Search

Recent interest in nanomedicine has skyrocketed because of mRNA vaccine lipid nanoparticles (LNPs) against COVID-19. Ironically, despite this success, the innovative nexus between nanotechnology and biochemistry, and the impact of nanoparticles on enzyme biochemical activity is poorly understood. The studies of this group on zinc nanoparticle (ZNP) compositions suggest that nanorod morphologies are preferred and that ZNP doped with manganese or iron can increase activity against model enzymes such as luciferase, DNA polymerase, and β-galactosidase (β-Gal), with the latter previously being associated with antimicrobial activity. SARS-CoV-2 encodes several of these types of oxido-reductase, polymerase, or hydrolase types of enzymes, and while metamaterials or nanoparticle composites have become important in many fields, their application against SARS-CoV-2 has only recently been considered. Recently, this group discovered the antiviral activity of manganese-doped zinc sulfide (MnZnS), and here the interactions of this nanoparticle composite with β-Gal, angiotensin converting enzyme (ACE), and human ACE2 (hACE2), the SARS-CoV-2 receptor, are demonstrated. Low UV, circular dichroism, and zeta potential results confirm their enzyme interaction and inhibition by fluorometric area under the curve (AUC) measurements. The IC

The aim of this study was to investigate the distribution, tolerance, and anticancer and antiviral activity of Zn-based physiometacomposites (PMCs). Manganese, iron, nickel and cobalt-doped ZnO, ZnS or ZnSe were synthesized. Cell uptake, distribution into 3D culture and mice, and biochemical and chemotherapeutic activity were studied by fluorescence/bioluminescence, confocal microscopy, flow cytometry, viability, antitumor and virus titer assays. Luminescence and inductively coupled plasma mass spectrometry analysis showed that nanoparticle distribution was liver >spleen >kidney >lung >brain, without tissue or blood pathology. Photophysical characterization as ex vivo tissue probes and LL37 peptide, antisense oligomer or aptamer delivery targeting RAS/Ras binding domain (RBD) was investigated. Treatment at 25 μg/ml for 48 h showed ≥98–99% cell viability, 3D organoid uptake, 3-log inhibition of β-Galactosidase and porcine reproductive respiratory virus infection. Data support the preclinical development of PMCs for imaging and delivery targeting cancer and infectious disease.

Extracellular vesicles (EVs) are heterogenous populations of proteolipid bi-layered vesicles secreted by cells as an important biological process. EVs cargo can reflect the cellular environmental conditions in which cells grow. The use of serum-free conditioned media to harvest EVs leads to stress-mediated cellular changes with longer incubation time and impacts EV production and functionality. This study aims to explore the role of incubation time and temperature on EV production and proteomic cargo. For this purpose, an optimized ultrafiltration-size exclusion chromatography-based technique is developed, which isolates small EVs ranging from 130 to 220 nm. The result shows higher EVs production in cancerous cells (K7M2) compared to noncancerous cells (NIH/3T3), which increases with longer incubation time and elevated temperature. Mass spectrometry-based proteomic characterization of EVs showed incubation time and temperature-dependent proteomic profile. A set of enriched EV proteins were identified in EVs isolated at nutrient-stress (72 h incubation time) and heat-stress (40 °C incubation temperature) environment. Enrichment of Serpinb1a in EVs isolated in heat stress was further validated via immunoblot. Gene enrichment analysis revealed that enriched EV proteins following nutrient stress were involved in negative regulation of transcription, response to oxidative stress, and protein folding. Likewise, enriched EV proteins following heat stress were involved in oxaloacetate and aspartate metabolism, and glutamate catabolic process. EVs isolated under nutrient stress showed pro-proliferative activity whereas EVs isolated under heat stress showed anti-proliferative activity. Our results show that incubation time and temperature can alter EV production, its proteomic cargo, and functionality, which can be used to design need-based standard isolation parameters for reproducible EV research.

The interfacial contact between TiO2 and graphitic carbon in a hybrid composite plays a critical role in electron transfer behavior, and in turn, its photocatalytic efficiency. Herein, we report a new approach for improving the interfacial contact and delaying charge carrier recombination in the hybrid by wrapping short single-wall carbon nanotubes (SWCNTs) on TiO2 particles (100 nm) via a hydration-condensation technique. Short SWCNTs with an average length of 125 ± 90 nm were obtained from an ultrasonication-assisted cutting process of pristine SWCNTs (1–3 μm in length). In comparison to conventional TiO2–SWCNT composites synthesized from long SWCNTs (1.2 ± 0.7 μm), TiO2 wrapped with short SWCNTs showed longer lifetimes of photogenerated electrons and holes, as well as a superior photocatalytic activity in the gas-phase degradation of acetaldehyde. In addition, upon comparison with a TiO2–nanographene “quasi-core–shell” structure, TiO2-short SWCNT structures offer better electron-capturing efficiency and slightly higher photocatalytic performance, revealing the impact of the dimensions of graphitic structures on the interfacial transfer of electrons and light penetration to TiO2. The engineering of the TiO2–SWCNT structure is expected to benefit photocatalytic degradation of other volatile organic compounds, and provide alternative pathways to further improve the efficiency of other carbon-based photocatalysts.

Major concerns have arisen with respect to using viral vectors for gene therapies. Collateral effects include cancer resistance, development of new cancers, and even systemic deaths. For this reason, researchers have focused on the alternative of using nonviral nanocarriers for gene therapy. In this study, a gene delivery nanocarrier was developed, comprising a cell-penetrating peptide called WTAS as a primary nanocarrier and a poly(β-amino ester) (PBAE) polymer as a secondary nanocarrier. Here, the PBAE polymer is used to protect the WTAS peptide from early degradation while further facilitating the transportation into cells. WTAS is a peptide that penetrates cell nuclei within a few minutes after exposure, which makes it an ideal candidate to transport genetic materials. The PBAE-WTAS nanocarrier was assembled and tested against three cell lines (NSC, B16F10, and GL26). Cytotoxic studies demonstrated the relatively low toxicity of the PBAE-WTAS nanocarrier and PBAE-WTAS loaded with green fluorescent protein (GFP) plasmid DNA (pDNA@PBAE-WTAS) against all three cell lines. Cell transfection experiments were carried out using GL26 cells. These studies demonstrated a very high transfection rate of PBAE-WTAS loaded with GFP plasmid DNA, leading to virtually complete transfection (90%). In conclusion, we report a very promising gene delivery nanocarrier, which can be further modified to transport a variety of genetic materials for targeted therapy of multiple diseases.

Peptide nanosponges of low polydispersity are spontaneously formed from trigonal supramolecular building blocks in aqueous buffers, which feature cationic and/or anionic oligopeptides (n = 5–20) and a hydrophobic unit. In contrast to classical liposomes/vesicles, nanosponges feature interwoven hydrophilic and hydrophobic nanodomains and are readily taken up by mammalian cells. Perillyl alcohol is known to be a simple, but effective small molecule drug against glioma multiforme. However, its efficacy is limited by a poor bioavailability. In order to make perillyl alcohol bioavailable, two nanosponges consisting of 10 aspartates, to which perillyl alcohol is attached by means of an ester bond, and 20 lysines or arginines (type (D-POH)10K20 and (D-POH)10R20) were synthesized, purified, and characterized by dynamic light scattering (DLS) and atomic force microscopy (AFM). These nanosponges were then tested in cell cultures of murine glioma cells (GL26) and murine neural progenitor cells (NPC) because the latt...

Thermal therapies are under investigation as part of multi-modality strategies for the treatment of pancreatic cancer. In the present study, we determined the kinetics of thermal injury to pancreatic cancer cells in vitro and evaluated predictive models for thermal injury. Cell viability was measured in two murine pancreatic cancer cell lines (KPC, Pan02) and a normal fibroblast (STO) cell line following in vitro heating in the range 42.5–50 °C for 3–60 min. Based on measured viability data, the kinetic parameters of thermal injury were used to predict the extent of heat-induced damage. Of the three thermal injury models considered in this study, the Arrhenius model with time delay provided the most accurate prediction (root mean square error = 8.48%) for all cell lines. Pan02 and STO cells were the most resistant and susceptible to hyperthermia treatments, respectively. The presented data may contribute to studies investigating the use of thermal therapies as part of pancreatic cancer treatment strategies and inform the design of treatment planning strategies.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder with a skewed sex-based diagnostic ratio. While males are at a higher risk for ASD, it is critical to understand the neurobiology of the disorder to develop better treatments for both males and females. Our prior work has demonstrated that VPA (valproic acid) treated offspring had impaired performance on an attentional set-shifting task. The current study used MRI and regions of interest analyses to measure the volumes of cerebellar subregions in VPA and controls rats that had participated in the attentional set-shifting task. VPA males had significantly more volume in lobule VI compared to male controls. VPA female rats had significantly less volume in lobules I, IV and X compared to female controls. In addition, it was revealed that decreases in volume for VPA females was associated with worse performance. Males with increases in lobule VI were also impaired on the set-shifting task. Similar volumetric differences within the cerebellum have been observed in humans with ASD, which suggests that the VPA model is capturing some of the same brain changes observed in humans with ASD, and that these changes in volume may be impacting cognition.

Red blood cells (RBCs) are the natural resident of the vascular lumen, therefore delivery of any agents within the vascular lumen could benefit by unique natural transporting features of RBCs. RBCs continuously circulate for ∼100 days before being sequestered in the spleen, they only extravasate at sites of vascular hemorrhage. Taking advantages of these features, we engineered RBC as a carrier in order to design a unique delivery system capable of delivering X-ray computed tomography (CT) contrast agents, gold nanoparticles (AuNPs), thereby acting as CT-contrast agent. A strategic membrane fusion technique was used to engineer the surface of RBC with gold nanoparticles in this in vitro study without altering its shape, size, and surface properties.

The interfacial contact between TiO

Luminol-based bioluminescence imaging allows noninvasive tracking of oxidatively active cells such as neutrophils. Luminol is given intravenously or intraperitoneally, followed by bioluminescence imaging at 425 nm. Here we describe a method for tracking neutrophil extravasation into an inflammatory site, especially focusing on mammary carcinoma.

Integrating small-animal experimental hyperthermia instrumentation with magnetic resonance imaging (MRI) affords real-time monitoring of spatial temperature profiles. This study reports on the development and preliminary in vivo characterisation of a 2.45 GHz microwave hyperthermia system for pre-clinical small animal investigations, integrated within a 14 T ultra-high-field MRI scanner.The presented system incorporates a 3.5 mm (OD) directional microwave hyperthermia antenna, positioned adjacent to the small-animal target, radiating microwave energy for localised heating of subcutaneous tumours. The applicator is integrated within the 30 mm bore of the MRI system. 3D electromagnetic and biothermal simulations were implemented to characterise hyperthermia profiles from the directional microwave antenna. Experiments in tissue mimicking phantoms were performed to assess hyperthermia profiles and validate MR thermometry against fibre-optic temperature measurements. The feasibility of delivering in vivo hyperthermia exposures to subcutaneous 4T1 tumours in experimental mice under simultaneous MR thermometry guidance was assessed.Simulations and experiments in tissue mimicking phantoms demonstrated the feasibility of heating 21-982 mmA platform for small-animal hyperthermia investigations under ultra-high-field MR thermometry was developed and applied to heating subcutaneous tumours in vivo.

The structure of novel binary nanosponges consisting of (cholesterol-(K/D)nDEVDGC)3-trimaleimide units possessing a trigonal maleimide linker, to which either lysine (K)20 or aspartic acid (D)20 are tethered, has been elucidated by means of TEM. A high degree of agreement between these findings and structure predictions through explicit solvent and then coarse-grained molecular dynamics (MD) simulations has been found. Based on the nanosponges' structure and dynamics, caspase-6 mediated release of the model drug 5(6)-carboxyfluorescein has been demonstrated. Furthermore, the binary (DK20) nanosponges have been found to be virtually non-toxic in cultures of neural progenitor cells. It is of a special importance for the future development of cell-based therapies that DK20 nanosponges were taken up efficiently by leucocytes (WBC) in peripheral blood within 3 h of exposure. The percentage of live cells among the WBC was not significantly decreased by the DK20 nanosponges. In contrast to stem cell or leucocyte cell cultures, which have to be matched to the patient, autologous cells are optimal for cell-mediated therapy. Therefore, the nanosponges hold great promise for effective cell-based tumor targeting.

Luminol-based bioluminescence imaging allows noninvasive tracking of oxidatively active cells such as neutrophils. Luminol is given intravenously or intraperitoneally, followed by bioluminescence imaging at 425 nm. Here we describe a method for tracking neutrophil extravasation into an inflammatory site, especially focusing on mammary carcinoma.

Numerous proteases, such as matrix metalloproteinases (MMPs), cathepsins (CTS), and urokinase plasminogen activator (UpA), are dysfunctional (that is, over- or under-expressed) in solid tumors, when compared to healthy human subjects. This offers the opportunity to detect early tumors by liquid biopsies. This approach is of particular advantage for the early detection of pancreatic cancer, which is a “silent killer”. We have developed fluorescence nanobiosensors for ultrasensitive (sub-femtomolar) arginase and protease detection, consisting of water-dispersible Fe/Fe3O4 core/shell nanoparticles and two tethered fluorescent dyes: TCPP (Tetrakis(4-carboxyphenyl)porphyrin) and cyanine 5.5. Upon posttranslational modification or enzymatic cleavage, the fluorescence of TCPP increases, which enables the detection of proteases at sub-femtomolar activities utilizing conventional plate readers. We have identified an enzymatic signature for the detection of pancreatic adenocarcinomas in serum, consisting of arginase, matrix metalloproteinase-1, -3, and - 9, cathepsin-B and -E, urokinase plasminogen activator, and neutrophil elastase, which is a potential game-changer.

We have revisited the photochromic spiro-dihydroindolizine/betaine system by comparing state-of-the-art density functional theory calculations with experimental data. Time-dependent density functional theory calculations are employed to examine the transformations occurring after photoexcitation. This study confirms that photoexcitation of the spiro-dihydroindolizine leads to the formation of the cis-betaine. However, isomerization to the trans-betaine follows through a complicated and formerly unknown potential energy landscape, which consists of a network of transition states and intermediates. The available pathways across this potential energy landscape will determine the kinetics of the forward reaction from the cis-betaine to the trans-betaine and then, even more importantly, the back-reaction. Virtually all practical applications of this optical switch rely on these reactions and, therefore, occur within this landscape. Predicting the network of transition states and intermediates for substituted spiro-dihydroindolizine/betaine systems will enable the in-silico design of optical switches with enhanced performance.

The capacity of iron oxide nanocrystals to heat tissue when subjected to an alternating magnetic field (AMF hyperthermia) is shape-selective. Although iron oxide nanostructures with numerous shapes have been synthesized to date, hexagonal Fe3O4 prisms of low toxicity remained elusive. Here, we report the use of a dual ligand system permitting feasible reaction conditions to synthesize nearly perfect hexagonal Fe3O4 nanoplatelet structures, with edge length of 45 ± 5 nm and thickness of 5 to 6 nm. Their Specific Absorption Rate (SAR) is >750 W g(Fe)−1. The Fe3O4 hexagons were coated with a dopamine-based ligand to increase dispersibility in aqueous buffers. The Fe3O4 hexagons were only minimally toxic to RAW264.7 cells, which can be utilized in cell-based cancer targeting approaches.

A novel type of supramolecular aggregate, named a “nanosponge” was synthesized through the interaction of novel supramolecular building blocks with trigonal geometry. The cholesterol-(K/D) n DEVDGC) 3 -trimaleimide unit consists of a trigonal maleimide linker to which homopeptides (either K or D) of variable lengths (n = 5, 10, 15, 20) and a consensus sequence for executioner caspases (DEVDGC) are added via Michael addition. Upon mixing in aqueous buffer cholesterol-(K) n DEVDGC) 3 -trimaleimides and a 1:1 mixture of cholesterol-(K/D) n DEVDGC) 3 -trimaleimides form stable nanosponges, whereas cholesterol-(D) n DEVDGC) 3 -trimaleimide is unable to form supramolecular aggregates with itself. The structure of the novel nanosponges was investigated through explicit solvent and then coarse-grained molecular dynamics (MD) simulations. The nanosponges are between 80 nm and several micrometers in diameters and virtually non-toxic to monocyte/macrophage-like cells.

Fast drug delivery is very important to utilize drug molecules that are short-lived under physiological conditions. Techniques that can release model molecules under physiological conditions could play an important role to discover the pharmacokinetics of short-lived substances in the body. Here an experimental method is developed for the fast release of the liposomes' payload without a significant increase in (local) temperatures. This goal is achieved by using short magnetic pulses to disrupt the lipid bilayer of liposomes loaded with magnetic nanoparticles. The drug release has been tested by two independent assays. The first assay relies on the AC impedance measurements of MgSO4 released from the magnetic liposomes. The second standard release assay is based on the increase of the fluorescence signal from 5(6)-carboxyfluorescein dye when the dye is released from the magneto liposomes. The efficiency of drug release ranges from a few percent to up to 40% in the case of the MgSO4. The experiments also indicate that the magnetic nanoparticles generate ultrasound, which is assumed to have a role in the release of the model drugs from the magneto liposomes.

Macrophages take advantage of the antibacterial properties of copper ions in the killing of bacterial intruders. However, despite the importance of copper for innate immune functions, coordinated efforts to exploit copper ions for therapeutic interventions against bacterial infections are not yet in place. Here we report a novel high-throughput screening platform specifically developed for the discovery and characterization of compounds with copper-dependent antibacterial properties toward methicillin-resistant Staphylococcus aureus (MRSA). We detail how one of the identified compounds, glyoxal-bis(N4-methylthiosemicarbazone) (GTSM), exerts its potent strictly copper-dependent antibacterial properties on MRSA. Our data indicate that the activity of the GTSM-copper complex goes beyond the general antibacterial effects of accumulated copper ions and suggest that, in contrast to prevailing opinion, copper complexes can indeed exhibit species- and target-specific activities. Based on experimental evidence, we propose that copper ions impose structural changes upon binding to the otherwise inactive GTSM ligand and transfer antibacterial properties to the chelate. In turn, GTSM determines target specificity and utilizes a redox-sensitive release mechanism through which copper ions are deployed at or in close proximity to a putative target. According to our proof-of-concept screen, copper activation is not a rare event and even extends to already established drugs. Thus, copper-activated compounds could define a novel class of anti-MRSA agents that amplify copper-dependent innate immune functions of the host. To this end, we provide a blueprint for a high-throughput drug screening campaign which considers the antibacterial properties of copper ions at the host-pathogen interface.

A new application of two Negishi-type coupling reactions for the synthesis of coelenterazine is reported. The synthesis of coelenterazine in high purity on a gram scale will enable numerous approaches to bioluminescence imaging and possibly photodynamic therapy of deep-seated tumors. Coelenterazine is the substrate for several luciferases, among them Gaussia luciferase (gLuc). This synthesis starts with pyrazin-2-amine and uses inexpensive starting materials and catalysts.

The mycobacterial porin MspA is one of the most stable channel proteins known to date. MspA forms vesicles at low concentrations in aqueous buffers. Evidence from dynamic light scattering, transmission electron microscopy and zeta-potential measurements by electrophoretic light scattering indicate that MspA behaves like a nanoscale surfactant. The extreme thermostability of MspA allows these investigations to be carried out at temperatures as high as 343 K, at which most other proteins would quickly denature. The principles of vesicle formation of MspA as a function of temperature and the underlying thermodynamic factors are discussed here. The results obtained provide crucial evidence in support of the hypothesis that, during vesicle formation, nanoscopic surfactant molecules, such as MspA, deviate from the principles underlined in classical surface chemistry.

Cytotherapies, or cell-based therapies, have spurred increasing interest due to the numerous potential therapies cells may be able to take part in. Magnetic nanoparticles have been found to be a very useful tool in developing cytotherapies. Primarily, magnetic nanoparticles have been used to track the distribution and activity of cells in vivo because they show large T2 and T2* shifts in magnetic resonance imaging. Magnetic nanoparticles paired with MRI have been able to track a wide variety of cells to multiple different tissues and diseases, helping to define the potential of cytotherapy and develop potential therapies. Beyond merely tracking, though, magnetic nanoparticles can confer new treatment abilities on cells when paired with magnetic hyperthermia. Cells can carry magnetic nanoparticles selectively to the site of therapy where they can absorb energy from oscillating magnetic fields, transferring that energy as heat to the surrounding tissue. Continuing to develop the partnership between cytotherapy and magnetic nanoparticles is likely to continue yielding exciting results.

A nanobiosensor for arginase detection was designed and synthesized. It features a central dopamine-coated iron/iron oxide nanoparticle to which sulfonated cyanine 7.0 is tethered via a stable amide bond. Cyanine 5.5 is linked to the N-terminal of the peptide sequence GRRRRRRRG. Arginine (R) reacts to ornithine (O) in the presence of arginase. Based on calibration with commercially obtained arginase II, the limit of detection (LOD) is picomolar. It is noteworthy that the nanobiosensor for arginase detection does not show a fluorescence increase when incubated with the enzyme NO-reductase, which also uses arginase as substrate, but is indicative of an inflammatory response by the host to cancer and infections. Arginase activity was determined in a syngeneic mouse model for aggressive breast cancer (4T1 tumors in BALB/c mice). It was found that the arginase activity is systemically enhanced, but especially pronounced in the active tumor regions.

Two photochromic spirodihydroindolizine/betaine systems for tethering to peptides and proteins via a maleimide function have been prepared. The absorption spectra of the betaines are in the red region of the visible spectrum and in the near-IR spectral domain, which are suitable energies of light for future in vivo applications. The half-times of cyclization have been determined for both DHI/betaine systems. The findings are consistent with a thermal barrier of varying size between the transoid and cisoid conformers of the betaines.

We have transfected murine neural stem cells (NSCs) and rat umbilical cord matrix-derived stem cells (RUCMSCs) with a plasmid expressing gaussia luciferase (gLuc). These cells are engineered to secrete the luciferase. We have used gLuc containing supernatant from culturing the NSCs to perform in vitro photodynamic therapy of murine melanoma cells (B16F10), and RUCMSCs to perform in vivo PDT of lung melanomas in C57BL/6 mice. The treatment system was comprised of aminolevulic acid as a prodrug for the synthesis of the photosensitizer protoporphyrin IX, gaussia luciferase, and its' substrate coelenterazine. A significant reduction of the number of live melanoma cells in vitro and a borderline significant retardation of tumour growth in vivo was observed after coelenterazine-mediated PDT.

The targeted delivery of therapeutics to the tumor site is highly desirable in cancer treatment, because it is capable of minimizing collateral damage. Herein, we report the synthesis of a nanoplatform, which is composed of a 15 ± 1 nm diameter core/shell Fe/Fe3O4 magnetic nanoparticles (MNPs) and the topoisomerase I blocker SN38 bound to the surface of the MNPs via a carboxylesterase cleavable linker. This nanoplatform demonstrated high heating ability (SAR = 522 ± 40 W/g) in an AC-magnetic field. For the purpose of targeted delivery, this nanoplatform was loaded into tumor-homing double-stable RAW264.7 cells (mouse monocyte/macrophage-like cells (Mo/Ma)), which have been engineered to express intracellular carboxylesterase (InCE) upon addition of doxycycline by a Tet-On Advanced system. The nanoplatform was taken up efficiently by these tumor-homing cells. They showed low toxicity even at high nanoplatform concentration. SN38 was released successfully by switching on the Tet-On Advanced system. We have demonstrated that this nanoplatform can be potentially used for thermochemotherapy. We will be able to achieve the following goals: (1) Specifically deliver the SN38 prodrug and magnetic nanoparticles to the cancer site as the payload of tumor-homing double-stable RAW264.7 cells; (2) Release of chemotherapeutic SN38 at the cancer site by means of the self-containing Tet-On Advanced system; (3) Provide localized magnetic hyperthermia to enhance the cancer treatment, both by killing cancer cells through magnetic heating and by activating the immune system.

Matthew T Basel1, Sivasai Balivada1, Hongwang Wang2, Tej B Shrestha1, Gwi Moon Seo1, Marla Pyle1, Gayani Abayaweera2, Raj Dani2, Olga B Koper2, Masaaki Tamura1, Viktor Chikan2, Stefan H Bossmann2, Deryl L Troyer11Department of Anatomy and Physiology, College of Veterinary Medicine, 2Department of Chemistry, Kansas State University, Manhattan, KS, USAAbstract: Using magnetic nanoparticles to absorb alternating magnetic field energy as a method of generating localized hyperthermia has been shown to be a potential cancer treatment. This report demonstrates a system that uses tumor homing cells to actively carry iron/iron oxide nanoparticles into tumor tissue for alternating magnetic field treatment. Paramagnetic iron/iron oxide nanoparticles were synthesized and loaded into RAW264.7 cells (mouse monocyte/macrophage-like cells), which have been shown to be tumor homing cells. A murine model of disseminated peritoneal pancreatic cancer was then generated by intraperitoneal injection of Pan02 cells. After tumor development, monocyte/macrophage-like cells loaded with iron/iron oxide nanoparticles were injected intraperitoneally and allowed to migrate into the tumor. Three days after injection, mice were exposed to an alternating magnetic field for 20 minutes to cause the cell-delivered nanoparticles to generate heat. This treatment regimen was repeated three times. A survival study demonstrated that this system can significantly increase survival in a murine pancreatic cancer model, with an average post-tumor insertion life expectancy increase of 31%. This system has the potential to become a useful method for specifically and actively delivering nanoparticles for local hyperthermia treatment of cancer.Keywords: cytotherapy, pancreatic cancer, disseminated peritoneal carcinomatosis, targeted magnetic hyperthermia, nanoparticles

Hydroxyl soybean oils, also called soy polyols, are biobased chemicals designed to replace petroleum-based polyols mainly for polyurethane (PU) applications. Soy polyols are obtained by acid-catalyzed ring opening of expoxidized soybean oils or other epoxidized plant oils by nucleophilic SN2 attack of methanol. Recyclable heterogeneous catalysts are preferred for the ring-opening reactions over non-recyclable homogeneous catalysts because they minimize environmental impact. The drawbacks of current solid catalysts such as SAC 13 and Amberlite 15 are low production yield and high energy consumption. Here, we demonstrate a greener synthetic pathway of soy polyols with low energy consumption and excellent atom economy and environment (E) factor by using novel sulfamic acid-functionalized iron (iron/iron oxide core shell) nanoparticles (NPs) as a heterogeneous catalyst. The excellent selectivity of the reaction with the recyclable NPs was confirmed by 1H NMR, 1H-1H COSY NMR, and ESI-MS comparable to non-recyclable H2SO4. The synthetic route with the NPs resulted in higher product yield (almost 100%) as H2SO4 at room temperature for 30 min over the SAC 13 (83% yield at 60 °C for 60 min) and Amberlite 15 (87% yield at 60 °C for 100 min). Life cycle assessment (LCA) revealed that the NP synthetic technology for soy polyol production is superior or equal to the competing routes (H2SO4, SAC 13, and Amberlite 15 methods) with respect to 9 environmental impacts (acidification potential, ozone depletion potential, smog formation potential, global warming potential, human toxicity by ingestion, human toxicity by inhalation, persistence, bioaccumulation, and abiotic resource depletion potential).

Gene-directed enzyme prodrug therapy (GDEPT) has been investigated as a means of cancer treatment without affecting normal tissues. This system is based on the delivery of a suicide gene, a gene encoding an enzyme which is able to convert its substrate from non-toxic prodrug to cytotoxin. In this experiment, we have developed a targeted suicide gene therapeutic system that is completely contained within tumor-tropic cells and have tested this system for melanoma therapy in a preclinical model. First, we established double stable RAW264.7 monocyte/macrophage-like cells (Mo/Ma) containing a Tet-On® Advanced system for intracellular carboxylesterase (InCE) expression. Second, we loaded a prodrug into the delivery cells, double stable Mo/Ma. Third, we activated the enzyme system to convert the prodrug, irinotecan, to the cytotoxin, SN-38. Our double stable Mo/Ma homed to the lung melanomas after 1 day and successfully delivered the prodrug-activating enzyme/prodrug package to the tumors. We observed that our system significantly reduced tumor weights and numbers as targeted tumor therapy after activation of the InCE. Therefore, we propose that this system may be a useful targeted melanoma therapy system for pulmonary metastatic tumors with minimal side effects, particularly if it is combined with other treatments.

The progression elevated gene-3 (PEG-3) promoter is a rodent gene that has shown strong activity in tumor progression. Demonstrating tumor specificity and activity in at least five different human cancers, PEG-3 is considered a novel promoter for tumor-specific gene expression. Understanding how PEG-3 controls expression of reporter proteins is of biomedical significance because of the role it could play in new therapeutic strategies against certain types of cancer. In this study, we aim to use the PEG-3 promoter to observe the expression of firefly luciferase 2 (luc 2), a bioluminescent reporter protein, in the transfection of mammalian cells. Ultimately, we plan to use PEG-3 to express a therapeutic gene, cytosine deaminase, in cancer specific areas of breast, lung, and ovary. Citation Format: Ruben Pando, Tej Shrestha, Marla Pyle, Deryl Troyer. Selective protein expression in tumor cells controlled by progression elevated gene-3 promoter [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 1481.

There is a significantly increased interest in using antimicrobial peptides for anticancer therapy. D-K6L9, LKLLKKLLKKLLKLL is an antimicrobial peptide that has been explored. It kills cancer cells by depolarizing their cell membranes, thus inducing apoptosis. Further modification of the peptide for increased toxicity and safe packaging into a delivery vehicle for targeted delivery is highly desired for the in vivo applications. Here, the peptide was modified with two extra amino acids (serine and alanine) at both C and N terminals, resulting in SA-LKLLKKLLKKLLKLL-AS. The sequence and structure of the modified peptide were determined by means of 2D 1H-1H -COSY, NOESY, and TOCSY-NMR spectroscopy. The 3D structure of the peptide in the solution phase was generated by CNS software using a distance constraint generated by NOE spectroscopy. The 3-D structure of SA-D-K6L9-AS is maintained, as well as the amphiphilicity required for insertion into cell membranes. This peptide was tested on the following mouse cancer cell lines: GL 26 (glioma), B16-F10 (melanoma lung metastases) and 4T1 (metastasizing breast cancer). The LC50 values of the modified peptide were found to be 0.707 µM for B16-F10, 6.237 µM for 4T1 and 1.707 µM for GL 26, which is 5- 10 fold more active than the original D-K6L9. To explore the findings using the modified peptide, SA-D-K6L9-AS tagged with a rhodamine dye was incubated with GL 26 cancer cells. Sequential confocal imaging (every 30 seconds) revealed that the peptide gets internalized into the cytoplasm in less than 5 min and then localizes in the mitochondria. This peptide is found to be toxic to neuronal stem cells and monocytes as well. To avoid the non-specific toxicity of the peptide for in vivo applications, highly mesoporous silica nanoparticles (MSN) were synthesized. The peptide was loaded into the MSN. MSN were further coated with a polysilazane as a “gift wrap” after loading the peptide. This gift wrap can hold the contents inside the MSN, showing no toxicity at 24 hours and subsequent slow release of the peptide payload into the cytoplasm within 72 hours. This gift wrapping of the highly toxic peptide into the MSN could be very useful for in vivo cancer therapy by means of targeted delivery to the cancer site with appropriate surface modification of MSN. Citation Format: Tej B. Shrestha, Jing Yu, Stefan Bossmann, Deryl Troyer. Structure determination, mode of action and safe delivery of an improved K6L9-type peptide [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 3730.

We have synthesized a prototype of a photochromic styrylquinolyl-dihydroindolizine (DHI), which forms a highly coloured and fluorescent betaine upon irradiation with lambda400 nm. Embedding this photochromic DHI in a thin polymethyl methacrylate (PMMA) film permits the non-destructive readout via fluorescence at low temperature (77 K). Thus, either a non-destructive photoswitch or an information recording system becomes available. Both possibilities have been explored: image recording and read-out, as well as information storage (at 77 K) have been demonstrated. Cluster- and single molecule-fluorescence upon laser excitation (lambda=355 nm) of the styrylquinolyl-dihydroindolizine in a PMMA matrix, and the effect of fluorescence blinking has been observed.

We elucidated the photochromic spiro-4a,5-dihydropyrrolo[1,2-b]pyridazine/betaine (DPP/betaine) system by comparing state-of-the-art density functional theory calculations with nanosecond/millisecond UV-vis absorption spectroscopy, as well as steady-state absorption and cyclization kinetics. Time-dependent density functional theory calculations are employed to examine the transformations occurring after photoexcitation. This study shows that the photochromic spiro-4a,5-dihydropyrrolo[1,2-b]pyridazine and spiro-1,8a-dihydroindolizine (DHI) systems react according to similar pathways. However, notable differences exist. Although photoexcitation of the spiro-DPP system also leads to cis-betaines, which then isomerize to trans-betaines, we found two distinct classes of cis isomers (cis-betaine rotamer-1 and cis-betaine rotamer-2), which do not exist in spiro-1,8a-dihydroindolizine. Similar to our previous study on the spiro-DHI/betaine system, a complicated potential-energy landscape between cis and trans isomers exists in the spiro-DPP system, consisting of a network of transition states and intermediates. Because the spiro-DPP/betaine is even more complicated than the spiro-DHI/betaine system, (substituted) photochromic systems featuring a 4a,5-dihydropyrrolo[1,2-b]pyridazine functional unit will require thorough in silico design to function properly as logical gates or in devices for information storage.

Interleukin 12 (IL-12) is a heterodimeric cytokine encoded by two genes, p35 and p40. IL-12, also known as T cell-stimulating factor, induces proliferation of T-lymphocytes and natural killer (NK) cells, while also demonstrating an anti-angiogenic effect and inhibition of regulatory T cells. Similarly, LIGHT (TNFSF14) is a transmembrane protein which acts as a costimulatory factor for the activation lymphoid cells and stimulates the proliferation of T cells, leading to increased apoptosis of tumor cells. Expression of IL-12 and LIGHT specifically in the tumor region could activate T cells and stimulate the immune system to attenuate the tumor. Tumor homing neuronal stem cells C17.2 (NSC) were genetically engineered to express the mouse-LIGHT gene and IL-12 using a retrovirus. The expression of LIGHT and IL-12 genes in NSC was confirmed by PCR, ELISA and Western blot. To test the antitumor effects of the engineered cells, Balb/C mice bearing 4T1 mammary tumors were treated with NSC-LIGHT, NSC-IL-12 and NSC-LIGHT/IL-12 cells intratumorally (I.T.) at day nine. Repeated tumor measurement over time showed attenuation of mammary tumor growth in the both NSC/IL-12 and NSC/LIGHT groups in comparison with control groups PBS and NSC. Tumor growth was further reduced by treating the mice with NSC expressing both cytokines LIGHT and IL-12. Tumor metastasis was also evaluated by removing the primary tumor surgically and observing mice for any sign of metastatic burden. Treatment groups had less metastatic tumor burden and survived longer than the control group. Therefore, tumor homing NPC-LIGHT/IL-12 cells could be effective for the treatment of highly metastatic mammary tumors. Citation Format: Tej B. Shrestha, Dezhang Lu, Matthew T. Basel, Marla Pyle, Stefan H. Bossmann, Deryl L. Troyer. Genetically modified neuronal stem cells expressing IL-12 and TNFSF14 attenuate highly metastatic mammary tumors in a mouse model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1613. doi:10.1158/1538-7445.AM2017-1613

Animal models are essential to preclinical cancer research and are used clinically to determine optimal treatment regimens, but current xenograft models are limited in their utility, especially due to the lack of a competent immune system. Here we demonstrate that a xenograft tumor model can be developed in immunocompetent mice by tolerizing murine fetuses to human tumor cells. A375 human melanoma cells were injected into day E14 fetuses and, after birth, mice were challenged again with A375 cells to determine their ability to develop tumors. Intravenous injections of A375 cells after tolerization resulted in metastatic-like lung tumors, which were verified to be human in origin by immunohistochemistry and PCR. The development of lung neoplasms was dependent on fetal tolerization; non-tolerized mice did not develop tumors after injection. Interestingly, subcutaneous injected cells did not form tumors, but this was shown to be due to an innate, non-adaptive immune response and did not create lasting rejection of tumor cells. This procedure was repeated with several different tumor lines to show the universal nature of the method: BxPC3 (human pancreatic cancer), M21 (human melanoma), HeLa (human cervical cancer), and MDA231 (human breast carcinoma). Citation Format: Matthew T. Basel, Sanjeev Narayanan, Chanran Ganta, Tej B. Shrestha, Marla Pyle, Stefan H. Bossmann, Deryl L. Troyer. Developing a xenograft human tumor model in immunocompetent mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4820. doi:10.1158/1538-7445.AM2017-4820

A new application of two Negishi-type coupling reactions for the synthesis of coelenterazine is reported. The synthesis of coelenterazine in high purity on a gram scale will enable numerous approaches to bioluminescence imaging and possibly photodynamic therapy of deep-seated tumors. Coelenterazine is the substrate for several luciferases, among them Gaussia luciferase (gLuc). This synthesis starts with pyrazin-2-amine and uses inexpensive starting materials and catalysts.

Cell-based therapeutics have advanced significantly over the past decade and are poised to become a major pillar of modern medicine. Three cell types in particular have been studied in detail for their ability to home to tumors and to deliver a variety of different payloads. Neural stem cells, mesenchymal stem cells and monocytes have each been shown to have great potential as future delivery systems for cancer therapy. A variety of other cell types have also been studied. These results demonstrate that the field of cell-based therapeutics will only continue to grow.

Polymorphonuclear neutrophils (PMNs) are the most abundant circulating blood leukocytes. They are part of the innate immune system and provide a first line of defense by migrating toward areas of inflammation in response to chemical signals released from the site. Some solid tumors, such as breast cancer, also cause recruitment and activation of PMNs and release of myeloperoxidase. In this study, we demonstrate that administration of luminol to mice that have been transplanted with 4T1 mammary tumor cells permits the detection of myeloperoxidase activity, and consequently, the location of the tumor. Luminol allowed detection of activated PMNs only two days after cancer cell transplantation, even though tumors were not yet palpable. In conclusion, luminol-bioluminescence imaging (BLI) can provide a pathway towards detection of solid tumors at an early stage in preclinical tumor models.

We and others recently identified copper resistance as important for virulence of Mycobacterium tuberculosis . Here, we introduce a high-throughput screening assay for agents that induce a copper hypersensitivity phenotype in M. tuberculosis and demonstrate that such copper-boosting compounds are effective against replicating and nonreplicating M. tuberculosis strains.

Enzyme-activated prodrugs have been investigated and sought after as highly specific, low-side-effect treatments, especially for cancer therapy. Unfortunately, excellent targets for enzyme-activated therapy are rare. Here a system based on cell delivery that can carry both a prodrug and an activating enzyme to the cancer site is demonstrated. Raw264.7 cells (mouse monocyte/macrophage-like cells, Mo/Ma) are engineered to express intracellular rabbit carboxylesterase (InCE), which is a potent activator of the prodrug irinotecan to SN38. InCE expression is regulated by the TetOn® system, which silences the gene unless a tetracycline, such as doxycycline, is present. Concurrently, an irinotecan-like prodrug, which is conjugated to dextran and can be loaded into the cytoplasm of Mo/Ma, is synthesized. To test the system, a murine pancreatic cancer model is generated by intraperitoneal (i.p.) injection of Pan02 cells. Engineered Mo/Ma are loaded with the prodrug and are injected i.p. Two days later, doxycycline was given i.p. to activate InCE, which activated the prodrug. A survival study demonstrates that this system significantly increased survival in a murine pancreatic cancer model. Thus, for the first time, a prodrug/activating enzyme system, which is self-contained within tumor-homing cells and can prolong the life of i.p. pancreatic tumor bearing mice, is demonstrated.