Tuning sterol extraction kinetics yields a renal-sparing polyene antifungal.

Decades of previous efforts to develop renal-sparing polyene antifungals were misguided by the classic membrane permeabilization model1. Recently, the clinically vital but also highly renal-toxic small-molecule natural product amphotericin B was instead found to kill fungi primarily by forming extramembraneous sponge-like aggregates that extract ergosterol from lipid bilayers2-6. Here we show that rapid and selective extraction of fungal ergosterol can yield potent and renal-sparing polyene antifungals. Cholesterol extraction was found to drive the toxicity of amphotericin B to human renal cells. Our examination of high-resolution structures of amphotericin B sponges in sterol-free and sterol-bound states guided us to a promising structural derivative that does not bind cholesterol and is thus renal sparing. This derivative was also less potent because it extracts ergosterol more slowly. Selective acceleration of ergosterol extraction with a second structural modification yielded a new polyene, AM-2-19, that is renal sparing in mice and primary human renal cells, potent against hundreds of pathogenic fungal strains, resistance evasive following serial passage in vitro and highly efficacious in animal models of invasive fungal infections. Thus, rational tuning of the dynamics of interactions between small molecules may lead to better treatments for fungal infections that still kill millions of people annually7,8 and potentially other resistance-evasive antimicrobials, including those that have recently been shown to operate through supramolecular structures that target specific lipids9.

Minimizing higher-order aggregation maximizes iron mobilization by small molecules.

The natural product hinokitiol mobilizes iron across lipid bilayers at low concentrations and restores hemoglobinization in iron transporter protein-deficient systems. But hinokitiol fails to similarly mobilize iron at higher concentrations, limiting its uses in chemical biology and medicine. Here we show that at higher concentrations, hinokitiol3:Fe(III) complexes form large, higher-order aggregates, leading to loss of transmembrane iron mobilization. Guided by this understanding and systematic structure-function studies enabled by modular synthesis, we identified FeM-1269, which minimally aggregates and dose-dependently mobilizes iron across lipid bilayers even at very high concentrations. In contrast to hinokitiol, FeM-1269 is also well-tolerated in animals at high doses for extended periods of time. In a mouse model of anemia of inflammation, FeM-1269 increases serum iron, transferrin saturation, hemoglobin and hematocrit. This rationally developed iron-mobilizing small molecule has enhanced potential as a molecular prosthetic for understanding and potentially treating iron transporter deficiencies.

B7-H3 is widely expressed in soft tissue sarcomas.

PURPOSE: Targeted therapy development in soft tissue sarcoma (STS) has been burdened by the heterogeneity of this group of rare tumors. B7 homolog 3 protein (B7-H3) is a molecule in the same family as programmed death-ligand 1 (PD-L1). It has limited expression in noncancerous tissues and is overexpressed in many cancers, making it an attractive target for cancer therapy, and clinical trials targeting B7-H3 are actively underway. While available data demonstrate high expression levels of B7-H3 in individual sarcoma subtypes, its expression patterns across STS subtypes are not well described. The purpose of this study was to characterize the expression patterns of B7-H3 in STS. PATIENTS AND METHODS: This retrospective analysis evaluated STS tumor specimens from patients with a variety of different subtypes. Specimens were evaluated by immunohistochemistry (IHC) for expression and staining pattern of B7-H3 both in tumors and in associated vasculature. RESULTS: Specimens from 153 sarcoma patients included 15 different STS subtypes. B7-H3 was broadly expressed in 97% of samples (95% CI 0.93-0.99) and 69.2% demonstrated high levels of B7-H3 expression (95% CI 0.61-0.76). No significant association between B7-H3 positivity or expression level and prior treatment(s), tumor size, tumor grade, or patient age. B7-H3 positivity in vessels was found in 94.7% (145/153) of samples. In tumors that had been previously assessed for PD-L1 and PD-1, there was no correlation between B7-H3 positivity or expression and the positivity or expression level of PD-L1 or PD-1. CONCLUSION: These data show high levels of B7-H3 positivity across soft tissue sarcoma subtypes, suggesting its feasibility as a therapeutic target for future sarcoma treatments. Future clinical trials are needed to evaluate whether targeting B7-H3 can provide clinical benefit to help patients with sarcoma.

Engineered ACE2 decoy mitigates lung injury and death induced by SARS-CoV-2 variants.

Vaccine hesitancy and emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) escaping vaccine-induced immune responses highlight the urgency for new COVID-19 therapeutics. Engineered angiotensin-converting enzyme 2 (ACE2) proteins with augmented binding affinities for SARS-CoV-2 spike (S) protein may prove to be especially efficacious against multiple variants. Using molecular dynamics simulations and functional assays, we show that three amino acid substitutions in an engineered soluble ACE2 protein markedly augmented the affinity for the S protein of the SARS-CoV-2 WA-1/2020 isolate and multiple VOCs: B.1.1.7 (Alpha), B.1.351 (Beta), P.1 (Gamma) and B.1.617.2 (Delta). In humanized K18-hACE2 mice infected with the SARS-CoV-2 WA-1/2020 or P.1 variant, prophylactic and therapeutic injections of soluble ACE22.v2.4-IgG1 prevented lung vascular injury and edema formation, essential features of CoV-2-induced SARS, and above all improved survival. These studies demonstrate broad efficacy in vivo of an engineered ACE2 decoy against SARS-CoV-2 variants in mice and point to its therapeutic potential.

Phase I study of procaspase-activating compound-1 (PAC-1) in the treatment of advanced malignancies.

BACKGROUND: Procaspase-3 (PC-3) is overexpressed in multiple tumour types and procaspase-activating compound 1 (PAC-1) directly activates PC-3 and induces apoptosis in cancer cells. This report describes the first-in-human, phase I study of PAC-1 assessing maximum tolerated dose, safety, and pharmacokinetics. METHODS: Modified-Fibonacci dose-escalation 3 + 3 design was used. PAC-1 was administered orally at 7 dose levels (DL) on days 1-21 of a 28-day cycle. Dose-limiting toxicity (DLT) was assessed during the first two cycles of therapy, and pharmacokinetics analysis was conducted on days 1 and 21 of the first cycle. Neurologic and neurocognitive function (NNCF) tests were performed throughout the study. RESULTS: Forty-eight patients were enrolled with 33 completing ≥2 cycles of therapy and evaluable for DLT. DL 7 (750 mg/day) was established as the recommended phase 2 dose, with grade 1 and 2 neurological adverse events noted, while NNCF testing showed stable neurologic and cognitive evaluations. PAC-1's t1/2 was 28.5 h after multi-dosing, and systemic drug exposures achieved predicted therapeutic concentrations. PAC-1 clinical activity was observed in patients with neuroendocrine tumour (NET) with 2/5 patients achieving durable partial response. CONCLUSIONS: PAC-1 dose at 750 mg/day was recommended for phase 2 studies. Activity of PAC-1 in treatment-refractory NET warrants further investigation. CLINICAL TRIAL REGISTRATION: Clinical Trials.gov: NCT02355535.

Target-Agnostic P-Glycoprotein Assessment Yields Strategies to Evade Efflux, Leading to a BRAF Inhibitor with Intracranial Efficacy.

The blood-brain barrier (BBB) presents a major hurdle in the development of central nervous system (CNS) active therapeutics, and expression of the P-glycoprotein (P-gp) efflux transporter at the blood-brain interface further impedes BBB penetrance of most small molecules. Designing efflux liabilities out of compounds can be laborious, and there is currently no generalizable approach to directly transform periphery-limited agents to ones active in the CNS. Here, we describe a target-agnostic, prospective assessment of P-gp efflux using diverse compounds. Our results demonstrate that reducing the molecular size or appending a carboxylic acid in many cases enables evasion of P-gp efflux in cell-based experiments and in mice. These strategies were then applied to transform a periphery-limited V600EBRAF inhibitor, dabrafenib, into versions that possess potent and selective anti-cancer activity but now also evade P-gp-mediated efflux. When compared to dabrafenib, the compound developed herein (everafenib) has superior BBB penetrance and superior efficacy in an intracranial mouse model of metastatic melanoma, suggesting it as a lead candidate for the treatment of melanoma metastases to the brain and gliomas with BRAF mutation. More generally, the results described herein suggest the actionability of the trends observed in these target-agnostic efflux studies and provide guidance for the conversion of non-BBB-penetrant drugs into versions that are BBB-penetrant and efficacious.

Investigating PSMA differential expression in canine uroepithelial carcinomas to aid disease-based stratification and guide therapeutic selection.

BACKGROUND: In male dogs, uroepithelial cancers include invasive urothelial carcinoma (iUC) and prostate carcinoma (PCA). The inability to distinguish iUC involving the prostate from PCA results in indiscriminate clinical management strategies that could be suboptimal as first-line chemotherapy for iUC (cisplatin) and PCA (docetaxel) differ in people. Prostate specific membrane antigen (PSMA) is a transmembrane protein, and its overexpression has been identified in human prostate carcinoma and neovasculature associated with solid tumor growth. This study investigates whether differential PSMA expression exists between presumptive canine iUC and PCA among cell lines and archived patient samples, which might allow for improved accuracy in disease-based stratification and optimal chemotherapy selection. Additionally, in vitro sensitivities of reported canine iUC and PCA cell lines to uroepithelial directed chemotherapeutic agents were characterized. RESULTS: Normalized PSMA gene and protein expressions were not significantly different between 5 iUC and 4 PCA cell lines. PSMA protein expression was uniformly observed in uroepithelial cancers regardless of anatomic origin from archived patient samples, further confirming that PSMA cannot differentiate iUC from PCA. In vitro sensitivity of cell lines to uroepithelial directed chemotherapeutics revealed that vinblastine exerted the broadest cytotoxic activity. CONCLUSIONS: Differential expression of PSMA was not identified between canine iUC and PCA cell lines or archived patient samples, and PSMA alone cannot be used for disease stratification. Nonetheless given its conserved overexpression, PSMA may be a targetable surface marker for both canine iUC and PCA. Lastly, in uroepithelial carcinomas, vinblastine might exert the broadest anticancer activity regardless of cellular origin.

The use of alkaline phosphatase and runx2 to distinguish osteosarcoma from other common malignant primary bone tumors in dogs.

In dogs, primary bone tumors can be difficult to distinguish with histopathology. Of those tumors, osteosarcoma (OSA) is the most common and aggressive. In this study, 4 immunohistochemistry markers-alkaline phosphatase (ALP), osteonectin (ON), osteopontin (OP), and runx2-were evaluated for their ability to distinguish OSA from other primary bone tumors. The 42 formalin-fixed, paraffin-embedded, primary canine bone tumors included 15 OSAs, 8 chondrosarcomas, 11 fibrosarcomas, and 8 histiocytic sarcomas. All 4 antibodies were highly sensitive for detection of osteosarcoma. ALP was the most sensitive at 100% and runx2 the most specific at 78%. Running ALP and runx2 in series resulted in a sensitivity of 87% and a specificity of 85%. This combination of immunomarkers resulted in a diagnostic panel for distinguishing osteosarcoma from other primary bone tumors.

A 10% Tomato Diet Selectively Reduces Radiation-Induced Damage in TRAMP Mice.

BACKGROUND: Tomatoes contain carotenoids that have the potential to alter the effects of external beam radiation therapy (EBRT). OBJECTIVES: We hypothesized that dietary lyophilized tomato paste (TP) would reduce apoptosis within carotenoid-containing nonneoplastic tissues in EBRT-treated TRansgenic Adenocarcinoma of the Mouse Prostate (TRAMP) mice. METHODS: Male TRAMP mice (n = 73) were provided an AIN-93G diet or a modified AIN-93G diet containing 10% TP (wt:wt) at 4 wk of age. Prostate tumor growth was monitored by ultrasound. The caudal half of the mouse was irradiated with 7.5 Gy (Rad) or 0 Gy (sham) at 24 wk of age or after the tumor volume exceeded 1000 mm3 with a Cobalt-60 source. Mice were euthanized 24 h postradiation. Carotenoids and α-tocopherol were measured by HPLC and compared by a t test. Tissues were assessed for radiation-induced changes (hematoxylin and eosin) and apoptosis [cleaved caspase-3 (CC3)] and compared by Kruskal-Wallis test or Freedman-Lane's permutation test. RESULTS: Serum concentrations of lycopene (52% lower), phytoene (26% lower), and α-tocopherol (22% lower) were decreased in TP-fed irradiated mice (TP-Rad) compared with TP-fed sham mice (P < 0.05). CC3 scores increased within the prostate tumor with radiation treatments (P < 0.05), but were not affected by tomato consumption. In nonneoplastic tissues, TP-Rad had a lower percentage of CC3-positive cells within the cranial (67% lower) and caudal (75% lower) duodenum than irradiated mice on the control diet (Rad) (P < 0.005). Likewise, CC3 scores within the dorsolateral prostate of TP-Rad trended toward lower scores than for Rad (P = 0.07). CONCLUSIONS: TP selectively reduces radiation-induced apoptosis in extratumoral tissues without decreasing radiation-induced apoptosis within the prostate tumor in TRAMP mice. Additional studies are needed to confirm and expand upon these findings.

Pharmacokinetics of a cytosine arabinoside subcutaneous protocol in dogs with meningoencephalomyelitis of unknown aetiology.

Cytosine arabinoside (CA) is a commonly used treatment for dogs with meningoencephalomyelitis of unknown aetiology (MUE) with various proposed protocols, many requiring 24 hours (h) of hospitalization or two visits within 24 h. This is a unidirectional study evaluating the pharmacokinetics of a CA subcutaneous (SC) protocol and a standard constant rate infusion (CRI) protocol in 8 dogs with MUE. Dogs received the CRI (200 mg/m2 IV over 24 h), followed by a SC protocol (50 mg/m2 every 2 h for 4 treatments) four weeks later. Plasma CA concentrations were measured by high-pressure liquid chromatography-tandem mass spectrometry (HPLC-MS). Median peak CA concentration for the SC protocol (3.40 µg/ml, range 1.60-9.70 µg/ml) was significantly higher than the CRI (1.09 µg/ml, range 0.77-1.67 µg/ml; p = .02). Median concentration at 1h and 8h following initiation of treatment was significantly higher for the SC protocol (CA1 2.28 µg/ml, range 0.97-2.67; CA8 1.83 µg/ml, range 0.77-2.84) compared to the CRI (CA1 0.01 µg/ml, range 0-0.45; CA8 0.74 µg/ml, range 0.67-1.11; p = .01). While the PK properties of CA when administered as a CRI has been previously investigated, this study demonstrated that CA when administered via repeated 50 mg/m2 injections every 2 h over an 8-h period, provided sustained plasma levels above its therapeutic target and for a significantly longer duration of time than did a standard CRI protocol.

Pharmacokinetics of platinum and safety evaluation of carboplatin-impregnated calcium sulfate hemihydrate beads after implantation in healthy cats.

OBJECTIVE: To evaluate the pharmacokinetics (PK) of platinum (Pt) and safety of carboplatin-impregnated calcium sulfate hemihydrate (C-I CSH) beads after implantation in healthy cats. STUDY DESIGN: In vivo experimental study. ANIMALS: Six healthy adult cats. METHODS: Three C-I CSH beads were implanted in muscle pockets over the right and left hemithoraces of each cat (~3.9 mg/kg of Pt; 60.4 mg/m2 of calculated carboplatin). Hematology and blood chemistry were tested at baseline and 3, 7, 14, and 21 days postimplantation. Serum was analyzed for Pt at specific times from 1 hour to 21 days. Tissue was obtained for histopathology and analysis of Pt at 3, 7, 14, and 21 days at standardized distances from implantation sites. RESULTS: Platinum was detected in tissues at all times and distances (range, 0.1-4.19 µg/g). Serum Pt increased up to 2.6 hours (3.25 µg/mL) then decreased sharply. Samples containing muscle had higher Pt compared with samples without muscle (P = .004). Mild hypercalcemia was noted in four cats, and mild inflammatory reaction was noted on histopathology of all samples. CONCLUSION: Platinum was released from C-I CSH beads differentially into surrounding tissues over 21 days. Systemic absorption of Pt was minimal, but mild hypercalcemia occurred. CLINICAL SIGNIFICANCE: Implantation was well tolerated by healthy adult cats. Securing beads within muscle may limit Pt diffusion to targeted tissue. Although Pt concentrations did not achieve levels reported to be cytotoxic for feline sarcoma cells in culture, results provide evidence to support evaluation of efficacy in the tumor microenvironment of cats with locally invasive cancers.

Global analysis of osteosarcoma lipidomes reveal altered lipid profiles in metastatic versus nonmetastatic cells.

Osteosarcoma (OS) is the most common form of primary bone cancer in humans. The early detection and subsequent control of metastasis has been challenging in OS. Lipids are important constituents of cells that maintain structural integrity that can be converted into lipid-signaling molecules and are reprogrammed in cancerous states. Here, we investigate the global lipidomic differences in metastatic (143B) and nonmetastatic (HOS) human OS cells as compared with normal fetal osteoblast cells (FOB) using lipidomics. We detect 15 distinct lipid classes in all three cell lines that included over 1,000 lipid species across various classes including phospholipids, sphingolipids and ceramides, glycolipids, and cholesterol. We identify a key class of lipids, diacylglycerols, which are overexpressed in metastatic OS cells as compared with their nonmetastatic or nontumorigenic counterparts. As a proof of concept, we show that blocking diacylglycerol synthesis reduces cellular viability and reduces cell migration in metastatic OS cells. Thus, the differentially regulated lipids identified in this study might aid in biomarker discovery, and the synthesis and metabolism of specific lipids could serve as future targets for therapeutic development.

Selective in vivo metabolic cell-labeling-mediated cancer targeting.

Distinguishing cancer cells from normal cells through surface receptors is vital for cancer diagnosis and targeted therapy. Metabolic glycoengineering of unnatural sugars provides a powerful tool to manually introduce chemical receptors onto the cell surface; however, cancer-selective labeling still remains a great challenge. Herein we report the design of sugars that can selectively label cancer cells both in vitro and in vivo. Specifically, we inhibit the cell-labeling activity of tetraacetyl-N-azidoacetylmannosamine (Ac4ManAz) by converting its anomeric acetyl group to a caged ether bond that can be selectively cleaved by cancer-overexpressed enzymes and thus enables the overexpression of azido groups on the surface of cancer cells. Histone deacetylase and cathepsin L-responsive acetylated azidomannosamine, one such enzymatically activatable Ac4ManAz analog developed, mediated cancer-selective labeling in vivo, which enhanced tumor accumulation of a dibenzocyclooctyne-doxorubicin conjugate via click chemistry and enabled targeted therapy against LS174T colon cancer, MDA-MB-231 triple-negative breast cancer and 4T1 metastatic breast cancer in mice.

Pamidronate functionalized nanoconjugates for targeted therapy of focal skeletal malignant osteolysis.

Malignant osteolysis associated with inoperable primary bone tumors and multifocal skeletal metastases remains a challenging clinical problem in cancer patients. Nanomedicine that is able to target and deliver therapeutic agents to diseased bone sites could potentially provide an effective treatment option for different types of skeletal cancers. Here, we report the development of polylactide nanoparticles (NPs) loaded with doxorubicin (Doxo) and coated with bone-seeking pamidronate (Pam) for the targeted treatment of malignant skeletal tumors. In vivo biodistribution of radiolabeled targeted Pam-NPs demonstrated enhanced bone tumor accumulation and prolonged retention compared with nontargeted NPs. In a murine model of focal malignant osteolysis, Pam-functionalized, Doxo-loaded NPs (Pam-Doxo-NPs) significantly attenuated localized osteosarcoma (OS) progression compared with nontargeted Doxo-NPs. Importantly, we report on the first evaluation to our knowlege of Pam-Doxo-NPs in dogs with OS, which possess tumors of anatomic size and physiology comparable to those in humans. The repeat dosing of Pam-Doxo-NPs in dogs with naturally occurring OS indicated the therapeutic was well tolerated without hematologic, nonhematologic, and cardiac toxicities. By nuclear scintigraphy, the biodistribution of Pam-Doxo-NPs demonstrated malignant bone-targeting capability and exerted measurable anticancer activities as confirmed with percent tumor necrosis histopathology assessment.

In vitro chemosensitivity of feline injection site-associated sarcoma cell lines to carboplatin.

OBJECTIVE: To determine the in vitro chemosensitivity of feline injection site-associated sarcoma (FISAS) cells to carboplatin concentrations generated by elution of carboplatin-impregnated calcium sulfate hemihydrate (CI-CSH) beads. STUDY DESIGN: In vitro study. SAMPLE: Five immortalized cell lines from histologically confirmed, primary FISASs. METHODS: For each cell line, one 96-well microplate was used for each time point (24, 48, 72 hours). In each microplate, 3 wells were seeded with ∼7.5 × 103 cells per well for every carboplatin treatment added, ranging from 5 to 450 µM. Microculture plates were incubated for 24, 48, or 72 hours. Drug efficacy was assessed via a bioreductive fluorometric assay. For apoptosis analysis, 3 wells were seeded with ∼5 × 104 cells per well for every carboplatin treatment added, ranging from 5 to 450 µM. Flow cytometry was performed and the relative percentages of viable, apoptotic, and late apoptotic/necrotic cells were reported. All experiments were run in triplicates. RESULTS: Carboplatin exerted dose-dependent and time-dependent effects on FISAS cell viability. The IC50 values were within the range of carboplatin concentrations eluted from CI-CSH beads. CONCLUSION: Elution of carboplatin from CI-CSH beads generate concentrations sufficient to result in 50% growth inhibition of FISAS cells in vitro. Local tumor control might be achieved by implantation of CI-CSH beads immediately following radical or marginal excision of the primary tumor or by implantation without tumor resection.

Interfacial geometry dictates cancer cell tumorigenicity.

Within the heterogeneous architecture of tumour tissue there exists an elusive population of stem-like cells that are implicated in both recurrence and metastasis. Here, by using engineered extracellular matrices, we show that geometric features at the perimeter of tumour tissue will prime a population of cells with a stem-cell-like phenotype. These cells show characteristics of cancer stem cells in vitro, as well as enhanced tumorigenicity in murine models of primary tumour growth and pulmonary metastases. We also show that interfacial geometry modulates cell shape, adhesion through integrin α5ß1, MAPK and STAT activity, and initiation of pluripotency signalling. Our results for several human cancer cell lines suggest that interfacial geometry triggers a general mechanism for the regulation of cancer-cell state. Similar to how a growing tumour can co-opt normal soluble signalling pathways, our findings demonstrate how cancer can also exploit geometry to orchestrate oncogenesis.

Pharmacokinetics and derivation of an anticancer dosing regimen for the novel anti-cancer agent isobutyl-deoxynyboquinone (IB-DNQ), a NQO1 bioactivatable molecule, in the domestic felid species.

Isobutyl-deoxynyboquinone (IB-DNQ) is a selective substrate for NAD(P)H:quinone oxidoreductase (NQO1), an enzyme overexpressed in many solid tumors. Following activation by NQO1, IB-DNQ participates in a catalytic futile reduction/reoxidation cycle with consequent toxic reactive oxygen species generation within the tumor microenvironment. To elucidate the potential of IB-DNQ to serve as a novel anticancer agent, in vitro studies coupled with in vivo pharmacokinetic and toxicologic investigations in the domestic felid species were conducted to investigate the tractability of IB-DNQ as a translationally applicable anticancer agent. First, using feline oral squamous cell carcinoma (OSCC) as a comparative cancer model, expressions of NQO1 were characterized in not only human, but also feline OSCC tissue microarrays. Second, IB-DNQ mediated cytotoxicity in three immortalized feline OSCC cell lines were studied under dose-dependent and sequential exposure conditions. Third, the feasibility of administering IB-DNQ at doses predicted to achieve cytotoxic plasma concentrations and biologically relevant durations of exposure were investigated through pharmacokinetic and tolerability studies in healthy research felines. Intravenous administration of IB-DNQ at 1.0-2.0 mg/kg achieved peak plasma concentrations and durations of exposure reaching or exceeding predicted in vitro cytotoxic concentrations. Clinical adverse side effects including ptyalism and tachypnea exhibited during and post-IV infusion of IB-DNQ were transient and tolerable. Additionally, IB-DNQ administration did not produce acute or delayed-onset unacceptable hematologic, non-hematologic, or off-target oxidative toxicities. Collectively, the findings reported here within provide important safety and pharmacokinetic data to support the continued development of IB-DNQ as a novel anticancer strategy for NQO1 expressing cancers.

Investigating the optimal size of anticancer nanomedicine.

Nanomedicines (NMs) offer new solutions for cancer diagnosis and therapy. However, extension of progression-free interval and overall survival time achieved by Food and Drug Administration-approved NMs remain modest. To develop next generation NMs to achieve superior anticancer activities, it is crucial to investigate and understand the correlation between the physicochemical properties of NMs (particle size in particular) and their interactions with biological systems to establish criteria for NM optimization. Here, we systematically evaluated the size-dependent biological profiles of three monodisperse drug-silica nanoconjugates (NCs; 20, 50, and 200 nm) through both experiments and mathematical modeling and aimed to identify the optimal size for the most effective anticancer drug delivery. Among the three NCs investigated, the 50-nm NC shows the highest tumor tissue retention integrated over time, which is the collective outcome of deep tumor tissue penetration and efficient cancer cell internalization as well as slow tumor clearance, and thus, the highest efficacy against both primary and metastatic tumors in vivo.

Direct Capture of Functional Proteins from Mammalian Plasma Membranes into Nanodiscs.

Mammalian plasma membrane proteins make up the largest class of drug targets yet are difficult to study in a cell free system because of their intransigent nature. Herein, we perform direct encapsulation of plasma membrane proteins derived from mammalian cells into a functional nanodisc library. Peptide fingerprinting was used to analyze the proteome of the incorporated proteins in nanodiscs and to further demonstrate that the lipid composition of the nanodiscs directly affects the class of protein that is incorporated. Furthermore, the functionality of the incorporated membrane proteome was evaluated by measuring the activity of membrane proteins: Na(+)/K(+)-ATPase and receptor tyrosine kinases. This work is the first report of the successful establishment and characterization of a cell free functional library of mammalian membrane proteins into nanodiscs.

A summary of the osteosarcoma banking efforts: a report from the Children's Oncology Group and the QuadW Foundation.

BACKGROUND: Survival rates of patients with osteosarcoma have remained stagnant over the last thirty years. Better understanding of biology, new therapeutics, and improved biomarkers are needed. The Children's Oncology Group (COG) addressed this need by developing one of the largest osteosarcoma biorepositories ever, containing over 15,000 tumor and tissue samples from over 1,500 patients. PROCEDURE: The biology study P9851 and the banking study AOST06B1 has enrolled 1,787 patients (as of September, 2013). Clinical information was lacking on 510 patients on P9851, who were not enrolled on a concurrent therapeutic trial. The value of these specimens was diminished. The lack of statistical support available for biology projects slowed the analysis of several critical studies. The QuadW Foundation, CureSearch, and the COG formed the Childhood Sarcoma Biostatistics and Annotation Office (CSBAO) to provide the infrastructure and address these needs by linking clinically annotated patient data to archived tissue samples and to develop biostatistical support for childhood sarcoma research. RESULTS: Originally 5.3% of samples from the 510 patients on P9851 not enrolled on a therapeutic study had full clinical annotation. The efforts of the CSBAO have linked clinical annotation to 90.8% of those specimens and provided statistical analyses to several studies that had used COG samples. As a result, 24 biology studies in osteosarcoma have been completed and published in peer-reviewed journals. CONCLUSIONS: These samples and in-silico data are available to the research community for basic and translational science projects to improve the biological understanding and treatment of patients affected by osteosarcoma.