Taurine supplementation alters gene expression profiles in white adipose tissue of obese C57BL/6J mice: Inflammation and lipid synthesis perspectives.

This work aimed to identify the mechanisms by which taurine exerts its anti-obesity effects in the C57BL/6J ob/ob mice model and determine if taurine supplementation increases the amelioration of inflammation and lipogenesis linked genes in the adipose and liver tissues. Three groups of C57BL/6J mice were fed a standard chow diet for a period of 10 weeks the C57BL/6J normal group, the C57BL/6J ob/ob negative control group with no taurine intake and C57BL/6J ob/ob taurine group with taurine intake. Real time PCR was used to examine the gene expression profile in the experimental groups intrascapular brown adipose tissue (BAT), inguinal white adipose tissue (WAT) and liver. TNF-alpha, Ccl2, Adgre and illb genes that are associated with inflammation were found to have varying level of expression in the three tissues. In comparison to BAT and liver these genes were expressed at a much lower level in WAT, with enhanced serum adiponectin levels.

Environment Knowledge-Driven Generic Models to Detect Coughs From Audio Recordings.

Goal: Millions of people are dying due to respiratory diseases, such as COVID-19 and asthma, which are often characterized by some common symptoms, including coughing. Therefore, objective reporting of cough symptoms utilizing environment-adaptive machine-learning models with microphone sensing can directly contribute to respiratory disease diagnosis and patient care. Methods: In this work, we present three generic modeling approaches - unguided, semi-guided, and guided approaches considering three potential scenarios, i.e., when a user has no prior knowledge, some knowledge, and detailed knowledge about the environments, respectively. Results: From detailed analysis with three datasets, we find that guided models are up to 28% more accurate than the unguided models. We find reasonable performance when assessing the applicability of our models using three additional datasets, including two open-sourced cough datasets. Conclusions: Though guided models outperform other models, they require a better understanding of the environment.

A fully automated primary neuron purification system using continuous centrifugal microfluidics.

Progress in neurological research has experienced bottlenecks owing to the limited availability of purified primary neurons. Since neuronal cells are non-proliferative, it is necessary to obtain purified neurons from animal models or human patients for experimental work. However, currently available methods for purifying primary neurons are time-consuming (taking approximately 1 week), and suffer from insufficient viability and purity. Here, we report a method for rapid enrichment of neurons from the mouse embryonic dorsal root ganglion (DRG), using a fully-automated continuous centrifugal microfluidics (CCM) based neuron purification disc (NPD). Non-neuronal cells were removed via negative depletion by combining density gradient centrifugation and immunomagnetic separation. The CCM-NPD platform enables effective isolation of intact neurons within 13 min, which is approximately 800 times faster than the conventional chemical purification method. Furthermore, the neurons purified using the CCM-NPD platform showed better neurite growth, along with higher viability (93.5%) and purity (97.0%) after 1 week of culture, compared to the chemical purification method. Therefore, the proposed automated and rapid system yields purified DRG neurons with high viability and purity, while avoiding the use of harsh chemicals. We believe this system will significantly mitigate the shortage of purified primary neurons and advance neurological research.

Injectable glycol chitosan thermogel formulation for efficient inner ear drug delivery.

We prepared a new injectable thermogel to enhance the efficiency of inner ear delivery of dexamethasone (DEX). Hexanoyl glycol chitosan (HGC) was synthesized and evaluated as an amphiphilic thermogel (Tgel ~ 32 °C) for use as a solubilizing agent as well as an injectable carrier for intratympanic delivery of the hydrophilic and hydrophobic forms of DEX. Various thermogel formulations with different drug types and concentrations were prepared, and their physicochemical and thermogelling properties were characterized by 1H NMR, ATR-FTIR, and rheometer. They exhibited versatile release kinetics from several hours to more than 2 weeks, depending on drug type and concentration. Our formulations further showed good residual stability for more than 21 days without any cytotoxicity or inflammation in the middle and inner ear and could deliver a considerably high drug concentration into the inner ear. Therefore, HGC thermogel has great potential as an effective and safe formulation for inner ear drug delivery.

Improving the Extraction of Catechins of Green Tea (Camellia sinensis) by Subcritical Water Extraction (SWE) Combined with Pulsed Electric Field (PEF) or Intense Pulsed Light (IPL) Pretreatment.

The aim of this study was to find the optimum condition of pulsed electric field (PEF) and intense pulsed light (IPL) for the enhancement of subcritical water extraction (SWE), which is an eco-friendly extraction method, for extracting tea catechins from green tea leaves (Camellia sinensis). The leaves were treated with PEF under conditions of electric field strength (1, 2 and 3 kV/cm) during 60 s. Moreover, IPL was applied at various voltages (800, 1000, and 1200 V) for 60 s. The SWE was performed for 5 min at varying temperatures (110, 130, 150, 170, and 190 °C). The maximum yield of total catechin was 44.35 ± 2.00 mg/g dry green tea leaves at PEF treatment conditions of 2 kV/cm during 60 s, as well as the SWE temperature of 130 °C. In the case of IPL treatment, the largest amount of total catechin was 48.06 ± 5.03 mg/g dry green tea leaves at 800 V during 60 s when the extraction temperature was 130 °C. The total catechin content was increased by 15.43% for PEF and 25.09% for IPL compared to the value of untreated leaves. This study verified that PEF and IPL had a positive effect on the enhancement of tea catechins extraction from green tea leaves using SWE.

Biologically Safe, Degradable Self-Destruction System for On-Demand, Programmable Transient Electronics.

The lifetime of transient electronic components can be programmed via the use of encapsulation/passivation layers or of on-demand, stimuli-responsive polymers (heat, light, or chemicals), but yet most research is limited to slow dissolution rate, hazardous constituents, or byproducts, or complicated synthesis of reactants. Here we present a physicochemical destruction system with dissolvable, nontoxic materials as an efficient, multipurpose platform, where chemically produced bubbles rapidly collapse device structures and acidic molecules accelerate dissolution of functional traces. Extensive studies of composites based on biodegradable polymers (gelatin and poly(lactic-co-glycolic acid)) and harmless blowing agents (organic acid and bicarbonate salt) validate the capability for the desired system. Integration with wearable/recyclable electronic components, fast-degradable device layouts, and wireless microfluidic devices highlights potential applicability toward versatile/multifunctional transient systems. In vivo toxicity tests demonstrate biological safety of the proposed system.

Self-Assembled Multi-Epitope Peptide Amphiphiles Enhance the Immune Response against Enterovirus 71.

Subunit vaccines consist of non-genetic material, such as peptides or proteins. They are considered safe because they have fewer side effects; however, they have low immunogenicity when used alone. We aimed to enhance the immune response of peptide-based vaccines by using self-assembled multimeric peptide amphiphiles (PAs). We designed two epitope PAs by conjugating epitope peptides from Enterovirus 71 (EV71) virus particle (VP) 1 and VP3 capsid proteins with different fatty acid chain lengths (VP1PA and VP3PA). These PAs self-assembled into supramolecular structures at a physiological pH, and the resulting structures were characterized using atomic force microscopy. Multi-epitope PAs (m-PAs) consisted of a 1:1 mixture of VP1PA and VP3PA solutions. To evaluate immunogenicity, m-PA constructs were injected with adjuvant subcutaneously into female Balb/c mice. Levels of antigen-specific immunoglobulin G (IgG) and IgG1 in m-PA-injected mice serum samples were analyzed using ELISA and Western blotting. Additionally, cytokine production stimulated by each antigen was measured in splenocytes cultured from immunized mice groups. We found that m-PA showed improved humoral and cellular immune responses compared to the control and peptide groups. The sera from m-PA immunized mice group could neutralize EV71 infection and protect host cells. Thus, self-assembled m-PAs can promote a protective immune response and can be developed as a potential platform technology to produce peptide vaccines against infectious viral diseases.

Self-Quenched Polysaccharide Nanoparticles with a Reactive Oxygen Species-Sensitive Cascade for Enhanced Photodynamic Therapy.

Tumor microenvironment (TME)-responsive nanocarrier systems that keep the photosensitizer (PS) inactive during systemic circulation and then efficiently release or activate the PS in response to unique TME conditions have attracted much attention. Herein, we report novel TME-responsive, self-quenched polysaccharide nanoparticles (NPs) with a reactive oxygen species (ROS)-sensitive cascade. The PS, pheophorbide A (PhA), was conjugated to a water-soluble glycol chitosan (GC) through an ROS-sensitive thioketal (TK) linker. The amphiphilic GC-TK-PhA conjugates could arrange themselves into NPs and remain photoinactive due to their self-quenching effects. Upon reaching the ROS-rich hypoxic core of the tumor tissue, the NPs release the PS in a photoactive form by efficient, ROS-sensitive TK bond cleavage, thus generating potent phototoxic effects. Following near-infrared irradiation, the increase in locoregional ROS levels further accelerates the release and activation of PS. These cascade reactions caused a significant reduction in the tumor volume, demonstrating good antitumor potential.

Epitope Peptide Amphiphile-Based Nanofiber as an Effective Vaccine for Viral Infectious Diseases.

Peptide-based vaccines are relatively safe but have weak immune responses even with an adjuvant. In order to overcome the limitations of peptide-based vaccines, we developed peptide amphiphile (PA)-based nanofibers to enhance the immune responses for preventing enterovirus 71 (EV71) infectious disease (i.e., Hand, Foot, and Mouth Disease). PAs are peptides conjugated with fatty acid alkyl chain and able to self-assemble into various structures including high-aspectratio nanofibers. We designed PAs by coupling EV71 virus particle 1 (VP1) epitope peptides and spacer-crosslinker to the N-terminal of long-chain fatty acids (VP1-PA). PAs then self-assembled into nanofibers at physiological pH (pH 7.4). PA nanofibers were characterized by atomic force microscopy (AFM). For the immunization studies, C57BL/6 mice were injected intraperitoneally (i.p.) with recombinant VP1 with adjuvant (alum), VP1 epitope peptide with or without adjuvant, VP1-PA nanofibers with or without adjuvant, and PBS. To assess the immunogenecity of the VP1-PA nanofibers on serum samples from the immunized mice was analyzed by Western blot for the evaluation of VP1-specific IgG. The PA group showed a higher immune response than the peptide group. We expect that self-assembling VP1-PA based nanofibers as an immune stimulator could enhance immune responses effectively against EV71 infection and overcome the limitations of peptide-based vaccine.

Bioactivatable reactive oxygen species-sensitive nanoparticulate system for chemo-photodynamic therapy.

Bioactivatable polymer nanoparticles (NPs) have attracted considerable attention as a prospective cancer therapy. Herein, we describe bioactivatable reactive oxygen species (ROS)-sensitive prodrug NPs designed to elicit spatiotemporally controlled, phototriggered chemo-photodynamic therapy. First, an effective anticancer agent, doxorubicin (DOX), was conjugated to poly(ethylene glycol) (PEG) via an ROS-responsive degradable thioketal (TK) linker. The resulting amphiphilic PEG-DOX conjugate (PEG-TK-DOX) self-assembled into a bioactivatable ROS-responsive NP system could efficiently encapsulate a hydrophobic photodynamic therapy (PDT) agent, pheophorbide A (PhA), with good colloidal stability and unimodal size distribution. Second, after the selective retention of NPs in the tumor, the site-specific release of DOX and PhA was spatiotemporally controlled, initially by endogenous ROS and subsequently by exogenous ROS produced during PDT. The locoregional treatment not only photoactivates PhA molecules to generate cytotoxic ROS but also triggers an ROS cascade, which accelerates the release of DOX and PhA via the ROS-mediated structural destruction of NPs, resulting in an enhanced anticancer therapeutic effect. This prodrug-NP system may function as an effective nanomedicine platform, working synergistically to maximize the efficacy of the combination of chemotherapy and photodynamic therapy with a remote-controlled release mechanism. STATEMENT OF SIGNIFICANCE: Photodynamic therapy (PDT) is a noninvasive therapy involving local ROS generation through the activation of photosensitizer (PS) molecules induced via external irradiation with near-infrared (NIR) light. Combinational therapies with PDT could synergistically enhance the therapeutic efficacy and overcome the limitations of monotherapy. In this study, we describe bioactivatable reactive oxygen species (ROS)-sensitive prodrug nanoparticles designed to elicit spatiotemporally controlled, photo triggered chemo-photodynamic therapy. Upon accumulation in tumor by enhanced permeation and retention (EPR) effect, the nanoparticles exhibited target-specific release of chemo-drug and photosensitizer in a spatiotemporally controlled cascade manner by endogenous ROS in the initial stage and the excessive production of exogenous ROS during PDT, leading to a further ROS cascade that accelerates the release of therapeutic cargo.

Long circulating photoactivable nanomicelles with tumor localized activation and ROS triggered self-accelerating drug release for enhanced locoregional chemo-photodynamic therapy.

Although chemo-photodynamic therapy demonstrates promising synergetic therapeutic effect in malignant cancers, the currently available nanocarriers offer the limited capabilities for selective toxicity, drug release and tumor penetration. Herein, we developed photoactivatable nanomicelles, which are constructed by self-assembling of poly (ethylene glycol) (PEG)-stearamine (C18) conjugate (PTS) with a ROS-sensitive thioketal linker (TL) and co-loaded with doxorubicin (DOX) and photosensitizer pheophorbide A (PhA), for enhanced locoregional chemo-photodynamic therapy. Upon accumulation in tumor region, the resulting PTS nanomicelles loaded with Dox and PhA (PTS-DP) demonstrated reactive oxygen species (ROS) cascade responsive release of the DOX and PhA loaded inside. Initial intracellular release of DOX and PhA from the PTS-DP was triggered by the intrinsic presence of endogenous ROS within cancer cells. Furthermore, upon laser irradiation on the tumor region, enhanced singlet oxygen (1O2) was generated by PhA released initially in cancer cells, which in turns accelerated the cytoplasmic release of DOX through rapid dissociation of nanomicelles. The gradual elevation of local ROS level generated by light-activated PhA subsequent ROS-triggered release of DOX synergistically inhibited tumor growth and enhances the anti-tumor immunity. Findings of our study suggested that ROS-sensitive PTS nanomicelles could be a promising and innovative nanocarrier for locoregional chemo-photodynamic therapy.

Synthesis and characterization of bioreducible cationic biarm polymer for efficient gene delivery.

We synthesized a new cationic AB2 miktoarm block copolymer consisting of one poly (ethylene glycol) (PEG) block and two cationic poly (l-lysine) (PLL) blocks, wherein the PLL blocks were conjugated to the PEG blocks with or without a bioreducible linker (disulfide bonds). Bioreducible and non-bioreducible miktoarm block copolymers (mPEG-(ss-PLL)2 and mPEG-PLL2) were prepared for efficient gene delivery as a non-viral gene delivery approach. Both cationic copolymers (bioreducible and nonbioreducible) efficiently formed the nanopolyplexes with plasmid DNA (pDNA) through electrostatic interaction at different weight ratio of polymer and pDNA. Gene condensation ability of the polymers and release of the DNA under reduction condition were measured by gel electrophoresis. Dynamic light scattering (DLS) and field-emission transmission electron microscopy (FE-TEM) were used to measure the average hydrodynamic diameter and morphology of the nanoparticles, respectively. The bioreducible nanopolyplexes showed lower cytotoxicity and higher gene expression than the non-reducible nanopolyplexes in cancer cells.

Neuroprotective Effects of Antidepressants via Upregulation of Neurotrophic Factors in the MPTP Model of Parkinson's Disease.

Neurotrophic factors are essential for neuronal survival, plasticity, and development and have been implicated in the action mechanism of antidepressants. In this study, we assessed the neurotrophic factor-inducing and neuroprotective properties of antidepressants. In the first part of the study, we found that fluoxetine, imipramine, and milnacipran (i.p., 20 mg/kg/day for 1 week or 3 weeks) upregulated brain-derived neurotrophic factor in the striatum and substantia nigra both at 1 week and 3 weeks. In contrast, an increase in the glial-derived neurotrophic factor was more obvious at 3 weeks after the antidepressants treatment. Specifically, it was found that fluoxetine and imipramine are more potent in raising the levels of neurotrophic factors than milnacipran. Furthermore, antidepressants elevated the phosphorylation of extracellular signal-regulated-protein kinase (ERK1/2) and the serine/threonine kinase Akt. In the second part of the study, we compared the neuroprotective effects of fluoxetine, imipramine, and milnacipran in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of Parkinson's disease. Pretreament with fluoxetine, imipramine or milnacipran for 3 weeks reduced MPTP-induced dopaminergic neurodegeneration and microglial activation in the nigrostriatal pathway. Neurochemical analysis by HPLC exhibited that antidepressants attenuated the depletion of striatal dopamine. In consistent, beam test showed that behavioral impairment was ameliorated by antidepressants. Neuroprotective effects were more prominent in the fluoxetine or imipramine treatment group than in milnacipran treatment group. Finally, we found that neuroprotection of the antidepressants against 1-methyl-4-phenylpyridinium neurotoxicity in SH-SY5Y cells was attenuated by ERK or Akt inhibitor. These results indicate that neuroprotection by antidepressants might be associated with the induction of neurotrophic factors, and antidepressant could be a potential therapeutic intervention for treatment of Parkinson's disease.