High-efficiency antibacterial calcium alginate/lysozyme/AgNPs composite sponge for wound healing.

Infection poses a significant barrier to effective wound repair, leading to increased inflammatory responses that ultimately result in incomplete and prolonged wound healing. To address this challenge, numerous antibacterial ingredients have been incorporated into dressings to inhibit wound infection. Our previous work demonstrated that lysozyme/silver nanoparticles (LYZ/AgNPs) complexes, prepared using an eco-friendly one-step aqueous method, exhibited excellent antibacterial efficacy with favorable biosafety. To further explore its potential application in advancing wound healing, calcium alginate (CA) with good porosity, water absorption, and water retention capacities was formulated with LYZ/AgNPs to prepare composite sponge (CA/LYZ/AgNPs). As expected, in vivo experiments involving full-thickness skin wound and scald wound healing experiments demonstrated that CA-LYZ-AgNPs composite sponges with excellent biocompatibility exhibited remarkable antibacterial activity against gram-positive bacteria, gram-negative bacteria and fungi, and outperformed the wound healing process efficacy of other commercially available AgNPs-loaded wound dressings. In summary, this work introduces a CA/LYZ/AgNPs sponge featuring exceptional antibacterial efficacy and biocompatibility, thus holding promising potential in wound care applications.

Recent advances in plasmon-enhanced luminescence for biosensing and bioimaging.

Plasmon-enhanced luminescence (PEL) is a unique photophysical phenomenon in which the interaction between luminescent moieties and metal nanostructures results in a marked luminescence enhancement. PEL offers several advantages and has been extensively used to design robust biosensing platforms for luminescence-based detection and diagnostics applications, as well as for the development of many efficient bioimaging platforms, enabling high-contrast non-invasive real-time optical imaging of biological tissues, cells, and organelles with high spatial and temporal resolution. This review summarizes recent progress in the development of various PEL-based biosensors and bioimaging platforms for diverse biological and biomedical applications. Specifically, we comprehensively assessed rationally designed PEL-based biosensors that can efficiently detect biomarkers (proteins and nucleic acids) in point-of-care tests, highlighting significant improvements in the sensing performance upon the integration of PEL. In addition to discussing the merits and demerits of recently developed PEL-based biosensors on substrates or in solutions, we include a brief discussion on integrating PEL-based biosensing platforms into microfluidic devices as a promising multi-responsive detection method. The review also presents comprehensive details about the recent advances in the development of various PEL-based multi-functional (passive targeting, active targeting, and stimuli-responsive) bioimaging probes, highlighting the scope of future improvements in devising robust PEL-based nanosystems to achieve more effective diagnostic and therapeutic insights by enabling imaging-guided therapy.

Hemoglobin Nanocrystals for Drugs Free, Synergistic Theranostics of Colon Tumor.

The conventional approach in cancer nanomedicine involves advanced drug nanocarriers delivering preloaded therapeutics to targeted tumor sites to maximize drug efficiency. However, both cancer drugs and nanocarriers inevitably produce side effects and systemic toxicity. Herein, hemoglobin nanocrystals (HbC) as drug-free theranostic nanoformulations with the tumor microenvironment (TME) activated diagnostic and therapeutic abilities towards colon tumors are introduced. HbC can release Fe2+ oxidized to Fe3+ in the Fenton reaction with tumor endogenous H2 O2 , concurrently with the generation of cytotoxic hydroxyl radicals (•OH) that allow for chemodynamic therapy (CDT). Furthermore, in situ-produced Fe3+ reacts with colon tumor-abundant H2 S, resulting in the production of Fe1- x S, which provides magnetic resonance imaging (MRI) contrast and allows for NIR light-inducible photothermal therapy (PTT). In vitro and in vivo studies revealed that HbC produced CDT towards 4T1 tumors, and MRI-guided, synergistically enhanced combination of CDT and PTT against H2 S abundant colon tumors (CT26), with negligible toxicity towards normal tissues, enlightening HbC as highly efficient and biocompatible TME activated theranostic nanoplatform specific against colon cancer without any traditional drugs and drug carriers.

Tumor-Microenvironment-Activated NIR-II Nanotheranostic Platform for Precise Diagnosis and Treatment of Colon Cancer.

Rational design of tumor-microenvironment (TME)-activated nanoformulation for precisely targeted cancer treatment has recently attracted an enormous attention. However, the all-in-one TME-activated theranostic nanosystems with a simple preparation and high biocompatibility are still rarely reported. Herein, catalase nanocrystals (CatCry) are first introduced as a tumor microenvironment activatable nanoplatform for selective theranostics of colon cancer. They are engaged as (i) a "nanoreactor" for silver nanoparticles (AgNP) synthesis, (ii) a nanovehicle for tumor delivery of anticancer drug doxorubicin (DOX), and (iii) an in situ O2 generator to relief tumor hypoxia. When CatCry-AgNP-DOX nanoformulation is within a tumor, the intratumoral H2S turns AgNP into Ag2S nanoparticles, inducing a photothermal effect and NIR-II emission under 808 nm laser irradiation and also triggering DOX release. Simultaneously, CatCry catalyzes intratumoral H2O2 into O2, relieving hypoxia and enhancing chemotherapy. In contrast, when delivered to healthy tissue without increased concentration of H2S, the developed nanoformulation remains in the "off" state and no theranostic action takes place. Studies with colon cancer cells in vitro and a murine colon cancer model in vivo demonstrated that CatCry-AgNP-DOX delivered a synergistic combination of PTT and enhanced chemotherapy, enabling complete eradication of tumor with minimal side effects. This work not only introduces nanoplatform for theranostics of H2S-rich tumors but also suggests a general strategy for protein-crystal-based nanomedicine.

Catalase Nanocrystals Loaded with Methylene Blue as Oxygen Self-Supplied, Imaging-Guided Platform for Photodynamic Therapy of Hypoxic Tumors.

Photodynamic therapy (PDT) is a well-known method for cancer therapy in the clinic. However, the inherent hypoxia microenvironment of solid tumors enormously restricts the PDT efficiency. Herein, catalase nanocrystals (CatCry) are introduced as in situ oxygen (O2 )-generating system to relieve tumor hypoxia and enhance PDT efficiency for solid tumors. After loading with photosensitizer methylene blue (MB), a PDT drug platform (CatCry-MB) emerges, allowing for significant increasing PDT efficiency instigated by three factors. First, the high stability and recyclable catalytic activity of CatCry enable a long-term endogenous H2 O2 decomposition for continuous O2 supply for sustained relief of tumor hypoxia. Second, both the produced O2 and loaded MB are confined within CatCry nanoporous structure, shortening the diffusion distance between O2 and MB to maximize the production of singlet oxygen (1 O2 ). Third, the MB molecules are uniformly dispersed within CatCry lattice, avoiding MB aggregation and causing more MB molecules be activated to produce more 1 O2 . With the three complementary mechanisms, tumor hypoxia is eradicated and the resulted enhancement in PDT efficiency is demonstrated in vitro and in vivo. The proposed approach opens up a new venue for the development of other O2 -dependent tumor treatments, such as chemotherapy, radiotherapy, and immunotherapy.

Biofunctionalization of Microgroove Surfaces with Antibacterial Nanocoatings.

OBJECTIVES: To investigate the physical properties of the modified microgroove (MG) and antibacterial nanocoated surfaces. In addition, the biological interactions of the modified surfaces with human gingival fibroblasts (HGFs) and the antibacterial activity of the surfaces against Porphyromonas gingivalis were studied. METHODS: The titanium nitride (TiN) and silver (Ag) coatings were deposited onto the smooth and MG surfaces using magnetron sputtering. A smooth titanium surface (Ti-S) was used as the control. The physicochemical properties including surface morphology, roughness, and hydrophilicity were characterized using scanning electron microscopy, atomic force microscopy, and an optical contact angle analyzer. The "contact guidance" morphology was assessed using confocal laser scanning microscopy. Cell proliferation was analyzed using the Cell Counting Kit-8 assay. The expression level of the main focal adhesion-related structural protein vinculin was compared using quantitative reverse transcription PCR and Western blotting. The antibacterial activity against P. gingivalis was evaluated using the LIVE/DEAD BacLight™ Bacterial Viability Kit. RESULTS: The Ag and TiN antibacterial nanocoatings were successfully deposited onto the smooth and MG surfaces using magnetron sputtering technology. TiN coating on a grooved surface (TiN-MG) resulted in less nanoroughness and greater surface hydrophilicity than Ag coating on a smooth surface (Ag-S), which was more hydrophobic. Cell proliferation and expression of vinculin were higher on the TiN-MG surface than on the Ag-coated surfaces. Ag-coated surfaces showed the strongest antibacterial activity, followed by TiN-coated surfaces. CONCLUSION: Nano-Ag coating resulted in good antimicrobial activity; however, the biocompatibility was questionable. TiN nanocoating on an MG surface showed antibacterial properties with an optimal biocompatibility and maintained the "contact guidance" effects for HGFs.

Optimization for silver remediation from aqueous solution by novel bacterial isolates using response surface methodology: Recovery and characterization of biogenic AgNPs.

Silver is a toxic but precious heavy metal that has been implemented in diverse biomedical and environmental sectors. Extensive use of this metal has provoked severe environmental concerns. Hence there is an increasing demand for the development of a simple, inexpensive and eco-friendly approach for the remediation and recovery of silver. In this study, novel bacterial strains Enterobacter cloacae SMP1, Cupriavidus necator SMP2, and Bacillus megaterium SMP3 were isolated from silver mining site for the sake of silver remediation. Various experimental factors including temperature, pH and inoculum size (I_S) were optimized for silver remediation by SMP1 using central composite design (CCD) based on response surface methodology (RSM). For maximum 100% removal of silver the optimized values of temperature, pH and I_S were 23.5 °C, 7.5 and 2% (v/v) respectively in less than 10 h of incubation. Simultaneously, silver nanoparticles (AgNPs) were harvested through centrifugation (M1) and by applying voltage (M2) to the crude remediation mixture. The AgNPs, characterized by UV-vis spectroscopy, dynamic light scattering (DLS), and cryo-scanning transmission electron microscopy (Cryo-SETM), were spherical shaped and 1.75-8.7 nm in diameter. The average zeta potentials (ZP) of AgNPs isolated by M1, and M2 were -35.8 mV and -45.2 mV respectively.

Enhanced remediation of bispyribac sodium by wheat (Triticum aestivum) and a bispyribac sodium degrading bacterial consortium (BDAM).

The use of plant-bacterial association is a promising approach for the enhanced remediation of pesticides. Generally, both rhizo- and endosphere bacteria assist their host plants to survive in the contaminated environment. In this work, we have studied the individual and combined effects of wheat (Triticum aestivum) and a previously optimized bispyribac sodium (BS) degrading bacterial consortium (BDAM) on the degradation of BS and plant biomass production. Results showed that the bacterial strains of the BDAM have successfully survived in the plant rhizo-as well as endosphere and enhanced degradation of BS and plant biomass. In soil spiked with 2 mg/kg and 5 mg/kg of BS and was planted and inoculated with BDAM (P_I) showed 100% degradation of BS both in rhizosphere soil and endosphere of the plant. However, during the same period (45 days) the degradation of BS was 96 and 90%, and 93 and 84% in inoculated but un-planted (I_UP) and planted but un-inoculated (P_UI) soils spiked with 2 and 5 mg/kg, respectively. Liquid chromatography-mass spectrometry (LC-MS) analysis of the treated samples showed novel degradation products of BS. Based on the results, we concluded that plant-bacterial association is an efficient tool for enhanced remediation of BS contaminated soil and herbicide free crop production.

Iron/iron oxide nanoparticles: advances in microbial fabrication, mechanism study, biomedical, and environmental applications.

Microbially synthesized iron oxide nanoparticles (FeONPs) hold great potential for biomedical, clinical, and environmental applications owing to their several unique features. Biomineralization, a process that exists in almost every living organism playing a significant role in the fabrication of FeONPs through the involvement of 5-100 nm sized protein compartments such as dodecameric (Dps), ferritin, and encapsulin with their diameters 9, 12, and ∼32 nm, respectively. This contribution provides a detailed overview of the green synthesis of FeONPs by microbes and their applications in biomedical and environmental fields. The first part describes our understanding in the biological fabrication of zero-valent FeONPs with special emphasis on ferroxidase (FO) mediated series of steps involving in the translocation, oxidation, nucleation, and storage of iron in Dps, ferritin, and encapsulin protein nano-compartments. Secondly, this review elaborates the significance of biologically synthesized FeONPs in biomedical science for the detection, treatment, and prevention of various diseases. Thirdly, we tried to provide the recent advances of using FeONPs in the environmental process, e.g. detection, degradation, remediation and treatment of toxic pesticides, dyes, metals, and wastewater.

Biological synthesis of metallic nanoparticles (MNPs) by plants and microbes: their cellular uptake, biocompatibility, and biomedical applications.

Metallic nanoparticles (MNPs) with their diverse physical and chemical properties have been applied in various biomedical domains. The increasing demand for MNPs has attracted researchers to develop straightforward, inexpensive, simple, and eco-friendly processes for the enhanced production of MNPs. To discover new biomedical applications first requires knowledge of the interactions of MNPs with target cells. This review focuses on plant and microbial synthesis of biological MNPs, their cellular uptake, biocompatibility, any biological consequences such as cytotoxicity, and biomedical applications. We highlighted the involvement of biomolecules in capping and stabilization of MNPs and the effect of physicochemical parameters particularly the pH on the synthesis of MNPs. Recently achieved milestones to understand the role of synthetic biology (SynBiol) in the synthesis of tailored MNPs are also discussed.

Effects of large gradient high magnetic field (LG-HMF) on the long-term culture of aquatic organisms: Planarians example.

Large gradient high magnetic field (LG-HMF) is a powerful tool to study the effects of altered gravity on organisms. In our study, a platform for the long-term culture of aquatic organisms was designed based on a special superconducting magnet with an LG-HMF, which can provide three apparent gravity levels (µ g, 1 g, and 2 g), along with a control condition on the ground. Planarians, Dugesia japonica, were head-amputated and cultured for 5 days in a platform for head reconstruction. After planarian head regeneration, all samples were taken out from the superconducting magnet for a behavioral test under geomagnetic field and normal gravity conditions. To analyze differences among the four groups, four aspects of the planarians were considered, including head regeneration rate, phototaxis response, locomotor velocity, and righting behavior. Data showed that there was no significant difference in the planarian head regeneration rate under simulated altered gravity. According to statistical analysis of the behavioral test, all of the groups had normal functioning of the phototaxis response, while the planarians that underwent head reconstruction under the microgravity environment had significantly slower locomotor velocity and spent more time in righting behavior. Furthermore, histological staining and immunohistochemistry results helped us reveal that the locomotor system of planarians was affected by the simulated microgravity environment. We further demonstrated that the circular muscle of the planarians was weakened (hematoxylin and eosin staining), and the epithelial cilia of the planarians were reduced (anti-acetylated tubulin staining) under the simulated microgravity environment. Bioelectromagnetics. 2018;39:428-440. © 2018 Wiley Periodicals, Inc.

Ligand-binding characterization of simulated ß-adrenergic-like octopamine receptor in Schistocerca gregaria via progressive structure simulation.

It is important to design insecticides having both low drug resistance and less undesirable toxicity for desert locust control. Specific GPCRs of Schistocerca gregaria, especially ß-adrenergic-like octopamine receptor (SgOctßR), can be considered as its potential effective insecticide targets. However, either the unavailability of SgOctßR's structure or the inadequate capability of its sequence lead the development of insecticide for Schistocerca gregaria meets its plateau. To relax this difficulty, this paper develops a promising progressive structure simulation from SgOctßR's sequence, to its predicted structure of SgOctßR in vacuum, to its conformation as well as its complex with endogenous ligand octopamine in a solvent-membrane system. The combined approach of multiple sequence alignment, static structural characterization, and dynamic process of conformational change during binding octopamine reveal three important aspects. The first one is the characterization of SgOctßR's active pocket, including the attending secondary structure elements, its hydrophobic residues and nonpolar surface. The second one is the interaction with octopamine, especially the involved hydrogen bonds and an aromatic stacking of pi-pi interactions. The third one is the potential binding sites, including six highly conserved residues and one highly variable residue for locust insecticide design. This work is definitely helpful for the further structure-based drug design for efficient and eco-friendly insecticides, as well as site-directed mutagenesis biochemical research of SgOctßR.

Myocyte enhancer factor 2C and its directly-interacting proteins: A review.

Myocyte enhancer factor 2C (MEF2C) is a transcription factor of MADS box family involved in the early development of several human cells including muscle (i.e., skeletal, cardiac, and smooth), neural, chondroid, immune, and endothelial cells. Dysfunction of MEF2C leads to embryo hypoplasia, disorganized myofibers and perinatal lethality. The main role of MEF2C is its regulation of muscle development. It has been reported that MEF2C-knockout mice die on embryonic day 9.5 from unnatural development of cardiovascular. The effects of MEF2C are mediated by its directly-interacting proteins; therefore, the investigation of these interactions is critical in order to clarify MEF2C's biological function. In this study, we review twenty-five proteins that directly interact with MEF2C, including nineteen proteins related to muscle development, four proteins related to neural cell development, one protein related to chondroid cell development, four proteins related to immune cell development, and two proteins related to endothelial cell development. Among these proteins, the interaction of MEF2C with MRFs is important for differentiation of developing muscle cells. MEF2C interacts with Sox18 for endothelial vessel morphogenesis. The interaction of MEF2C with Cabin1 is important for maintaining T-cell inactivation. Investigating the interactions of MEF2C and its directly-interacting proteins is not only helpful to understand of the physiological function of MEF2C, but also provides a target for future rational drug design.

RNA binding motif protein 3: a potential biomarker in cancer and therapeutic target in neuroprotection.

RNA binding motif 3 (RBM3) is a highly conserved cold-induced RNA binding protein that is transcriptionally up-regulated in response to harsh stresses. Featured as RNA binding protein, RBM3 is involved in mRNA biogenesis as well as stimulating protein synthesis, promoting proliferation and exerting anti-apoptotic functions. Nowadays, accumulating immunohistochemically studies have suggested RBM3 function as a proto-oncogene that is associated with tumor progression and metastasis in various cancers. Moreover, emerging evidences have also indicated that RBM3 is equally effective in neuroprotection. In the present review, we provide an overview of current knowledge concerning the role of RBM3 in various cancers and neuroprotection. Additionally, its potential roles as a promising diagnostic marker for cancer and a possible therapeutic target for neuro-related diseases are discussed.

Preparation of cross-linked hen-egg white lysozyme crystals free of cracks.

Cross-linked protein crystals (CLPCs) are very useful materials in applications such as biosensors, catalysis, and X-ray crystallography. Hence, preparation of CLPCs is an important research direction. During the preparation of CLPCs, an often encountered problem is that cracks may appear in the crystals, which may finally lead to shattering of the crystals into small pieces and cause problem in practical applications. To avoid cross-link induced cracking, it is necessary to study the cracking phenomenon in the preparation process. In this paper, we present an investigation on how to avoid cracking during preparation of CLPCs. An orthogonal experiment was designed to study the phenomenon of cross-link induced cracking of hen-egg white lysozyme (HEWL) crystals against five parameters (temperature, solution pH, crystal growth time, glutaraldehyde concentration, and cross-linking time). The experimental results showed that, the solution pH and crystal growth time can significantly affect cross-link induced cracking. The possible mechanism was studied, and optimized conditions for obtaining crack-free CLPCs were obtained and experimentally verified.

A Systematic Analysis of the Structures of Heterologously Expressed Proteins and Those from Their Native Hosts in the RCSB PDB Archive.

Recombinant expression of proteins has become an indispensable tool in modern day research. The large yields of recombinantly expressed proteins accelerate the structural and functional characterization of proteins. Nevertheless, there are literature reported that the recombinant proteins show some differences in structure and function as compared with the native ones. Now there have been more than 100,000 structures (from both recombinant and native sources) publicly available in the Protein Data Bank (PDB) archive, which makes it possible to investigate if there exist any proteins in the RCSB PDB archive that have identical sequence but have some difference in structures. In this paper, we present the results of a systematic comparative study of the 3D structures of identical naturally purified versus recombinantly expressed proteins. The structural data and sequence information of the proteins were mined from the RCSB PDB archive. The combinatorial extension (CE), FATCAT-flexible and TM-Align methods were employed to align the protein structures. The root-mean-square distance (RMSD), TM-score, P-value, Z-score, secondary structural elements and hydrogen bonds were used to assess the structure similarity. A thorough analysis of the PDB archive generated five-hundred-seventeen pairs of native and recombinant proteins that have identical sequence. There were no pairs of proteins that had the same sequence and significantly different structural fold, which support the hypothesis that expression in a heterologous host usually could fold correctly into their native forms.

[Progresses in predicting the crystallizability of proteins].

Determination of protein 3-dimensional structure offers very important information in biology researches, especially for understanding protein functions and redundant drug design. The X-ray crystallography is still the main technique for protein structure determination. Obtaining protein crystals is an essential procedure after protein purification in this technique. However, there is only 42% of soluble purified proteins yield crystals by statistics. Experimental verification of protein crystallizability is relatively expensive and time-consuming. Thus it is desired to predict the protein crystallizability by a computational method before starting the experiment. In this paper, combined with our own efforts, some successful in silico methods to predict the protein crystallizability are reviewed.

Correlation between protein sequence similarity and crystallization reagents in the biological macromolecule crystallization database.

The protein structural entries grew far slower than the sequence entries. This is partly due to the bottleneck in obtaining diffraction quality protein crystals for structural determination using X-ray crystallography. The first step to achieve protein crystallization is to find out suitable chemical reagents. However, it is not an easy task. Exhausting trial and error tests of numerous combinations of different reagents mixed with the protein solution are usually necessary to screen out the pursuing crystallization conditions. Therefore, any attempts to help find suitable reagents for protein crystallization are helpful. In this paper, an analysis of the relationship between the protein sequence similarity and the crystallization reagents according to the information from the existing databases is presented. We extracted information of reagents and sequences from the Biological Macromolecule Crystallization Database (BMCD) and the Protein Data Bank (PDB) database, classified the proteins into different clusters according to the sequence similarity, and statistically analyzed the relationship between the sequence similarity and the crystallization reagents. The results showed that there is a pronounced positive correlation between them. Therefore, according to the correlation, prediction of feasible chemical reagents that are suitable to be used in crystallization screens for a specific protein is possible.

[Viral pathogens of acute lower respiratory tract infection in hospitalized children from East Guangdong of China].

OBJECTIVE: To investigate the viral pathogens of acute lower respiratory tract infection (ALRTI) in hospitalized children from East Guangdong Province of China and the relationship of the pathogens with age and seasons. METHODS: The nasopharyngeal aspirates samples obtained from 345 hospitalized children with ALRTI were investigated for respiratory syncytial virus (RSV), human bocavirus (HBoV), human metapneumovirus (hMPV), influenza virus types A and B, rhinovirus, parainfluenza virus types 1 and 3 and adenovirus by PCR. RESULTS: Viral pathogens were detected in 178 patients (51.6%). RSV was the most frequent (19.3%). Novel viruses hMPV (3.2%) and HBoV (3.2%) were found. A highest detection rate (61.9%) of virus was found between January to March. The infants aged 1 to 6 months showed a higher detection rate (71.3%) of virus than the other age groups. The detection rate of viral pathogens was 72.6% in children with bronchiolitis, followed by asthmatic bronchitis (70.0%) and bronchial pneumonia (44.6%). CONCLUSIONS: RSV remained the leading viral pathogens in children with ALRTI in East Guangdong of China. Novel viruses HBoV and hMPV were also important pathogens. The detection rate of viral pathogens was associated with seasonal changes and age. Different respiratory infectious diseases had different viral detection rates, with highest detection rate in bronchiolitis cases.