Development of a New Hyaluronic Acid Based Redox-Responsive Nanohydrogel for the Encapsulation of Oncolytic Viruses for Cancer Immunotherapy

Oncolytic viruses (OVs) are emerging as promising and potential anti-cancer therapeutic agents, not only able to kill cancer cells directly by selective intracellular viral replication, but also to promote an immune response against tumor. Unfortunately, the bioavailability under systemic administration of OVs is limited because of undesired inactivation caused by host immune system and neutralizing antibodies in the bloodstream. To address this issue, a novel hyaluronic acid based redox responsive nanohydrogel was developed in this study as delivery system for OVs, with the aim to protect the OVs following systemic administration. The nanohydrogel was formulated by water in oil (W/O) nanoemulsion method and cross-linked by disulfide bonds derived from the thiol groups of synthesized thiolated hyaluronic acid. One DNA OV Ad[I/PPT-E1A] and one RNA OV Rigvir® ECHO-7 were encapsulated into the developed nanohydrogel, respectively, in view of their potential of immunovirotherapy to treat cancers. The nanohydrogels showed particle size of approximately 300–400 nm and negative zeta potential of around −13 mV by dynamic light scattering (DLS). A uniform spherical shape of the nanohydrogel was observed under the scanning electron microscope (SEM) and transmission electron microscope (TEM), especially, the successfully loading of OV into nanohydrogel was revealed by TEM. The crosslinking between the hyaluronic acid chains was confirmed by the appearance of new peak assigned to disulfide bond in Raman spectrum. Furthermore, the redox responsive ability of the nanohydrogel was determined by incubating the nanohydrogel into phosphate buffered saline (PBS) pH 7.4 with 10 μM or 10 mM glutathione at 37 °C which stimulate the normal physiological environment (extracellular) or reductive environment (intracellular or tumoral). The relative turbidity of the sample was real time monitored by DLS which indicated that the nanohydrogel could rapidly degrade within 10 h in the reductive environment due to the cleavage of disulfide bonds, while maintaining the stability in the normal physiological environment after 5 days. Additionally, in vitro cytotoxicity assays demonstrated a good oncolytic activity of OVs-loaded nanohydrogel against the specific cancer cell lines. Overall, the results indicated that the developed nanohydrogel is a delivery system appropriate for viral drugs, due to its hydrophilic and porous nature, and also thanks to its capacity to maintain the stability and activity of encapsulated viruses. Thus, nanohydrogel can be considered as a promising candidate carrier for systemic administration of oncolytic immunovirotherap

Dually Cross-Linked Core-Shell Structure Nanohydrogel with Redox–Responsive Degradability for Intracellular Delivery

A redox-responsive nanocarrier is a promising strategy for the intracellular drug release because it protects the payload, prevents its undesirable leakage during extracellular transport, and favors site-specific drug delivery. In this study, we developed a novel redox responsive core-shell structure nanohydrogel prepared by a water in oil nanoemulsion method using two biocompatible synthetic polymers: vinyl sulfonated poly(N-(2-hydroxypropyl) methacrylamide mono/dilactate)-polyethylene glycol-poly(N-(2-hydroxypropyl) methacrylamide mono/dilactate) triblock copolymer, and thiolated hyaluronic acid. The influence on the nanohydrogel particle size and distribution of formulation parameters was investigated by a three-level full factorial design to optimize the preparation conditions. The surface and core-shell morphology of the nanohydrogel were observed by scanning electron microscope, transmission electronmicroscopy, and further confirmed by Fourier transforminfrared spectroscopy and Raman spectroscopy from the standpoint of chemical composition. The redox-responsive biodegradability of the nanohydrogel in reducing environments was determined using glutathione as reducing agent. A nanohydrogel with particle size around 250 nm and polydispersity index around 0.1 is characterized by a thermosensitive shell which jellifies at body temperature and crosslinks at the interface of a redox-responsive hyaluronic acid core via theMichael addition reaction. The nanohydrogel showed good encapsulation efficiency for model macromolecules of different molecular weight (93% for cytochrome C, 47% for horseradish peroxidase, and 90% for bovine serum albumin), capacity to retain the peroxidase-like enzymatic activity (around 90%) of cytochrome C and horseradish peroxidase, and specific redox-responsive release behavior. Additionally, the nanohydrogel exhibited excellent cytocompatibility and internalization efficiency into macrophages. Therefore, the developed core-shell structure nanohydrogel can be considered a promising tool for the potential intracellular delivery of different pharmaceutical applications, including for cancer therapy

Structure and chemical composition reversibility during Li-ion rocking chair battery operation based on ZFO anodes

Structure and composition changes of ZFO-C ( carbon covered ZnFe2O4) nanoparticles [1] used in anodes during Li+ batteries charge and discharge cycles was monitored at the atomic level as a function of time by using XAS [2], a chemical sensitive and short range probe, and by selectively tuning the detection depth by collecting electrons, total and partial yield, and photon fluorescence yield. ZFO (ZnFe2O4) spinel partially inverts [1] after Li insertion in octahedral sites and concomitant migration of Zn from tetrahedral sites. This mechanism is competitive with the conversion alloying mechanism of LiO2, LiZn and separation of metallic Fe. The reversibility of the present transformation is difficult to be tracked by conventional techniques as the disorder dominates and the diffraction techniques fail in following the microscopic phases during the charging and discharging cycle. X-ray absorption experiments have been conceived and realized to study the modification of the signals related to the structure during the lithiation process. To this aim a full multiple scattering calculation was employed, with assistance of full potential to best treat the open structures by using a virtual bcc network of empty spheres. This method will be used for k-shells while L2,3 edges will be studied by means of the empirical program (CTM4XAS) [3]. The nanostructrues of the anode material, consisting of 30-50 nm size covered ZFO particles covered by C, interact with battery environment made by binder ( carboxymethylcellulose) , solid electrolyte (LiPF6) and solvent (mixture of ethylene and dimethyl carbonate). XAS allows to grasp the inner mechanisms of the interface formation and cycling mechanism at the basis of the high capacitance material. In particular the role of the surface and of a partially reversible interface increasing the Li storage limit is under study by the present methods. References 1.Bresser D., Adv. Energy Mater. 2013, 3, 513–523 2. Di Cicco et al., Adv. Enegy Mater. 1500642 (2015

Development of a high temperature diamond anvil cell for x ray absorption experiments under extreme conditions

X-ray absorption spectroscopy (XAS) is presently a powerful and established tool to investigate solid and liquid matter at high pressure and high temperature (HP-HT). HP-HT XAS experiments rely on high pressure technology whose continuous development has extended the achievable range up to 100 GPa and more. In high pressure devices, high temperature conditions are typically obtained by using internal and external resistive heaters or by laser heating. We have recently developed a novel design for an internally heated diamond anvil cell (DAC) allowing XAS measurements under controlled high temperature conditions (tested up to about 1300 K). The sample in the new device can be rapidly heated or cooled (seconds or less) so the cell is suitable for studying melting/crystallization dynamics when coupled with a time-resolved XAS setup (second and sub-second ranges). Here we describe the internally heated DAC device which has been realized and tested in experiments on pure selenium at the energy dispersive ODE beamline of Synchrotron SOLEIL. We also present results obtained in XAS experiments of elemental Se using a large volume Paris-Edinburgh press, as an example of the relevance of structural studies of matter under extreme conditions

A new internally heated diamond anvil cell system for time-resolved optical and x-ray measurements

We have developed a new internally heated diamond anvil cell (DAC) system for in situ high-pressure and high-temperature x-ray and optical experiments. We have adopted a self-heating W/Re gasket design allowing for both sample confinement and heating. This solution has been seldom used in the past but proved to be very efficient to reduce the size of the heating spot near the sample region, improving heating and cooling rates as compared to other resistive heating strategies. The system has been widely tested under high-temperature conditions by performing several thermal emission measurements. A robust relationship between electric power and average sample temperature inside the DAC has been established up to about 1500 K by a measurement campaign on different simple substances. A micro-Raman spectrometer was used for various in situ optical measurements and allowed us to map the temperature distribution of the sample. The distribution resulted to be uniform within the typical uncertainty of these measurements (5% at 1000 K). The high-temperature performances of the DAC were also verified in a series of XAS (x-ray absorption spectroscopy) experiments using both nano-polycrystalline and single-crystal diamond anvils. XAS measurements of germanium at 3.5 GPa were obtained in the 300 K-1300 K range, studying the melting transition and nucleation to the crystal phase. The achievable heating and cooling rates of the DAC were studied exploiting a XAS dispersive setup, collecting series of near-edge XAS spectra with sub-second time resolution. An original XAS-based dynamical temperature calibration procedure was developed and used to monitor the sample and diamond temperatures during the application of constant power cycles, indicating that heating and cooling rates in the 100 K/s range can be easily achieved using this device

Valence State of Pb in Transition Metal Perovskites PbTMO3 (TM= Ti, Ni) Determined From X-Ray Absorption Near-Edge Spectroscopy

We present a combined experimental and theoretical Pb‐L3 X‐ray absorption near‐edge spectroscopy (XANES) to investigate the chemical state of Pb in transition metal perovskites PbTMO3 (TM= Ti, Ni). A pre‐edge feature originated from the excitation of a 2p core electron to the 6s orbital is only observed in PbNiO3, from which the valence of Pb is determined to be Pb4+ with two 6s holes. However, no such 2p–6s related excitation was observed in PbTiO3, indicating the formation of Pb2+ with fully occupied 6s2 state in this materials. Our results demonstrate that this pre‐edge peak from dipole allowed 2p–6s transition is a sensitive finger‐print of the Pb valence state in solid state materials

Metallic Interface Induced Ionic Redistribution within Amorphous MoO3 Films

Advanced Materials Interfaces published by Wiley-VCH GmbH.The phase evolution and ionic redistribution in amorphous MoO3 films, deposited on metallic aluminium (Al) and copper (Cu) substrates and subjected to distinct thermal treatments, are systematically investigated in this work. It is shown that the metallic interface significantly modifies the formation and dynamics of oxygen vacancies within the resulted structure, reducing the oxygen content of the MoO3 up to x < 2.94. The concentration of the oxygen vacancies can also be extended to the bulk via thermal treatment up to 400 °C. It is demonstrated that the MoO3 structure on metallic substrates is affected either by the diffusion of the metallic atoms inserted from the interface, which results in a formation of the meta-stable alloy phases in case of Cu, or by the introduction of the oxygen vacancies into the crystalline matrix in case of Al. The oxygen vacancy density in the MoO3 films with a metallic interface can be tuned via optimal choice of the metal and treatment parameters such as temperature and oxygen partial pressure. Furthermore, the intrinsic defects present in the amorphous structure enhance the ionic mobility and diffusion of the metallic ions inside the crystalline structure.11Nsciescopu