Quantum Defect Sensitization via Phase-Changing Supercharged Antibody Fragments

Quantum defects in single-walled carbon nanotubes promote exciton localization, which enables potential applications in biodevices and quantum light sources. However, the effects of local electric fields on the emissive energy states of quantum defects and how they can be controlled are unexplored. Here, we investigate quantum defect sensitization by engineering an intrinsically disordered protein to undergo a phase change at a quantum defect site. We designed a supercharged single-chain antibody fragment (scFv) to enable a full ligand-induced folding transition from an intrinsically disordered state to a compact folded state in the presence of a cytokine. The supercharged scFv was conjugated to a quantum defect to induce a substantial local electric change upon ligand binding. Employing the detection of a proinflammatory biomarker, interleukin-6, as a representative model system, supercharged scFv-coupled quantum defects exhibited robust fluorescence wavelength shifts concomitant with the protein folding transition. Quantum chemical simulations suggest that the quantum defects amplify the optical response to the localization of charges produced upon the antigen-induced folding of the proteins, which is difficult to achieve in unmodified nanotubes. These findings portend new approaches to modulate quantum defect emission for biomarker sensing and protein biophysics and to engineer proteins to modulate binding signal transduction.

Uterine washings as a novel method for early detection of ovarian cancer: Trials and tribulations

Given the tubal origin of high-grade serous ovarian cancer (HGSC), we sought to investigate intrauterine lavage (IUL) as a novel method of biomarker detection. IUL and serum samples were collected from patients with HGSC or benign pathology. Although CA-125 and HE4 concentrations were significantly higher in IUL samples compared to serum, they were similar between IUL samples from patients with HGSC vs benign conditions. In contrast, CA-125 and HE4 serum concentrations differed between HGSC and benign pathology (P =.002 for both). IUL and tumor samples from patients with HGSC were subjected to targeted panel sequencing and droplet digital PCR (ddPCR). Tumor mutations were found in 75 % of matched IUL samples. Serum CA-125 and HE4 biomarker levels allowed for better differentiation of HGSC and benign pathology compared to IUL samples. We believe using IUL for early detection of HGSC requires optimization, and current strategies should focus on prevention until early detection strategies improve.

NDUFA4L2 reduces mitochondrial respiration resulting in defective lysosomal trafficking in clear cell renal cell carcinoma

In clear cell renal cell carcinoma (ccRCC), activation of hypoxic signaling induces NADH dehydrogenase (ubiquinone) 1 alpha subcomplex, 4-like 2 (NDUFA4L2) expression. Over 90% of ccRCCs exhibit overexpression of NDUFA4L2, which we previously showed contributes to ccRCC proliferation and survival. The function of NDUFA4L2 in ccRCC has not been fully elucidated. NDUFA4L2 was reported to reduce mitochondrial respiration via mitochondrial complex I inhibition. We found that NDUFA4L2 expression in human ccRCC cells increases the extracellular acidification rate, indicative of elevated glycolysis. Conversely, NDUFA4L2 expression in non-cancerous kidney epithelial cells decreases oxygen consumption rate while increasing extracellular acidification rate, suggesting that a Warburg-like effect is induced by NDUFA4L2 alone. We performed mass-spectrometry (MS)-based proteomics of NDUFA4L2 associated complexes. Comparing RCC4-P (parental) ccRCC cells with RCC4 in which NDUFA4L2 is knocked out by CRISPR-Cas9 (RCC4-KO-643), we identified 3,215 proteins enriched in the NDUFA4L2 immunoprecipitates. Among the top-ranking pathways were "Metabolic Reprogramming in Cancer" and "Glycolysis Activation in Cancer (Warburg Effect)." We also show that NDUFA4L2 enhances mitochondrial fragmentation, interacts with lysosomes, and increases mitochondrial-lysosomal associations, as assessed by high-resolution fluorescence microscopy and live cell imaging. We identified 161 lysosomal proteins, including Niemann-Pick Disease Type C Intracellular Cholesterol Transporters 1 and 2 (NPC1, NPC2), that are associated with NDUFA4L2 in RCC4-P cells. RCC4-P cells have larger and decreased numbers of lysosomes relative to RCC4 NDUFA4L2 knockout cells. These findings suggest that NDUFA4L2 regulates mitochondrial-lysosomal associations and potentially lysosomal size and abundance. Consequently, NDUFA4L2 may regulate not only mitochondrial, but also lysosomal functions in ccRCC.

Fragment-based drug nanoaggregation reveals drivers of self-assembly

Drug nanoaggregates are particles that can deleteriously cause false positive results during drug screening efforts, but alternatively, they may be used to improve pharmacokinetics when developed for drug delivery purposes. The structural features of molecules that drive nanoaggregate formation remain elusive, however, and the prediction of intracellular aggregation and rational design of nanoaggregate-based carriers are still challenging. We investigate nanoaggregate self-assembly mechanisms using small molecule fragments to identify the critical molecular forces that contribute to self-assembly. We find that aromatic groups and hydrogen bond acceptors/donors are essential for nanoaggregate formation, suggesting that both π-π stacking and hydrogen bonding are drivers of nanoaggregation. We apply structure-assembly-relationship analysis to the drug sorafenib and discover that nanoaggregate formation can be predicted entirely using drug fragment substructures. We also find that drug nanoaggregates are stabilized in an amorphous core-shell structure. These findings demonstrate that rational design can address intracellular aggregation and pharmacologic/delivery challenges in conventional and fragment-based drug development processes.

Nanoreporter Identifies Lysosomal Storage Disease Lipid Accumulation Intracranially

Dysregulated lipid metabolism contributes to neurodegenerative pathologies and neurological decline in lysosomal storage disorders as well as more common neurodegenerative diseases. Niemann-Pick type A (NPA) is a fatal neurodegenerative lysosomal storage disease characterized by abnormal sphingomyelin accumulation in the endolysosomal lumen. The ability to monitor abnormalities in lipid homeostasis intracranially could improve basic investigations and the development of effective treatment strategies. We investigated the carbon nanotube-based detection of intracranial lipid content. We found that the near-infrared emission of a carbon nanotube-based lipid sensor responds to lipid accumulation in neuronal and in vivo models of NPA. The nanosensor detected lipid accumulation intracranially in an acid sphingomyelinase knockout mouse via noninvasive near-infrared spectroscopy. This work indicates a tool to improve drug development processes in NPA, other lysosomal storage diseases, and neurodegenerative diseases.

Nanosensor-based monitoring of autophagy-associated lysosomal acidification in vivo

Autophagy is a cellular process with important functions that drive neurodegenerative diseases and cancers. Lysosomal hyperacidification is a hallmark of autophagy. Lysosomal pH is currently measured by fluorescent probes in cell culture, but existing methods do not allow for quantitative, transient or in vivo measurements. In the present study, we developed near-infrared optical nanosensors using organic color centers (covalent sp3 defects on carbon nanotubes) to measure autophagy-mediated endolysosomal hyperacidification in live cells and in vivo. The nanosensors localize to the lysosomes, where the emission band shifts in response to local pH, enabling spatial, dynamic and quantitative mapping of subtle changes in lysosomal pH. Using the sensor, we observed cellular and intratumoral hyperacidification on administration of mTORC1 and V-ATPase modulators, revealing that lysosomal acidification mirrors the dynamics of S6K dephosphorylation and LC3B lipidation while diverging from p62 degradation. This sensor enables the transient and in vivo monitoring of the autophagy-lysosomal pathway.

Ambient Light Resistant Shortwave Infrared Fluorescence Imaging for Preclinical Tumor Delineation via the pH Low-Insertion Peptide Conjugated to Indocyanine Green

Shortwave infrared (900-1,700 nm) fluorescence imaging (SWIRFI) has shown significant advantages over visible (400-650 nm) and near-infrared (700-900 nm) fluorescence imaging (reduced autofluorescence, improved contrast, tissue resolution, and depth sensitivity). However, there is a major lag in the clinical translation of preclinical SWIRFI systems and targeted SWIRFI probes. Methods: We preclinically show that the pH low-insertion peptide conjugated to indocyanine green (pHLIP ICG), currently in clinical trials, is an excellent candidate for cancer-targeted SWIRFI. Results: pHLIP ICG SWIRFI achieved picomolar sensitivity (0.4 nM) with binary and unambiguous tumor screening and resection up to 96 h after injection in an orthotopic breast cancer mouse model. SWIRFI tumor screening and resection had ambient light resistance (possible without gating or filtering) with outstanding signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) values at exposures from 10 to 0.1 ms. These SNR and CNR values were also found for the extended emission of pHLIP ICG in vivo (>1,100 nm, 300 ms). Conclusion: SWIRFI sensitivity and ambient light resistance enabled continued tracer clearance tracking with unparalleled SNR and CNR values at video rates for tumor delineation (achieving a tumor-to-muscle ratio above 20). In total, we provide a direct precedent for the democratic translation of an ambient light resistant SWIRFI and pHLIP ICG ecosystem, which can instantly improve tumor resection.

Micro-engineering and nano-engineering approaches to investigate tumour ecosystems

The interactions among tumour cells, the tumour microenvironment (TME) and non-tumour tissues are of interest to many cancer researchers. Micro-engineering approaches and nanotechnologies are under extensive exploration for modelling these interactions and measuring them in situ and in vivo to investigate therapeutic vulnerabilities in cancer and extend a systemic view of tumour ecosystems. Here we highlight the greatest opportunities for improving the understanding of tumour ecosystems using microfluidic devices, bioprinting or organ-on-a-chip approaches. We also discuss the potential of nanosensors that can transmit information from within the TME or elsewhere in the body to address scientific and clinical questions about changes in chemical gradients, enzymatic activities, metabolic and immune profiles of the TME and circulating analytes. This Review aims to connect the cancer biology and engineering communities, presenting biomedical technologies that may expand the methodologies of the former, while inspiring the latter to develop approaches for interrogating cancer ecosystems.

Hematoxylin Nuclear Stain Reports Oxidative Stress via Near-Infrared Emission

Hematoxylin & eosin (H&E) is the gold standard histological stain used for medical diagnosis and has been used for over a century. Herein, we examined the near-infrared II (NIR-II) fluorescence of this stain. We observed significant NIR-II emission from the hematoxylin component of the H&E stain. We found that the emission intensity, using the common aluminum(III) hematoxylin mordant, could be modulated by the availability of endogenous iron(III), and this emission intensity increased at higher oxidative stress. Our mechanistic investigations found that hematoxylin emission reported the nuclear translocation of the iron via the protein ferritin. In human tumor tissue samples, oxidative stress biomarkers correlated with hematoxylin NIR-II emission intensity. Emission response of the stain was also observed in human Alzheimer's disease brain tissue regions affected by disease progression, suggesting that ferritin nuclear translocation is preserved in these regions as an oxidative stress response. These findings indicate that NIR-II emission from the H&E stain provides a new source of redox information in tissues with implications for biomedical research and clinical practice.

Abstract 1992: P-selectin-targeted delivery of intracranial therapeutics across an intact BBB in Sonic Hedgehog medulloblastoma

Medulloblastoma (MB) is the most common malignant pediatric brain tumor with ~30% mediated by Sonic hedgehog (SHH) signaling. While SHH effector Smoothened inhibition is promising, therapeutic index is reduced by high systemic doses required for sufficient intracranial drug concentrations. Treatment-related toxicities associated with radiation therapy result in lifelong morbidity, and SHH pathway inhibition in children notably results in permanent bone defects. Here, we found that nanoparticle-mediated P-selectin targeting on tumor vasculature induces caveolin-1-dependent transcellular passage across the blood-brain barrier. A vismodegib nanocarrier that targets P-selectin exhibited striking efficacy and markedly reduced both bone-related toxicities and drug exposure to healthy brain. These findings demonstrate a potent strategy and novel mechanism for targeted intracranial pharmacodelivery that overcomes the restrictive endothelial barrier to achieve enhanced tumor-selective penetration and has therapeutic implications for other diseases within the central nervous system.

Citation Format: Daniel A. Heller, Daniel Tylawsky, G. Praveen Raju. P-selectin-targeted delivery of intracranial therapeutics across an intact BBB in Sonic Hedgehog medulloblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1992.

P-selectin-targeted nanocarriers induce active crossing of the blood-brain barrier via caveolin-1-dependent transcytosis

Medulloblastoma is the most common malignant paediatric brain tumour, with ~30% mediated by Sonic hedgehog signalling. Vismodegib-mediated inhibition of the Sonic hedgehog effector Smoothened inhibits tumour growth but causes growth plate fusion at effective doses. Here, we report a nanotherapeutic approach targeting endothelial tumour vasculature to enhance blood-brain barrier crossing. We use fucoidan-based nanocarriers targeting endothelial P-selectin to induce caveolin-1-dependent transcytosis and thus nanocarrier transport into the brain tumour microenvironment in a selective and active manner, the efficiency of which is increased by radiation treatment. In a Sonic hedgehog medulloblastoma animal model, fucoidan-based nanoparticles encapsulating vismodegib exhibit a striking efficacy and marked reduced bone toxicity and drug exposure to healthy brain tissue. Overall, these findings demonstrate a potent strategy for targeted intracranial pharmacodelivery that overcomes the restrictive blood-brain barrier to achieve enhanced tumour-selective penetration and has therapeutic implications for diseases within the central nervous system.

Drug-Eluting Rubber Bands for Tissue Ligation

Rubber band ligation is a commonly used method for the removal of tissue abnormalities. Most often, rubber band ligation is performed to remove internal hemorrhoids unresponsive to first line treatments to avoid surgery. While the procedure is considered safe, patients experience mild to significant pain and discomfort until the tissue sloughs off. As patients often require multiple bandings and sessions, reducing these side effects can have a considerable effect on patient adherence and quality of life. To reduce pain and discomfort, we developed drug-eluting rubber bands for ligation procedures. We investigated the potential for a band to elute anesthetics and drug combinations to durably manage pain for a period of up to 5 days while exhibiting similar mechanical properties to conventional rubber bands. We show that the rubber bands retain their mechanical properties despite significant drug loading. Lidocaine, released from the bands, successfully altered the calcium dynamics of cardiomyocytes in vitro and modulated heart rate in zebrafish embryos, while the bands exhibited lower cytotoxicity than conventional bands. Ex vivo studies demonstrated substantial local drug release in enteric tissues. These latex-free bands exhibited sufficient mechanical and drug-eluting properties to serve both ligation and local analgesic functions, potentially enabling pain reduction for multiple indications.

Abstract 302: MEKi-FGFRi combination nanoparticles for use against KRASmt/FGFR-compensatory lung tumors

Targeting oncogenic signaling in the MAPK pathway can be achieved with small molecules such as trametinib, a MEK inhibitor (MEKi). Trametinib-induced MEK inhibition in KRAS-mutant (KRASmt) lung cancer, however, results in compensatory MAPK pathway re-activation through fibroblast growth factor receptor 1 (FGFR1). Combining MEK inhibition with FGFR1 inhibition should thereby combat this compensation; nonetheless, systemic administration of combination therapy faces its own set of challenges. Such challenges include delivering appropriate kinase inhibitor concentrations to target tumor tissue while avoiding dose-limiting additive toxicities.

Although previous work has identified that combination therapy involving trametinib and FGFR inhibitor (FGFRi) ponatinib synergistically inhibits growth and proliferation of KRASmt cells, ponatinib interacts with a variety of targets and may mediate its synergistic effects via mechanisms not specific to FGFR1. To improve the efficacy at which we target KRASmt/FGFR-compensatory lung tumors, we encapsulated trametinib with a variety of FGFR1-specific inhibitors to form P-selectin-targeted nanoparticles. By formulating these nanoparticles, compensatory MAPK pathway activation through FGFR1 can be more efficaciously inhibited. Concurrently, greater concentrations of kinase inhibitor combinations can be locally delivered to lung tumors while mitigating toxic side effects that occur from systemic free drug. Here we show that these MEKi-FGFRi combination nanoparticles can be formulated to efficaciously inhibit growth and proliferation in KRASmt/FGFR-compensatory cancer cells.

Citation Format: Arianna R. Izawa-Ishiguro, Ramya Sridharan, Christopher Wun, Tabassum J. Sami, Daniel A. Heller. MEKi-FGFRi combination nanoparticles for use against KRASmt/FGFR-compensatory lung tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 302.

Abstract 501: Acute kidney injury induced by allogeneic hematopoietic stem cell transplantation: disease understanding and treatment with nanotechnology-based therapeutics

Allogeneic hematopoietic stem cell transplantation (allo-HCT) is a highly effective treatment for a variety of hematologic malignancies, but also associated with serious complications, such as graft-versus-host-disease (GVHD), a severe immune condition that manifests in multiple organs including the kidneys. Kidney injury in the setting of allo-HSCT has an incidence as high as 80% and leads to high patient morbidity and mortality, however, its progression and mechanisms remain poorly characterized. Moreover, no approved drugs for AKI of any etiology exist, as most experimental therapies have poor pharmacokinetic profiles and minimal efficacy in treating AKI in humans. We have characterized the pathology, genetic and molecular signatures of GVHD-mediated AKI in a murine model of HCT. GVHD results in AKI characterized predominantly by T-cell infiltration and activation of inflammatory pathways in both donor infiltrating inflammatory cells, as well as resident cells (i.e. tubules). By RNA sequencing, we have identified specific inflammatory pathways that are differentially expressed between healthy and GVHD mice and can serve as targets for therapeutic intervention. Moreover, we have synthesized nanoparticles that can specifically target proteins overexpressed in GVHD-kidneys and can encapsulate a variety of small molecule drugs. The complete understanding of this disease and development of this technology has a high potential to improve clinical practice and patient prognosis after allo-HCT, but it can also serve as a platform for treating other forms of cancer-associated kidney injury (e.g. induced by nephrotoxic chemotherapy), thus affecting the life of numerous patients.

Citation Format: Magdalini Panagiotakopoulou, Emma Grabarnik, Edgar A. Jaimes, Marcel R. van den Brink, Daniel A. Heller. Acute kidney injury induced by allogeneic hematopoietic stem cell transplantation: disease understanding and treatment with nanotechnology-based therapeutics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 501.

Optical Nanosensor for Intracellular and Intracranial Detection of Amyloid-Beta

Amyloid-beta (Aβ) deposition occurs in the early stages of Alzheimer's disease (AD), but the early detection of Aβ is a persistent challenge. Herein, we engineered a near-infrared optical nanosensor capable of detecting Aβ intracellularly in live cells and intracranially in vivo. The sensor is composed of single-walled carbon nanotubes functionalized with Aβ wherein Aβ-Aβ interactions drive the response. We found that the Aβ nanosensors selectively responded to Aβ via solvatochromic modulation of the near-infrared emission of the nanotube. The sensor tracked Aβ accumulation in live cells and, upon intracranial administration in a genetic model of AD, signaled distinct responses in aged mice. This technology enables the interrogation of molecular mechanisms underlying Aβ neurotoxicity in the development of AD in living systems.

The IFNγ-PDL1 Pathway Enhances CD8T-DCT Interaction to Promote Hypertension

BACKGROUND

Renal T cells contribute importantly to hypertension, but the underlying mechanism is incompletely understood. We reported that CD8Ts directly stimulate distal convoluted tubule cells (DCTs) to increase sodium chloride co-transporter expression and salt reabsorption. However, the mechanistic basis of this pathogenic pathway that promotes hypertension remains to be elucidated.

METHODS

We used mouse models of DOCA+salt (DOCA) treatment and adoptive transfer of CD8⁺ T cells (CD8T) from hypertensive animals to normotensive animals in in-vivo studies. Co-culture of mouse DCTs and CD8Ts was used as in-vitro model to test the effect of CD8T activation in promoting sodium chloride co-transporter-mediated sodium retention and to identify critical molecular players contributing to the CD8T-DCT interaction. IFNγ (interferon γ)-KO mice and mice receiving renal tubule-specific knockdown of PDL1 were used to verify in-vitro findings. Blood pressure was continuously monitored via radio-biotelemetry, and kidney samples were saved at experimental end points for analysis.

RESULTS

We identified critical molecular players and demonstrated their roles in augmenting the CD8T-DCT interaction leading to salt-sensitive hypertension. We found that activated CD8Ts exhibit enhanced interaction with DCTs via IFN-γ-induced upregulation of MHC-I and PDL1 in DCTs, thereby stimulating higher expression of sodium chloride co-transporter in DCTs to cause excessive salt retention and progressive elevation of blood pressure. Eliminating IFN-γ or renal tubule-specific knockdown of PDL1 prevented T cell homing into the kidney, thereby attenuating hypertension in 2 different mouse models.

CONCLUSIONS

Our results identified the role of activated CD8Ts in contributing to increased sodium retention in DCTS through the IFN-γ-PDL1 pathway. These findings provide a new mechanism for T cell involvement in the pathogenesis of hypertension and reveal novel therapeutic targets.

Detection of ovarian cancer via the spectral fingerprinting of quantum-defect-modified carbon nanotubes in serum by machine learning

Serum biomarkers are often insufficiently sensitive or specific to facilitate cancer screening or diagnostic testing. In ovarian cancer, the few established serum biomarkers are highly specific, yet insufficiently sensitive to detect early-stage disease and to impact the mortality rates of patients with this cancer. Here we show that a 'disease fingerprint' acquired via machine learning from the spectra of near-infrared fluorescence emissions of an array of carbon nanotubes functionalized with quantum defects detects high-grade serous ovarian carcinoma in serum samples from symptomatic individuals with 87% sensitivity at 98% specificity (compared with 84% sensitivity at 98% specificity for the current best clinical screening test, which uses measurements of cancer antigen 125 and transvaginal ultrasonography). We used 269 serum samples to train and validate several machine-learning classifiers for the discrimination of patients with ovarian cancer from those with other diseases and from healthy individuals. The predictive values of the best classifier could not be attained via known protein biomarkers, suggesting that the array of nanotube sensors responds to unidentified serum biomarkers.

Hyperspectral Counting of Multiplexed Nanoparticle Emitters in Single Cells and Organelles

Nanomaterials are the subject of a range of biomedical, commercial, and environmental investigations involving measurements in living cells and tissues. Accurate quantification of nanomaterials, at the tissue, cell, and organelle levels, is often difficult, however, in part due to their inhomogeneity. Here, we propose a method that uses the distinct optical properties of a heterogeneous nanomaterial preparation in order to improve quantification at the single-cell and organelle level. We developed "hyperspectral counting", which employs diffraction-limited imaging via hyperspectral microscopy of a diverse set of fluorescent nanomaterials to estimate particle number counts in live cells and subcellular structures. A mathematical model was developed, and Monte Carlo simulations were employed, to improve the accuracy of these estimates, enabling quantification with single-cell and single-endosome resolution. We applied this nanometrology technique with single-walled carbon nanotubes and identified an upper limit of the rate of uptake into cells─approximately 3,000 nanotubes endocytosed within 30 min. In contrast, conventional region-of-interest counting results in a 230% undercount. The method identified significant heterogeneity and a broad non-Gaussian distribution of carbon nanotube uptake within cells. For example, while a particular cell contained an average of 1 nanotube per endosome, the heterogeneous distribution resulted in over 7 nanotubes localizing within some endosomes, substantially changing the accounting of subcellular nanoparticle concentration distributions. This work presents a method to quantify the cellular and subcellular concentrations of a heterogeneous carbon nanotube reference material, with implications for the nanotoxicology, drug/gene delivery, and nanosensor fields.

Kidney-Targeted Renalase Agonist Prevents Cisplatin-Induced Chronic Kidney Disease by Inhibiting Regulated Necrosis and Inflammation

BACKGROUND

Repeated administration of cisplatin causes CKD. In previous studies, we reported that the kidney-secreted survival protein renalase (RNLS) and an agonist peptide protected mice from cisplatin-induced AKI.

METHODS

To investigate whether kidney-targeted delivery of RNLS might prevent cisplatin-induced CKD in a mouse model, we achieved specific delivery of a RNLS agonist peptide (RP81) to the renal proximal tubule by encapsulating the peptide in mesoscale nanoparticles (MNPs). We used genetic deletion of RNLS, single-cell RNA sequencing analysis, and Western blotting to determine efficacy and to explore underlying mechanisms. We also measured plasma RNLS in patients with advanced head and neck squamous cell carcinoma receiving their first dose of cisplatin chemotherapy.

RESULTS

In mice with CKD induced by cisplatin, we observed an approximate 60% reduction of kidney RNLS; genetic deletion of RNLS was associated with significantly more severe cisplatin-induced CKD. In this severe model of cisplatin-induced CKD, systemic administration of MNP-encapsulated RP81 (RP81-MNP) significantly reduced CKD as assessed by plasma creatinine and histology. It also decreased inflammatory cytokines in plasma and inhibited regulated necrosis in kidney. Single-cell RNA sequencing analyses revealed that RP81-MNP preserved epithelial components of the nephron and the vasculature and suppressed inflammatory macrophages and myofibroblasts. In patients receiving their first dose of cisplatin chemotherapy, plasma RNLS levels trended lower at day 14 post-treatment.

CONCLUSIONS

Kidney-targeted delivery of RNLS agonist RP81-MNP protects against cisplatin-induced CKD by decreasing cell death and improving the viability of the renal proximal tubule. These findings suggest that such an approach might mitigate the development of CKD in patients receiving cisplatin cancer chemotherapy.

Kidney-Targeted Redox Scavenger Therapy Prevents Cisplatin-Induced Acute Kidney Injury

Cisplatin-induced acute kidney injury (CI-AKI) is a significant co-morbidity of chemotherapeutic regimens. While this condition is associated with substantially lower survival and increased economic burden, there is no pharmacological agent to effectively treat CI-AKI. The disease is hallmarked by acute tubular necrosis of the proximal tubular epithelial cells primarily due to increased oxidative stress. We investigated a drug delivery strategy to improve the pharmacokinetics of an approved therapy that does not normally demonstrate appreciable efficacy in CI-AKI, as a preventive intervention. In prior work, we developed a kidney-selective mesoscale nanoparticle (MNP) that targets the renal proximal tubular epithelium. Here, we found that the nanoparticles target the kidneys in a mouse model of CI-AKI with significant damage. We evaluated MNPs loaded with the reactive oxygen species scavenger edaravone, currently used to treat stroke and ALS. We found a marked and significant therapeutic benefit with edaravone-loaded MNPs, including improved renal function, which we demonstrated was likely due to a decrease in tubular epithelial cell damage and death imparted by the specific delivery of edaravone. The results suggest that renal-selective edaravone delivery holds potential for the prevention of acute kidney injury among patients undergoing cisplatin-based chemotherapy.

A perception-based nanosensor platform to detect cancer biomarkers

Conventional molecular recognition elements, such as antibodies, present issues for developing biomolecular assays for use in certain technologies, such as implantable devices. Additionally, antibody development and use, especially for highly multiplexed applications, can be slow and costly. We developed a perception-based platform based on an optical nanosensor array that leverages machine learning algorithms to detect multiple protein biomarkers in biofluids. We demonstrated this platform in gynecologic cancers, often diagnosed at advanced stages, leading to low survival rates. We investigated the detection of protein biomarkers in uterine lavage samples, which are enriched with certain cancer markers compared to blood. We found that the method enables the simultaneous detection of multiple biomarkers in patient samples, with F1-scores of ~0.95 in uterine lavage samples from patients with cancer. This work demonstrates the potential of perception-based systems for the development of multiplexed sensors of disease biomarkers without the need for specific molecular recognition elements.

Non-Covalent Coatings on Carbon Nanotubes Mediate Photosensitizer Interactions

Carbon nanotube-based donor-acceptor devices are used in applications ranging from photovoltaics and sensors to environmental remediation. Non-covalent contacts between donor dyes and nanotubes are often used to optimize sensitization and scalability. However, inconsistency is often observed despite donor dye studies reporting strong donor-acceptor interactions. Here, we demonstrate that the dye binding location is an important factor in this process: we used coated-acceptor chromatic responses and find that dye binding is affected by the coating layer. The emission response to free- and protein-sequestered porphyrin was tested to compare direct and indirect dye contact. An acceptor complex that preferentially red-shifts in response to sequestered porphyrin was identified. We observe inconsistent optical signals that suggest porphyrin-dye interactions are best described as coating-centric; therefore, the coating interface must be considered in application and assay design.

Single-Chirality Near-Infrared Carbon Nanotube Sub-Cellular Imaging and FRET Probes

Applications of single-walled carbon nanotubes (SWCNTs) in bioimaging and biosensing have been limited by difficulties with isolating single-chirality nanotube preparations with desired functionalities. Unique optical properties, such as multiple narrow near-infrared bands and several modes of signal transduction, including solvatochromism and FRET, are ideal for live cell/organism imaging and sensing applications. However, internanotube FRET has not been investigated in biological contexts. We developed single-chirality subcellular SWCNT imaging probes and investigated their internanotube FRET capabilities in live cells. To functionalize SWCNTs, we replaced the surfactant coating of aqueous two-phase extraction-sorted single-chirality nanotubes with helical polycarbodiimide polymers containing different functionalities. We achieved single-chirality SWCNT targeting of different subcellular structures, including the nucleus, to enable multiplexed imaging. We also targeted purified (6,5) and (7,6) chiralities to the same structures and observed internanotube FRET within these organelles. This work portends the use of single-chirality carbon nanotube optical probes for applications in biomedical research.

En route to single-step, two-phase purification of carbon nanotubes facilitated by high-throughput spectroscopy

Chirality purification of single-walled carbon nanotubes (SWCNTs) is desirable for applications in many fields, but general utility is currently hampered by low throughput. We discovered a method to obtain single-chirality SWCNT enrichment by the aqueous two-phase extraction (ATPE) method in a single step. To achieve appropriate resolution, a biphasic system of non-ionic tri-block copolymer surfactant is varied with an ionic surfactant. A nearly-monochiral fraction of SWCNTs can then be harvested from the top phase. We also found, via high-throughput, near-infrared excitation-emission photoluminescence spectroscopy, that the parameter space of ATPE can be mapped to probe the mechanics of the separation process. Finally, we found that optimized conditions can be used for sorting of SWCNTs wrapped with ssDNA as well. Elimination of the need for surfactant exchange and simplicity of the separation process make the approach promising for high-yield generation of purified single-chirality SWCNT preparations.

Targeted drug delivery strategies for precision medicines

Progress in the field of precision medicine has changed the landscape of cancer therapy. Precision medicine is propelled by technologies that enable molecular profiling, genomic analysis, and optimized drug design to tailor treatments for individual patients. Although precision medicines have resulted in some clinical successes, the use of many potential therapeutics has been hindered by pharmacological issues, including toxicities and drug resistance. Drug delivery materials and approaches have now advanced to a point where they can enable the modulation of a drug's pharmacological parameters without compromising the desired effect on molecular targets. Specifically, they can modulate a drug's pharmacokinetics, stability, absorption, and exposure to tumours and healthy tissues, and facilitate the administration of synergistic drug combinations. This Review highlights recent progress in precision therapeutics and drug delivery, and identifies opportunities for strategies to improve the therapeutic index of cancer drugs, and consequently, clinical outcomes.

Abstract PO-068: Developing ovarian cancer sensors using molecular perceptron

Ovarian cancer patient prognosis and quality of life are significantly affected by the failure to accurately diagnose disease at early stage. Currently, less than 15% of ovarian cancer patients are diagnosed at stage 1, when 5-year survival rates are near 93%. Early detection may save more than 80% of women diagnosed with ovarian cancer. Our goal is to develop clinical long-term implantable carbon nanotube-based sensors for ovarian cancer biomarkers to transiently detect and monitor their levels in patients. The proposed sensors will harness the unique optical properties and sensitivity of single-walled carbon nanotubes. To improve sensitivity and specificity of such sensors, previously developed to detect ovarian cancer biomarkers in vivo, we used molecular perceptron—data analytics-based methods to detect specific spectroscopic fingerprints from the binding of protein biomarkers to the nanotube surface.

Citation Format: Zvi Yaari, Yoona Yang, Anand Jagota, Ming Zheng, Daniel A. Heller. Developing ovarian cancer sensors using molecular perceptron [abstract]. In: Proceedings of the AACR Virtual Special Conference on Artificial Intelligence, Diagnosis, and Imaging; 2021 Jan 13-14. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(5_Suppl):Abstract nr PO-068.

Harnessing nanotechnology to expand the toolbox of chemical biology

Although nanotechnology often addresses biomedical needs, nanoscale tools can also facilitate broad biological discovery. Nanoscale delivery, imaging, biosensing, and bioreactor technologies may address unmet questions at the interface between chemistry and biology. Currently, many chemical biologists do not include nanomaterials in their toolbox, and few investigators develop nanomaterials in the context of chemical tools to answer biological questions. We reason that the two fields are ripe with opportunity for greater synergy. Nanotechnologies can expand the utility of chemical tools in the hands of chemical biologists, for example, through controlled delivery of reactive and/or toxic compounds or signal-binding events of small molecules in living systems. Conversely, chemical biologists can work with nanotechnologists to address challenging biological questions that are inaccessible to both communities. This Perspective aims to introduce the chemical biology community to nanotechnologies that may expand their methodologies while inspiring nanotechnologists to address questions relevant to chemical biology.

Nanoreporter of an Enzymatic Suicide Inactivation Pathway

Enzymatic suicide inactivation, a route of permanent enzyme inhibition, is the mechanism of action for a wide array of pharmaceuticals. Here, we developed the first nanosensor that selectively reports the suicide inactivation pathway of an enzyme. The sensor is based on modulation of the near-infrared fluorescence of an enzyme-bound carbon nanotube. The nanosensor responded selectively to substrate-mediated suicide inactivation of the tyrosinase enzyme via bathochromic shifting of the nanotube emission wavelength. Mechanistic investigations revealed that singlet oxygen generated by the suicide inactivation pathway induced the response. We used the nanosensor to quantify the degree of enzymatic inactivation by measuring response rates to small molecule tyrosinase modulators. This work resulted in a new capability of interrogating a specific route of enzymatic death. Potential applications include drug screening and hit-validation for compounds that elicit or inhibit enzymatic inactivation and single-molecule measurements to assess population heterogeneity in enzyme activity.

Glutathione-S-transferase Fusion Protein Nanosensor

Fusion protein tags are widely used to capture and track proteins in research and industrial bioreactor processes. Quantifying fusion-tagged proteins normally requires several purification steps coupled with classical protein assays. Here, we developed a broadly applicable nanosensor platform that quantifies glutathione-S-transferase (GST) fusion proteins in real-time. We synthesized a glutathione-DNA-carbon nanotube system to investigate glutathione-GST interactions via semiconducting single-walled carbon nanotube (SWCNT) photoluminescence. We found that SWCNT fluorescence wavelength and intensity modulation occurred specifically in response to GST and GST-fusions. The sensor response was dependent on SWCNT structure, wherein mod(n - m, 3) = 1 nanotube wavelength and intensity responses correlated with nanotube diameter distinctly from mod(n - m, 3) = 2 SWCNT responses. We also found broad functionality of this sensor to diverse GST-tagged proteins. This work comprises the first label-free optical sensor for GST and has implications for the assessment of protein expression in situ, including in imaging and industrial bioreactor settings.

Renal proximal tubular NEMO plays a critical role in ischemic acute kidney injury

We determined that renal proximal tubular (PT) NF-κB essential modulator (NEMO) plays a direct and critical role in ischemic acute kidney injury (AKI) using mice lacking renal PT NEMO and by targeted renal PT NEMO inhibition with mesoscale nanoparticle-encapsulated NEMO binding peptide (NBP MNP). We subjected renal PT NEMO-deficient mice, WT mice, and C57BL/6 mice to sham surgery or 30 minutes of renal ischemia and reperfusion (IR). C57BL/6 mice received NBP MNP or empty MNP before renal IR injury. Mice treated with NBP MNP and mice deficient in renal PT NEMO were protected against ischemic AKI, having decreased renal tubular necrosis, inflammation, and apoptosis compared with control MNP-treated or WT mice, respectively. Recombinant peptidylarginine deiminase type 4 (rPAD4) targeted kidney PT NEMO to exacerbate ischemic AKI in that exogenous rPAD4 exacerbated renal IR injury in WT mice but not in renal PT NEMO-deficient mice. Furthermore, rPAD4 upregulated proinflammatory cytokine mRNA and NF-κB activation in freshly isolated renal proximal tubules from WT mice but not from PT NEMO-deficient mice. Taken together, our studies suggest that renal PT NEMO plays a critical role in ischemic AKI by promoting renal tubular inflammation, apoptosis, and necrosis.

Abstract 2032: Renal tubule-targeted supportive care nanotherapy for cisplatin-induced acute kidney injury

Acute kidney injury (AKI) develops in up to 30% of patients who receive cisplatin-based chemotherapy. In this setting, AKI can result in delays in completion of treatment and/or the need to switch to other potentially less effective therapeutic regimens. Despite its high incidence and associated increased morbidity and mortality, there is no effective pharmacologic intervention to treat AKI of any etiology, including AKI resulting from cisplatin or any other nephrotoxic treatments. In the case of cisplatin-induced AKI, it is also imperative that any pharmacologic intervention that could be effective for AKI will not interfere with the systemic chemotherapeutic effects of cisplatin. In prior studies (Nano Letters, 2015), we reported the development of mesoscale nanoparticles (MNPs), composed of poly(lactic-co-glycolic acid) and polyethylene glycol (PLGA-PEG) that localize to the kidneys with a high affinity, primarily to the proximal tubules (the site of injury in AKI), and persist at that location for up to a week. Herein, we encapsulated a small molecule reactive oxygen species scavenger, (edaravone) in the MNPs. Experiments were performed in male C57BL/6 mice with cisplatin-induced AKI (25 mg/kg IP). To assess therapeutic efficacy, tail vein injections of 50 mg/kg edaravone-containing MNPs, 50 mg/kg empty control MNPs, or 30 mg/kg free edaravone were performed 24 hours after cisplatin injection (n=6-8 per group). Mice were euthanized at 72 hours post-cisplatin administration, and kidney and serum were saved for analysis. In a separate group of mice bearing metastatic small cell lung cancer, fluorescent MNPs were injected to determine whether MNPs still localize to the kidneys rather than to the tumor as has been described for other types of nanoparticles. Mice receiving cisplatin had a ~5 fold increase in serum creatinine and severe acute tubular necrosis as compared to controls. In contrast to mice receiving cisplatin alone, mice receiving edaravone-containing MNPs along with cisplatin had normal creatinine and histology similar to controls. Neither treatment with free edaravone nor empty MNPs resulted in a significant improvement in renal function or severity of tubular necrosis in mice with cisplatin-induced AKI. In the presence of AKI, the distribution of MNPs was still highly selective to the renal proximal tubules. In mice with metastatic lung tumors, we determined that MNPs maintain their specific renal distribution and do not localize to tumors as has been described with other smaller nanoparticle systems. These studies demonstrate that edaravone-containing MNPs can be an effective treatment for cisplatin-induced AKI while avoiding the possible therapeutic abatement associated with tumor deposition of reactive oxygen species scavengers. We anticipate that these studies will constitute the basis for the development of novel strategies for the treatment and prevention of cisplatin-induced AKI in humans.

Citation Format: Daniel A. Heller, Edgar Jaimes, Ryan Williams, Janki Shah. Renal tubule-targeted supportive care nanotherapy for cisplatin-induced acute kidney injury [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 2032.

Senescence-Induced Vascular Remodeling Creates Therapeutic Vulnerabilities in Pancreas Cancer

KRAS mutant pancreatic ductal adenocarcinoma (PDAC) is characterized by a desmoplastic response that promotes hypovascularity, immunosuppression, and resistance to chemo- and immunotherapies. We show that a combination of MEK and CDK4/6 inhibitors that target KRAS-directed oncogenic signaling can suppress PDAC proliferation through induction of retinoblastoma (RB) protein-mediated senescence. In preclinical mouse models of PDAC, this senescence-inducing therapy produces a senescence-associated secretory phenotype (SASP) that includes pro-angiogenic factors that promote tumor vascularization, which in turn enhances drug delivery and efficacy of cytotoxic gemcitabine chemotherapy. In addition, SASP-mediated endothelial cell activation stimulates the accumulation of CD8⁺ T cells into otherwise immunologically "cold" tumors, sensitizing tumors to PD-1 checkpoint blockade. Therefore, in PDAC models, therapy-induced senescence can establish emergent susceptibilities to otherwise ineffective chemo- and immunotherapies through SASP-dependent effects on the tumor vasculature and immune system.

Selective nanoparticle-mediated targeting of renal tubular Toll-like receptor 9 attenuates ischemic acute kidney injury

We developed an innovative therapy for ischemic acute kidney injury with discerning kidney-targeted delivery of a selective Toll-like receptor 9 (TLR9) antagonist in mice subjected to renal ischemia reperfusion injury. Our previous studies showed that mice deficient in renal proximal tubular TLR9 were protected against renal ischemia reperfusion injury demonstrating a critical role for renal proximal tubular TLR9 in generating ischemic acute kidney injury. Herein, we used 300-400 nm polymer-based mesoscale nanoparticles that localize to the renal tubules after intravenous injection. Mice were subjected to sham surgery or 30 minutes renal ischemia and reperfusion injury after receiving mesoscale nanoparticles encapsulated with a selective TLR9 antagonist (unmethylated CpG oligonucleotide ODN2088) or mesoscale nanoparticles encapsulating a negative control oligonucleotide. Mice treated with the encapsulated TLR9 antagonist either six hours before renal ischemia, at the time of reperfusion or 1.5 hours after reperfusion were protected against ischemic acute kidney injury. The ODN2088-encapsulated nanoparticles attenuated renal tubular necrosis, inflammation, decreased proinflammatory cytokine synthesis. neutrophil and macrophage infiltration and apoptosis, decreased DNA fragmentation and caspase 3/8 activation when compared to the negative control nanoparticle treated mice. Taken together, our studies further suggest that renal proximal tubular TLR9 activation exacerbates ischemic acute kidney injury by promoting renal tubular inflammation, apoptosis and necrosis after ischemia reperfusion. Thus, our studies suggest a potential promising therapy for ischemic acute kidney injury with selective kidney tubular targeting of TLR9 using mesoscale nanoparticle-based drug delivery.

Can Fish and Cell Phones Teach Us about Our Health?

Biologging is a scientific endeavor that studies the environment and animals within it by outfitting the latter with sensors of their dynamics as they roam freely in their natural habitats. As wearable technologies advance for the monitoring of human health, it may be instructive to reflect on the successes and failures of biologging in field biology over the past few decades. Several lessons may be of value. Physiological sensors can "encode" for a wider number of states than the one explicitly targeted, although the limits of this are debatable. The combination of orthogonal sensors turns out to be critical to delivering a high value data set. Sensor fusion and engineering for longevity are also important for success. This Perspective highlights successful strategies for biologging that hold promise for human health monitoring.

An optical nanoreporter of endolysosomal lipid accumulation reveals enduring effects of diet on hepatic macrophages in vivo

The abnormal accumulation of lipids within the endolysosomal lumen occurs in many conditions, including lysosomal storage disorders, atherosclerosis, nonalcoholic fatty liver disease (NAFLD), and drug-induced phospholipidosis. Current methods cannot monitor endolysosomal lipid content in vivo, hindering preclinical drug development and research into the mechanisms linking endolysosomal lipid accumulation to disease progression. We developed a single-walled carbon nanotube-based optical reporter that noninvasively measures endolysosomal lipid accumulation via bandgap modulation of its intrinsic near-infrared emission. The reporter detected lipid accumulation in Niemann-Pick disease, atherosclerosis, and NAFLD models in vivo. By applying the reporter to the study of NAFLD, we found that elevated lipid quantities in hepatic macrophages caused by a high-fat diet persist long after reverting to a normal diet. The reporter dynamically monitored endolysosomal lipid accumulation in vivo over time scales ranging from minutes to weeks, indicating its potential to accelerate preclinical research and drug development processes.

Optical Voltammetry of Polymer-Encapsulated Single-Walled Carbon Nanotubes

The semiconducting single-walled carbon nanotube (SWCNT), noncovalently wrapped by a polymeric monolayer, is a nanoscale semiconductor-electrolyte interface under investigation for sensing, photonics, and photovoltaic applications. SWCNT complexes are routinely observed to sensitize various electrochemical/redox phenomena, even in the absence of an external field. While the photoluminescence response to gate voltage depends on the redox potential of the nanotube, analogous optical voltammetry of functionalized carbon nanotubes could be conducted in suspension without applying voltage but by varying the solution conditions as well as the chemistry of the encapsulating polymer. Steady-state photoluminescence, absorbance, and in situ measurements of O2/H2O reactivity show correlation with the pH/pK a-dependent reactivity of π-rich coatings. The nanotube emission responses suggest that the presence of photogenerated potential may explain the observed coating electrochemical reactivity. This work finds that electronic and chemical interactions of the nanotube with the encapsulating polymer may play a critical role in applications that depend on radiative recombination, such as optical sensing.

Synthetic molecular recognition nanosensor paint for microalbuminuria

Microalbuminuria is an important clinical marker of several cardiovascular, metabolic, and other diseases such as diabetes, hypertension, atherosclerosis, and cancer. The accurate detection of microalbuminuria relies on albumin quantification in the urine, usually via an immunoturbidity assay; however, like many antibody-based assessments, this method may not be robust enough to function in global health applications, point-of-care assays, or wearable devices. Here, we develop an antibody-free approach using synthetic molecular recognition by constructing a polymer to mimic fatty acid binding to the albumin, informed by the albumin crystal structure. A single-walled carbon nanotube, encapsulated by the polymer, as the transduction element produces a hypsochromic (blue) shift in photoluminescence upon the binding of albumin in clinical urine samples. This complex, incorporated into an acrylic material, results in a nanosensor paint that enables the detection of microalbuminuria in patient samples and comprises a rapid point-of-care sensor robust enough to be deployed in resource-limited settings.

An in Vivo Nanosensor Measures Compartmental Doxorubicin Exposure

Preclinical measurements of drug exposure to specific organs and tissues is normally performed by destructive methods. Tissue-specific measurements are important, especially for drugs with intractable dose-limiting toxicities, such as doxorubicin-mediated cardiotoxicity. We developed a method to rapidly quantify doxorubicin exposure to tissues within living organisms using an implantable optical nanosensor that can be interrogated noninvasively following surgical implantation. The near-infrared fluorescence of single-walled carbon nanotubes functionalized with DNA was found to respond to doxorubicin via a large and uniform red-shift. We found this to be common to DNA-intercalating agents, including anthracycline compounds such as doxorubicin. Doxorubicin was measured in buffer and serum, intracellularly, and from single nanotubes on a surface. Doxorubicin adsorption to the DNA-suspended nanotubes did not displace DNA but bound irreversibly. We incorporated the nanosensors into an implantable membrane which allowed cumulative detection of doxorubicin exposure in vivo. On implanting the devices into different compartments, such as subcutaneously and within the peritoneal cavity, we achieved real-time, minimally invasive detection of doxorubicin injected into the peritoneal cavity, as well as compartment-specific measurements. We measured doxorubicin translocation across the peritoneal membrane in vivo. Robust, minimally invasive pharmacokinetic measurements in vivo suggest the suitability of this technology for preclinical drug discovery applications.

Abstract 1938: Implantable nanosensor for non-invasive ovarian cancer biomarker detection with wearable interface

Patients with high-grade serous ovarian carcinoma (HGSC) exhibit poor 5-year survival rates, which may be significantly improved by early-stage detection. The US FDA-approved biomarkers for HGSC—CA-125 and HE4—do not generally appear at detectable levels in the serum until advanced stages of the disease. An implantable device placed proximal to disease sites, such as in or near the fallopian tube, ovary, uterine cavity, or peritoneal cavity, may constitute a feasible strategy to improve detection of HGSC. Furthermore, a sensor implant under the skin may allow real-time measurements after diagnosis, to monitor treatment for example, via interrogation using a wearable device. We engineered a prototype optical sensor composed of an antibody-functionalized carbon nanotube complex, which responds quantitatively to HE4 via modulation of the nanotube optical bandgap. The complexes measured HE4 with nanomolar sensitivity to differentiate disease from benign patient biofluids. The sensors were implanted into four models of ovarian cancer, within a semipermeable membrane, enabling the optical detection of HE4 within the live animals. We thus present the first in vivo optical nanosensor capable of noninvasive cancer biomarker detection in orthotopic models of disease. This technology may potentially be implanted locally in the uterine cavity, for point-of-care measurement, or under the skin, to then interface with a wearable device.

Citation Format: Daniel A. Heller, Ryan M. Williams, Douglas A. Levine. Implantable nanosensor for non-invasive ovarian cancer biomarker detection with wearable interface [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1938.

HIV Detection via a Carbon Nanotube RNA Sensor

Viral illnesses remain a significant concern in global health. Rapid and quantitative early detection of viral oligonucleotides without the need for purification, amplification, or labeling would be valuable in guiding successful treatment strategies. Single-walled carbon nanotube-based sensors recently demonstrated optical detection of small, free oligonucleotides in biofluids and in vivo, although proteins diminished sensitivity. Here, we discovered an unexpected phenomenon wherein the carbon nanotube optical response to nucleic acids can be enhanced by denatured proteins. Mechanistic studies found that hydrophobic patches of the denatured protein chain interact with the freed nanotube surface after hybridization, resulting in enhanced shifting of the nanotube emission. We employed this mechanism to detect an intact HIV in serum, resulting in specific responses within minutes. This work portends a route toward point-of-care optical detection of viruses or other nucleic acid-based analytes.

A Fluorescent Carbon Nanotube Sensor Detects the Metastatic Prostate Cancer Biomarker uPA

Therapeutic outcomes in patients with prostate cancer are hindered by the inability to discern indolent versus aggressive disease. To address this problem, we developed a quantitative fluorescent nanosensor for the cancer biomarker urokinase plasminogen activator (uPA). We used the unique fluorescent characteristics of single-walled carbon nanotubes (SWCNT) to engineer an optical sensor that responds to uPA via optical bandgap modulation in complex protein environments. The sensing characteristics of this construct were modulated by passivation of the hydrophobic SWCNT surface with bovine serum albumin (BSA). The sensor enabled quantitative detection of known uPA concentrations in human blood products. These experiments potentiate future use of this technology as a rapid, point-of-care sensor for biomarker measurements in patient fluid samples. We expect that further work will develop a method to discern aggressive vs indolent prostate cancer and reduce overtreatment of this disease.

Abstract 4652: Targeted nanomedicines improve therapeutic indices of RAF and MEK inhibitors

Potent kinase inhibitors have been developed to treat tumors, but they suppress signaling in normal cells so that their dosing and ability to inhibit the pathway are limited by toxicity, resulting in a narrow therapeutic index. We developed a novel drug delivery strategy which efficiently encapsulates and targets kinase inhibitors to the tumor microenvironment while obviating the sources of dose-limiting toxicities. The platform employs nanoparticle scaffolds that we modified to target caveolae and P-selectin, that can both be overexpressed on tumor vasculature. We assessed the targeted drug delivery properties of the nanoparticles, encapsulating the RAF inhibitor sorafenib and MEK inhibitor trametinib. Strikingly, we found selective tumor uptake and exceptional net anti-tumor efficacies in patient-derived xenografts and genetically modified mouse models. The nanomedicine strategy also prevented the inhibition of ERK phosphorylation in the skin, demonstrating that this targeting strategy may abrogate dose-limiting toxicities of kinase inhibitors to improve their therapeutic indices.

Citation Format: Daniel A. Heller, Yosi Shamay. Targeted nanomedicines improve therapeutic indices of RAF and MEK inhibitors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4652.

Noninvasive ovarian cancer biomarker detection via an optical nanosensor implant

Patients with high-grade serous ovarian carcinoma (HGSC) exhibit poor 5-year survival rates, which may be significantly improved by early-stage detection. The U.S. Food and Drug Administration-approved biomarkers for HGSC-CA-125 (cancer antigen 125) and HE4 (human epididymis protein 4)-do not generally appear at detectable levels in the serum until advanced stages of the disease. An implantable device placed proximal to disease sites, such as in or near the fallopian tube, ovary, uterine cavity, or peritoneal cavity, may constitute a feasible strategy to improve detection of HGSC. We engineered a prototype optical sensor composed of an antibody-functionalized carbon nanotube complex, which responds quantitatively to HE4 via modulation of the nanotube optical bandgap. The complexes measured HE4 with nanomolar sensitivity to differentiate disease from benign patient biofluids. The sensors were implanted into four models of ovarian cancer, within a semipermeable membrane, enabling the optical detection of HE4 within the live animals. We present the first in vivo optical nanosensor capable of noninvasive cancer biomarker detection in orthotopic models of disease.

Quantitative self-assembly prediction yields targeted nanomedicines

Development of targeted nanoparticle drug carriers often requires complex synthetic schemes involving both supramolecular self-assembly and chemical modification. These processes are generally difficult to predict, execute, and control. We describe herein a targeted drug delivery system that is accurately and quantitatively predicted to self-assemble into nanoparticles based on the molecular structures of precursor molecules, which are the drugs themselves. The drugs assemble with the aid of sulfated indocyanines into particles with ultrahigh drug loadings of up to 90%. We devised quantitative structure-nanoparticle assembly prediction (QSNAP) models to identify and validate electrotopological molecular descriptors as highly predictive indicators of nano-assembly and nanoparticle size. The resulting nanoparticles selectively targeted kinase inhibitors to caveolin-1-expressing human colon cancer and autochthonous liver cancer models to yield striking therapeutic effects while avoiding pERK inhibition in healthy skin. This finding enables the computational design of nanomedicines based on quantitative models for drug payload selection.

P-selectin is a nanotherapeutic delivery target in the tumor microenvironment

Disseminated tumors are poorly accessible to nanoscale drug delivery systems because of the vascular barrier, which attenuates extravasation at the tumor site. We investigated P-selectin, a molecule expressed on activated vasculature that facilitates metastasis by arresting tumor cells at the endothelium, for its potential to target metastases by arresting nanomedicines at the tumor endothelium. We found that P-selectin is expressed on cancer cells in many human tumors. To develop a targeted drug delivery platform, we used a fucosylated polysaccharide with nanomolar affinity to P-selectin. The nanoparticles targeted the tumor microenvironment to localize chemotherapeutics and a targeted MEK (mitogen-activated protein kinase kinase) inhibitor at tumor sites in both primary and metastatic models, resulting in superior antitumor efficacy. In tumors devoid of P-selectin, we found that ionizing radiation guided the nanoparticles to the disease site by inducing P-selectin expression. Radiation concomitantly produced an abscopal-like phenomenon wherein P-selectin appeared in unirradiated tumor vasculature, suggesting a potential strategy to target disparate drug classes to almost any tumor.

A Carbon Nanotube Optical Reporter Maps Endolysosomal Lipid Flux

Lipid accumulation within the lumen of endolysosomal vesicles is observed in various pathologies including atherosclerosis, liver disease, neurological disorders, lysosomal storage disorders, and cancer. Current methods cannot measure lipid flux specifically within the lysosomal lumen of live cells. We developed an optical reporter, composed of a photoluminescent carbon nanotube of a single chirality, that responds to lipid accumulation via modulation of the nanotube's optical band gap. The engineered nanomaterial, composed of short, single-stranded DNA and a single nanotube chirality, localizes exclusively to the lumen of endolysosomal organelles without adversely affecting cell viability or proliferation or organelle morphology, integrity, or function. The emission wavelength of the reporter can be spatially resolved from within the endolysosomal lumen to generate quantitative maps of lipid content in live cells. Endolysosomal lipid accumulation in cell lines, an example of drug-induced phospholipidosis, was observed for multiple drugs in macrophages, and measurements of patient-derived Niemann-Pick type C fibroblasts identified lipid accumulation and phenotypic reversal of this lysosomal storage disease. Single-cell measurements using the reporter discerned subcellular differences in equilibrium lipid content, illuminating significant intracellular heterogeneity among endolysosomal organelles of differentiating bone-marrow-derived monocytes. Single-cell kinetics of lipoprotein-derived cholesterol accumulation within macrophages revealed rates that differed among cells by an order of magnitude. This carbon nanotube optical reporter of endolysosomal lipid content in live cells confers additional capabilities for drug development processes and the investigation of lipid-linked diseases.

Selective Nanoparticle Targeting of the Renal Tubules

Direct targeting to the kidneys is a promising strategy to improve drug therapeutic index for the treatment of kidney diseases. We sought to investigate the renal selectivity and safety of kidney-targeted mesoscale nanoparticle technology. We found that direct intravenous administration of these particles resulted in 26-fold renal selectivity and localized negligibly in the liver or other organs. The nanoparticles targeted the renal proximal tubular epithelial cells, as evidenced by intravital microscopy and ex vivo imaging. Mice treated with the nanoparticles exhibited no negative systemic consequences, immune reaction, liver impairment, or renal impairment. The localization of material selectively to the renal tubules is uncommon, and this work portends the development of renal-targeted drugs for the treatment of kidney diseases.

Control of Carbon Nanotube Solvatochromic Response to Chemotherapeutic Agents

Alkylating agents such as cisplatin play an essential role in chemotherapy regimens, but initial and acquired resistance in many cancer types often dampen therapeutic response. The poor understanding of the mechanisms of resistance highlight the need for quantitative measurements of alkylating agent distribution at both the tissue and subcellular levels. Sensors for use in live animals and cells would allow for more effective study of drug action and resistance. Toward this end, single-walled carbon nanotubes suspended with single-stranded DNA have suitable optical properties for in vivo sensors, such as near-infrared emission and sensitivity to the local environment via solvatochromic responses. Currently, solvatochromic changes of such sensors have been limited by the chemical nature of the analyte, making it impossible to control the direction of energy emission changes. Here, we describe a new approach to control the direction and magnitude of solvatochromic responses of carbon nanotubes. We found that the alkylation of DNA on the nanotube surface can result in small changes in DNA conformation that allow the adsorption of amphiphiles to produce large differences (>14 nm) in response to different drugs. The technique surprisingly revealed differences among drugs upon alkylation. The ability to control carbon nanotube solvatochromism as desired may potentially expand the application of nanotube-based optical sensors for new classes of analytes.