nanoparticles activate the fluorescence signal following internalization in macaque endometrial stromal cells and ablate them by increasing cellular temperature to 53 ^° C upon interaction with NIR light. To demonstrate in vivo efficiency of the nanoparticles, biopsies of endometrium and endometriosis from rhesus macaques are transplanted into immunodeficient mice. Imaging with the intraoperative Fluobeam 800 system reveals that 24 h following intravenous injection, nanoparticles efficiently accumulate in, and demarcate, endometriotic grafts with fluorescence. Finally, the nanoparticles increase the temperature of endometriotic grafts up to 47 °C upon exposure to NIR light, completely eradicating them after a single treatment.

Biodegradable Hypericin-Containing Nanoparticles for Necrosis Targeting and Fluorescence Imaging

Necrosis targeting and imaging has significant implications for evaluating tumor growth, therapeutic response, and delivery of therapeutics to perinecrotic tumor zones. Hypericin is a hydrophobic molecule with high necrosis affinity and fluorescence imaging properties. To date, the safe and effective delivery of hypericin to areas of necrosis in vivo remains a challenge because of its incompatible biophysical properties. To address this issue, we have developed a biodegradable nanoparticle (Hyp-NP) for delivery of hypericin to tumors for necrosis targeting and fluorescence imaging. The nanoparticle was developed using methoxy poly(ethylene glycol)-b-poly(ε-caprolactone) and hypericin by a modified solvent evaporation technique. The size of Hyp-NP was 19.0 ± 1.8 nm from cryo-TEM and 37.3 ± 0.7 nm from dynamic light-scattering analysis with a polydispersity index of 0.15 ± 0.01. The encapsulation efficiency of hypericin was 95.05% w/w by UV-vis absorption. After storage for 30 days, 91.4% hypericin was retained in Hyp-NP with nearly no change in hydrodynamic size, representing nanoparticle stability. In an ovarian cancer cell line, Hyp-NP demonstrated cellular internalization with intracellular cytoplasmic localization and preserved fluorescence and necrosis affinity. In a mouse subcutaneous tumor model, tumor accumulation was noted at 8 h postinjection, with near-complete clearance at 96 h postinjection. Hyp-NP was shown to be tightly localized within necrotic tumor zones. Histological analysis of harvested organs demonstrated no gross abnormalities, and in vitro, no hemolysis was observed. This proof-of-concept study demonstrates the potential clinical applications of Hyp-NP for necrosis targeting.

Strategy to enhance lung cancer treatment by five essential elements: inhalation delivery, nanotechnology, tumor-receptor targeting, chemo- and gene therapy

Non-Small Cell Lung Carcinoma (NSCLC), is the most common type of lung cancer (more than 80% of all cases). Small molecule Tyrosine Kinase (TK) Inhibitors acting on the Epidermal Growth Factor Receptors (EGFRs) are standard therapies for patients with NSCLC harboring EGFR-TK inhibitor-sensitizing mutations. However, fewer than 10 % of patients with NSCLC benefit from this therapy. Moreover, even the latest generation of EGFR inhibitors can cause severe systemic toxicities and are ineffective in preventing non-canonical EGFR signaling. In order to minimize and even overcome these limitations, we are proposing a novel multi-tier biotechnology treatment approach that includes: (1) suppression of all four types of EGFR-TKs by a pool of small interfering RNAs (siRNAs); (2) induction of cell death by an anticancer drug, (3) enhancing the efficiency of the treatment by the local inhalation delivery of therapeutic agents directly to the lungs (passive targeting), (4) active receptor-mediated targeting of the therapy specifically to cancer cells that in turn should minimize adverse side effects of treatment and (5) increasing the stability, solubility, and cellular penetration of siRNA and drug by using tumor targeted Nanostructured Lipid Carriers (NLC). Methods: NLCs targeted to NSCLC cells by a synthetic Luteinizing Hormone-Releasing Hormone (LHRH) decapeptide was used for the simultaneous delivery of paclitaxel (TAX) and a pool of siRNAs targeted to the four major forms of EGFR-TKs. LHRH-NLC-siRNAs-TAX nanoparticles were synthesized, characterized and tested in vitro using human lung cancer cells with different sensitivities to gefitinib (inhibitor of EGFR) and in vivo on an orthotopic NSCLC mouse model. Results: Proposed nanoparticle-based complex containing an anticancer drug, inhibitors of different types of EGFR-TKs and peptide targeted to the tumor-specific receptors (LHRH-NLC-siRNAs-TAX) demonstrated a favorable organ distribution and superior anticancer effect when compared with treatment by a single drug, inhibitor of one EGFR-TK and non-targeted therapy. Conclusions: The use of a multifunctional NLC-based delivery system substantially enhanced the efficiency of therapy for NSCLC and possibly will limit adverse side effects of the treatments. The results obtained have the potential to significantly impact the field of drug delivery and to improve the efficiency of therapy of lung and other types of cancer.

Single photon DNA photocleavage at 830 nm by quinoline dicarbocyanine dyes

We have synthesized symmetrical carbocyanine dyes in which two 4-quinolinium rings are joined by a pentamethine bridge that is meso-substituted with H or Cl. Irradiation of the halogenated dye at 830 nm produces hydroxyl radicals that generate DNA direct strand breaks. This represents the first reported example of DNA photocleavage upon single photon excitation of a chromophore at wavelengths above 800 nm.

Biocompatible Nanoclusters with High Heating Efficiency for Systemically Delivered Magnetic Hyperthermia

Despite its promising therapeutic potential, nanoparticle-mediated magnetic hyperthermia is currently limited to the treatment of localized and relatively accessible cancer tumors because the required therapeutic temperatures above 40 °C can only be achieved by direct intratumoral injection of conventional iron oxide nanoparticles. To realize the true potential of magnetic hyperthermia for cancer treatment, there is an unmet need for nanoparticles with high heating capacity that can efficiently accumulate at tumor sites following systemic administration and generate desirable intratumoral temperatures upon exposure to an alternating magnetic field (AMF). Although there have been many attempts to develop the desired nanoparticles, reported animal studies reveal the challenges associated with reaching therapeutically relevant intratumoral temperatures following systemic administration at clinically relevant doses. Therefore, we developed efficient magnetic nanoclusters with enhanced heating efficiency for systemically delivered magnetic hyperthermia that are composed of cobalt- and manganese-doped, hexagon-shaped iron oxide nanoparticles (CoMn-IONP) encapsulated in biocompatible PEG-PCL (poly(ethylene glycol)- b-poly(ε-caprolactone))-based nanocarriers. Animal studies validated that the developed nanoclusters are nontoxic, efficiently accumulate in ovarian cancer tumors following a single intravenous injection, and elevate intratumoral temperature up to 44 °C upon exposure to safe and tolerable AMF. Moreover, the obtained results confirmed the efficiency of the nanoclusters to generate the required intratumoral temperature after repeated injections and demonstrated that nanocluster-mediated magnetic hyperthermia significantly inhibits cancer growth. In summary, this nanoplatform is a milestone in the development of systemically delivered magnetic hyperthermia for the treatment of cancer tumors that are difficult to access for intratumoral injection.

Transarterial Delivery of a Biodegradable Single-Agent Theranostic Nanoprobe for Liver Tumor Imaging and Combinatorial Phototherapy

PURPOSE

To assess selective accumulation of biodegradable nanoparticles within hepatic tumors after transarterial delivery for in vivo localization and combinatorial phototherapy.

MATERIALS AND METHODS

A VX2 hepatic tumor model was used in New Zealand white rabbits. Transarterial delivery of silicon naphthalocyanine biodegradable nanoparticles was performed using a microcatheter via the proper hepatic artery. Tumors were exposed via laparotomy, and nanoparticles were observed by near-infrared (NIR) fluorescence imaging. For phototherapy, a handheld NIR laser (785 nm) at 0.6 W/cm² was used to expose tumor or background liver, and tissue temperatures were assessed with a fiberoptic temperature probe. Intratumoral reactive oxygen species formation was assessed using a fluorophore (2',7'-dichlorodihydrofluorescein diacetate).

RESULTS

Nanoparticles selectively accumulated within viable tumor by NIR fluorescence. Necrotic portions of tumor did not accumulate nanoparticles, consistent with a vascular distribution. NIR-dependent heat generation was observed with nanoparticle-containing tumors, but not in background liver. No heat was generated in the absence of NIR laser light. Reactive oxygen species were formed in nanoparticle-containing tumors exposed to NIR laser light, but not in background liver treated with NIR laser or in tumors in the absence of NIR light.

CONCLUSIONS

Biodegradable nanoparticle delivery to liver tumors from a transarterial approach enabled selective in vivo tumor imaging and combinatorial phototherapy.

Nanocarrier-based systems for targeted and site specific therapeutic delivery

Systemic drug delivery methods such as oral or parenteral administration of free drugs possess relatively low treatment efficiency and marked adverse side effects. The use of nanoparticles for drug delivery in most cases substantially enhances drug efficacy, improves pharmacokinetics and drug release and limits their side effects. However, further enhancement in drug efficacy and significant limitation of adverse side effects can be achieved by specific targeting of nanocarrier-based delivery systems especially in combination with local administration. The present review describes major advantages and limitations of organic and inorganic nanocarriers or living cell-based drug and nucleic acid delivery systems. Among these, different nanoparticles, supramolecular gels, therapeutic cells as living drug carriers etc. have emerged as a new frontier in modern medicine.

Increasing lean muscle mass in mice via nanoparticle-mediated hepatic delivery of follistatin mRNA

Muscle atrophy occurs during chronic diseases, resulting in diminished quality of life and compromised treatment outcomes. There is a high demand for therapeutics that increase muscle mass while abrogating the need for special dietary and exercise requirements. Therefore, we developed an efficient nanomedicine approach capable of increasing muscle mass.

Methods: The therapy is based on nanoparticle-mediated delivery of follistatin messenger RNA (mRNA) to the liver after subcutaneous administration. The delivered mRNA directs hepatic cellular machinery to produce follistatin, a glycoprotein that increases lean mass through inhibition of negative regulators of muscle mass (myostatin and activin A). These factors are elevated in numerous disease states, thereby providing a target for therapeutic intervention.

Results: Animal studies validated that mRNA-loaded nanoparticles enter systemic circulation following subcutaneous injection, accumulate and internalize in the liver, where the mRNA is translated into follistatin. Follistatin serum levels were elevated for 72 h post injection and efficiently reduced activin A and myostatin serum concentrations. After eight weeks of repeated injections, the lean mass of mice in the treatment group was ~10% higher when compared to that of the controls.

Conclusion: Based on the obtained results demonstrating an increased muscle mass as well as restricted fat accumulation, this nanoplatform might be a milestone in the development of mRNA technologies and the treatment of muscle wasting disorders.

A Preliminary Proteomic Investigation of Circulating Exosomes and Discovery of Biomarkers Associated with the Progression of Osteosarcoma in a Clinical Model of Spontaneous Disease

Circulating cancer exosomes are microvesicles which originate from malignant cells and other organs influenced by the disease and can be found in blood. The exosomal proteomic cargo can often be traced to the cells from which they originated, reflecting the physiological status of these cells. The similarities between cancer exosomes and the tumor cells they originate from exhibit the potential of these vesicles as an invaluable target for liquid biopsies. Exosomes were isolated from the serum of eight osteosarcoma-bearing dogs, five healthy dogs, and five dogs with traumatic fractures. We also characterized exosomes which were collected longitudinally from patients with osteosarcoma prior and 2 weeks after amputation, and eventually upon detection of lung metastasis. Exosomal proteins fraction were analyzed by label-free mass spectrometry proteomics and were validated with immunoblots of selected proteins. Ten exosomal proteins were found that collectively discriminate serum of osteosarcoma patients from serum healthy or fractured dogs with an accuracy of 85%. Additionally, serum from different disease stages could be distinguished with an accuracy of 77% based on exosomal proteomic composition. The most discriminating protein changes for both sample group comparisons were related to complement regulation, suggesting an immune evasion mechanism in early stages of osteosarcoma as well as in advanced disease.

Intraperitoneal nanotherapy for metastatic ovarian cancer based on siRNA-mediated suppression of DJ-1 protein combined with a low dose of cisplatin

Herein, we report an efficient combinatorial therapy for metastatic ovarian cancer based on siRNA-mediated suppression of DJ-1 protein combined with a low dose of cisplatin. DJ-1 protein modulates, either directly or indirectly, different oncogenic pathways that support and promote survival, growth, and invasion of ovarian cancer cells. To evaluate the potential of this novel therapy, we have engineered a cancer-targeted nanoplatform and validated that DJ-1 siRNA delivered by this nanoplatform after intraperitoneal injection efficiently downregulates the DJ-1 protein in metastatic ovarian cancer tumors and ascites. In vivo experiments revealed that DJ-1 siRNA monotherapy outperformed cisplatin alone by inhibiting tumor growth and increasing survival of mice with metastatic ovarian cancer. Finally, three cycles of siRNA-mediated DJ-1 therapy in combination with a low dose of cisplatin completely eradicated ovarian cancer tumors from the mice, and there was no cancer recurrence detected for the duration of the study, which lasted 35 weeks.

A Tumor-Activatable Theranostic Nanomedicine Platform for NIR Fluorescence-Guided Surgery and Combinatorial Phototherapy

Fluorescence image-guided surgery combined with intraoperative therapeutic modalities has great potential for intraoperative detection of oncologic targets and eradication of unresectable cancer residues. Therefore, we have developed an activatable theranostic nanoplatform that can be used concurrently for two purposes: (1) tumor delineation with real-time near infrared (NIR) fluorescence signal during surgery, and (2) intraoperative targeted treatment to further eliminate unresected disease sites by non-toxic phototherapy.

Methods: The developed nanoplatform is based on a single agent, silicon naphthalocyanine (SiNc), encapsulated in biodegradable PEG-PCL (poly (ethylene glycol)-b-poly(ɛ-caprolactone)) nanoparticles. It is engineered to be non-fluorescent initially via dense SiNc packing within the nanoparticle's hydrophobic core, with NIR fluorescence activation after accumulation at the tumor site. The activatable nanoplatform was evaluated in vitro and in two different murine cancer models, including an ovarian intraperitoneal metastasis-mimicking model. Furthermore, fluorescence image-guided surgery mediated by this nanoplatform was performed on the employed animal models using a Fluobeam^® 800 imaging system. Finally, the phototherapeutic efficacy of the developed nanoplatform was demonstrated in vivo.

Results: Our in vitro data suggest that the intracellular environment of cancer cells is capable of compromising the integrity of self-assembled nanoparticles and thus causes disruption of the tight dye packing inside the hydrophobic cores and activation of the NIR fluorescence. Animal studies demonstrated accumulation of activatable nanoparticles at the tumor site following systemic administration, as well as release and fluorescence recovery of SiNc from the polymeric carrier. It was also validated that the developed nanoparticles are compatible with the intraoperative imaging system Fluobeam® 800, and nanoparticle-mediated image-guided surgery provides successful resection of cancer tumors. Finally, in vivo studies revealed that combinatorial phototherapy mediated by the nanoparticles could efficiently eradicate chemoresistant ovarian cancer tumors.

Conclusion: The revealed properties of the activatable nanoplatform make it highly promising for further application in clinical image-guided surgery and combined phototherapy, facilitating a potential translation to clinical studies.

Abstract DPOC-012: THERANOSTIC NANOPLATFORM FOR IMAGE–GUIDED SURGERY AND INTRAOPERATIVE PHOTOTHERAPY FOR OVARIAN CANCER TREATMENT

PURPOSE: Surgery plays a decisive role in cancer treatment and patient prognosis is closely linked to the size of residual tumors after cytoreduction. Even with the best surgical techniques, however, palpation and visual inspection do not always permit discrimination between malignant and normal tissue types and can lead to incomplete cancer resection. It is extremely important, therefore, to improve tumor delineation during surgery and provide efficient adjuvant treatment intraoperatively, to further eliminate occult disease sites that may be left behind. Among the explored fluorescent agents, near infrared (NIR, 750 – 900 nm) fluorescent imaging agents possess advantages of deep tissue penetration and minimal tissue autofluorescence and light scattering, making them promising candidates for optical imaging guided cancer debulking surgery. Our study is aimed to develop a nanomedicine capable of maximizing selective tumor detection via fluorescence imaging and immediate phototherapy for tumor tissue eradication.

METHODS: To develop an effective theranostic probe, silicon naphthalocyanine (SiNc) with strong light absorption in the NIR region was loaded into a biodegradable polymeric nanoparticle based on the amphiphilic block polymer, poly (ethylene glycol)–poly(ε–caprolactone) (PEG–PCL). Such a design has provided a possibility to control and improve fluorescence and phototherapeutic properties of the SiNc–based theranostic agent.

RESULTS: As a theranostic agent, the developed SiNc polymeric nanoparticles were evaluated by DLS, TEM (around 20 nm), NIR absorbance and fluorescence spectroscopies, ROS and hyperthermia production. The safety and effectiveness of SiNc–nanoparticles as a bioimaging agent was confirm in vitro and in vivo. In addition, high photostability of SiNc–nanoparticles have been detected. The efficiency of SiNc–nanoparticles as an NIR bioimaging agent was confirmed by recording the strong fluorescence signal in the ovarian cancer tumors. The in vitro and in vivo studies demonstrated that, after efficient tumor accumulation via i.v. administration, phototherapy mediated by SiNc can efficiently destroy ovarian cancer tumors.

CONCLUSIONS: We have developed a photostable NIR theranostic nanomedicine platform that provides florescence detection of subcutaneous and orthotopic tumor xenographs as well as effective phototherapy resulting in complete tumor eradication. This theranostic agent can be potentially employed concurrently for tumor delineation with real–time NIR fluorescence signal during surgery and intraoperative targeted treatment to further eliminate non–surgically removable disease sites by non–toxic phototherapy.

Citation Format: Oleh Taratula, Olena Taratula, Xiaoning Li, Canan Schumann, Shay Bracha, Milan Milovancev, Adam W. G. Alani. THERANOSTIC NANOPLATFORM FOR IMAGE–GUIDED SURGERY AND INTRAOPERATIVE PHOTOTHERAPY FOR OVARIAN CANCER TREATMENT [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr DPOC-012.

LHRH-Targeted Drug Delivery Systems for Cancer Therapy

Targeted delivery of therapeutic and diagnostic agents to cancer sites has significant potential to improve the therapeutic outcome of treatment while minimizing severe side effects. It is widely accepted that decoration of the drug delivery systems with targeting ligands that bind specifically to the receptors on the cancer cells is a promising strategy that may substantially enhance accumulation of anticancer agents in the tumors. Due to the transformed cellular nature, cancer cells exhibit a variety of overexpressed cell surface receptors for peptides, hormones, and essential nutrients, providing a significant number of target candidates for selective drug delivery. Among others, luteinizing hormonereleasing hormone (LHRH) receptors are overexpressed in the majority of cancers, while their expression in healthy tissues, apart from pituitary cells, is limited. The recent studies indicate that LHRH peptides can be employed to efficiently guide anticancer and imaging agents directly to cancerous cells, thereby increasing the amount of these substances in tumor tissue and preventing normal cells from unnecessary exposure. This manuscript provides an overview of the targeted drug delivery platforms that take advantage of the LHRH receptors overexpression by cancer cells.

Phototheranostic nanoplatform based on a single cyanine dye for image-guided combinatorial phototherapy

This study represents a novel phototheranostic nanoplatform based on the near-infrared (NIR) heptamethine cyanine dye, IR775, which is capable of concurrent real-time fluorescence imaging and cancer eradication with combinatorial phototherapy. To achieve water solubility and enhance tumor delivery, the hydrophobic IR775 dye was loaded into a biocompatible polymeric nanoparticle with a diameter of ~40nm and slightly negative surface charge (-2.34mV). The nanoparticle-encapsulated hydrophobic IR775 dye (IR775-NP) is characterized by an enhanced fluorescence quantum yield (16%) when compared to the water soluble analogs such as ICG (2.7%) and IR783 (8%). Furthermore, the developed IR-775-NP efficiently generates both heat and reactive oxygen species under NIR light irradiation, eradicating cancer cells in vitro. Finally, animal studies revealed that the IR775-NP accumulates in cancer tumors after systemic administration, efficiently delineates them with NIR fluorescence signal and completely eradicates chemo resistant cancer tissue after a single dose of combinatorial phototherapy.

Precision targeted therapy of ovarian cancer

The review is aimed at describing modern approaches to detection as well as precision and personalized treatment of ovarian cancer. Modern methods and future directions of nanotechnology-based targeted and personalized therapy are discussed.

Mesenchymal Stromal Cell-derived Extracellular Vesicles Promote Myeloid-biased Multipotent Hematopoietic Progenitor Expansion via Toll-Like Receptor Engagement

Mesenchymal stromal cells (MSCs) present in the bone marrow microenvironment secrete cytokines and angiogenic factors that support the maintenance and regenerative expansion of hematopoietic stem and progenitor cells (HSPCs). Here, we tested the hypothesis that extracellular vesicles (EVs) released by MSCs contribute to the paracrine crosstalk that shapes hematopoietic function. We systematically characterized EV release by murine stromal cells and demonstrate that MSC-derived EVs prompt a loss of HSPC quiescence with concomitant expansion of murine myeloid progenitors. Our studies reveal that HSPC expansion by MSC EVs is mediated via the MyD88 adapter protein and is partially blocked by treatment with a TLR4 inhibitor. Imaging of fluorescence protein-tagged MSC EVs corroborated their cellular co-localization with TLR4 and endosomal Rab5 compartments in HSPCs. The dissection of downstream responses to TLR4 activation reveals that the mechanism by which MSC EVs impact HSPCs involves canonical NF-κB signaling and downstream activation of Hif-1α and CCL2 target genes. Our aggregate data identify a previously unknown role for MSC-derived EVs in the regulation of hematopoiesis through innate immune mechanisms and illustrate the expansive cell-cell crosstalk in the bone marrow microenvironment.

Mechanistic Nanotherapeutic Approach Based on siRNA-Mediated DJ-1 Protein Suppression for Platinum-Resistant Ovarian Cancer

We report an efficient therapeutic modality for platinum resistant ovarian cancer based on siRNA-mediated suppression of a multifunctional DJ-1 protein that is responsible for the proliferation, growth, invasion, oxidative stress, and overall survival of various cancers. The developed therapeutic strategy can work alone or in concert with a low dose of the first line chemotherapeutic agent cisplatin, to elicit a maximal therapeutic response. To achieve an efficient DJ-1 knockdown, we constructed the polypropylenimine dendrimer-based nanoplatform targeted to LHRH receptors overexpressed on ovarian cancer cells. The quantitative PCR and Western immunoblotting analysis revealed that the delivered DJ-1 siRNA downregulated the expression of targeted mRNA and corresponding protein by more than 80% in various ovarian cancer cells. It was further demonstrated that siRNA-mediated DJ-1 suppression dramatically impaired proliferation, viability, and migration of the employed ovarian cancer cells. Finally, the combinatorial approach led to the most pronounced therapeutic response in all the studied cell lines, outperforming both siRNA-mediated DJ-1 knockdown and cisplatin treatment alone. It is noteworthy that the platinum-resistant cancer cells (A2780/CDDP) with the highest basal level of DJ-1 protein are most susceptible to the developed therapy and this susceptibility declines with decreasing basal levels of DJ-1. Finally, we interrogate the molecular underpinnings of the DJ-1 knockdown effects in the treatment of the ovarian cancer cells. By using various experimental techniques, it was revealed that DJ-1 depletion (1) decreases the activity of the Akt pathway, thereby reducing cellular proliferation and migration and increasing the antiproliferative effect of cisplatin on ovarian cancer cells; (2) enhances the activity of p53 tumor suppressor protein therefore restoring cell cycle arrest functionality and upregulating the Bax-caspase pathway, triggering cell death; and (3) weakens the cellular defense mechanisms against inherited oxidative stress thereby increasing toxic intracellular radicals and amplifying the reactive oxygen species created by the administration of cisplatin.

Abstract 4405: Tumor-targeted nanotherapeutics

Directing anticancer agents specifically to tumors and/or cancer cells by targeting specific extracellular receptors fulfills the following three most important tasks: (1) preventing or at least substantially limiting adverse side effects on healthy tissues, (2) enhancing drug internalization by cancer cells, and (3) overcoming (at least in part) resistance mechanisms that are based on the active efflux of exogenous drugs from cancer cells.

We developed several tumor-targeted nanoscale-based formulations: various nanocarriers (liposomes, lipid nanoparticles, dendrimers, polymers, quantum dots, mesoporous silica and supermagnetic iron oxide nanoparticles); different anticancer drugs (doxorubicin, paclitaxel, camptothecin, and cisplatin); suppressors of cellular drug resistance and tumor grows (antisense oligonucleotides or siRNA targeted to BCL2, MDR1, MRP1, HIF1A, CD44 mRNA); and tumor-targeting agent - luteinizing hormone-releasing hormone (LHRH).

The proposed nanotherapeutics were tested in vitro and in vivo using established lung and ovarian cancer cell lines and highly metastatic cancer cells isolated from malignant intraperitoneal ascites from patients with advanced ovarian carcinoma. These cells were used to initiate orthotopic models of lung and ovarian cancers in nude mice that were often accompanied by the development of metastases. Tumor-targeted nanoscale-based drug formulations were delivered intravenously and intraperitoneally (for ovarian cancer) or intravenously and by inhalation (for lung cancer). Treatment with the developed therapeutics led to the suppression of targeted proteins, efficient induction of cell death, effective tumor shrinkage, prevention the development of metastases and limitation of adverse side effects.

Acknowledgements: The work was supported by R01CA100098, R01CA111766, and R01CA138533 grants from NIH.

Note: This abstract was not presented at the meeting.

Citation Format: Olga B. Garbuzenko, Andriy Kuzmov, Justin E. Sapiezynski, Oleh Taratula, Vatsal Shah, Min Zhang, Ronak Savla, Shali John, Lorna Rodriguez-Rodriguez, Tamara Minko. Tumor-targeted nanotherapeutics. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4405. doi:10.1158/1538-7445.AM2015-4405

Phthalocyanine-loaded graphene nanoplatform for imaging-guided combinatorial phototherapy

We report a novel cancer-targeted nanomedicine platform for imaging and prospect for future treatment of unresected ovarian cancer tumors by intraoperative multimodal phototherapy. To develop the required theranostic system, novel low-oxygen graphene nanosheets were chemically modified with polypropylenimine dendrimers loaded with phthalocyanine (Pc) as a photosensitizer. Such a molecular design prevents fluorescence quenching of the Pc by graphene nanosheets, providing the possibility of fluorescence imaging. Furthermore, the developed nanoplatform was conjugated with poly(ethylene glycol), to improve biocompatibility, and with luteinizing hormone-releasing hormone (LHRH) peptide, for tumor-targeted delivery. Notably, a low-power near-infrared (NIR) irradiation of single wavelength was used for both heat generation by the graphene nanosheets (photothermal therapy [PTT]) and for reactive oxygen species (ROS)-production by Pc (photodynamic therapy [PDT]). The combinatorial phototherapy resulted in an enhanced destruction of ovarian cancer cells, with a killing efficacy of 90%-95% at low Pc and low-oxygen graphene dosages, presumably conferring cytotoxicity to the synergistic effects of generated ROS and mild hyperthermia. An animal study confirmed that Pc loaded into the nanoplatform can be employed as a NIR fluorescence agent for imaging-guided drug delivery. Hence, the newly developed Pc-graphene nanoplatform has the significant potential as an effective NIR theranostic probe for imaging and combinatorial phototherapy.

Dendrimer-encapsulated naphthalocyanine as a single agent-based theranostic nanoplatform for near-infrared fluorescence imaging and combinatorial anticancer phototherapy

Multifunctional theranostic platforms capable of concurrent near-infrared (NIR) fluorescence imaging and phototherapies are strongly desired for cancer diagnosis and treatment. However, the integration of separate imaging and therapeutic components into nanocarriers results in complex theranostic systems with limited translational potential. A single agent-based theranostic nanoplatform, therefore, was developed for concurrent NIR fluorescence imaging and combinatorial phototherapy with dual photodynamic (PDT) and photothermal (PTT) therapeutic mechanisms. The transformation of a substituted silicon naphthalocyanine (SiNc) into a biocompatible nanoplatform (SiNc-NP) was achieved by SiNc encapsulation into the hydrophobic interior of a generation 5 polypropylenimine dendrimer following surface modification with polyethylene glycol. Encapsulation provides aqueous solubility to SiNc and preserves its NIR fluorescence, PDT and PTT properties. Moreover, an impressive photostability in the dendrimer-encapsulated SiNc has been detected. Under NIR irradiation (785 nm, 1.3 W cm(-2)), SiNc-NP manifested robust heat generation capability (ΔT = 40 °C) and efficiently produced reactive oxygen species essential for PTT and PDT, respectively, without releasing SiNc from the nanopaltform. By varying the laser power density from 0.3 W cm(-2) to 1.3 W cm(-2) the therapeutic mechanism of SiNc-NP could be switched from PDT to combinatorial PDT-PTT treatment. In vitro and in vivo studies confirmed that phototherapy mediated by SiNc can efficiently destroy chemotherapy resistant ovarian cancer cells. Remarkably, solid tumors treated with a single dose of SiNc-NP combined with NIR irradiation were completely eradicated without cancer recurrence. Finally, the efficiency of SiNc-NP as an NIR imaging agent was confirmed by recording the strong fluorescence signal in the tumor, which was not photobleached during the phototherapeutic procedure.

Temperature-tunable iron oxide nanoparticles for remote-controlled drug release

Herein, we report the successful development of a novel nanosystem capable of an efficient delivery and temperature-triggered drug release specifically aimed at cancer. The water-soluble 130.1 ± 0.2 nm iron oxide nanoparticles (IONPs) were obtained via synthesis of a monodispersed iron oxide core stabilized with tetramethylammonium hydroxide pentahydrate (TMAOH), followed by coating with the thermoresponsive copolymer poly-(NIPAM-stat-AAm)-block-PEI (PNAP). The PNAP layer on the surface of the IONP undergoes reversible temperature-dependent structural changes from a swollen to a collapsed state resulting in the controlled release of anticancer drugs loaded in the delivery vehicle. We demonstrated that the phase transition temperature of the prepared copolymer can be precisely tuned to the desired value in the range of 36°C-44°C by changing the monomers ratio during the preparation of the nanoparticles. Evidence of modification of the IONPs with the thermoresponsive copolymer is proven by ATR-FTIR and a quantitative analysis of the polymeric and iron oxide content obtained by thermogravimetric analysis. When loaded with doxorubicin (DOX), the IONPs-PNAP revealed a triggered drug release at a temperature that is a few degrees higher than the phase transition temperature of a copolymer. Furthermore, an in vitro study demonstrated an efficient internalization of the nanoparticles into the cancer cells and showed that the drug-free IONPs-PNAP were nontoxic toward the cells. In contrast, sufficient therapeutic effect was observed for the DOX-loaded nanosystem as a function of temperature. Thus, the developed temperature-tunable IONPs-based delivery system showed high potential for remotely triggered drug delivery and the eradication of cancer cells.

Inhalation treatment of lung cancer: the influence of composition, size and shape of nanocarriers on their lung accumulation and retention

Objective

Various nanoparticles have been designed and tested in order to select optimal carriers for the inhalation delivery of anticancer drugs to the lungs.

Methods

The following nanocarriers were studied: micelles, liposomes, mesoporous silica nanoparticles (MSNs), poly propyleneimine (PPI) dendrimer-siRNA complexes nanoparticles, quantum dots (QDs), and poly (ethylene glycol) polymers. All particles were characterized using the following methods: dynamic light scattering, zeta potential, atomic force microscopy, in vitro cyto- and genotoxicity. In vivo organ distribution of all nanoparticles, retention in the lungs, and anticancer effects of liposomes loaded with doxorubicin were examined in nude mice after the pulmonary or intravenous delivery.

Results

Significant differences in lung uptake were found after the inhalation delivery of lipid-based and non-lipid-based nanoparticles. The accumulation of liposomes and micelles in lungs remained relatively high even 24 h after inhalation when compared with MSNs, QDs, and PPI dendrimers. There were notable differences between nanoparticle accumulation in the lungs and other organs 1 and 3 h after inhalation or intravenous administrations, but 24 h after intravenous injection all nanoparticles were mainly accumulated in the liver, kidneys, and spleen. Inhalation delivery of doxorubicin by liposomes significantly enhanced its anticancer effect and prevented severe adverse side effects of the treatment in mice bearing the orthotopic model of lung cancer.

Conclusion

The results of the study demonstrate that lipid-based nanocarriers had considerably higher accumulation and longer retention time in the lungs when compared with non-lipid-based carriers after the inhalation delivery. These particles are most suitable for effective inhalation treatment of lung cancer.

Targeted nanomedicine for suppression of CD44 and simultaneous cell death induction in ovarian cancer: an optimal delivery of siRNA and anticancer drug

PURPOSE

The proposed project is aimed at enhancing the efficiency of epithelial ovarian cancer treatment and reducing adverse side effects of chemotherapy using nanotechnology. Overexpression of the CD44 membrane receptor results in tumor initiation, growth, cancer stem cells' specific behavior, development of drug resistance, and metastases. We hypothesize that a developed cancer-targeted delivery system that combines CD44 siRNA with paclitaxel would successfully deliver its payload inside cancer cells, effectively induce cell death, and prevent metastases.

EXPERIMENTAL DESIGN

We synthesized, characterized, and tested a nanoscale-based drug delivery system (DDS) containing a modified polypropylenimine (PPI) dendrimer as a carrier; anticancer drug paclitaxel as a cell death inducer; a synthetic analog of luteinizing hormone-releasing hormone (LHRH) peptide as a tumor-targeting moiety; and siRNA targeted to CD44 mRNA. The proposed DDS was tested in vitro and in vivo using metastatic ovarian cancer cells isolated from patients with malignant ascites.

RESULTS

We found that in contrast with cells isolated from primary tumors, CD44 was highly overexpressed in metastatic cancer cells. Treatment with the proposed tumor-targeted nanoscale-based nucleic acid and DDS led to the suppression of CD44 mRNA and protein, efficient induction of cell death, effective tumor shrinkage, and prevention of adverse side effects on healthy organs.

CONCLUSION

We show a high therapeutic potential for combinatorial treatment of ovarian carcinoma with a novel DDS that effectively transports siRNA targeting to CD44 mRNA simultaneously with cytotoxic agents. Clin Cancer Res; 19(22); 6193-204. ©2013 AACR.

Genotoxicity of different nanocarriers: possible modifications for the delivery of nucleic acids

The prevention of cyto- and genotoxicity of nanocarriers is an important task in nanomedicine. In the present investigation, we, at the first time using similar experimental conditions, compared genotoxicity of nanocarriers with different composition, architecture, size, molecular weight and charge. Poly(ethylene glycol) polymers, neutral and cationic liposomes, micelles, poly(amindo amine) and poly(propyleneimine) dendrimers, quantum dots, mesoporous silica, and supermagnetic iron oxide (SPIO) nanoparticles were studied. All nanoparticles were used in non-cytotoxic concentrations. However, even in these concentrations, positively charged cationic liposomes, dendrimers, and SPIO nanoparticles induced genotoxicity leading to the significant formation of micronuclei in cells. Negatively charged and neutral nanocarriers were not genotoxic. A strong positive correlation was found between the number of formed micronuclei and the positive charge of nanocarriers. We proposed modifications of both types of dendrimers and SPIO nanoparticles that substantially decreased their genotoxicity and allowed for an efficient intracellular delivery of nucleic acids.

Innovative strategy for treatment of lung cancer: targeted nanotechnology-based inhalation co-delivery of anticancer drugs and siRNA

A tumor targeted mesoporous silica nanoparticles (MSN)-based drug delivery system (DDS) was developed for inhalation treatment of lung cancer. The system was capable of effectively delivering inside cancer cells anticancer drugs (doxorubicin and cisplatin) combined with two types of siRNA targeted to MRP1 and BCL2 mRNA for suppression of pump and nonpump cellular resistance in non-small cell lung carcinoma, respectively. Targeting of MSN to cancer cells was achieved by the conjugation of LHRH peptide on the surface of MSN via poly(ethylene glycol) spacer. The delivered anticancer drugs and siRNA preserved their specific activity leading to the cell death induction and inhibition of targeted mRNA. Suppression of cellular resistance by siRNA effectively delivered inside cancer cells and substantially enhanced the cytotoxicity of anticancer drugs. Local delivery of MSN by inhalation led to the preferential accumulation of nanoparticles in the mouse lungs, prevented the escape of MSN into the systemic circulation, and limited their accumulation in other organs. The experimental data confirm that the developed DDS satisfies the major prerequisites for effective treatment of non-small cell lung carcinoma. Therefore, the proposed cancer-targeted MSN-based system for complex delivery of drugs and siRNA has high potential in the effective treatment of lung cancer.