Porous-carbon/manganese composite catalyst transformed from waste biomass as peroxymonosulfate activator for carbamazepine degradation.

Activation of peroxymonosulfate (PMS) with solid catalysts for organic pharmaceutical degradation still faces challenge due to the demand of inexpensive catalysts. In this study, manganese-oxidizing microalgae (MOM) and its associated biogenic manganese oxides (BMO) were employed to prepare biomass-transformed porous-carbon/manganese (B-PC/Mn) catalyst through high-temperature calcination (850 °C). Remarkably, 100 % of carbamazepine (CBZ) was degraded within 30 min in the B-PC/Mn/PMS system. The degradation kinetic constant was 0.1718 min-1, which was 44.0 times higher than that of the biomass-transformed porous carbon mixed with MnOx activated PMS system. 1O2 was generated in the B-PC/Mn/PMS system, which is responsible for CBZ degradation. The MOM-BMO-associated structure greatly increased the specific surface areas and the contents of the C = O and pyrrolic-N groups, which facilitated PMS activation. The structure also induced the generation of Mn5C2, which exhibited a strong adsorption towards PMS. This study provides a novel strategy for preparing catalysts by using waste biomass.

Sleep quality during pregnancy and fetal growth: A prospective cohort study.

The aim of this study is to investigate the association between sleep quality during pregnancy and fetal growth. Pregnant women and their fetuses at 16-20 gestational weeks in Nantong Maternal and Child Health Hospital were recruited. Women were classified as having "good sleep quality" (Pittsburgh Sleep Quality Index score ≤ 5) and "poor sleep quality" (Pittsburgh Sleep Quality Index score > 5) according to the Pittsburgh Sleep Quality Index scores. The fetal growth was evaluated by three ultrasonographic examinations, birth weight and birth length. We used general linear model and multiple linear regression models to estimate the associations. A total of 386 pairs of mother and infant were included in the data analysis. After adjusting for gestational weight gain, anxiety and depression, fetuses in the good sleep quality group had greater abdominal circumference (p = 0.039 for 28-31+6 weeks gestation, p = 0.012 for 37-40+6 weeks gestation) and femur length (p = 0.014 for 28-31+6 weeks gestation, p = 0.041for 37-40+6 weeks gestation) at 28-31+6 weeks gestation and 37-40+6 weeks gestation, and increased femur length (p = 0.007) at 28-31+6 weeks gestation. Birth weights (p = 0.018) were positively associated with sleep quality. Poor sleep quality was associated with poor intrauterine physical development, decreased abdominal circumference and femur length, and lower birth weight after adjusting for confounding factors. Attention to the fetal growth of pregnant women with poor sleep quality has the potential to decrease the risk of adverse fetal outcomes.

ZBP1 inhibits the replication of Senecavirus A by enhancing NF-κB signaling pathway mediated antiviral response in porcine alveolar macrophage 3D4/21 cells.

BACKGROUND: Senecavirus A (SVA) caused porcine idiopathic vesicular disease (PIVD) showing worldwide spread with economic losses in swine industry. Although some progress has been made on host factors regulating the replication of SVA, the role of Z-DNA binding protein 1 (ZBP1) remains unclear. METHODS: The expression of ZBP1 in SVA-infected 3D/421 cells was analyzed by quantitative real-time PCR (qRT-PCR) and western blot. Western blot and qRT-PCR were used to detect the effects of over and interference expression of ZBP1 on SVA VP2 gene and protein. Viral growth curves were prepared to measure the viral proliferation. The effect on type I interferons (IFNs), interferon-stimulated genes (ISGs), and pro-inflammatory cytokines in SVA infection was analyzed by qRT-PCR. Western blot was used to analysis the effect of ZBP1 on NF-κB signaling pathway and inhibitor are used to confirm. RESULTS: ZBP1 is shown to inhibit the replication of SVA by enhancing NF-κB signaling pathway mediated antiviral response. SVA infection significantly up-regulated the expression of ZBP1 in 3D4/21 cells. Infection of cells with overexpression of ZBP1 showed that the replication of SVA was inhibited with the enhanced expression of IFNs (IFN-α, IFN-ß), ISGs (ISG15, PKR, and IFIT1) and pro-inflammatory cytokines (IL-6, IL-8, and TNF-α), while, infected-cells with interference expression of ZBP1 showed opposite effects. Further results showed that antiviral effect of ZBP1 is achieved by activation the NF-κB signaling pathway and specific inhibitor of NF-κB also confirmed this. CONCLUSIONS: ZBP1 is an important host antiviral factor in SVA infection and indicates that ZBP1 may be a novel target against SVA.

The aging behavior of degradable plastic polylactic acid under the interaction of environmental factors.

Microplastics leaching from aging biodegradable plastics pose potential environmental threats. This study used response surface methodology (RSM) to investigate the impact of temperature, light, and humidity on the aging characteristics of polylactic acid (PLA). Key evaluation metrics included the C/O ratio, functional groups, crystallinity, surface topography, and mechanical properties. Humidity was discovered to have the greatest effect on the ageing of PLA, followed by light and temperature. The interactions between temperature and light, as well as humidity and sunlight, significantly impact the aging of PLA. XPS analysis revealed PLA underwent aging due to the cleavage of the ester bond (O-C=O), resulting in the addition of C=O and C-O. The aging process of PLA was characterized by alterations in surface morphology and augmentation in crystallinity, resulting in a decline in both tensile strength and elongation. These findings might offer insights into the aging behavior of degradable plastics under diverse environmental conditions.

IFITM1 and IFITM2 inhibit the replication of senecavirus A by positive feedback with RIG-I signaling pathway.

The role of host factors in the replication of emerging senecavirus A (SVA) which induced porcine idiopathic vesicular disease (PIVD) distributed worldwide remains obscure. Here, interferon-induced transmembrane (IFITM) protein 1 and 2 inhibit SVA replication by positive feedback with RIG-I signaling pathway was reported. The expression levels of IFITM1 and IFITM2 increased significantly in SVA infected 3D4/21 cells. Infection experiments of cells with over and interference expression of IFITM1 and IFITM2 showed that these two proteins inhibit SVA replication by regulating the expression of interferon beta (IFN-ß), IFN-stimulated gene 15 (ISG-15), interleukin 6 (IL-6), IL-8, tumor necrosis factor alpha (TNF-α), IFN regulatory factor-3 (IRF3), and IRF7. Further results showed that antiviral responses of IFITM1 and IFITM2 were achieved by activating retinoic acid-inducible gene I (RIG-I) signaling pathway which in turn enhanced the expression of IFITM1 and IFITM2. It is noteworthy that conserved domains of these two proteins also paly the similar role. These findings provide new data on the role of host factors in infection and replication of SVA and help to develop new agents against the virus.

Zn2+ Binding Increases Parallel Structure in the Aß(16-22) Oligomer by Disrupting Salt Bridge in Antiparallel Structure.

The aggregation of monomeric amyloid ß protein (Aß) into oligomers and amyloid plaque in the brain is associated with Alzheimer's disease. The hydrophobic central core Aß16-22 has been widely studied due to its essential role in the fibrillization of full-length Aß peptides. Compared to the homogeneous antiparallel structure of Aß16-22 at the late stage, the early-stage prefibrillar aggregates contain varying proportions of different ß structures. In this work, we studied the appearance probabilities of various self-assembly structures of Aß16-22 and the effects of Zn2+ on these probabilities by replica exchange molecular dynamics simulations. It was found that at room temperature, Aß16-22 can readily form assembled ß-sheet structures in pure water, where a typical antiparallel arrangement dominates (24.8% of all sampled trimer structures). The addition of Zn2+ to the Aß16-22 solution will dramatically decrease the appearance probability of antiparallel trimer structures to 12.5% by disrupting the formation of the Lys16-Glu22 salt bridge. Meanwhile, the probabilities of hybrid antiparallel/parallel structures increase. Our simulation results not only reveal the competition between antiparallel and parallel structures in the Aß16-22 oligomers but also show that Zn2+ can affect the oligomer structures. The results also provide insights into the role of metal ions in the self-assembly of short peptides.

CD46 inhibits the replication of swine influenza viruses by promoting the production of type I IFNs in PK-15 cells.

Swine flu caused by swine influenza A virus (swIAV) is an acute respiratory viral disease that is spreading in swine herds worldwide. Although the effect of some host factors on replication of swIAV has been identified, the role of CD46 in this process is unclear. Here, we report that CD46 inhibits the replication of swIAV by promoting the production of type I interferons (IFNs) in porcine kidney (PK-15) cells. CD46 knockout (CD46-KO) and stably expressing (CD46-overexpression) PK-15 cells were prepared using lentivirus-mediated CRISPR/Cas9 gene editing and seamless cloning technology. The results of virus infection in CD46-overexpression PK-15 cells showed that the replication of H1N1 and H3N2 swIAVs were inhibited, and the production of type I IFNs (IFN-α, IFN-ß), interferon regulatory factor (IRF) 3, and mitochondrial antiviral-signaling protein (MAVS) was enhanced. Virus infection in CD46-KO PK-15 cells showed the opposite results. Further results showed that CD46-KO PK-15 cells have a favorable ability to proliferate influenza viruses compared to Madin-Darby canine kidney (MDCK) and PK-15 cells. These findings indicate that CD46 acts as promising target regulating the replication of swIAV, and help to develop new agents against infection and replication of the virus.

Gelatinase-responsive biodegradable targeted microneedle patch for abscess wound treatment of S. aureus infection.

Abscess wound caused by bacterial infection is usually difficult to heal, thus greatly affect people's quality of life. In this study, a biodegradable drug-loaded microneedle patch (MN) is designed for targeted eradication of S. aureus infection and repair of abscess wound. Firstly, the bacterial responsive composite nanoparticle (Ce6@GNP-Van) with a size of about 182.6 nm is constructed by loading the photosensitizer Ce6 into gelatin nanoparticle (GNP) and coupling vancomycin (Van), which can specifically target S. aureus and effectively shield the phototoxicity of photosensitizer during delivery. When Ce6@GNP-Van is targeted and enriched in the infected regions, the gelatinase secreted by the bacteria can degrade GNP in situ and release Ce6, which can kill the bacteria by generating ROS under laser irradiation. In vivo experiments show that the microneedle is basically degraded in 10 min after inserting into skin, and the abscess wound is completely healed within 13 d after applying Ce6@GNP-Van-loaded MN patch to the abscess wound of the bacterial infected mice with laser irradiation, which can simultaneously achieve the eradication of biofilm and subsequent wound healing cascade activation, showing excellent synergistic antibacterial effect. In conclusion, this work establishes a synergistic treatment strategy to facilitate the repair of chronic abscess wound.

Thermally Reduced Graphene Oxide Membranes Revealed Selective Adsorption of Gold Ions from Mixed Ionic Solutions.

The recovery of gold from water is an important research area. Recent reports have highlighted the ultrahigh capacity and selective extraction of gold from electronic waste using reduced graphene oxide (rGO). Here, we made a further attempt with the thermal rGO membranes and found that the thermal rGO membranes also had a similarly high adsorption efficiency (1.79 g gold per gram of rGO membranes at 1000 ppm). Furthermore, we paid special attention to the detailed selectivity between Au3+ and other ions by rGO membranes. The maximum adsorption capacity for Au3+ ions was about 16 times that of Cu2+ ions and 10 times that of Fe3+ ions in a mixture solution with equal proportions of Au3+/Cu2+ and Au3+/Fe3+. In a mixed-ion solution containing Au3+:Cu2+:Na+:Fe3+:Mg2+ of printed circuit board (PCB), the mass of Au3+:Cu2+:Na+:Fe3+:Mg2+ in rGO membranes is four orders of magnitude higher than the initial mass ratio. A theoretical analysis indicates that this selectivity may be attributed to the difference in the adsorption energy between the metal ions and the rGO membrane. The results are conducive to the usage of rGO membranes as adsorbents for Au capture from secondary metal resources in the industrial sector.

Recombinant Orf virus induced antibody production against capsid protein of porcine circovirus type 3 in mice.

The emerging worldwide distributed porcine circovirus type 3 (PCV3) infection poses a serious threat to swine herds. An important means of preventing and controlling PCV3 infection is the development of the vaccine, while, the inability to cultivate in vitro has become the biggest obstacle. Orf virus (ORFV), the prototypic member of the Parapoxviridae, has been proven to be a novel valid vaccine vector for preparing various candidate vaccines. Here, recombinant ORFV expressing capsid protein (Cap) of PCV3 was obtained and proved its favorable immunogenicity inducing antibody against Cap in BALB/c mice. Based on the enhanced green fluorescent protein (EGFP) as a selectable marker, the recombinant rORFVΔ132-PCV3Cap-EGFP was generated. Then, recombinant ORFV expressing Cap only, rORFVΔ132-PCV3Cap, was obtained based on rORFVΔ132-PCV3Cap-EGFP using a double homologous recombination method by screening single non-fluorescent virus plaque. Results of the western blot showed that the Cap can be detected in rORFVΔ132-PCV3Cap infected OFTu cells. The results of immune experiments in BALB/c mice indicated that a specific antibody against Cap of PCV3 in serum was induced by rORFVΔ132-PCV3Cap infection. The results presented here provide a candidate vaccine against PCV3 and a feasible technical platform for vaccine development based on ORFV.

Dynamic behavior of the single-strand DNA molecules from the hydrophilic to hydrophobic regions on graphene oxide surface driven by heating.

Heating affects the interfacial properties of two-dimensional nanomaterials, especially when they interact with biomolecules. Here, we theoretically studied the dynamic processes driving single-strand DNA (ssDNA) molecules from the hydrophilic to hydrophobic regions on the graphene oxide (GO) surface by heating, as reported by recent experiments. This was accomplished by using multi-sample molecular dynamics simulations in the NVT ensemble, with the temperature increasing from 300 K to 350 K. When the temperature increased, the lifetime of hydrogen bonds between water molecule and oxygen-containing groups on the GO surface decreased from 10.04 ps to 6.86 ps, and the end-to-end distance of 4-mer and 8-mer ssDNA molecules also decreased. This indicated that heating facilitated the breaking/formation of hydrogen bonds and enhanced the flexibility of ssDNA molecules. By heating, active hydrogen bonding first led to unbalanced interactions between the ssDNA molecule and GO surface, and the enhanced flexibility allowed the ssDNA molecule to release stress by moving on the GO surface and relaxing its structure. The ssDNA molecule constantly adjusted its structure by a competition between intra and inter π-π stacking structures. With dynamic cooperation of hydrogen bonding and π-π stacking, the ssDNA molecule moved from the hydrophilic to hydrophobic regions. Our results offer fundamental interfacial science insights into the effects of heating on the interactions between biomolecules and two-dimensional nanomaterials.

The screening for marine fungal strains with high potential in alkaloids production by in situ colony assay and LC-MS/MS based secondary metabolic profiling.

Background: Alkaloids are the second primary class of secondary metabolites (SMs) from marine organisms, most of which have antioxidant, antitumor, antibacterial, anti-inflammatory, and other activities. However, the SMs obtained by traditional isolation strategies have drawbacks such as highly reduplication and weak bioactivity. Therefore, it is significantly important to establish an efficient strategy for screening strains and mining novel compounds. Methods: In this study, we utilized in situ colony assay combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) to identify the strain with high potential in alkaloids production. The strain was identified by genetic marker genes and morphological analysis. The secondary metabolites from the strain were isolated by the combine use of vacuum liquid chromatography (VLC), ODS column chromatography, and Sephadex LH-20. Their structures were elucidated by 1D/2D NMR, HR-ESI-MS, and other spectroscopic technologies. Finally, these compounds bioactivity were assay, including anti-inflammatory and anti-ß aggregation. Results: Eighteen marine fungi were preliminarily screened for alkaloids production by in situ colony assay using Dragendorff reagent as dye, and nine of them turned orange, which indicated abundant alkaloids. By thin-layer chromatography (TLC), LC-MS/MS, and multiple approaches assisted Feature-Based Molecular Networking (FBMN) analysis of fermentation extracts, a strain ACD-5 (Penicillium mallochii with GenBank accession number OM368350) from sea cucumber gut was selected for its diverse alkaloids profiles especially azaphilones. In bioassays, the crude extracts of ACD-5 in Czapek-dox broth and brown rice medium showed moderate antioxidant, acetylcholinesterase inhibitory, anti-neuroinflammatory, and anti-ß aggregation activities. Three chlorinated azaphilone alkaloids, compounds 1-3 (sclerotioramine, isochromophilone VI, and isochromophilone IX, respectively), were isolated from the fermentation products of ACD-5 in brown rice medium guided by bioactivities and mass spectrometry analysis. Compound 1 had shown remarkable anti-neuroinflammatory activity in liposaccharide induced BV-2 cells. Conclusion: In summary, in situ colony screening together with LC-MS/MS, multi-approach assisted FBMN can act as an efficient screening method for strains with potential in alkaloids production.

A novel core-shell composite of PCN-222@MIPIL for ultrasensitive electrochemical sensing 4-nonylphenol.

A novel core-shell composite of PCN-222 and molecularly imprinted poly (ionic liquid) (PCN-222@MIPIL) with high conductivity and selectivity was prepared for electrochemical sensing 4-nonylphenol (4-NP). The electrical conductivities of some MOFs including PCN-222, ZIF-8, NH2-UIO-66, ZIF-67, and HKUST-1 were explored. The results indicated that PCN-222 had the highest conductivity and was then used as a novel imprinted support. PCN-222@MIPIL with core-shell and porous structure was synthesized using PCN-222 as support and 4-NP as template. The average pore volume of PCN-222@MIPIL was 0.085 m3 g-1. In addition, the average pore width of PCN-222@MIPIL was from 1.1 to 2.7 nm. The electrochemical response for PCN-222@MIPIL sensor for 4-NP was 2.54, 2.14, and 4.24 times that of non-molecularly imprinted poly (ionic liquid) (PCN-222@NIPIL), PCN-222, and MIPIL sensors, respectively, which result from superior conductivity and imprinted recognition sites of PCN-222@MIPIL. The current response of PCN-222@MIPIL sensor to 4-NP concentration from 1 × 10-4 to 10 µM presented an excellent linear relationship. The detection limit of 4-NP was 0.03 nM. The synergistic effect between the PCN-222 supporter with high conductivity, specific surface area and shell layer of surface MIPIL results in the outstanding performance of PCN-222@MIPIL. PCN-222@MIPIL sensor was adopted for detecting 4-NP in real samples and presented to be a reliable approach for determining 4-NP.

Collagen hydrogel with multiple antimicrobial mechanisms as anti-bacterial wound dressing.

Wound infection by multidrug-resistant bacteria seriously threatens human life. Chronic wounds, with necrosis, persistent inflammation, and covered by hypoxic tissue, seriously hinder anti-infection treatments. Herein, we have developed a multifunctional hydrogel dressing with antibacterial activity in the hypoxia environment to promote wound healing. The hydrogel comprises Cypate-conjugated antimicrobial peptides (AMP-Cypates), liposome-encapsulated perfluorodecalin, and recombinant type III collagen. AMP-Cypates exhibited outstanding antibacterial activity, jointly achieved through antimicrobial peptide (AMP) activity, photothermal therapy (PTT), and photodynamic therapy (PDT). The perfluorodecalin liposomes act as the oxygen carrier to mitigate wound hypoxia condition and enhance the efficacy of PDT. The recombinant type III collagen in the hydrogel further promoted the healing of the wounds together with the eradication of bacterial infection. Taken together, the hydrogel dressing provides a platform for integrating multiple antimicrobial mechanisms for the rapid removal of bacterial infection and the healing of chronic wounds.

Risk factors for ninety-day readmission following cervical surgery: a meta-analysis.

BACKGROUND: As an important evaluation index after cervical surgery, ninety-day readmission is gradually being valued. Our study collected the latest published relevant studies, analyzed the risk factors of ninety-day readmission after cervical surgery, and continuously improved the postoperative rehabilitation plan. This study focuses on two research hotspots: (1) What is the rate of ninety-day readmission after cervical surgery? (2) What are the risk factors affecting the ninety-day readmission? METHODS: Based on the Cochrane Library, PubMed, Web of Science, and Embase databases, this study searched for studies about ninety-day readmission after cervical surgery, from the establishment of the database to August 1, 2022. The evaluation indicators are as follows: age, American Society of Anesthesiology physical status (ASA) class, diabetes, hypertension, chronic heart diseases, chronic lung diseases, income, and payments for hospitalization. The meta-analysis was performed using Review Manager 5.4. RESULTS: Seven studies with 222,490 participants were eligible for our meta-analysis. The analysis displayed that there were statistically significant differences in the age (MD = - 4.60, 95%CI - 4.89-4.31, p < 0.001), diabetes (OR = 0.60, 95%CI 0.56-0.64, p < 0.00001), hypertension (OR = 0.40, 95%CI 0.30-0.54, p < 0.00001), chronic heart diseases (OR = 0.05, 95%CI 0.01-0.19, p < 0.00001), chronic lung diseases (OR = 0.46, 95%CI 0.43-0.49, p < 0.00001), income (OR = 2.85, 95%CI 1.82-4.46, p < 0.00001), and payments for hospitalization (OR = 2.29, 95%CI 1.14-4.59, p = 0.02) between readmission and no readmission groups. In terms of the ASA, there was no difference on the ninety-day readmission (p = 0.78). CONCLUSION: Age, diabetes, hypertension, chronic heart diseases, chronic lung diseases, income, and payments for hospitalization are the risk factors of ninety-day readmission following cervical surgery.

[Pollution Characteristics and Risk Assessment of Heavy Metals in the Bioretention Systems of Sponge Cities].

As an important water purification and seepage measure for sponge cities, biofiltration systems have been widely used in their construction in China. In order to identify the heavy metal accumulation, pollution, and its potential environmental risk in the biofiltration systems, this study examined the heavy metal contents and spatial distribution characteristics by taking the biofiltration systems of Yuelai new town, Chongqing, the first demonstration area of sponge city construction in China, as the research object, and conducted a risk evaluation of the pollution level and ecological environment in this new town using the contamination factor (CF), geo-accumulation Index (Igeo), and potential ecological risk coefficient (PERC). The results showed that, except for Mn, the average contents of Cu, Zn, Pb, Ni, and Cd in the biofiltration systems of Yuelai new town were 4.14, 1.77, 4.98, 1.23, and 6.51 times higher than the soil background values of Chongqing. In terms of spatial distribution, the contents of heavy metals in biofiltration systems along the roads in different functional areas showed great differences. The contents of Cu, Zn, Mn, Pb, Ni, and Cd in the industrial area were significantly higher than those of the same types of heavy metals in the biofiltration systems in other areas (P<0.05). The CF and Igeo showed that the pollution level of heavy metals was ranked as follows:Mn

Gelatinase Responsive Nanogel for Antibacterial Phototherapy and Wound Healing.

The unique bactericidal mechanism of metal nanoparticles (MNPs) is considered to be an effective strategy to deal with antibiotic resistance, but the oxidative stress damage caused by excessive accumulation of MNPs to normal cells cannot be ignored. Achieving on-demand release of nano-drugs in specific infection environments is highly attractive. Herein, we constructed a "core-shell" nanogel (G@CuS) based on a copper sulfide (CuS) antimicrobial agent and gelatin for targeted drug release and bacterial clearance in a gelatinase infected microenvironment. G@CuS produced heat and reactive oxygen species (ROS) under the irradiation of a laser, which together with the released Cu2+ cause irreversible and efficient physical damage to the bacteria. Moreover, the encapsulation of gelatin not only limits the biotoxicity of CuS nanodots (NDs), but also effectively promotes the proliferation of mammalian cells. Under the synergy of multiple mechanisms, G@CuS eradicated the colonized bacteria in the wound of mice infected with Staphylococcus aureus (S. aureus) and accelerated wound healing. The proposed application strategy of nanogel is expected to provide a new idea for clinical transformation.

Degradable microneedle patches loaded with antibacterial gelatin nanoparticles to treat staphylococcal infection-induced chronic wounds.

Infection-induced chronic wounds cause prolonged pains, a high risk of amputation, and even increased mortality in immunocompromised patients. Here we report an antibacterial microneedle (MN) patch, which features high degradability in biological fluids and gelatinase-responsive release of an antibacterial photothermal peptide AMP-Cypate. We first synthesize gelatin nanoparticles (GNPs) and then conjugate the AMP-Cypate to afford composite AMP-Cypate@GNPs. The proteinaceous nanoparticles can responsively release AMP-Cypate in the presence of gelatinase, an enzyme secreted specifically by Staphylococcus aureus (S. aureus). AMP-Cypate@GNPs were then deposited in the tips of MNs fabricated by PVP and recombinant human type III collagen (Col III) to devise the antibacterial MN/AMP-Cypate@GNP patches. When applied to the infection site, MNs break through the epidermis and the stratum corneum, dissolve in the infected dermis, reach the bacterial colony or biofilm, release AMP-Cypate@GNPs, and exert a gelatinase-responsive photothermal therapy under near-infrared (NIR) irradiation to kill the pathogen S. aureus. In a rat model of staphylococcal infection-induced chronic wounds mimicking the condition of diabetic foot ulcer, the antibacterial MN/AMP-Cypate@GNP patches eradiated the bacterial infection and resulted in complete healing of the wounds, proving its potential application in the treatment of chronic wound infections and diabetic foot ulcers.

Bioprinted Gelatin-Recombinant Type III Collagen Hydrogel Promotes Wound Healing.

Artificial skins are biomaterials that can replace the lost skin or promote the regeneration of damaged skin. Skin regenerative biomaterials are highly applauded because they can exempt patients with severe burns from the painful procedure of autologous skin transplantation. Notwithstanding decades of research, biocompatible, degradable, and printable biomaterials that can effectively promote skin regeneration as a transplantation replacement in clinical use are still scarce. Here, we report one type of all-protein hydrogel material as the product of the enzymatic crosslinking reaction of gelatin and a recombinant type III collagen (rColIII) protein. Doping the rColIII protein in gelatin reduces the inflammatory response as an implant underneath the skin. The all-protein hydrogel can be bioprinted as scaffolds to support the growth and proliferation of 3T3 fibroblast cells. The hydrogel used as a wound dressing promotes wound healing in a rat model of skin damage, showing a faster and healthier recovery than the controls. The rColIII protein in the hydrogel has been shown to play a critical role in skin regeneration. Altogether, this work manifests the development of all-protein gelatin-rColIII hydrogel and demonstrates its use in wound healing. The gelatin-collagen hydrogel wound dressing thereby may become a promising treatment of severe wounds in the future.

Antimicrobial Peptide-Loaded Gelatinase-Responsive Photothermal Nanogel for the Treatment of Staphylococcus aureus-Infected Wounds.

As the most common pathogen of community and nosocomial infection, the resistance of Staphylococcus aureus (S. aureus) to traditional antibiotics is still increasing with years. Although the potent antibacterial activity of antimicrobial peptides (AMPs) has been widely confirmed, the unpredictable cytotoxicity remains the biggest obstacle to their clinical application. The development of a targeted drug delivery system for S. aureus is a practical strategy to ameliorate the inherent limitations of AMPs. In this work, we constructed an AMP release nanogel (cypate-GNPs@Cy3-AMP, CGCA) of S. aureus infection microenvironment using gelatinase nanoparticles (GNPs) for toxicity control and bacterial clearance. Gelatinase present in the infected site degrades GNPs, thus releasing Cy3-AMP in situ to destroy bacterial cells. Cypate modified on the surface of GNPs supports CGCA to generate localized heat under near-infrared (NIR) laser irradiation, which together with AMPs could cause irreversible physical damage to bacteria. In addition, the encapsulation from GNPs not only effectively limited the toxicity of AMPs but also significantly promoted cell proliferation and migration in vitro. In the mouse infection model, CGCA also exhibited excellent effects of bacterial clearance and wound healing, providing a potential direction for the correct use of AMPs.