Exploration of ß-glucosidase-producing microorganisms community structure and key communities driving cellulose degradation during composting of pure corn straw by multi-interaction analysis.

Poor management of crop residues leads to environmental pollution and composting is a sustainable practice for addressing the challenge. However, knowledge about composting with pure crop straw is still limited, which is a novel and feasible composting strategy. In this study, pure corn straw was in-situ composted for better management. Community structure of ß-glucosidase-producing microorganisms during composting was deciphered using high-throughput sequencing. Results showed that the compost was mature with organic matter content of 37.83% and pH value of 7.36 and pure corn straw could be composted successfully. Cooling phase was major period for cellulose degradation with the highest ß-glucosidase activity (476.25 µmol·p-Nitr/kg·dw·min) and microbial diversity (Shannon index, 3.63; Chao1 index, 500.81). Significant compositional succession was observed in the functional communities during composting with Streptomyces (14.32%), Trichoderma (13.85%) and Agromyces (11.68%) as dominant genera. ß-Glucosidase-producing bacteria and fungi worked synergistically as a network to degrade cellulose with Streptomyces (0.3045**) as the key community revealed by multi-interaction analysis. Organic matter (-0.415***) and temperature (-0.327***) were key environmental parameters regulating cellulose degradation via influencing ß-glucosidase-producing communities, and ß-glucosidase played a key role in mediating this process. The above results indicated that responses of ß-glucosidase-producing microorganisms to cellulose degradation were reflected at both network and individual levels and multi-interaction analysis could better explain the relationship between variables concerning composting cellulose degradation. The work is of significance for understanding cellulose degradation microbial communities and process during composting of pure corn straw.

Spontaneous reduction of KMnO4 with MoS2 quantum dots for glutathione sensing in tumors.

Transition-metal dichalcogenides (TMDCs) have attracted a lot of attention due to their electronic, optical, mechanical, and catalytic properties. In addition, TMDCs possess rich redox chemistry that enables the decoration of metal nanoparticles directly on their surfaces. In this paper, MnO2/MoS2 nanocomplexes were obtained by the spontaneous reduction of KMnO4 with MoS2 QDs as the reductive agent. The formed MnO2/MoS2 nanocomplexes exhibited activated fluorescence and MR imaging signal in the presence of glutathione (GSH). After conjugation with an AS1411 aptamer, specific in vivo MR imaging and fluorescence labeling of the 786-O tumor cells were realized, showing their promising potential for biomedical applications.

Extrusion Printing of Surface-Functionalized Metal-Organic Framework Inks for a High-Performance Wearable Volatile Organic Compound Sensor.

Wearable sensors hold immense potential for real-time and non-destructive sensing of volatile organic compounds (VOCs), requiring both efficient sensing performance and robust mechanical properties. However, conventional colorimetric sensor arrays, acting as artificial olfactory systems for highly selective VOC profiling, often fail to meet these requirements simultaneously. Here, a high-performance wearable sensor array for VOC visual detection is proposed by extrusion printing of hybrid inks containing surface-functionalized sensing materials. Surface-modified hydrophobic polydimethylsiloxane (PDMS) improves the humidity resistance and VOC sensitivity of PDMS-coated dye/metal-organic frameworks (MOFs) composites. It also enhances their dispersion within liquid PDMS matrix, thereby promoting the hybrid liquid as high-quality extrusion-printing inks. The inks enable direct and precise printing on diverse substrates, forming a uniform and high particle-loading (70 wt%) film. The printed film on a flexible PDMS substrate demonstrates satisfactory flexibility and stretchability while retaining excellent sensing performance from dye/MOFs@PDMS particles. Further, the printed sensor array exhibits enhanced sensitivity to sub-ppm VOC levels, remarkable resistance to high relative humidity (RH) of 90%, and the differentiation ability for eight distinct VOCs. Finally, the wearable sensor proves practical by in situ monitoring of wheat scab-related VOC biomarkers. This study presents a versatile strategy for designing effective wearable gas sensors with widespread applications.

A novel risperidone-loaded SAIB-PLGA mixture matrix depot with a reduced burst release: effects of solvents and PLGA on drug release behaviors in vitro/in vivo.

The purpose of this study was to develop an in situ forming SAIB (sucrose acetate isobutyrate)-PLGA (poly (d, lactide-co-glycolide)) mixture matrix depot for sustained release of risperidone. The factors affecting the risperidone release kinetics were investigated to obtain further insight into the drug release mechanisms. The burst release in vitro was significantly reduced (4.95%) by using DMSO as solvent. And, increasing the PLGA content from 2 to 10% w/w decreased the initial release from 6.95 to 1.05%. The initial release in vivo decreased with increasing PLGA content (2.0% w/w PLGA, C(max) = 1161.7 ± 550.2 ng ml(-1); 10% w/w PLGA, C(max) = 280.3 ± 98.5 ng ml(-1)). The persistence (AUC(4-20 days)) over 20 days increased from 76.8 ± 20.7 to 362.8 ± 75.0 ng d ml(-1) by inclusion of 10% PLGA compared with the PLGA-free depot. These results demonstrate that the SAIB-PLGA mixture matrix depot could be useful as a sustained delivery system for risperidone.

Modulating the pKa Values of Hill-Type pH Probes for Biorelevant Acidic pH Range.

The pH-responsive profile of the traditional pH probes (the HH-type pH probes) is governed by the Henderson-Hasselbalch equation. Despite their widespread use, pH probes with further enhanced pH sensitivity, i.e., Hill-type pH probes, are sought after. As a result of positive cooperativity toward protonation, they exhibit a smaller acid-base transition width than that of a HH-type pH probe, which is 2 pH unit. As a result, the Hill-type pH probes have an improved capability to differentiate minor biorelevant pH changes. We previously devised a class of small-molecule Hill-type pH probes (PHX) with pKa in the range of 6.2-6.8. Subcellular organelles with a physiological pH lower than 6.2 are abundant and consequently Hill-type probes for use in these organelles are expected to exhibit a pKa lower than 6.2 as well. Through a rational and systematic structure-property relationship study, we showcased that the pKa values of the PHN type probes could be lowered by increasing the steric bulkiness or the electron-withdrawing capability of the dialkylamino groups on the bottom phenol moiety. The pKa values of the PHN-type probes now cover the wide biorelevant acidic range from 3.5 to 6.8. The potentials of these probes for biological imaging are exemplified and they are expected to be adopted in biological studies and medical diagnosis.

Cell membrane covered polydopamine nanoparticles with two-photon absorption for precise photothermal therapy of cancer.

HYPOTHESIS: In view of the photothermal effect of polydopamine (PDA) nanoparticles and their internal D-π-D structures during assembly, the two-photon excited properties of PDA were studied toward the biomedical application. Further, the PDA molecules were coordinated with Mn2+ and the assembled nanoparticles were covered by cancer cell membranes, the complex system could be used directly for the treatment of cancer with photothermal and chemodynamic therapy. EXPERIMENTS: The two-photon excited PDA-Mn2+ nanoparticles were used for the photothermal therapy combined with chemodynamic therapy. The complexes were coated with cancer cell membranes in order to enhance the tumor homologous efficiency. Multi-modal bioimaging and anti-tumor detections were carried out both in vitro and in vivo. FINDINGS: PDA nanoparticles were demonstrated to have both good two-photon excited fluorescence and photothermal efficiency. The assembled nanoparticles modified with Mn2+ and cancer cell membranes have an obvious targeting and synergetic anti-cancer efficiency. The system creates a simple way for a precise operation with multi-modal imaging function.

Enhancing biocompatibility and neuronal anti-inflammatory activity of polymyxin B through conjugation with gellan gum.

Polymyxins, as strong antibiotics with high liposaccharide deactivation abilities, are rarely used as neuronal anti-inflammatory agent because of their high cytotoxicity. In this study, polymyxin B (PMB) was conjugated with deacylated gellan gum for the sustained release of PMB to reduce its cytotoxicity at high concentration without affecting the antibacterial and liposaccharide binding activities. For the conjugate of original PMB/GN ratio of 1.0 (GPC), the conjugating rate was 96.40%, and the releasing ratio of PMB was 30.12% within 60 h. The FT-IR spectra of GPC indicated that the amino groups of PMB were covalently bonded with the COOH groups of gellan and other PMB molecules. Most GPCs were micelle shaped regardless of whether they were under dry conditions or in an aqueous solution. The inhibition zones of PMB against Escherichia coli and Pseudomonas aeruginosa were small, but the half maximal inhibitory concentration value against BV-2 cells increased from 15.63 µg/mL to 2000.00 µg/mL after conjugation. GPC can also effectively depress the liposaccharide-stimulated overexpression of cytotoxic nitric oxide by BV-2 cells. This study revealed the possibility of using polymyxins for neuronal anti-inflammation and that this gellan/PMB conjugate can potentially be applied to wound healing and implants.

[Pyr1]-Apelin-13 delivery via nano-liposomal encapsulation attenuates pressure overload-induced cardiac dysfunction.

Nanoparticle-mediated sustained delivery of therapeutics is one of the highly effective and increasingly utilized applications of nanomedicine. Here, we report the development and application of a drug delivery system consisting of polyethylene glycol (PEG)-conjugated liposomal nanoparticles as an efficient in vivo delivery approach for [Pyr1]-apelin-13 polypeptide. Apelin is an adipokine that regulates a variety of biological functions including cardiac hypertrophy and hypertrophy-induced heart failure. The clinical use of apelin has been greatly impaired by its remarkably short half-life in circulation. Here, we investigate whether [Pyr1]-apelin-13 encapsulation in liposome nanocarriers, conjugated with PEG polymer on their surface, can prolong apelin stability in the blood stream and potentiate apelin beneficial effects in cardiac function. Atomic force microscopy and dynamic light scattering were used to assess the structure and size distribution of drug-laden nanoparticles. [Pyr1]-apelin-13 encapsulation in PEGylated liposomal nanocarriers resulted in sustained and extended drug release both in vitro and in vivo. Moreover, intraperitoneal injection of [Pyr1]-apelin-13 nanocarriers in a mouse model of pressure-overload induced heart failure demonstrated a sustainable long-term effect of [Pyr1]-apelin-13 in preventing cardiac dysfunction. We concluded that this engineered nanocarrier system can serve as a delivery platform for treating heart injuries through sustained bioavailability of cardioprotective therapeutics.

The effect of bioengineered acellular collagen patch on cardiac remodeling and ventricular function post myocardial infarction.

Regeneration of the damaged myocardium is one of the most challenging fronts in the field of tissue engineering due to the limited capacity of adult heart tissue to heal and to the mechanical and structural constraints of the cardiac tissue. In this study we demonstrate that an engineered acellular scaffold comprising type I collagen, endowed with specific physiomechanical properties, improves cardiac function when used as a cardiac patch following myocardial infarction. Patches were grafted onto the infarcted myocardium in adult murine hearts immediately after ligation of left anterior descending artery and the physiological outcomes were monitored by echocardiography, and by hemodynamic and histological analyses four weeks post infarction. In comparison to infarcted hearts with no treatment, hearts bearing patches preserved contractility and significantly protected the cardiac tissue from injury at the anatomical and functional levels. This improvement was accompanied by attenuated left ventricular remodeling, diminished fibrosis, and formation of a network of interconnected blood vessels within the infarct. Histological and immunostaining confirmed integration of the patch with native cardiac cells including fibroblasts, smooth muscle cells, epicardial cells, and immature cardiomyocytes. In summary, an acellular biomaterial with specific biomechanical properties promotes the endogenous capacity of the infarcted myocardium to attenuate remodeling and improve heart function following myocardial infarction.