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We investigated the carboxylated conjugated polymer poly 3-(3-carboxypropyl)thiophene-2,5-diyl as a nanosized (200–350 nm) biomolecule receptor layer on the channel of organic electrochemical trans...

Dolutegravir (DTG) is a first-line antiretroviral drug (ARV) used in combination therapy for the treatment of human immunodeficiency virus type-1 (HIV-1) infection. The drug is effective, safe, and well tolerated. Nonetheless, concerns have recently emerged for its usage in pregnant women or those of child-bearing age. Notably, DTG-based ARV regimens have been linked to birth defects seen as a consequence of periconceptional usages. To this end, uncovering an underlying mechanism for DTG-associated adverse fetal development outcomes has gained clinical and basic research interest. We now report that DTG inhibits matrix metalloproteinases (MMPs) activities that could affect fetal neurodevelopment. DTG is a broad-spectrum MMPs inhibitor and binds to Zn++ at the enzyme’s catalytic domain. Studies performed in pregnant mice show that DTG readily reaches the fetal central nervous system during gestation and inhibits MMP activity. Postnatal screenings of brain health in mice pups identified neuroinflammation and neuronal impairment. These abnormalities persist as a consequence of in utero DTG exposure. We conclude that DTG inhibition of MMPs activities during gestation has the potential to affect prenatal and postnatal neurodevelopment. Supplementary Information The online version contains supplementary material available at 10.1007/s12035-021-02508-5.

OBJECTIVE: Antiretroviral drug (ARV) theranostics facilitates the monitoring of biodistribution and efficacy of therapies designed to target human immunodeficiency virus type-1 (HIV-1) reservoirs. To this end, we have now deployed intrinsic drug chemical exchange saturation transfer (CEST) contrasts to detect ARVs within the central nervous system (CNS). DESIGN AND METHODS: CEST effects for lamivudine (3TC) and emtricitabine (FTC) were measured by asymmetric magnetization transfer ratio analyses. The biodistribution of 3TC in different brain sub-regions of C57BL/6 mice treated with lipopolysaccharides was determined using magnetic resonance imaging (MRI). CEST effects of 3TC protons were quantitated by Lorentzian fitting analysis. 3TC levels in plasma and brain regions were measured using ultraperformance liquid chromatography tandem mass spectrometry to affirm the CEST test results. RESULTS: CEST effects of the hydroxyl and amino protons in 3TC and FTC linearly correlated to drug concentrations. 3TC was successfully detected in vivo in brain sub-regions by MRI. The imaging results were validated by measurements of CNS drug concentrations. CONCLUSION: CEST contrasts can be used to detect ARVs using MRI. Such detection can be used to assess spatial-temporal drug biodistribution. This is most notable within the CNS where drug biodistribution may be more limited with the final goal of better understanding ARV-associated efficacy and potential toxicity.

The nature of and the ability to control biasing across dielectrics is a key area of research for the design of more versatile organic field-effect transistors (OFETs). One important technique to a...

The improvement of conjugated polymer-based gas sensors involves fine tuning the backbone electronic structure and solid-state microstructure to combine high stability and sensitivity. We had previously developed a series of diketopyrrolopyrrole (DPP)-based polymer semiconductors by introducing a variety of fluorene linkers to study the trends and mechanisms governing gas sensitivities and electronic stability in air and under gate and drain bias stress. The proportional on-current change of organic field-effect transistors (OFETs) using a dithienyl DPP–fluorene polymer reached ∼600% for a sequential exposure from 0.5–20 ppm of NO2 for 5 minutes and also a high response-to-drift ratio under dynamic bias stress. In the present work we specify the roles of static bias stress and traps in the sensing process for the first time. Apart from electronic structure, defects at the molecular and microstructural levels govern the ability to form and sustain traps and subsequent backbone dopability. A polymer with a twisted backbone was observed to be capable of creating an energetically broad trap distribution while a polymer with a high degree of solid-state order shows a tendency to form an energetically narrow trap distribution and a fast passivation of traps on exposure to air. The stability and energetic distribution of traps on subjecting the polymers to bias stress was related to electronic structure and solid-state packing; and the ability of NO2 and NH3 to fill/create traps further was evaluated. At a bias stress condition of VG = VD = −80 V, the polymers retain their NO2 sensitivity both post NO2-aided recovery and air-aided recovery. In order to verify the ability of NH3 to create traps, traps were erased from the OFET sensors by charging with the aid of a positive gate voltage leading to an increase in the NH3 response when compared to air controls. This work demonstrates that the charge-trap filling and generation response mechanism is predominant and can even be leveraged for higher responses to vapors. Backbone dopability appears to be a minor contributor to responses in this category of polymeric semiconductors with engineered defects. Finally, bias stress generally does not preclude this category of OFET vapor sensors from recovering their original sensitivities.

Ruan et al. show that brain-derived extracellular vesicles from human donors with Alzheimer’s disease propagate tau more efficiently when injected into the mouse hippocampus than oligomeric or fibrillary tau from the same donors. The extracellular vesicles preferentially spread tau pathology to interneurons., Extracellular vesicles are highly transmissible and play critical roles in the propagation of tau pathology, although the underlying mechanism remains elusive. Here, for the first time, we comprehensively characterized the physicochemical structure and pathogenic function of human brain-derived extracellular vesicles isolated from Alzheimer’s disease, prodromal Alzheimer’s disease, and non-demented control cases. Alzheimer’s disease extracellular vesicles were significantly enriched in epitope-specific tau oligomers in comparison to prodromal Alzheimer’s disease or control extracellular vesicles as determined by dot blot and atomic force microscopy. Alzheimer’s disease extracellular vesicles were more efficiently internalized by murine cortical neurons, as well as more efficient in transferring and misfolding tau, than prodromal Alzheimer’s disease and control extracellular vesicles in vitro. Strikingly, the inoculation of Alzheimer’s disease or prodromal Alzheimer’s disease extracellular vesicles containing only 300 pg of tau into the outer molecular layer of the dentate gyrus of 18-month-old C57BL/6 mice resulted in the accumulation of abnormally phosphorylated tau throughout the hippocampus by 4.5 months, whereas inoculation of an equal amount of tau from control extracellular vesicles, isolated tau oligomers, or fibrils from the same Alzheimer’s disease donor showed little tau pathology. Furthermore, Alzheimer’s disease extracellular vesicles induced misfolding of endogenous tau in both oligomeric and sarkosyl-insoluble forms in the hippocampal region. Unexpectedly, phosphorylated tau was primarily accumulated in glutamic acid decarboxylase 67 (GAD67) GABAergic interneurons and, to a lesser extent, glutamate receptor 2/3-positive excitatory mossy cells, showing preferential extracellular vesicle-mediated GABAergic interneuronal tau propagation. Whole-cell patch clamp recordings of CA1 pyramidal cells showed significant reduction in the amplitude of spontaneous inhibitory post-synaptic currents. This was accompanied by reductions in c-fos+ GAD67+ neurons and GAD67+ neuronal puncta surrounding pyramidal neurons in the CA1 region, confirming reduced GABAergic transmission in this region. Our study posits a novel mechanism for the spread of tau in hippocampal GABAergic interneurons via brain-derived extracellular vesicles and their subsequent neuronal dysfunction.

Ionic doping effects in conjugated polymers often cause nonspecific signaling and a low selectivity of bioelectronic sensing. Using remote-gate field-effect transistor characterization of molecular and ionic doping in poly(3-hexylthiophene) (P3HT) and acid-functionalized polythiophene, poly[3-(3-carboxypropyl) thiophene-2,5-diyl] (PT-COOH), we discovered that proton doping effects on the interfacial potential occurring in P3HT could be suppressed by sequentially doping P3HT by 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ). To be specific, intrinsic pH sensitivity shown by pure P3HT (18 mV/pH in a range from pH 3 to 9) was fully dissipated for doped P3HT:F4TCNQ. However, F4TCNQ sequential doping instead increases pH sensitivity of acid-functionalized polythiophene, PT-COOH (40 mV/pH), compared to that of a pure PT-COOH (30 mV/pH). Interactions between polythiophene backbone and side chains, which constrain the activity of COOH, are weakened by stronger F4TCNQ doping leaving behind responsive COOH groups exposed to aqueous solutions. This is supported by the reduced pH sensitivity of PT-COOH sequentially doped by a weaker dopant, tetracyanoethylene (TCNE) (21 mV/pH). Thus, doping is shown to stabilize a nonpolar conjugated polymer to pH-induced fluctuations on one hand, and to activate a COOH side chain to pH-induced response on the other.

F4TCNQ (2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane) is used widely as a hole-doping agent in photoresponsive organic semiconducting materials, yet relatively little is known about the pho...

Supramolecular materials derived from pi-conjugated peptidic macromolecules are well-established to self-assemble into 1D nanostructures. In the presence of KOH, which was used to more fully dissolve the peptide macromolecules prior to triggering the self-assembly by way of exposure to HCl vapor, we report here an unexpected mineralization of KCl as templated presumably by the glutamic acid residues that were present along the backbone of the peptide macromolecules. In order to decouple the peptidic side chains from the central pi-electron unit, three-carbon spacers were added between them on both sides. The assembled structures that resulted from the collective formation of β-sheets, π-orbital overlaps, and mineralization resulted in highly interconnected dendritic structures under suitable KOH concentrations. Electrical measurements indicated that when well-interconnected, these dendritic structures maintained conductivities comparable to those of metals at around 1800 S/cm. About 50 mA current was measured for 0.5 V/37.5 μm. Varying the gate voltage in a transistor configuration had no effect on the current levels, indicating a conductive instead of a semiconducting pathway. Control experiments without the peptide, measurements of conductivity over time, and conductivity quenching by ammonia suggested the conductivity of these dendritic networks was derived from proton doping of the central π-electron units in a strong acid environment and was facilitated by closely spaced chromophores, as suggested in the literature, leading to facile π-electron transfer along the interconnected dendritic pathways. Our findings suggest that mineralization templated by appropriate amino acids combined with peptide/π-electron self-assembly can lead to highly conductive dendritic macrostructures as well as control of nanowire growth in specific directions.

Human immunodeficiency virus theranostics facilitates the development of long acting (LA) antiretroviral drugs (ARVs) by defining drug-particle cell depots. Optimal drug formulations are made possible based on precise particle composition, structure, shape and size. Through the creation of rod-shaped particles of defined sizes reflective of native LA drugs, theranostic probes can be deployed to measure particle-cell and tissue biodistribution, antiretroviral activities and drug retention. Methods: Herein, we created multimodal rilpivirine (RPV) 177lutetium labeled bismuth sulfide nanorods (177LuBSNRs) then evaluated their structure, morphology, configuration, chemical composition, biological responses and adverse reactions. Particle biodistribution was analyzed by single photon emission computed tomography (SPECT/CT) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) imaging. Results: Nanoformulated RPV and BSNRs-RPV particles showed comparable physicochemical and cell biological properties. Drug-particle pharmacokinetics (PK) and biodistribution in lymphoid tissue macrophages proved equivalent, one with the other. Rapid particle uptake and tissue distribution were observed, without adverse reactions, in primary blood-derived and tissue macrophages. The latter was seen within the marginal zones of spleen. Conclusions: These data, taken together, support the use of 177LuBSNRs as theranostic probes as a rapid assessment tool for PK LA ARV measurements.

A carboxylated thiophene polymer-based chemiresistive device in a field-effect transistor (FET) configuration with unusual and enhanced responses to the widespread pollutants nitrogen dioxide (NO2) and ammonia (NH3) is described. The device based on a polymeric thiophene carboxylic acid showed a dramatic and superlinear increase in drain current (ID) of over 15 000% to a ramped exposure to 10 ppm NO2 over several minutes, while its ethyl ester counterpart had significantly lower response. Devices incorporating either an ester or carboxylic acid displayed comparable and previously unreported increases in ID from 10 ppm ramped NH3 exposure of 200–300%. Conventional poly(alkylthiophenes) showed the expected current decreases from similar NH3 exposures. Using threshold voltage shifts in silicon transistors coupled to our recently reported remote gate (RG) platform with thiophene polymer coatings, we determined that two differing response mechanisms are associated with the two gas exposures. By calculating the charge density induced in the polymers by NO2 exposure using the silicon transistor voltage shifts, we conclude that proton conduction contributes significantly to the high sensitivity of the carboxylic acid to NO2, in addition to doping that was observed for all four polymers. Furthermore, hydrogen bonding moieties of the carboxylic acid and ester may be able to physisorb NH3 and thus alter the charge distribution, rearrange polymer chains, and/or create a proton transfer network leading to the ID increase that is the opposite of the response obtained from non-carboxylated thiophene polymers.

We present two new polythiophene isomers, PQTC16-TT and PQTSC16-TT, with more separation and lower side chain density on the backbone compared with the typical polythiophenes, such as PQT(S)12 and ...

A subparts per million-sensitive nitrogen dioxide (NO2) sensing circuit with improved humid air stability was realized incorporating UV-ozone treatment on a poly(bisdodecylquaterthiophene)/polystyr...

International audience; Four serine/threonine kinases are present in all mycobacteria: PknA, PknB, PknG and PknL. PknA and PknB are essential for growth and replication, PknG regulates metabolism, but little is known about PknL. Inactivation of pknL and adjacent regulator MSMEG_4242 in rough colony M. smegmatis mc2155 produced both smooth and rough colonies. Upon restreaking rough colonies, smooth colonies appeared at a frequency of ~ 1/250. Smooth mutants did not form biofilms, showed increased sliding motility and anomalous lipids on thin-layer chromatography, identified by mass spectrometry as lipooligosaccharides and perhaps also glycopeptidolipids. RNA-seq and Sanger sequencing revealed that all smooth mutants had inactivated lsr2 genes due to mutations and different IS1096 insertions. When complemented with lsr2, the colonies became rough, anomalous lipids disappeared and sliding motility decreased. Smooth mutants showed increased expression of IS1096 transposase TnpA and MSMEG_4727, which encodes a protein similar to PKS5. When MSMEG_4727 was deleted, smooth pknL/MSMEG_4242/lsr2 mutants reverted to rough, formed good biofilms, their motility decreased slightly and their anomalous lipids disappeared. Rough delpknL/del4242 mutants formed poor biofilms and showed decreased, aberrant sliding motility and both phenotypes were complemented with the two deleted genes. Inactivation of lsr2 changes colony morphology from rough to smooth, augments sliding motility and increases expression of MSMEG_4727 and other enzymes synthesizing lipooligosaccharides, apparently preventing biofilm formation. Similar morphological phase changes occur in other mycobacteria, likely reflecting environmental adaptations. PknL and MSMEG_4242 regulate lipid components of the outer cell envelope and their absence selects for lsr2 inactivation. A regulatory, phosphorylation cascade model is proposed.

We synthesized highly branched and electron-donating side chain subunits and attached them to polystyrene (PS) used as a dielectric layer in a pentacene field-effect transistor. The influence of these groups on dielectric function, charge retention, and threshold voltage shifts (ΔVth) depending on their positions in dielectric multilayers was determined. We compared the observations made on an N-perphenylated iminobisaniline side chain with those from the same side chains modified with ZnO nanoparticles and with an adduct formed from tetracyanoethylene (TCNE). We also synthesized an analogue in which six methoxy groups are present instead of two amine nitrogens. At 6 mol % side chain, hopping transport was sufficient to cause shorting of the gate, while at 2 mol %, charge trapping was observable as transistor threshold voltage shifts (ΔVth). We created three types of devices: with the substituted PS layer as single-layer dielectric, on top of a cross-linked PS layer but in contact with the pentacene (bilayers), and sandwiched between two PS layers in trilayers. Especially large bias stress effects and ΔVth, larger than those in the case of the hexamethoxy and previously studied dimethoxy analogues, were observed in the second case, and the effects increased with the increasing electron-donating properties of the modified side chains. The highest ΔVth was consistent with a majority of the side chains stabilizing the trapped charge. Trilayer devices showed decreased charge storage capability compared to previous work in which we used less donating side chains but in higher concentrations. The ZnO and TCNE modifications resulted in slightly more and less negative ΔVth, respectively, when the side chain polystyrene was not in contact with the pentacene and isolated from the gate electrode. The results indicate a likely maximum combination of molecular charge stabilizing activity and side chain concentration that still allows gate dielectric function.

A once every eight-week cabotegravir (CAB) long-acting parenteral is more effective than daily oral emtricitabine and tenofovir disoproxil fumarate in preventing human immunodeficiency virus type one (HIV-1) transmission. Extending CAB dosing to a yearly injectable advances efforts for the elimination of viral transmission. Here we report rigor, reproducibility and mechanistic insights for a year-long CAB injectable. Pharmacokinetic (PK) profiles of this nanoformulated CAB prodrug (NM2CAB) are affirmed at three independent research laboratories. PK profiles in mice and rats show plasma CAB levels at or above the protein-adjusted 90% inhibitory concentration for a year after a single dose. Sustained native and prodrug concentrations are at the muscle injection site and in lymphoid tissues. The results parallel NM2CAB uptake and retention in human macrophages. NM2CAB nanocrystals are stable in blood and tissue homogenates. The long apparent drug half-life follows pH-dependent prodrug hydrolysis upon slow prodrug nanocrystal dissolution and absorption. In contrast, solubilized prodrug is hydrolyzed in hours in plasma and tissues from multiple mammalian species. No toxicities are observed in animals. These results affirm the pharmacological properties and extended apparent half-life for a nanoformulated CAB prodrug. The report serves to support the mechanistic design for drug formulation safety, rigor and reproducibility., Here, the authors provide a mechanism for an improved version of a nanoformulated myristoylated prodrug of cabotegravir (CAB), named NM2CAB, and its bioavailability, stability and pharmacokinetics in mice and rats performed in independent academic and a contracted research labs, suggesting that the extended half-life of the prodrug is not a property of enzymatic hydrolysis but rather release or dissolution of the prodrug from the nanocrystal.

Purpose A palmitoylated prodrug of emtricitabine (FTC) was synthesized to extend the drug's half-life, antiretroviral activities and biodistribution. Methods A modified FTC prodrug (MFTC) was synthesized by palmitoyl chloride esterification. MFTC's chemical structure was evaluated by nuclear magnetic resonance. The created hydrophobic prodrug nanocrystals were encased into a poloxamer surfactant and the pharmacokinetics (PK), biodistribution and antiretroviral activities of the nanoformulation (NMFTC) were assessed. The conversion of MFTC to FTC triphosphates was evaluated. Results MFTC coated with poloxamer formed stable nanocrystals (NMFTC). NMFTC demonstrated an average particle size, polydispersity index and zeta potential of 350 nm, 0.24 and -20 mV, respectively. Drug encapsulation efficiency was 90%. NMFTC was readily taken up by human monocyte-derived macrophages yielding readily detected intracellular FTC triphosphates and an extended PK profile. Conclusion NMFTC shows improved antiretroviral activities over native FTC. This is coordinate with its extended apparent half-life. The work represents an incremental advance in the development of a long-acting FTC formulation.

Over 80 heat treatment experiments have been made on samples of chloride-contaminated plutonium dioxide retrieved from two packages in storage at Sellafield. These packages dated from 1974 and 1980 and were produced in a batch process by conversion of plutonium oxalate in a furnace at around 550 °C. The storage package contained a poly(vinyl chloride) (PVC) bag between the screw top inner and outer metal cans. Degradation of the PVC has led to adsorption of hydrogen chloride together with other atmospheric gases onto the PuO2 surface. Analysis by caustic leaching and ion chromatography gave chloride contents of 2000 to >5000 ppm Cl (i.e., μgCl g-1 of the original sample). Although there are some subtle differences, in general, there is surprisingly good agreement in results from heat treatment experiments for all the samples from both cans. Mass loss on heating (LOH) plateaus at nearly 3 wt % above 700 °C, although samples that were long stored under an air atmosphere or preexposed to 95% relative humidity atmospheres, gave higher LOH up to â4 wt %. The majority of the mass loss is due to adsorbed water and other atmospheric gases rather than chloride. Heating volatilizes chloride only above â400 °C implying that simple physisorption of HCl is not the main cause of contamination. Interestingly, above 700 °C, >100% of the initial leachable chloride can be volatilized. Surface (leachable) chloride decreases quickly with heat treatment temperatures up to â600 °C but only slowly above this temperature. Storage in air atmosphere post-heat treatment apparently leads to a reequilibration as leachable chloride increases. The presence of a "nonleachable" form of chloride was thus inferred and subsequently confirmed in PuO2 samples (pre- A nd post-heat treatment) that were fully dissolved and analyzed for the total chloride inventory. Reheating samples in either air or argon at temperatures up to the first heat treatment temperature did not volatilize significant amounts of additional chloride. With regard to a thermal stabilization process, heat treatment in flowing air at 800 °C with cooling and packaging under dry argon appears optimal, particularly, if thinner powder beds can be maintained. From electron microscopy, heat treatment appeared to have the most effect on degrading the square platelet particles compared to those with the trapezoidal morphology.

We have previously described a midazolam limited sampling strategy employing a population pharmacokinetic (PK) approach to estimate constitutive cytochrome P450 (CYP) 3A activity. This study evaluated expansion of this approach to estimate CYP3A constitutive, inhibitory, and induction activities. Midazolam concentrations (n = 4441) from adults (n = 152) were obtained from previous studies after single, oral, or intravenous administration with intensive sample collection. Data were fit to a 2-compartment population PK model that incorporated CYP3A conditions as covariates for clearance (CL), volume of distribution, and bioavailability (F). Limited sampling models using single- or 2-time point concentrations were compared with full PK profiles using the empiric Bayesian post hoc estimations of midazolam area under the plasma concentration-time curve derived from the population PK model. Ketoconazole, rifampin, and pleconaril were significant covariates of CL, while ketoconazole, rifampin, and grapefruit juice were significant covariates for F. Typical midazolam CL and F estimates were 32.9 L/h and 0.31 for the constituent state, while the ratio of inducer/inhibitor for midazolam CL and CL/F for the induced/inhibited (rifampin/ketoconazole) states were 14.2 and 85.3. Upon comparison to the population PK model, the majority of evaluated single- and 2-time point limited sampling models estimated area under the plasma concentration-time curve had unacceptable r2 and/or unacceptable bias and precision. Exclusively during CYP3A inhibitory conditions, the 4- and 6-hour limited sampling model had acceptable limits of r2 , bias, and precision. Consequently, development of a single- or 2-time point midazolam limited sampling model for general, widespread use to simultaneously evaluate various CYP3A conditions remains elusive.

Organic field-effect transistor (OFET) based ammonia gas sensors were fabricated by incorporating a simple solution processed hybrid dielectric, which consisting of poly(methyl methacrylate) (PMMA) and Graphene Oxide (GO) sheets. By carefully optimizing the proportion of GO sheets in the dielectric, a remarkable improvement of sensing performance was obtained when exposed to various NH3 concentrations. Compared with those with pure PMMA dielectric, the sensitivity of OFET sensors with hybrid dielectric had two orders of magnitude enhancement from 1.4% to 30%. The GO/PMMA hybrid dielectric based OFET also shows good selectivity for NH3 against H2S, SO2, and NO2. By analyzing the hybrid dielectric and the 6,13-bis(triisopropyl-silylethynyl) pentacene (TIPS-pentacene) film through utilizing fourier transform infrared spectroscopy, X-ray diffraction and atomic force microscope, the enhanced sensing performance was attributed to the preferable interaction between functional groups on GO sheets and NH3 gas molecules. The improved sensing performance by the combination of GO and PMMA also suggests the possibility of proper dielectric functionality engineering for the further fabrication of OFET based gas sensors with high performance.

Long-acting antiretrovirals can improve therapy and prevention for HIV-1 infection. Current long-acting cabotegravir (CAB LAP) can be administered every other month. Previously, we demonstrated that a myristoylated CAB prodrug encased in poloxamer 407 provided extended plasma drug concentrations. We now demonstrate that this first-generation nanoformulated prodrug can sustain plasma CAB concentrations above the protein-adjusted 90% inhibitory concentration for 4 months in rhesus macaques. A 2.5-fold extension in CAB half-life and a 1.6-fold increase in area under the concentration-time curve were observed compared with CAB LAP.

Characterizing doping effects in a conductive polymer and physical diffusion in a passive polymer were performed using a remote-gate field-effect transistor (RG FET) detection system that was able to measure the electrical potential perturbation of a polymer film coupled to the gate of a silicon FET. Poly(3-hexylthiophene) (P3HT) film doped using various concentrations of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) solutions imposed additional positive potentials on the P3HT RG, resulting in a lower threshold voltage ( Vth) on the n-channel silicon FET. Changes in Vth were related to the induced hole concentrations and hole mobility in P3HT films by using our Vth shifting model for the RG FET. We discovered that the electron-donating P3HT and even inorganic materials, indium tin oxide and gold, showed similar electrical potential perturbations dependent on the concentration of F4TCNQ in overlying solutions as the dopant radical anions maximally covered the surfaces. This suggests that there are limited electroactive sites for F4TCNQ binding on electron donor surfaces which results in a similar number of positive charges in film materials forming dipoles with the F4TCNQ radical counteranions. The effect of electron acceptors such as 7,7,8,8-tetracyanoquinodimethane and tetracyanoethylene was compared to that of F4TCNQ in terms of Vth shift using our analytical tool, with differences attributed to acceptor size and reduction potential. Meanwhile, this FET analysis tool offered a means of monitoring the physical diffusion of small molecules, exemplified by F4TCNQ, in the passive polymer polystyrene, driven by concentration gradients. The technique allows for nondestructive, nonspectroscopic, ambient characterization of electron donor-acceptor interactions at surfaces.

Engagement of the BCR with Ags triggers signaling pathways for commitment of B lymphocyte responses that can be regulated, in part, by reactive oxygen species. To investigate the functional relevance of reactive oxygen species produced in primary B cells, we focused on the role of the hydrogen peroxide generator Duox1 in stimulated splenic B cells under the influence of the TH2 cytokine IL-4. We found that H2O2 production in wild type (WT) and Nox2-deficient CD19+ B cells was boosted concomitantly with enhanced expression of Duox1 following costimulation with BCR agonists together with IL-4, whereas stimulated Duox1−/− cells showed attenuated H2O2 release. We examined whether Duox1-derived H2O2 contributes to proliferative activity and Ig isotype production in CD19+ cells upon BCR stimulation. Duox1−/− CD19+ B cells showed normal responses of Ig production but a higher rate of proliferation than WT or Nox2-deficient cells. Furthermore, we demonstrated that the H2O2 scavenger catalase mimics the effect of Duox1 deficiency by enhancing proliferation of WT CD19+ B cells in vitro. Results from immunized mice reflected the in vitro observations: T cell–independent Ag induced increased B cell expansion in germinal centers from Duox1−/− mice relative to WT and Nox2−/− mice, whereas immunization with T cell–dependent or –independent Ag elicited normal Ig isotype secretion in the Duox1 mutant mice. These observations, obtained both by in vitro and in vivo approaches, strongly suggest that Duox1-derived hydrogen peroxide negatively regulates proliferative activity but not Ig isotype production in primary splenic CD19+ B cells.

This manuscript describes low-voltage epoxy-carbon nanotube composites with highly nonlinear resistances. Carbon nanotube paste was deposited on interdigitated electrodes and I-V characteristics were obtained over different voltage ranges and at different sweep speeds. In most cases, the injection process into the electrode-composite interface region was dominant, with exponential voltage dependence of the current.

We describe an approach to estimate state-of-charge and faded capacity of cobalt-based lithium-ion cell based on timedomain analysis of a short-term transient. This approach requires a relatively short-duration test and is suitable for repurposing cells for less demanding applications. The successful estimation requires previous characterization of the cells for the given family because lithium ion chemistries differ significantly. Two algorithms were considered for estimation of unknown state-of-charge and capacity: Bayesian inference and boosted regression trees. The achieved accuracy was 95 % of capacity estimations; estimations were within 2 % of the nominal cell capacity from the true value.

Background: Delivery of long-acting nanoformulated antiretroviral drugs (ARVs) to human immunodeficiency virus type one cell and tissue reservoirs underlies next generation antiretroviral therapeutics. Nanotheranostics, comprised of trackable nanoparticle adjuncts, can facilitate ARV delivery through real-time drug tracking made possible through bioimaging platforms. Methods: To model HIV-1 therapeutic delivery, europium sulfide (EuS) nanoprobes were developed, characterized and then deployed to cells, tissues, and rodents. Tests were performed with nanoformulated rilpivirine (NRPV), a non-nucleoside reverse transcriptase inhibitor (NNRTI) used clinically to suppress or prevent HIV-1 infection. First, CD4+ T cells and monocyte-derived macrophages were EuS-treated with and without endocytic blockers to identify nanoprobe uptake into cells. Second, Balb/c mice were co-dosed with NRPV and EuS or lutetium177-doped EuS (177LuEuS) theranostic nanoparticles to assess NRPV biodistribution via mass spectrometry. Third, single photon emission computed tomography (SPECT-CT) and magnetic resonance imaging (MRI) bioimaging were used to determine nanotheranostic and NRPV anatomic redistribution over time. Results: EuS nanoprobes and NRPV entered cells through dynamin-dependent pathways. SPECT-CT and MRI identified biodistribution patterns within the reticuloendothelial system for EuS that was coordinate with NRPV trafficking. Conclusions: EuS nanoprobes parallel the uptake and biodistribution of NRPV. These data support their use in modeling NRPV delivery to improve treatment strategies.

Muscle fatigue, pain and weakness are co-morbidities in people living with HIV-1 infection (PLWH), yet an underlying cause remains poorly understood. Herein we evaluated whether concentrations of efavirenz (EFV), atazanavir (ATV), and ritonavir (RTV) that reflect what is present in blood of PLWH could be contributing to the reported skeletal muscle co-morbidites by perturbing sarcoplasmic reticulum (SR) Ca(2+) cycling. In live-cell imaging, EFV (6.0 μM), ATV (6.0 μM), and RTV (3.0 μM) elicited Ca(2+) transients and blebbing of the plasma membranes of C2C12 skeletal muscle myotubes. Pretreating C2C12 skeletal muscle myotubes with the SR Ca(2+) release channel blocker ryanodine (50 μM), slowed the rate and amplitude of Ca(2+) release from and reuptake of Ca(2+) into the SR. EFV, ATV and RTV (1 nM - 20 μM) potentiated and then displaced [(3)H] ryanodine binding to rabbit skeletal muscle ryanodine receptor Ca(2+) release channel (RyR1). The drugs at concentrations 0.25 to 31.2 μM also increased and or decreased the open probability of RyR1 by altering its gating and conductance. ATV (≤ 5 μM) potentiated also inhibited the ability of sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA1) to hydrolyze ATP and transport Ca(2+). RTV (2.5 – 31.5 μM) dose-dependently inhibited SERCA1-mediated, ATP-dependent Ca(2+) transport. EFV (0.25 – 31.5 μM) had no measurable effect on SERCA1’s ability to hydrolyze ATP and transport Ca(2+). These data support the notion that EFV, ATV and RTV could be contributing to skeletal muscle co-morbidities in PLWH by modulating SR Ca(2+) homeostasis.

Organic electrochemical transistors functionalized with antigen-specific nanobodies can rapidly and specifically detect antigens at attomolar-to-nanomolar levels in bodily fluids.

Loss of dopaminergic neurons along the nigrostriatal axis, neuroinflammation, and peripheral immune dysfunction are the pathobiological hallmarks of Parkinson’s disease (PD). Granulocyte–macrophage colony-stimulating factor (GM-CSF) has been successfully tested for PD treatment. GM-CSF is a known immune modulator that induces regulatory T cells (Tregs) and serves as a neuronal protectant in a broad range of neurodegenerative diseases. Due to its short half-life, limited biodistribution, and potential adverse effects, alternative long-acting treatment schemes are of immediate need. A long-acting mouse GM-CSF (mPDM608) was developed through Calibr, a Division of Scripps Research. Following mPDM608 treatment, complete hematologic and chemistry profiles and T-cell phenotypes and functions were determined. Neuroprotective and anti-inflammatory capacities of mPDM608 were assessed in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-intoxicated mice that included transcriptomic immune profiles. Treatment with a single dose of mPDM608 resulted in dose-dependent spleen and white blood cell increases with parallel enhancements in Treg numbers and immunosuppressive function. A shift in CD4(+) T-cell gene expression towards an anti-inflammatory phenotype corresponded with decreased microgliosis and increased dopaminergic neuronal cell survival. mPDM608 elicited a neuroprotective peripheral immune transformation. The observed phenotypic shift and neuroprotective response was greater than observed with recombinant GM-CSF (rGM-CSF) suggesting human PDM608 as a candidate for PD treatment. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13311-020-00877-8) contains supplementary material, which is available to authorized users.

The development of high-performance-conjugated polymer-based gas sensors involves detailed structural tailoring such that high sensitivities are achieved without compromising the stability of the fabricated devices. In this work, we systematically developed a series of diketopyrrolopyrrole (DPP)-based polymer semiconductors by modifying the polymer backbone to achieve and rationalize enhancements in gas sensitivities and electronic stability in air. NO2- and NH3-responsive polymer-based organic field-effect transistors (OFETs) are described with improved air stability compared to all-thiophene conjugated polymers. Five DPP-fluorene-based polymers were synthesized and compared to two control polymers and used as active layers to detect a concentration of NO2 at least as low as 0.5 ppm. The hypothesis that the less electron-donating fluorene main-chain subunit would lead to increased signal/drift compared to thiophene and carbazole subunits was tested. The sensitivities exhibited a bias voltage-dependent behavior. The proportional on-current change of OFETs using a dithienyl DPP-fluorene polymer reached ∼614% for an exposure to 20 ppm of NO2 for 5 min, testing at a bias voltage of -33 V, among the higher reported NO2 sensitivities for conjugated polymers. Electronic and morphological studies reveal that introduction of the fluorene unit in the DPP backbone decreases the ease of backbone oxidation and induces traps in the thin films. The combination of thin-film morphology and oxidation potentials governs the gas-absorbing properties of these materials. The ratio of responses on exposure to NO2 and NH3 compared to drifts while taking the device through repeated gate voltage sweeps is the highest for two polymers incorporating electron-donating linkers connecting the DPP and thiophene units in the backbone, in this category of organic semiconductors. The responses to NO2 were much larger than that to NH3, indicating increased susceptibility to oxidizing vs reducing gases, and that the capability of oxidizing gases to induce additional charge density has a more dramatic electronic effect than when reducing gases create traps. This work demonstrates the capability of achieving improved stability with the retention of high sensitivity in conjugated polymer-based OFET sensors by modulating redox and morphological properties of polymer semiconductors by structural control.

Extracellular vesicles (EVs) propagate tau pathology for Alzheimer’s disease (AD). How EV transmission influences AD are, nonetheless, poorly understood. To these ends, the physicochemical and molecular structure-function relationships of human brain-derived EVs, from AD and prodromal AD (pAD), were compared to non-demented controls (CTRL). AD EVs were shown to be significantly enriched in epitope-specific tau oligomers versus pAD or CTRL EVs assayed by dot-blot and atomic force microscopy tests. AD EVs were efficiently internalized by murine cortical neurons and transferred tau with higher aggregation potency than pAD and CTRL EVs. Strikingly, inoculation of tau-containing AD EVs into the outer molecular layer of the dentate gyrus induced tau propagation throughout the hippocampus. This was seen in 22 months-old C57BL/6 mice at 4.5 months post-injection by semiquantitative brain-wide immunohistochemistry tests with multiple anti-phospho-tau (p-tau) antibodies. Inoculation of the equal amount of tau from CTRL EVs or as oligomer or fibril-enriched fraction from the same AD donor showed little propagation. AD EVs induced tau accumulation in the hippocampus as oligomers or sarkosyl-insoluble proteins. Unexpectedly, p-tau cells were mostly GAD67+ GABAergic neurons and to a lesser extent, GluR2/3+ excitatory mossy cells, showing preferential EV-mediated GABAergic neuronal tau propagation. Whole-cell patch clamp recording of Cornu Ammonis (CA1) pyramidal cells showed significant reduction in the amplitude of spontaneous inhibitory post-synaptic currents. This was accompanied by reductions in c-fos+ GAD67+GABAergic neurons and GAD67+ GABAergic neuronal puncta surrounding pyramidal neurons in the CA1 region confirming reduced interneuronal projections. Our study posits a novel tau-associated pathological mechanism for brain-derived EVs.

To mimic the reactions that have occurred between plutonium dioxide (PuO2) and degraded polyvinyl chloride during prolonged storage, batches of PuO2 powders with varying specific surface area (4–38 m2 g−1) were exposed to dry hydrogen chloride gas forming a surface-sorbed exchangeable chloride species that was readily leached by dilute caustic solution. One batch was also humidified under a 95% relative humidity atmosphere. Heat treatment at temperatures between 100 and 950 °C steadily reduced the leachable chloride content at least when the initial leachable chloride surface coverage was calculated to be > 0.5 monolayer (ML). Variations between samples are attributed to differences in surface area as well as production route and period of interim storage in air or humidified atmospheres. The data are consistent with surface species and reactions proposed in the literature for HCl adsorption on to TiO2. This indicates that it is interactions between hydrogen chloride/chloride and water/hydroxyl species on the PuO2 surface that are key to understanding the behaviour of these materials when heated in a furnace. These data will inform the design of a future thermal stabilisation process for chloride-contaminated PuO2.

The effect of a combination of low temperature heat treatments, microwave annealing, and low temperature vacuum annealing on the resistivity of 1% Al-doped ZnO thin films (AZO) deposited on both flexible polyimide films and rigid silicon substrates was investigated. The sol-gel deposition technique was used to deposit successive layers with a 0.5-hour heat treatment application prior to the deposition of additional layers. Following the final layer deposition and 0.5-hour treatment, the samples either underwent a final thermal annealing or microwave plus thermal annealing. Finally, a post-treatment annealing in a high vacuum chamber at 300 °C was administered. The films exhibited ultra-low resistivity of 14 Ω-cm on the polyimide with good adhesion qualities and a 0.08 Ω-cm resistivity on silicon wafers. A hexagonal wurtzite structure with the (002) c-axis orientation in the film growth direction was evident along with a dense microstructure of homogeneously distributed grains.

The properties of a mixed metallic and semiconducting carbon nanotube (CNT) sample dispersed in nonconjugated poly(methyl methacrylate) (PMMA) and conjugated poly(bisdodecylquaterthiophene) (PQT12) were compared, with and without p-doping by NOBF4. The CNTs were distributed much more evenly, and percolated at much lower concentrations (ca. 2%), in the PMMA as compared to PQT12, as judged by optical microscopy and electronic conductivity measurements. Seebeck coefficients (S) obtained on the PMMA samples indicated dominance by the metallic fraction, with values

Long-acting cabotegravir (CAB) extends antiretroviral drug administration from daily to monthly. However, dosing volumes, injection site reactions and health-care oversight are obstacles towards a broad usage. The creation of poloxamer-coated hydrophobic and lipophilic CAB prodrugs with controlled hydrolysis and tissue penetrance can overcome these obstacles. To such ends, fatty acid ester CAB nanocrystal prodrugs with 14, 18 and 22 added carbon chains were encased in biocompatible surfactants named NMCAB, NM2CAB and NM3CAB and tested for drug release, activation, cytotoxicity, antiretroviral activities, pharmacokinetics and biodistribution. Pharmacokinetics studies, performed in mice and rhesus macaques, with the lead 18-carbon ester chain NM2CAB, showed plasma CAB levels above the protein-adjusted 90% inhibitory concentration for up to a year. NM2CAB, compared with NMCAB and NM3CAB, demonstrated a prolonged drug release, plasma circulation time and tissue drug concentrations after a single 45 mg per kg body weight intramuscular injection. These prodrug modifications could substantially improve CAB’s effectiveness. Nanoformulated long-acting cabotegravir prodrugs are shown to be capable of extending the native drug’s antiretroviral activity, biodistribution and pharmacokinetics for up to 12 months in mice and rhesus macaques.

Charge storage and trapping properties of polymer dielectrics govern the charge densities of adjacent semiconductors and greatly influence the on–off switching voltage (threshold voltage, Vth) of o...

Nucleoside reverse transcriptase inhibitors (NRTIs) require intracellular phosphorylation to active triphosphate (TP) nucleotide metabolites before they can inhibit the HIV reverse transcriptase. However, monitoring these pharmacologically active TP metabolites is challenging due to their instability and their low concentrations at the pg/ml levels in blood and tissues. The combination of lamivudine (3TC) and abacavir (ABC) is one of the first lines for HIV therapy. Therefore, a sensitive, selective, accurate, and precise LC-MS/MS method was developed and validated for the simultaneous quantification of 3TC- and ABC-TP metabolites in mouse blood and tissues. Calibration curves were linear over the range of 10–100,000 pg/ml for 3TC-TP and 4– 40,000 pg/ml for carbovir-TP (CBV-TP; phosphorylated metabolite of ABC). This corresponds to 2.1– 21,322 fmol/10(6) cells for 3TC-TP and 0.8– 8,000 fmol/10(6) cells for CBV-TP. Accuracy and precision were less than 15% for all quality control sample (QCs), and absolute extraction recovery of were > 65 % for 3TC-TP and > 90 % for CVB-TP. The method was optimized to ensure stability of TP samples and standards during sample collection, preparation, analysis, and storage conditions. This method has enhanced sensitivity and requires smaller amounts of blood and tissue samples compared to previous LC-MS/MS methods for 3TC- and CBV-TP quantification. The developed method was successfully applied to characterize the pharmacokinetic profile of TP metabolites in mouse peripheral blood mononuclear cells (PBMCs), spleen, lymph nodes, and liver cells. In addition, another direct, simple, and high-throughput method for the quantification of TP standards was developed and used for the analysis of stability samples.

A field-effect transistor-based cortisol sensor was demonstrated in physiological conditions. An antibody-embedded polymer on the remote gate was proposed to overcome the Debye length issue (λ(D)). The sensing membrane was made by linking poly(styrene-co-methacrylic acid) (PSMA) with anticortisol before coating the modified polymer on the remote gate. The embedded receptor in the polymer showed sensitivity from 10 fg/mL to 10 ng/mL for cortisol and a limit of detection (LOD) of 1 pg/mL in 1× PBS where λ(D) is 0.2 nm. A LOD of 1 ng/mL was shown in lightly buffered artificial sweat. Finally, a sandwich ELISA confirmed the antibody binding activity of antibody-embedded PSMA.

Aim: While the therapeutic potential for current long-acting (LA) antiretroviral therapy (ART) is undeniable, ligand-decorated nanoformulated LA-ART could optimize drug delivery to viral reservoirs. The development of decorated ART hinges, however, on formulation processes and manufacture efficiencies. To this end, we compared manufacture and purification techniques for ligand-decorated antiretroviral drug nanocrystals. Materials & methods: Ligand-decorated nanoparticle manufacturing was tested using folic acid (FA) nanoformulated cabotegravir. Results: Direct manufacturing of FA-cabotegravir resulted in stable particles with high drug loading and monocyte–macrophage targeting. A one step ‘direct’ scheme proved superior over differential centrifugation or tangential flow filtration facilitating particle stability and preparation simplicity and efficiency. Conclusion: Direct manufacturing of FA nanoparticles provides a path toward large-scale clinical grade manufacturing of cell-targeted LA-ART., Lay abstract Folic acid (FA) decoration on the surface of nanocrystals can be achieved by mixing FA conjugated poloxamer 407 (FA-P407) and native P407 in varied ratios followed by size reduction by homogenization and differential centrifugation or tangential flow filtration to remove excess unbound polymers. The optimized manufacturing scheme is by direct homogenization with predetermined quantity of FA conjugated P407. Direct manufacturing method yields stable homogenous nanoparticles with high drug loading.

The biomolecule guanine and organic semiconductor pentacene were used to form a sensitive and selective organic field-effect transistor (OFET) pair sensitive to nitrogen dioxide gas and five other vapor analytes. OFETs with two configurations were fabricated, one of which used thermally deposited guanine and pentacene layer-by-layer to form the sensing unit, while the other one only adopted pentacene as the sensing element. First, the OFET using the guanine-pentacene sensing unit was more sensitive to nitrogen dioxide gas. Then, these two kinds of OFETs showed opposite responses and/or different response magnitudes to the other vapor analytes. The sensing responses of the two OFETs presented distinct patterns and thus could distinguish individual analytes including nitrogen dioxide. The work demonstrates the application of a low-cost and environmental-friendly biomolecule to organic electronic sensing.

Long-acting parenteral (LAP) antiretroviral drugs have generated considerable interest for treatment and prevention of HIV-1 infection. One new LAP is cabotegravir (CAB), a highly potent integrase inhibitor, with a half-life of up to 54 days, allowing for every other month parenteral administrations. Despite this excellent profile, high volume dosing, injection site reactions and low body fluid drug concentrations affect broad use for virus infected and susceptible people. To improve the drug delivery profile, we created a myristoylated CAB prodrug (MCAB). MCAB formed crystals that were formulated into nanoparticles (NMCAB) of stable size and shape facilitating avid monocyte-macrophage entry, retention and reticuloendothelial system depot formulation. Drug release kinetics paralleled sustained protection against HIV-1 challenge. After a single 45 mg/kg intramuscular injection to BALB/cJ mice, the NMCAB pharmacokinetic profiles was 4-times greater than that recorded for CAB LAP. These observations paralleled replicate measurements in rhesus macaques. The results coupled with improved viral restriction in human adult lymphocyte reconstituted NOD/SCID/IL2Rγc−/− mice led us to conclude that NMCAB can improve biodistribution and viral clearance profiles upon current CAB LAP formulations.