Metabolic regulation of protein N-alpha-acetylation by Bcl-xL promotes cell survival.

Previous experiments suggest a connection between the N-alpha-acetylation of proteins and sensitivity of cells to apoptotic signals. Here, we describe a biochemical assay to detect the acetylation status of proteins and demonstrate that protein N-alpha-acetylation is regulated by the availability of acetyl-CoA. Because the antiapoptotic protein Bcl-xL is known to influence mitochondrial metabolism, we reasoned that Bcl-xL may provide a link between protein N-alpha-acetylation and apoptosis. Indeed, Bcl-xL overexpression leads to a reduction in levels of acetyl-CoA and N-alpha-acetylated proteins in the cell. This effect is independent of Bax and Bak, the known binding partners of Bcl-xL. Increasing cellular levels of acetyl-CoA by addition of acetate or citrate restores protein N-alpha-acetylation in Bcl-xL-expressing cells and confers sensitivity to apoptotic stimuli. We propose that acetyl-CoA serves as a signaling molecule that couples apoptotic sensitivity to metabolism by regulating protein N-alpha-acetylation.

Metallacage-based enhanced PDT strategy for bacterial elimination via inhibiting endogenous NO production.

Antibiotics are among the most used weapons in fighting microbial infections and have greatly improved the quality of human life. However, bacteria can eventually evolve to exhibit antibiotic resistance to almost all prescribed antibiotic drugs. Photodynamic therapy (PDT) develops little antibiotic resistance and has become a promising strategy in fighting bacterial infection. To augment the killing effect of PDT, the conventional strategy is introducing excess ROS in various ways, such as applying high light doses, high photosensitizer concentrations, and exogenous oxygen. In this study, we report a metallacage-based PDT strategy that minimizes the use of ROS by jointly using gallium-metal organic framework rods to inhibit the production of bacterial endogenous NO, amplify ROS stress, and enhance the killing effect. The augmented bactericidal effect was demonstrated both in vitro and in vivo. This proposed enhanced PDT strategy will provide a new option for bacterial ablation.

Mesoporous MOFs with ROS scavenging capacity for the alleviation of inflammation through inhibiting stimulator of interferon genes to promote diabetic wound healing.

Excessive production of reactive oxygen species (ROS) and inflammation are the key problems that impede diabetic wound healing. In particular, dressings with ROS scavenging capacity play a crucial role in the process of chronic wound healing. Herein, Zr-based large-pore mesoporous metal-organic frameworks (mesoMOFs) were successfully developed for the construction of spatially organized cascade bioreactors. Natural superoxide dismutase (SOD) and an artificial enzyme were spatially organized in these hierarchical mesoMOFs, forming a cascade antioxidant defense system, and presenting efficient intracellular and extracellular ROS scavenging performance. In vivo experiments demonstrated that the SOD@HMUiO-MnTCPP nanoparticles (S@M@H NPs) significantly accelerated diabetic wound healing. Transcriptomic and western blot results further indicated that the nanocomposite could inhibit fibroblast senescence and ferroptosis as well as the stimulator of interferon genes (STING) signaling pathway activation in macrophages mediated by mitochondrial oxidative stress through ROS elimination. Thus, the biomimetic multi-enzyme cascade catalytic system with spatial ordering demonstrated a high potential for diabetic wound healing, where senescence, ferroptosis, and STING signaling pathways may be potential targets.

A Cascade Enzymatic Reaction Scheme for Irreversible Transpeptidative Protein Ligation.

Enzymatic peptide ligation holds great promise in the study of protein functions and development of protein therapeutics. Owing to their high catalytic efficiency and a minimal tripeptide recognition motif, peptidyl asparaginyl ligases (PALs) are particularly useful tools for bioconjugation. However, as an inherent limitation of transpeptidases, PAL-mediated ligation is reversible, requiring a large excess of one of the ligation partners to shift the reaction equilibrium in the forward direction. Herein, we report a method to make PAL-mediated intermolecular ligation irreversible by coupling it to glutaminyl cyclase (QC)-catalyzed pyroglutamyl formation. In this method, the acyl donor substrate of PALs is designed to have glutamine at the P1' position of the Asn-P1'-P2' tripeptide PAL recognition motif. Upon ligation with an acyl acceptor substrate, the acyl donor substrate releases a leaving group in which the exposed N-terminal glutamine is cyclized by QC, quenching the Gln Nα-amine in a lactam. Using this method, PAL-mediated ligation can achieve near-quantitative yields even at an equal molar ratio between the two ligation partners. We have demonstrated this method for a wide range of applications, including protein-to-protein ligations. We anticipate that this cascade enzymatic reaction scheme will make PAL enzymes well suited for numerous new uses in biotechnology.

Metabolome and transcriptome profiling of Theobroma cacao provides insights into the molecular basis of pod color variation.

The Theobroma cacao presents a wide diversity in pod color among different cultivars. Although flavonoid biosynthesis has been studied in many plants, molecular mechanisms governing the diversity of coloration in cacao pods are largely unknown. The flavonoid metabolite profiles and flavonoid biosynthetic gene expression in the pod exocarps of light green pod 'TAS 410' (GW), green pod 'TAS 166' (GF), and mauve pod 'TAS 168' (PF) were determined. Changes in flavonoid metabolites, particularly the anthocyanins (cyanidin 3-O-galactoside, cyanidin 3-O-glucoside, and cyanidin O-syringic acid) were significantly up-accumulated in the mauve phenotype (PF) compared to the light green or green phenotypes, endowing the pod color change from light green or green to mauve. Consistently, the PF phenotype showed different expression patterns of flavonoid biosynthetic structural genes in comparison with GW/GF phenotypes. The expression level of LAR and ANR in GW/GF was significantly higher than PF, while the expression level of UFGT in GW/GF was lower than PF. These genes likely generated more anthocyanins in the exocarps samples of PF than that of GW/GF. Simultaneously, colorless flavan-3-ols (catechin, epicatechin and proanthocyanidin) content in the exocarp samples of PF was lower than GW/GF. Additionally, MYB (gene18079) and bHLH (gene5045 and gene21575) may participate in the regulation of the pod color. This study sheds light on the molecular basis of cacao pod color variation, which will contribute to breeding cacao varieties with enhanced flavonoid profiles for nutritional applications.

Detecting Water Diversion Fingerprints in the Danjiangkou Reservoir from Satellite Gravimetry and Altimetry Data.

The Danjiangkou Reservoir (DJKR) is the freshwater source for the Middle Route of the South-to-North Water Diversion Project in China, and its water level and storage changes are important for water resource management. To maximize the potential capacity of the Gravity Recovery and Climate Experiment (GRACE) mission, an improved Lagrange multiplier method (ILMM) is first proposed to detect terrestrial water storage anomalies (TWSA) in the small-scale basin (DJKR). Moreover, for the first time, water diversion fingerprints are proposed to analyze the spatiotemporal pattern of the TWSA in the DJKR. The results indicate that the increased water level and storage signals due to the DJKR impoundment in 2014 can be effectively detected by using the ILMM, and they agree well with the results from altimetry and in situ data. Additionally, the water diversion fingerprints due to the DJKR impoundment are inferred, and describe the progression of spatiotemporal variability in water storage. The results show that water storage decreased in the upper Hanjiang River and increased in the DJKR as well as to the east of it during the period 2013-2015. Our research provides a scientific decision-making basis for monitoring the water resources of the DJKR and managing the South-to-North Water Diversion Project.

Combining CHAMP and Swarm Satellite Data to Invert the Lithospheric Magnetic Field in the Tibetan Plateau.

CHAMP and Swarm satellite magnetic data are combined to establish the lithospheric magnetic field over the Tibetan Plateau at satellite altitude by using zonal revised spherical cap harmonic analysis (R-SCHA). These data are integrated with geological structures data to analyze the relationship between magnetic anomaly signals and large-scale geological tectonic over the Tibetan Plateau and to explore the active tectonic region based on the angle of the magnetic anomaly. Results show that the model fitting error is small for a layer 250-500 km high, and the RMSE of the horizontal and radial geomagnetic components is better than 0.3 nT. The proposed model can accurately describe medium- to long-scale lithospheric magnetic anomalies. Analysis indicates that a negative magnetic anomaly in the Tibetan Plateau significantly differs with a positive magnetic anomaly in the surrounding area, and the boundary of the positive and negative regions is generally consistent with the geological tectonic boundary in the plateau region. Significant differences exist between the basement structures of the hinterland of the plateau and the surrounding area. The magnetic anomaly in the Central and Western Tibetan Plateau shows an east-west trend, which is identical to the direction of the geological structures. The magnetic anomaly in the eastern part is arc-shaped and extends along the northeast direction. Its direction is significantly different from the trend of the geological structures. The strongest negative anomaly is located in the Himalaya block, with a central strength of up to -9 nT at a height of 300 km. The presence of a strong negative anomaly implies that the Curie isotherm in this area is relatively shallow and deep geological tectonic activity may exist.

Precise Orbit Solution for Swarm Using Space-Borne GPS Data and Optimized Pseudo-Stochastic Pulses.

Swarm is a European Space Agency (ESA) project that was launched on 22 November 2013, which consists of three Swarm satellites. Swarm precise orbits are essential to the success of the above project. This study investigates how well Swarm zero-differenced (ZD) reduced-dynamic orbit solutions can be determined using space-borne GPS data and optimized pseudo-stochastic pulses under high ionospheric activity. We choose Swarm space-borne GPS data from 1-25 October 2014, and Swarm reduced-dynamic orbits are obtained. Orbit quality is assessed by GPS phase observation residuals and compared with Precise Science Orbits (PSOs) released by ESA. Results show that pseudo-stochastic pulses with a time interval of 6 min and a priori standard deviation (STD) of 10-2 mm/s in radial (R), along-track (T) and cross-track (N) directions are optimized to Swarm ZD reduced-dynamic precise orbit determination (POD). During high ionospheric activity, the mean Root Mean Square (RMS) of Swarm GPS phase residuals is at 9-11 mm, Swarm orbit solutions are also compared with Swarm PSOs released by ESA and the accuracy of Swarm orbits can reach 2-4 cm in R, T and N directions. Independent Satellite Laser Ranging (SLR) validation indicates that Swarm reduced-dynamic orbits have an accuracy of 2-4 cm. Swarm-B orbit quality is better than those of Swarm-A and Swarm-C. The Swarm orbits can be applied to the geomagnetic, geoelectric and gravity field recovery.

Distribution characteristics and integrated ecological risks evaluation modelling of microplastics and heavy metals in geological high background soil.

The microplastics (MPs), a novel pollutant, and heavy metals (HMs) significantly affect soil ecology. The study investigated HMs and MPs in Qianxi's high geological background soil, established a model for risk evaluation with MPs types and shapes, and proposed a two-dimensional comprehensive index model for MPs-HMs combined pollution and risk evaluation criterion. The results revealed a high soil Cd concentration, with a mean value of 0.38 mg·kg-1. Additionally, soils from soybean-wheat intercropping-potato-corn rotation (SWI-PCR) exhibited significantly higher concentrations of Hg, As, and Pb compared with those from soybean-wheat intercropping-corn rotation (SWI-CR). Moreover, the soil exhibited a high abundance of MPs (8667.66 ± 3864.26 items·kg-1), mainly characterized by PS and fiber. The mean of adjusted ecological risk index (ARI) for MPs in soil was 525.27, indicating a grade 3 risk. The two-dimensional combined index (TPI) was used to assess the ecological risk of MPs-HMs combined pollution, exhibiting an exceedance rate of 56 % with a mean of 445.07. The risk level of the combined pollution was graded as 6, indicating high risk. The microplastic risk evaluation model and the comprehensive evaluation method of combined pollution established in this study provide a reference for the future risk evaluation of multi-pollutant combined pollution.

Evaluation of niche, diversity, and risks of microplastics in farmland soils of different rocky desertification areas.

The occurrence, sources, effects, and risks of microplastics (MPs) in farmland soils have attracted considerable attention. However, the pollution and ecological characteristics of MPs in farmland soils at different levels of rocky desertification remain unclear. We collected and analyzed farmland soil samples from rocky desertification areas in Guizhou, China, ranging from no to heavy risks. We explored differences and migration of MPs across these areas, unveiled the relationship between diversity, niche, and risks of MPs, and determined influencing factors. The average abundance of soil MPs was 8721 ± 3938 item/kg, and the abundance and contamination factor (CF) of MPs escalated with the increase in rocky desertification level. Diversity, niche, and risk of soil MPs in different rocky desertification areas were significantly different. Rocky desertification caused both MP community differences and linked MP communities at different sites. Diversity and niche significantly affected MP risk (p < 0.05). Environmental factors with significant correlations (p < 0.05) with the abundance and ecological characteristics of MPs varied significantly in soils of different rocky desertification areas. This study advances our comprehension of MP pollution in farmland soils within rocky desertification areas, offering essential data and theoretical insights for the development of control strategies.

Changes in monthly surface area, water level, and storage of 194 lakes and reservoirs in the Yangtze River Basin during 1990-2021 using multisource remote sensing data.

Long-term, high spatiotemporal resolution of surface water area, water level, and storage changes in the Yangtze River Basin (YRB) has great scientific and practical importance for improving the management of water resources. Here, three distinct area estimations were first derived using the water classification enhancement method, automated water extraction method based on random forest, and the modified normalized difference water index. The optimized area data was determined by comparing against Sentinel-2 with the minimum root mean square error. A new area data was constructed with the optimized area as the primary data, while the remaining datasets were employed to fill in gaps. The elevation-area relationship was used to derive monthly water level. Changes in water storage were calculated by applying the pyramidal frustum formula from surface water area and water level data. Finally, a new comprehensive dataset of the monthly area, level, and storage changes in the 119 lakes and 75 reservoirs across the YRB with area larger than 10 km2 from 1990 to 2021 were first reconstructed. The spatiotemporal trends of surface water area/level/storage in lakes and reservoirs over 11 sub-basins of the YRB were quantified from 1990 to 2021, as well as before (1990-2003) and after (2003-2021) the construction of the Three Gorges Dam (TGD). During 1990-2021, there was a marked decrease in surface water area/level/storage in most of the YRB sub-basins, which contain 79 % of the lakes and 30 % of the reservoirs. After TGD was constructed, the surface water in lakes decreased by 10 %, while that of reservoirs remained consistent with the pre-construction. The surface water area/level/storage in the lower sub-basins of YRB exhibited a decline to an upward trend before and after the construction of TGD. This study provides a new comprehensive dataset for understanding the dynamic changes of water resource and climate change.

Hot-Pressing Enhances Mechanical Strength of PEO Solid Polymer Electrolyte for All-Solid-State Sodium Metal Batteries.

Poly(ethylene oxide) (PEO)-based solid polymer electrolytes (SPEs) are widely utilized in all-solid-state sodium metal batteries (ASSSMBs) due to their excellent flexibility and safety. However, poor ionic conductivity and mechanical strength limit its development. In this work, an emerging solvent-free hot-pressing method is used to prepare mechanically robust PEO-based SPE, while sodium superionic conductors Na3 Zr2 Si2 PO12 (NZSP) and NaClO4 are introduced to improve ionic conductivity. The as-prepared electrolyte exhibits a high ionic conductivity of 4.42 × 10-4 S cm-1 and a suitable electrochemical stability window (4.5 V vs Na/Na+ ). Furthermore, the SPE enables intimate contact with the electrode. The Na||Na3 V2 (PO4 )3 @C ASSSMB delivers a high-capacity retention of 97.1% after 100 cycles at 0.5 C and 60 °C, and exhibits excellent Coulombic efficiency (CE) (close to 100%). The ASSSMB with the 20 µm thick electrolyte also demonstrates excellent cyclic stability. This study provides a promising strategy for designing stable polymer-ceramic composite electrolyte membranes through hot-pressing to realize high-energy-density sodium metal batteries.

Molecular cloning and mRNA expression profile of sucrose transporter gene BnSUT1C from Brassica napus L.

The genomic and cDNA sequences of BnSUT1C were isolated from B. napus. Combination of cDNA and genomic DNA sequences revealed that the BnSUT1C gene contained three exons and two introns. The cDNA encodes a protein of 513 amino acids with a calculated molecular mass of 54.7 kDa and an isoelectric point of 9.12. It exhibits typical features of sucrose transporter with 12 trans-membranes spanning domains. BnSUT1C showed highly homologous with AtSUC1 and AtSUC5. A histidine residue, which is conserved across all functional sucrose transporter proteins in higher plants, is located at position 66 of the BnSUT1C. Two putative pollen-specific cis-elements, AGAAA and GTGA motifs, are located in 5'-upstream of BnSUT1C. The spatial and temporal expression patterns carried out by semi-quantitative RT-PCR and Real-Time PCR, which indicated that BnSUT1C predominantly expressed in later developmental stages of anther, as tapetal cells began to shrink and collapse. BnSUT1C could mediate the uptake of sucrose in the pollen and retrieval of tapetal degenerated products during pollen maturation.

Ultrathin Polyamide Nanofilms with Controlled Microporosity for Enhanced Solvent Permeation.

Organic solvent nanofiltration (OSN) technology shows reduced energy consumption by almost 90% with great potential in achieving low-carbon separation applications. Polyamide nanofilms with controlled intrinsic and extrinsic structures (e.g., thickness and porosity) are important for achieving such a goal but are technically challenging. Herein, ultrathin polyamide nanofilms with controlled microporosity and morphology were synthesized via a molecular layer deposition method for OSN. The key is that the polyamide synthesis is controlled in a homogenous organic phase, rather than an interface, not only involving no monomer kinetic diffusion but also broadening the applicability of amine monomers. The particular nonplanar and rigid amine monomers were superbly used to increase microporosity and the nanofilm was linearly controlled at the nanometer scale to decrease thickness. The composite membrane with the polyamide nanofilms as separation layers displayed highly superior performance to current counterparts. The ethanol and methanol permeances were up to 5.5 and 14.6 L m-2 h-1 bar-1, respectively, but the molecular weight cutoff was tailored as low as 300 Da. Such separation performance remained almost unchanged during a long-term operation. This work demonstrates a promising alternative that could synergistically control the physicochemical structures of ultrathin selective layers to fabricate high-performance OSN membranes for efficient separations.

Tailor-made ß-ketoenamine-linked covalent organic polymer nanofilms for precise molecular sieving.

The membranes that accurately separate solutes with close molecular weights in harsh solvents are of crucial importance for the development of highly-precise organic solvent nanofiltration (OSN). The physicochemical structures of the membrane need to be rationally designed to achieve this goal, such as customized crosslinked networks, thickness, and pore size. Herein, we synthesize a type of covalent organic polymer (COP) nanofilms with tailor-made thickness and pore structure using a cyclic deposition strategy for precise molecular sieving. By elaborately designing monomer structures and controlling deposition cycle numbers, the COP nanofilms linked by robust ß-ketoenamine blocks were endowed with sub-nanometer micropores and a linearly tunable thickness of 10-40 nm. The composite membranes integrating COP nanofilms exhibited adjustable solvent permeance. The membranes further demonstrated steep and finely-regulated rejection curves within the molecular weight range of 200 to 400 Da, where the difference value was as low as 40 Da. The efficient purification and concentration of the antibacterial drug and its intermediate was well achieved. Therefore, the exploited COP nanofilms markedly facilitate the application of microporous organic polymers for precise molecular separation in OSN.

Divergent spatiotemporal variability of terrestrial water storage and eight hydroclimatic components over three different scales of the Yangtze River basin.

Terrestrial water storage anomaly (TWSA) from Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-on was first exacted by using the forward modeling (FM) method at three different scales over the Yangtze River basin (YRB): whole basin, three middle sub-basins, and eleven small sub-basins (total 15 basins). The spatiotemporal variability of eight hydroclimatic variables, snow water storage change (SnWS), canopy water storage change (CnWS), surface water storage anomaly (SWSA), soil moisture storage anomaly (SMSA), groundwater storage anomaly (GWSA), precipitation (P), evapotranspiration (ET), and runoff (R), and their contribution to TWSA were comprehensively investigated over the YRB. The results showed that the root mean square error of TWS change after FM improved by 17 %, as validated by in situ P, ET, and R data. The seasonal, inter-annual, and trend revealed that TWSA over the YRB increased during 2003-2018. The seasonal TWSA signal increased from the lower to the upper of YRB, but the trend, sub-seasonal, and inter-annual signals receded from the lower to the upper of YRB. The contribution of CnWS to TWSA was small over the YRB. The contribution of SnWS to TWSA occurs mainly in the upper of YRB. The main contributors to TWSA were SMSA (~36 %), SWSA (~33 %), and GWSA (~30 %). GWSA can be affected by TWSA, but other hydrological elements may have a slight impact on groundwater in the YRB. The primary driver of TWSA over the YRB was P (~46 %), followed by ET and R (both ~27 %). The contribution of SMSA, SWSA, and P to TWSA increased from the upper to the lower of YRB. R was the key driver of TWSA in the lower of YRB. The proposed approaches and results of this study can provide valuable new insights for water resource management in the YRB and can be applied globally.

Silk fibroin-gelatin photo-crosslinked 3D-bioprinted hydrogel with MOF-methylene blue nanoparticles for infected wound healing.

Photo-crosslinked hydrogel (PH) is an outstanding candidate for three-dimensional (3D) printing as a wound dressing because of its high efficiency in crosslinking and injectability. In this study, methylene blue (MB)-loaded UiO-66(Ce) nanoparticles (NPs) were synthesized to prevent drug self-aggregation and achieve the photodynamic therapy (PDT) effect for efficient antibacterial action. Then, a composite photocrosslinked silk fibroin (SF)/gelatin hydrogel loaded with MB@UiO-66(Ce) NPs (MB@UiO-66(Ce)/PH) was fabricated. The printability and the improvement of the mechanical properties of the hydrogel by the NPs were clarified. The hydrogel exhibited good biocompatibility and promoted the migration and proliferation of fibroblasts. With the PDT effect of MB@UiO-66(Ce) NPs, the hydrogel showed an excellent antibacterial effect, which became more pronounced as the concentration increased. In vivo study showed that the MB@UiO-66(Ce)/PH could fill the defects without gaps and accelerate the repair rate of full-thickness skin defects in mice. The MB@UiO-66(Ce)/PH with antibacterial properties and tissue healing-promoting ability provides a new strategy involving 3D bioprinting for preparing wound dressings.

A dual functional Ti-Ga alloy: inhibiting biofilm formation and osteoclastogenesis differentiation via disturbing iron metabolism.

BACKGROUND: Although biomedical implants have been widely used in orthopedic treatments, two major clinical challenges remain to be solved, one is the bacterial infection resulting in biofilm formation, and the other is aseptic loosening during implantation due to over-activated osteoclastogenesis. These factors can cause many clinical issues and even lead to implant failure. Thus, it is necessary to endow implants with antibiofilm and aseptic loosening-prevention properties, to facilitate the integration between implants and bone tissues for successful implantation. To achieve this goal, this study aimed to develop a biocompatible titanium alloy with antibiofilm and anti-aseptic loosening dual function by utilizing gallium (Ga) as a component. METHODS: A series of Ti-Ga alloys were prepared. We examined the Ga content, Ga distribution, hardness, tensile strength, biocompatibility, and anti-biofilm performance in vitro and in vivo. We also explored how Ga3+ ions inhibited the biofilm formation of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) and osteoclast differentiation. RESULTS: The alloy exhibited outstanding antibiofilm properties against both S. aureus and E. coli in vitro and decent antibiofilm performance against S. aureus in vivo. The proteomics results demonstrated that Ga3+ ions could disturb the bacterial Fe metabolism of both S. aureus and E. coli, inhibiting bacterial biofilm formation. In addition, Ti-Ga alloys could inhibit receptor activator of nuclear factor-κB ligand (RANKL)-dependent osteoclast differentiation and function by targeting iron metabolism, then suppressing the activation of the NF-κB signaling pathway, thus, showing their potential to prevent aseptic loosening. CONCLUSION: This study provides an advanced Ti-Ga alloy that can be used as a promising orthopedic implant raw material for various clinical scenarios. This work also revealed that iron metabolism is the common target of Ga3+ ions to inhibit biofilm formation and osteoclast differentiation.

Advancement of Gallium and Gallium-Based Compounds as Antimicrobial Agents.

With the abuse and misuse of antibiotics, antimicrobial resistance has become a challenging issue in the medical system. Iatrogenic and non-iatrogenic infections caused by multidrug-resistant (MDR) pathogens pose serious threats to global human life and health because the efficacy of traditional antibiotics has been greatly reduced and the resulting socio-economic burden has increased. It is important to find and develop non-antibiotic-dependent antibacterial strategies because the development of new antibiotics can hardly keep pace with the emergence of resistant bacteria. Gallium (III) is a multi-target antibacterial agent that has an excellent antibacterial activity, especially against MDR pathogens; thus, a gallium (III)-based treatment is expected to become a new antibacterial strategy. However, some limitations of gallium ions as antimicrobials still exist, including low bioavailability and explosive release. In recent years, with the development of nanomaterials and clathrates, the progress of manufacturing technology, and the emergence of synergistic antibacterial strategies, the antibacterial activities of gallium have greatly improved, and the scope of application in medical systems has expanded. This review summarizes the advancement of current optimization for these key factors. This review will enrich the knowledge about the efficiency and mechanism of various gallium-based antibacterial agents and provide strategies for the improvement of the antibacterial activity of gallium-based compounds.

A polydopamine coated nanoscale FeS theranostic platform for the elimination of drug-resistant bacteria via photothermal-enhanced Fenton reaction.

Infections caused by drug-resistant bacteria pose a great threat to human health. Non-antibiotic-dependent antibacterial strategies have become the focus of research. Among them, chemical dynamic treatment-based (CDT) therapeutic systems, which catalyze the production of hydroxyl radicals by enzymes, have achieved tremendous success for antibacterial purposes. However, limited kinetics of the Fenton reaction, poor permeability, and short half-life of hydroxyl radicals compromise the antibacterial effects of CDT. In addition, difficulties in the early diagnosis of infection lead to drug abuse and delayed treatment. Herein, a polydopamine coated ferrous sulfide theranostic platform adsorbing a hypochlorite responsive probe with photothermal treatment (PTT) enhanced CDT was synthesized. The probe component was used for the early diagnosis of infection. PTT not only inactivated bacteria by hyperthermia but also accelerated the Fenton reaction to produce more ·OH. In vitro antibacterial experiments demonstrated that the multifunctional theranostic platform has a broad antibacterial spectrum, including methicillin-resistant Staphylococcus aureus (MRSA), drug-resistant Escherichia coli (DR E. coli), and Pseudomonas aeruginosa (P. aeruginosa). In addition, in vivo antibacterial experiments demonstrated that nanoparticles could effectively rescue S. aureus-infected full-thickness skin defects with negligible cytotoxicity. This study proposes an efficient and multifunctional theranostic platform for bacterial infection, providing an effective synergistic antibacterial strategy for the treatment of antibiotic resistance. STATEMENT OF SIGNIFICANCE: An infection responsive theranostic platform (ClO- probe@FeS@PDA) is prepared. ·CDT is enhanced prominently by PTT at a relative low temperature. · FeS@PDA exhibits good antibacterial performance against drug resistant bacteria in vitro and in vivo.