Prospective study on Maresin-1 and cytokine levels in medication-naïve adolescents with first-episode major depressive disorder.

Background: Inflammation and immune activation may play a role in the pathological mechanism of Major Depressive Disorder (MDD). Evidence from cross-sectional and longitudinal studies of adolescents and adults has shown that MDD is associated with increased plasma pro-inflammatory cytokines (e.g., IL-1ß, IL-6). It has been reported that Specialized Pro-resolving Mediators (SPMs) mediate inflammation resolution, and Maresin-1 can activate the process of inflammation and promote inflammation resolution by promoting macrophage phagocytosis. However, no clinical studies have been conducted to evaluate the relationship between the levels of Maresin-1 and cytokine and the severity of MDD symptomatology in adolescents. Methods: 40 untreated adolescent patients with primary and moderate to severe MDD and 30 healthy participants as the healthy control (HC) group aged between 13 and 18 years old were enrolled. They received clinical and Hamilton Depression Rating Scale (HDRS-17) evaluation and then, blood samples were collected. Patients in the MDD group were re-evaluated for HDRS-17, and blood samples were taken after a six to eight-week fluoxetine treatment. Results: The adolescent patients with MDD had lower serum levels of Maresin-1 and higher serum levels of interleukin 6 (IL-6) compared with the HC group. Fluoxetine treatment alleviated depressive symptoms in MDD adolescent patients, which was reflected by higher serum levels of Maresin-1 and IL-4 and lower HDRS-17 scores, serum levels of IL-6, and IL-1ß. Moreover, the serum level of Maresin-1 was negatively correlated with the depression severity scores on the HDRS-17. Conclusion: Adolescent patients with primary MDD had lower levels of Maresin-1 and higher levels of IL-6 compared with the HC group, implying that the peripheral level of pro-inflammatory cytokines may be elevated in MDD, resulting in the insufficiency of inflammation resolution. The Maresin-1 and IL-4 levels increased after anti-depressant treatment, whereas IL-6 and IL-1ß levels decreased significantly. Moreover, Maresin-1 level negatively correlated with depression severity, suggesting that reduced levels of Maresin-1 promoted the progression of MDD.

Recent advances in green carbon dots (2015-2022): synthesis, metal ion sensing, and biological applications.

Carbon dots (CDs) show extensive potential in various fields such as sensing, bioimaging, catalysis, medicine, optoelectronics, and drug delivery due to their unique properties, that is, low cytotoxicity, cytocompatibility, water-solubility, multicolor wavelength tuned emission, photo-stability, easy modification, strong chemical inertness, etc. This review article especially focuses on the recent advancement (2015-2022) in the green synthesis of CDs, their application in metal ions sensing and microbial bioimaging, detection, and viability studies as well as their applications in pathogenic control and plant growth promotion.

The Influence of Self-Esteem and Psychological Flexibility on Medical College Students' Mental Health: A Cross-Sectional Study.

Background: Mental health problems has become a major public health issue among medical students. Self-esteem and psychological flexibility were important associated factors for mental health, but their relations have not been discussed in medical students. The present study aimed to assess the status of mental health problems among medical students and identified whether psychological flexibility had a mediating role in the effects of self-esteem on the top three most common psychological symptoms. Methods: A total of 810 undergraduate students from 18 classes comprised in the sample. Nine dimensions of psychological symptoms was assessed by the Symptom Checklist-90-revised (SCL-90-R). Self-esteem was measured by the Self-esteem Scale (SES) and psychological flexibility was evaluated by the Acceptance and Action Questionnaire 2nd Edition (AAQ-II) and Cognitive Fusion Questionnaire (CFQ-F). Univariate analysis and logistic regression analysis were used to determine the relationship among the top three common psychological symptoms, self-esteem, psychological flexibility, and participants' characteristics. The mediating effect of psychological flexibility between self-esteem and psychological symptoms was detected by bootstrap method. Results: 57.8% of the medical undergraduate students reported positive at least one of the nine psychological symptom dimensions assessed by the SCL-90-R and 13.8% of students had moderate or more severe symptoms. The symptoms of obsessive-compulsiveness, interpersonal sensitivity, and depression were the three most common psychological symptoms among the medical students. Meanwhile, self-esteem and psychological flexibility were negatively associated to the symptoms of obsessive-compulsiveness, interpersonal sensitivity, and depression. And, almost 50% effects of self-esteem on these three symptoms in medical students exert indirect effects through psychological flexibility. Conclusions: Psychological distress was quite common in the Chinese medical students. The three most common psychological symptoms were successively obsessive-compulsiveness, interpersonal sensitivity, and depression. Low self-esteem and psychological inflexibility might be the risk factors for these top three symptoms, and psychological flexibility might play a mediating role in the effects of self-esteem on these psychological symptoms.

Synthesis of Photo, Oxidative, and Reductive Triple-Stimuli-Responsive Block Copolymer Micelles as Nanocarriers for Controlled Release.

With the rapid development of nanotechnology, stimuli-responsive nanomaterials have provided an alternative for designing controllable drug delivery systems due to their spatiotemporally controllable properties. The environment of the human body is complex and cancer cells proliferate rapidly; the traditional nanocarriers could not release the loaded drugs sufficiently, and the release level of the drug is not sufficient for the requirement of treatment. Herein, a photoresponsive, glutathione, and reactive oxygen species block copolymer mPEG2k-ONB-SS-PO-mPEG2k is prepared by Cu(I)-catalyzed azide-alkyne cycloaddition click polymerization. The ο-nitrobenzyl groups, peroxalate ester bonds, disulfide bonds, and triazole units are regularly and repeatedly arranged in hydrophobic blocks. The photo, oxidative, and reductive responsive characteristics of the copolymers in different conditions were investigated by ultraviolet and visible spectrophotometry, dynamic light scattering, and transmission electron microscopy. Nile Red is encapsulated into the core of micelles as a model drug and exhibits the drug release behaviors in various environments. This research provides a way to design potential drug carriers and a promising platform for efficient intracellular drug delivery in cancer therapy.

A simple strategy to enhance the luminescence of metal nanoclusters and its application for turn-on detection of 2-thiouracil and hyaluronidase.

Metal nanoclusters (NCs) as promising nanomaterials for sensing applications have attracted significant attention because of their unique photoluminescence properties. However, the quantum yields of metal NCs are still relatively low when compared to conventional quantum dots and organic dyes, posing a major obstacle to their assay application. It is challenging but important to pursue a way to improve the luminescence of metal NCs. In this work, we developed a novel strategy to enhance the luminescence of silver nanoclusters (Ag NCs) based on the binding with 6-aza-2-thiothymine (ATT) via Au3+ bridging. We studied the possible mechanism of this binding-induced luminescence enhancement and attributed it to the ligands rigidifying. Since 2-thiouracil (2-TU), a common anticancer, antithyroid, and antiviral agent, featured a similar molecular structure of ATT, this luminescence enhancement strategy can be designed to sensitive and selective turn-on detect 2-TU. As far as we know, this is the first report for the fluorescent turn-on detect 2-TU. Benefiting from the good performance of this method and the advantages of fluorescence assay, intracellular imaging of 2-TU, which has yet to be achieved based on currently developed analytical methods for 2-TU, was carried out via our approach. Moreover, to further expand the sensing application of the developed luminescence enhancement method, we constructed a universal detection platform. Taking hyaluronidase as a target, the feasibility of the detection platform was confirmed. The discoveries in this study offer a simple route to improve the optical properties of NCs and design their sensing applications.

Amphiphilic polymer-encapsulated Au nanoclusters with enhanced emission and stability for highly selective detection of hypochlorous acid.

It is of vital importance to develop probes to monitor hypochlorous acid (HClO) in biological systems as HClO is associated with many important physiological and pathological processes. Metal nanoclusters (NCs) are promising luminescent nanomaterials for highly reactive oxygen species (hROS) detection on the basis of their strong reaction ability with hROS. However, metal NCs typically can respond to most common hROS and are susceptible to etching by biothiols, hindering their application in the construction of effective HClO probes. Herein, we proposed a strategy to develop a nanoprobe based on Au NCs for highly sensitive and selective detection of HClO. We synthesized luminescent benzyl mercaptan-stabilized Au NCs and encapsulated them with an amphiphilic polymer (DSPE-PEG). After encapsulation, an obvious emission enhancement and good resistance to the etching by biothiols for Au NCs were achieved. More importantly, the DSPE-PEG encapsulated Au NCs can be used as a nanoprobe for detection of HClO with good performance. The luminescence of the Au NCs was effectively and selectively quenched by HClO. A good linear relationship with the concentration of HClO in the range of 5-35 µM and a limit of detection (LOD) of 1.4 µM were obtained. Additionally, this nanoprobe was successfully used for bioimaging and monitoring of HClO changes in live cells, suggesting the application potential of the as-prepared amphiphilic polymer-encapsulated Au NCs for further HClO-related biomedical research.

Aggregation-Induced Emission of Au/Ag Alloy Nanoclusters for Fluorescence Detection of Inorganic Pyrophosphate and Pyrophosphatase Activity.

The development of sensitive and accurate detection of inorganic pyrophosphate (PPi) and pyrophosphatase activity (PPase) is important as they play vital roles in biological systems. However, it is still not satisfactory for most of the analytical methods for PPi and PPase because of their Cu2+-dependence and poor accuracy. Although the metal ion triggered aggregation-induced emission (AIE) of metal nanoclusters (NCs) offers a new approach to design a Cu2+-free strategy for the accurate determination of PPi and PPase recently, current methods are all focused on utilizing pure metal NCs. Alloy NCs incorporating the advantages of diverse metal usually can achieve improved behaviors in the application, such as enhanced sensitivity and stability. In this work, glutathione stabilized alloy Au/Ag NCs were synthesized via a simple method and used for the fluorescence detection of PPi and PPase based on a Zn2+-regulated AIE strategy. The controlled release of Zn2+ by PPi and PPase could regulate the AIE of Au/Ag NCs and be employed to response PPi concentration and PPase activity. This method processes simple procedure, high sensitivity and stability, and low toxicity. In addition, we also studied the AIE behaviors of this Au/Ag NCs and offer some fundamental understanding of the AIE properties of water-soluble alloy NCs. This study not only provides a straightforward and new approach for PPi and PPase determination but a basis for further study on the AIE properties of alloy NCs and their application.

Redox-responsive hollow mesoporous silica nanoparticles constructed via host-guest interactions for controllable drug release.

A novel redox-responsive hollow mesoporous silica (HMS) was constructed by host-guest interaction between ß-cyclodextrin modified hollow mesoporus silica nanoparticles (HMS@ß-CD) and the ferrocene-containing amphiphilic block copolymer PEG-b-PMAFc (PPFc), the prepared HMS@ß-CD@PPFc system was used to control drug delivery in targeted cancer therapy through redox stimulus. The self-assembled morphology was investigated by transmission electron microscopy (TEM) and dynamic light scattering (DLS). Intracellular localization of DOX-loaded HMS@ß-CD@PPFc in A549 cells was further investigated by confocal laser scanning microscopy (CLSM), and the results indicated that DOX-loaded HMS@ß-CD@PPFc was ingested by A549 cells effectively. Furthermore, the redox agent H2O2 was used to trigger the release of DOX. The cytotoxicity evaluated by MTT method indicated that HMS@ß-CD@PPFc had good biocompatibility and was promising as the drug carrier.

A novel strategy to synthesize dual-responsive polymeric nanocarriers for investigating the activity and stability of immobilized pectinase.

A dual-stimuli-responsive support material for pectinase immobilization through ionic bonding was prepared. Specifically, polystyrene-b-polymethylacrylic (PS-b-PMAA), light- and pH-sensitive polystyrene-(5-propargylether-2-nitrobenzyl bromoisobutyrate)-b-poly(diethylamino)ethyl methacrylate-b-poly(polyethylene glycol methacrylate) (PS-ONB-PDEAEMA-b-PPEGMA) were synthesized through atom transfer radical polymerization, click chemistry, and hydrolysis. The two parts could self-assemble into the micelles in an aqueous solution. The micelles shrunk at a higher pH, and their size reduced under UV irradiation. The stimuli-responsive properties of micelles were characterized by dynamic light scattering and transmission electron microscopy. It has been found that this support was able to adsorb 10 U/mL of immobilized pectinase (approximately 223 mg/g) at pH 5.0 and 60 °C for 60 Min. Meanwhile, the highest relative activity of immobilized pectinase was up to approximately 95% at pH 5.0 and 60 °C. The immobilized pectinase retained more than 50% of the initial activity after eight cycles. The relative activity of the pectinase immobilized on the supports without UV irradiation was approximately 3% lower than that after UV irradiation at 60 °C, indicating that tailoring of enzyme activity was achieved by changing environmental conditions. Apparently, the original enzymatic support material had a great application prospect on enzyme immobilization.

Synthesis of temperature, pH, light and dual-redox quintuple-stimuli-responsive shell-crosslinked polymeric nanoparticles for controlled release.

Herein, we prepared a novel quintuple-stimuli-responsive shell-crosslinked (SCL) nanocontainer in respond to temperature, pH, light, and oxidation or reduction species. The well-defined amphiphilic diblock copolymer poly(2-methacryloyloxyethyl ferrocenecarboxylate)-(5-propargylether-2-nitrobenzyl bromoisobutyrate)-poly(dimethylaminoethyl methacrylate) (PMAEFc-ONB-PDMAEMA) was synthesized via atom transfer radical polymerization (ATRP) and click chemistry. The diblock copolymer self-assembled into spherical micelles with a uniform size in aqueous media as non-crosslinked (NCL) micelles, and then the micelles were crosslinked by N,N'-bis(bromoacetyl) cystamine (BBAC) through quaternization reaction between the nitrogen of DMAEMA and the bromine of BBAC to receive the SCL micelles which shrunk at higher temperature, swelled at acidic pH or a low concentration of hydrogen peroxide (H2O2), decrosslinked by a small amount of DL-dithiothreitol (DTT), and were disrupted with DTT and UV light. The multi-stimuli-sensitive properties of the SCL micelles were characterized in detail by dynamic light scattering (DLS), transmission electron microscopy (TEM), fluorescence spectra, and UV-Vis spectra. Owing to the protective effect of the crosslinked network, light response behaviors of the NCL and SCL micelles were different. In contrast to the single stimulus, the combined stimuli could trigger and regulate the release of hydrophobic drug model more effectively and precisely from the SCL micelles. The obtained multi-stimuli-responsive nanocontainers may lead to a new generation of controlled release in the fields of nanotechnology and biotechnology.

Improving Photovoltaic Performance of a Fused-Ring Azepinedione Copolymer via a D-A-A Design.

Two conjugated copolymer donors, PTTABDT and PBTTABDT, based on a fused-ring azepinedione acceptor unit, 5-(2-octyldodecyl)-4H-thieno[2',3':4,5]thieno[3,2-c]thieno[2',3':4,5]thieno[2,3-e]azepine-4,6(5H)-dione (TTA), are prepared. PTTABDT possesses a conventional donor-acceptor (D-A) structure with one TTA in the repeat unit, while PBTTABDT has a D-A-A structure with two TTAs in the repeat unit. Compared with PTTABDT, PBTTABDT shows a deeper highest occupied molecular orbital (HOMO) level, a narrower bandgap, and a higher hole mobility, and exhibits better performance in bulk heterojunction solar cells. Power conversion efficiencies of 6.18% and 7.81% are achieved from PTTABDT:PC71 BM and PBTTABDT:PC71 BM solar cells, respectively. The higher performance of PBTTABDT:PC71 BM solar cells results from the enhanced open-circuit voltage (V oc ) and short-circuit current density ( J sc ).

Synthesis of pH-responsive ß-CD-based star polymer and impact of its self-assembly behavior on pectinase activity.

A novel type of pH-responsive star polymer based on ß-cyclodextrin (ß-CD) was synthesized and further covalently conjugated with enzyme. The impact of its self-assembly behavior on enzyme activity was investigated. In our design, azide containing the polymer (N3 )7 -ß-CD-(PtBA)14 was synthesized via atom transfer radical polymerization of tert-butyl acrylate using (N3 )7 -ß-CD-(Br)14 as the multifunctional initiator. The final product (N3 )7 -ß-CD-(PAA)14 was obtained via hydrolysis and covalently conjugating pectinase onto pH-responsive polyacrylic acid (PAA) arms. PAA can change its conformation with the self-assembly by altered pH, leading its nanostructure into micellar nanoparticles in aqueous solution and further affecting the activity of immobilized pectinase. The results were proved by fluorescence spectroscopy and dynamic light scattering. This system proves that the activity of immobilized enzyme can be tailored predictably, and this pH-responsive polymer holds great potential for controllable delivery of enzymes.

Synthesis of the light/pH responsive polymer for immobilization of α-amylase.

In this study, light/pH responsive methoxy poly (ethylene glycol)-(5-propargylether-2-nitrobenzyl bromoisobutyrate)-poly methylacrylic acid-b-polystyrene (mPEG-ONB-PMAA-b-PS) polymers were synthesized, and successfully utilized to fabricate micelles and immobilize α-amylase. The critical micelle concentrations (CMC) of the polymers were measured with Pyrene Fluorescent Probe Technique. The morphology and diameter of micelles were characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS). In addition, the effects of pH, temperature and light-responsive on the catalytic activity were investigated. The optimized fabrication conditions of α-amylase-loaded micelles which α-amylase gave the higher activity were as follows: Immobilization time, 60min; Immobilization temperature, 50°C; enzyme concentration, 10UmL-1; PBS buffer, pH=5.4. α-Amylase immobilized in these micelles was much more stable than that free α-amylase.

Silicon dioxide hollow microspheres with porous composite structure: synthesis and characterization.

In this paper, a strategy for hollow porous silica microspheres with ideally flower structure is presented. SiO(2)/PAM hybrid composite microspheres with porous were synthesized by the reaction that the porous polyacrylamide (PAM) micro-gels immersed in tetraethoxysilane (TEOS) anhydrous alcohol solution and water in a moist atmosphere, with ammonium hydroxide as a catalyst. The SiO(2) hollow microspheres with porous were obtained after calcination of the composite microspheres at 550 °C for 4 h. The morphology, composition, and crystalline structure of the microspheres were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermo-gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FI-IR), and X-ray diffraction (XRD), N(2) absorption analysis, respectively. The results indicated that the obtained hollow porous SiO(2) microspheres were a perfect flower structure.

Synthesis and properties of immobilized pectinase onto the macroporous polyacrylamide microspheres.

Pectinase was covalently immobilized onto the macroporous polyacrylamide (PAM) microspheres synthesized via an inverse suspension polymerization approach, resulting in 81.7% immobilization yield. The stability of the macroporous PAM support, which has a large surface area, is not impeded by the adsorbed proteins despite the fact that up to 296.3 mg of enzyme is immobilized per gram of the carrier particles. The immobilized enzyme retained more than 75% of its initial activity over 30 days, and the optimum temperature/pH also increased to the range of 50-60 °C/3.0-5.0. The immobilized enzyme also exhibited great operational stability, and more than 75% residual activity was observed after 10 batch reactions. The kinetics of a model reaction catalyzed by the immobilized pectinase was finally investigated. Moreover, the immobilized pectinase could be recovered by centrifuging and showed durable activity at the process of recycle.

Fe3O4/SiO2-g-PSStNa polymer nanocomposite microspheres (PNCMs) from a surface-initiated atom transfer radical polymerization (SI-ATRP) approach for pectinase immobilization.

Polymer nanocomposite microspheres (PNCMs) as solid supports can improve the efficiency of immobilized enzymes by reducing diffusional limitation as well as by increasing the surface area per mass unit. In this work, pectinase was immobilized on Fe(3)O(4)/SiO2-g-poly(PSStNa) nanocomposite microspheres by covalent attachment. Biochemical studies showed an improved storage stability of the immobilized pectinase as well as enhanced performance at higher temperatures and over a wider pH range. The immobilized enzyme retained >50% of its initial activity over 30 days, and the optimum temperature and pH also increased to the ranges of 50-60 degrees C and 3.0-4.7, respectively. The kinetics of a model reaction catalyzed by the immobilized pectinase was finally investigated by the Michaelis-Menten equation. The PSStNa support presents a very simple, mild, and time-saving process for enzyme immobilization, and this strategy of immobilizing pectinase also makes use of expensive enzymes economically viable, strengthening repeated use of them as catalysts following their rapid and easy separation with a magnet.

One-step synthesis of silver nanoparticles by sonication or heating using amphiphilic block copolymer as templates.

Block copolymer-supported Ag Nps (nanoparticles) have either a "cherry"-like or "raspberry"-like morphology [Antonietti, et al., Adv. Mater. 7 (1995) 1000-1005] depending on the amount of silver nitrate loading and the external conditions. Sonication favors silver nitrate and polyethyleneimine diffusion; the nucleation sites are well distributed in the micellar cores, so it is easy to form the cherry-like Ag NP colloids. However, when the amount of silver nitrate is decreased, it is heating that induces the formation of raspberry-like Ag NP colloids. The Ag NP colloids were investigated by transmission electron microscopy to demonstrate the nanosize dimensions and the location of the Ag NPs in the micelles. X-ray diffraction was employed to determine the crystal structure of the Ag NPs. UV-vis spectroscopy was employed for further qualitative characterization of the optical properties of Ag NPs.

Preparation and properties of immobilized pectinase onto the amphiphilic PS-b-PAA diblock copolymers.

Well-defined amphiphilic block copolymers poly(styrene-b-acrylic acid) (PS-b-PAA) with controlled block length were synthesized using atom transfer radical polymerization (ATRP). Pectinase enzyme was immobilized on the well-defined amphiphilic block copolymers PS-b-PAA. The carboxyl groups on the amphiphilic PS-b-PAA diblock copolymers present a very simple, mild, and time-saving process for enzyme immobilization. Various characteristics of immobilized pectinase such as the pH and temperature stability, thermal stability, and storage stability were valuated. Among them the pH optimum and temperature optimum of free and immobilized pectinase were found to be pH 6.0 and 65 degrees C.

Fabrication of CdSe composite by using the amphiphilic block copolymer as template.

CdSe nanoparticles of improved stability against aggregation were synthesized by using amphiphilic block copolymer polyacrylonitrile-block-poly(ethylene glycol)-block-polyacrylonitrile (PAN-b-PEG-b-PAN, PEA). The products were characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopic (HRTEM). The optical properties were characterized by UV-vis spectrophotometer and the room temperature photoluminescence (PL). The results revealed that the CdSe nanoparticles have been uniformly distributed throughout the copolymer with diameters of 6-7 nm and the produced novel hybrid nanocomposites displayed obviously quantum size effects and interesting fluorescence features. FTIR results provided the information on the interaction between the copolymer and the nanoparticles. The TGA revealed that the thermal property of the copolymer enhanced due to the interaction of the nanoparticles and the groups of the copolymer.