Chlorogenic acid/carboxymethyl chitosan nanoparticle-assisted biomultifunctional hyaluronic acid-based hydrogel scaffolds for burn skin repair.

Burns are a prevalent type of injury worldwide, affecting tens of millions of people each year and significantly impacting the physical and psychological well-being of patients. Consequently, prompt treatment of burn wounds is imperative, with oxidative stress and excessive inflammation identified as primary factors contributing to delayed healing. In recent years, there has been growing interest in in situ crosslinked multifunctional hydrogels as a minimally invasive approach for personalized treatment delivery. To address these, a photocrosslinkable methacryloyl hyaluronic acid hydrogel scaffold embedded with chlorogenic acid/carboxymethyl chitosan nanoparticles (CGA/CMCS-HAMA, CCH), was developed for the treatment of burn wounds. The hydrogel prepared degraded by over 50 % by day 20, demonstrating stability and meeting the therapeutic requirements for burn wounds. Leveraging the extracellular matrix-like properties of HAMA and the antioxidant capabilities of CGA/CMCS NPs, this hydrogel demonstrates the ability to locally and continuously scavenge ROS and inhibit lipid peroxidation, inhibiting ferroptosis. Moreover, hydrogels well modulate the expression of macrophage- and fibroblast-associated inflammatory factors. Additionally, the hydrogel promotes cell adhesion and migration, further supporting the healing process. Overall, this innovative approach offers a safe and promising solution for burn wound treatment, addressing drug breakthrough and safety concerns while being adaptable to various irregular wound types.

Electrospun Nanofiber Scaffold for Skin Tissue Engineering: A Review.

Skin tissue engineering (STE) is widely regarded as an effective approach for skin regeneration. Several synthetic biomaterials utilized for STE have demonstrated favorable fibrillar characteristics, facilitating the regeneration of skin tissue at the site of injury, yet they have exhibited a lack of in situ degradation. Various types of skin regenerative materials, such as hydrogels, nanofiber scaffolds, and 3D-printing composite scaffolds, have recently emerged for use in STE. Electrospun nanofiber scaffolds possess distinct advantages, such as their wide availability, similarity to natural structures, and notable tissue regenerative capabilities, which have garnered the attention of researchers. Hence, electrospun nanofiber scaffolds may serve as innovative biological materials possessing the necessary characteristics and potential for use in tissue engineering. Recent research has demonstrated the potential of electrospun nanofiber scaffolds to facilitate regeneration of skin tissues. Nevertheless, there is a need to enhance the rapid degradation and limited mechanical properties of electrospun nanofiber scaffolds in order to strengthen their effectiveness in soft tissue engineering applications in clinical settings. This Review centers on advanced research into electrospun nanofiber scaffolds, encompassing preparation methods, materials, fundamental research, and preclinical applications in the field of science, technology, and engineering. The existing challenges and prospects of electrospun nanofiber scaffolds in STE are also addressed.

Gelatin-Based Hydrogel Functionalized with Dopamine and Layered Double Hydroxide for Wound Healing.

Hydrogels with adhesion properties and a wetted structure are promising alternatives to traditional wound dressing materials. The insufficiency of gelatin hydrogels in terms of their adhesive and mechanical strength limits their application in wound dressings. This work presents the design and preparation of a gelatin-based hydrogel functionalized with dopamine (DA) and layered double hydroxide (LDH). The combination of DA and LDH improves the hydrogel's adhesion properties in terms of interfacial adhesion and inner cohesion. Hydrogels with 8% DA and 4% LDH attained the highest adhesion strength of 266.5 kPa, which increased to 295.5 and 343.3 kPa after hydrophobically modifying the gelatin with octanoyl and decanoyl aldehydes, respectively. The gelatin-based hydrogels also demonstrated a macroporous structure, excellent biocompatibility, and a good anti-inflammatory effect. The developed hydrogels accelerated wound healing in Sprague Dawley rat skin full-thickness wound models.

Osteogenic effect and mechanism of IL-10 in diabetic rat jaw defect mode.

OBJECTIVE: The aim of this study was to investigate the effect of IL-10 on the phenotype polarization of macrophages and osteogenesis in diabetes mellitus type 2 (T2DM) rat jaw defects. METHODS: Lipopolysaccharide (LPS) and interleukin-10 (IL-10) were chosen to induce the polarization of macrophages. In vitro assessment included wound-healing assay, western blotting, and alizarin red staining after co-culture of the bone marrow-derived mesenchymal stem cells (BMSCs) and induced macrophages. For in vivo study, IL-10 was loaded on GelMA-Heparin and applied to bone defects of the alveolar ridge in diabetic rats, while Bio-Oss Collagen, simple GelMA-Heparin, and blank control groups were set for contrast experiment. The mandibles of rats were processed for micro-computed tomography, histology, and immunohistochemistry 1 week and 4 weeks after the operation. RESULTS: IL-10 induced expression of arginase 1, TGF-ß1, EGR2, and Mannose Receptor (CD206), whereas LPS induced expression of iNOS, TNF-α, IL-6, CD80. The BMSCs co-cultured with macrophages induced by IL-10 showed increased migration, osteogenic differentiation, and mineralization in vitro. Notably, the IL-10-laden GelMA-Heparin group showed quicker new bone formation and a higher M2/M1 ratio of macrophages in the jawbone defect area compared with the control groups. CONCLUSIONS: IL-10 can stably induce macrophages to M2 type, thereby influencing BMSCs and improving the osteogenesis of jaw bone defects.

Preparation and identification of novel antioxidant peptides from camel bone protein.

Collagen hydrolysates are a vital source of bioactive peptides. The objective of this study was to prepare camel bone collagen hydrolysates with antioxidant activity, and to identify the peptides responsible for the antioxidant activity. To this end, single-factor and orthogonal tests were performed to explore the optimum preparation conditions. A hydrolysis time of 5 h, enzyme:substrate ratio of 1200 U/g, pH of 7.0, and a material:water ratio of 1:3.0 were adopted. Subsequently, the hydrolysates were purified using a series of chromatography procedures, and three novel peptides, GPPGPPGPPGPPGPPSGGFDF (hydroxylation), PATGDLTDFLK, and GSPGPQGPPGSIGPQ, possessing antioxidant abilities, were identified from the fraction using liquid chromatography-tandem mass spectrometry. The peptide PATGDLTDFLK showed excellent DPPH scavenging activity (39%) and a good cytoprotective effect on H2O2-induced oxidative stress damage in HepG2 cells with a 21.1% increase observed.

Assessing the mechanism for flood control: a case of plain river network cities under extreme rainfalls.

In recent years, frequent floods hit Chinese cities and caused heavy casualties and property losses, making China faced with severe flood problems. In this study, Nanhai Future City in the IX Flood Control Area of Yancheng City, Jiangsu Province, was selected as the research area to simulate water-level changes under different control schemes meeting extreme rainfalls. MIKE model simulated the inundation with the designed storm of different return periods. The results showed that flooding inside the research area was severe. Higher drainage capacity of the pump stations with more engineering and non-engineering measures can reduce the adverse effect of extreme rainfall. The results provide a reference for planning future infrastructure and flood control decisions for Nanhai Future City and the surrounding areas.

Rapid Fabrication of MgNH4PO4·H2O/SrHPO4 Porous Composite Scaffolds with Improved Radiopacity via 3D Printing Process.

Although bone repair scaffolds are required to possess high radiopacity to be distinguished from natural bone tissues in clinical applications, the intrinsic radiopacity of them is usually insufficient. For improving the radiopacity, combining X-ray contrast agents with bone repair scaffolds is an effective method. In the present research, MgNH4PO4·H2O/SrHPO4 3D porous composite scaffolds with improved radiopacity were fabricated via the 3D printing technique. Here, SrHPO4 was firstly used as a radiopaque agent to improve the radiopacity of magnesium phosphate scaffolds. X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS) were used to characterize the phases, morphologies, and element compositions of the 3D porous composite scaffolds. The radiography image showed that greater SrHPO4 contents corresponded to higher radiopacity. When the SrHPO4 content reached 9.34%, the radiopacity of the composite scaffolds was equal to that of a 6.8 mm Al ladder. The porosity and in vitro degradation of the porous composite scaffolds were studied in detail. The results show that magnesium phosphate scaffolds with various Sr contents could sustainably degrade and release the Mg, Sr, and P elements during the experiment period of 28 days. In addition, the cytotoxicity on MC3T3-E1 osteoblast precursor cells was evaluated, and the results show that the porous composite scaffolds with a SrHPO4 content of 9.34% possessed superior cytocompatibility compared to that of the pure MgNH4PO4·H2O scaffolds when the extract concentration was 0.1 g/mL. Cell adhesion experiments showed that all of the scaffolds could support MC3T3-E1 cellular attachment well. This research indicates that MgNH4PO4·H2O/SrHPO4 porous composite scaffolds have potential applications in the bone repair fields.

A GelMA-PEGDA-nHA Composite Hydrogel for Bone Tissue Engineering.

A new gelatin methacrylamine (GelMA)-poly (ethylene glycol) diacrylate (PEGDA)-nano hydroxyapatite (nHA) composite hydrogel scaffold was developed using UV photo-crosslinking technology. The Ca2+ from nHA can form a [HO]Ca2+ [OH] bridging structure with the hydroxyl group in GelMA, thereby enhancing the stability. Compared with GelMA-PEGDA hydrogel, the addition of nHA can control the mechanical properties of the composite hydrogel and reduce the degradation rate. In vitro cell culture showed that osteoblast can adhere and proliferate on the surface of the hydrogel, indicating that the GelMA-PEGDA-nHA hydrogel had good cell viability and biocompatibility. Furthermore, GelMA-PEGDA-nHA has excellent injectability and rapid prototyping properties and is a promising 3D printed bone repair scaffold material.

Cell Proliferation Stimulation Ability and Osteogenic Activity of Low Molecular Weight Peptides Derived from Bovine Gelatin Hydrolysates.

It has been recognized that collagen peptides of MW 878 Da (CP1) promote osteoblast proliferation and mineralization. The objective of this study is to identify the peptides responsible for proliferation of osteoblast growth, enhancement of ALP (alkaline phosphatase) activity in osteoblasts and promotion of osteoblast mineralization. To this end, the CP1 were fractioned by a series of chromatography procedures, and 51 peptides from the fraction possessing the most powerful cell proliferation ability were identified by LC-MS-MS. The peptides, GPAGPSGPAGK and GPPGSPGPR, were validated on a simultaneous basis as possessing enhanced bioactivity-inducing properties. In particular, the ALP activity of the cells treated with these two peptides was almost twice that of the control cells. Hydrogen bonds were formed, and the hydrophobic interactions with the EGFR (epidermal growth factor receptor) might be responsible for the osteoblast proliferation activity. On this basis, the two peptides might be potential lead compounds against osteoporosis and osteoarthritis.

Development of a Photo-Crosslinking, Biodegradable GelMA/PEGDA Hydrogel for Guided Bone Regeneration Materials.

Gelatin-based hydrogel, which mimics the natural dermal extracellular matrix, is a promising tissue engineering material. However, insufficient and uncontrollable mechanical and degradation properties remain the major obstacles for its application in medical bone regeneration material. Herein, we develop a facile but efficient strategy for a novel hydrogel as guided bone regeneration (GBR) material. In this study, methacrylic anhydride (MA) has been used to modify gelatin to obtain photo-crosslinkable methacrylated gelatin (GelMA). Moreover, the GelMA/PEGDA hydrogel was prepared by photo-crosslinking GelMA and PEGDA with photoinitiator I2959 under UV treatment. Compared with the GelMA hydrogel, the GelMA/PEGDA hydrogel exhibits several times stronger mechanical properties than pure GelMA hydrogel. The GelMA/PEGDA hydrogel shows a suitable degradation rate of more than 4 weeks, which is beneficial to implant in body. In vitro cell culture showed that osteoblast can adhere and proliferate on the surface of the hydrogel, indicating that the GelMA/PEGDA hydrogel had good cell viability and biocompatibility. Furthermore, by changing the quantities of GelMA, I2959, and PEGDA, the gelation time can be controlled easily to meet the requirement of its applications. In short, this study demonstrated that PEGDA enhanced the performance and extended the applications of GelMA hydrogels, turning the GelMA/PEGDA hydrogel into an excellent GBR material.

Biotoxin Tropolone Contamination Associated with Nationwide Occurrence of Pathogen Burkholderia plantarii in Agricultural Environments in China.

Tropolone, a biotoxin produced by the agricultural pathogen Burkholderia plantarii, exerts cytotoxicity toward a wide array of biota. However, due to the lack of quantitative and qualitative approach, both B. plantarii occurrence and tropolone contamination in agricultural environments remain poorly understood. Here, we presented a sensitive and reliable method for detection of B. plantarii in artificial, plant, and environmental matrices by tropolone-targeted gas chromatography-triple-quadrupole tandem mass spectrometry analysis. Limits of detection for B. plantarii and tropolone were 10 colony-forming units (CFU)/mL and 0.017 µg/kg, respectively. In a series of simulation trials, we found that B. plantarii from 10 to 108 CFU/mL produced tropolone between 0.006 and 107.8 mg/kg in a cell-population-dependent manner, regardless of habitat. Correlation analysis clarified a reliable reflection of B. plantarii density by tropolone level with R2 values from 0.9201 to 0.9756 ( p < 0.01). Through a nationwide pilot study conducted in China, tropolone contamination was observed at 0.014-0.157 mg/kg in paddy soil and rice grains, and subsequent redundancy analysis revealed soil organic matter to be a dominant environmental factor, having a positive correlation with tropolone contamination. In this context, our results imply that potential ecological and dietary risks posed by long-term exposure to trace levels of tropolone contamination are of concern.

Residue Analysis of Benzobicyclon in Soil and Sediment Samples by Ultra High-Performance Liquid Chromatography-Tandem Mass Spectrometry.

A reliable and rapid method was developed to determine benzobicyclon residue in different soil and sediment samples. After extraction via a modified quick, easy, cheap, effective, rugged, and safe method, samples were purified by SPE cleanup with HLB cartridges. Quantitative determination was performed by ultra-HPLC (UPLC)-tandem MS (MS/MS) in electrospray positive ionization and multiple reaction monitoring modes. When samples were fortified at concentrations of 5, 50, and 500 µg/L, recoveries of 80.2 to 114.5% were obtained, with the repeatability (intraday RSDr) and reproducibility (interday RSDR) <14.1 and <21.4%, respectively. The instrumental LODs and LOQs for matrix-matched standards and the method LOQs for sample test were 0.19-1.34 µg/L, 0.64-4.48 µg/L, and 0.32-2.24 µg/kg, respectively. The linear range was 5-1000 µg/L (R2 > 0.99). The established UPLC-MS/MS method was applied in the detection of benzobicyclon in real soil samples, which were collected during the supervised field trial. Results showed that the maximum concentration of benzobicyclon in the soil was 4.87 mg/kg and its degradation half-life (t0.5) was 6.7 days. Generally, the proposed method could be an effective tool for controlling and monitoring the risks posed by benzobicyclon to human health and environmental safety.

Degradation properties and identification of metabolites of 6-Cl-PMNI in soil and water.

In order to provide the scientific basis for the environmental risk assessment of cycloxaprid and 6-Cl-PMNI (intermediate of cycloxaprid), the degradation properties of 6-Cl-PMNI in aerobic, anaerobic and/or sterile soil, as well as in water with different pH values at different temperature were explored under laboratory conditions using HPLC for its kinetics study and UPLC-MS/MS for the identification of its metabolites/degradation products. Fortification study showed that the recoveries of 71.4-100.5% with the maximum coefficient variation (CV) of 7.47% were obtained. The linear range was 0.1-10 mg/L with the good linearity of R(2) = 0.9990. For standard, the method LOD (limit of detection) and LOQ (limit of quantification) was 0.03 mg/L and 0.1 mg/L, respectively. Results demonstrated the good performance of the developed method. Kinetics study indicated that the degradation half-lives (t0.5) in pH 3-pH 10 buffers varied from 111.8 d to 288.8 d at 25 °C but rapidly shortened to 1.6-25.7 d at 70 °C. Good negative linear ships (R(2) ≥ 0.8423) between half life and temperature were found. 6-Cl-PMNI could be readily degraded in non-sterile soil (t0.5 0.8-7.5 d) while slowly degraded in sterile soil (t0.5 64.8-91.2 d). Three hydrolytic products and one metabolite of 6-Cl-PMNI in aerobic soil were identified. The CC olefinic bond reacted with H2O by Markovnikov Additive Reaction and the split of C-Cl were mainly proposed as the possible reaction pathway for 6-Cl-PMNI degradation in water and in soil, respectively.

Combined oral administration of bovine collagen peptides with calcium citrate inhibits bone loss in ovariectomized rats.

PURPOSE: Collagen peptides (CPs) and calcium citrate are commonly used as bone health supplements for treating osteoporosis. However, it remains unknown whether the combination of oral bovine CPs with calcium citrate is more effective than administration of either agent alone. METHODS: Forty 12-week-old Sprague-Dawley rats were randomly divided into five groups (n = 8) for once-daily intragastric administration of different treatments for 3 months at 3 months after ovariectomy (OVX) as follows: sham + vehicle; OVX + vehicle; OVX + 750 mg/kg CP; OVX + CP-calcium citrate (75 mg/kg); OVX + calcium citrate (75 mg/kg). After euthanasia, the femurs were removed and analyzed by dual energy X-ray absorptiometry and micro-computed tomography, and serum samples were analyzed for bone metabolic markers. RESULTS: OVX rats supplemented with CPs or CP-calcium citrate showed osteoprotective effects, with reductions in the OVX-induced decreases in their femoral bone mineral density. Moreover, CP-calcium citrate prevented trabecular bone loss, improved the microarchitecture of the distal femur, and significantly inhibited bone loss with increased bone volume, connectivity density, and trabecular number compared with OVX control rats. CP or CP-calcium citrate administration significantly increased serum procollagen type I N-terminal propeptide levels and reduced serum bone-specific alkaline phosphatase, osteocalcin, and C-telopeptide of type I collagen levels. CONCLUSIONS: Our data indicate that combined oral administration of bovine CPs with calcium citrate inhibits bone loss in OVX rats. The present findings suggest that combined oral administration of bovine CPs with calcium citrate is a promising alternative for reducing bone loss in osteopenic postmenopausal women.

Bovine collagen peptides compounds promote the proliferation and differentiation of MC3T3-E1 pre-osteoblasts.

OBJECTIVE: Collagen peptides (CP) compounds, as bone health supplements, are known to play a role in the treatment of osteoporosis. However, the molecular mechanisms of this process remain unclear. This study aimed to investigate the effects of bovine CP compounds on the proliferation and differentiation of MC3T3-E1 cells. METHODS: Mouse pre-osteoblast cell line MC3T3-E1 subclone 4 cells were treated with bovine CP compounds. Cell proliferation was analyzed by MTT assays and the cell cycle was evaluated by flow cytometry scanning. Furthermore, MC3T3-E1 cell differentiation was analyzed at the RNA level by real-time PCR and at the protein level by western blot analysis for runt-related transcription factor 2 (Runx2), a colorimetric p-nitrophenyl phosphate assay for alkaline phosphatase (ALP), and ELISA for osteocalcin (OC). Finally, alizarin red staining for mineralization was measured using Image Software Pro Plus 6.0. RESULTS: Cell proliferation was very efficient after treatment with different concentrations of bovine CP compounds, and the best concentration was 3 mg/mL. Bovine CP compounds significantly increased the percentage of MC3T3-E1 cells in G2/S phase. Runx2 expression, ALP activity, and OC production were significantly increased after treatment with bovine CP compounds for 7 or 14 days. Quantitative analyses with alizarin red staining showed significantly increased mineralization of MC3T3-E1 cells after treatment with bovine CP compounds for 14 or 21 days. CONCLUSIONS: Bovine CP compounds increased osteoblast proliferation, and played positive roles in osteoblast differentiation and mineralized bone matrix formation. Taking all the experiments together, our study indicates a molecular mechanism for the potential treatment of osteoarthritis and osteoporosis.

Effect of c-fos antisense probe on prostaglandin E2-induced upregulation of vascular endothelial growth factor mRNA in human liver cancer cells.

AIM: To examine the effect of prostaglandin E2 (PGE2) on the expression of vascular endothelial growth factor (VEGF) mRNA in the human hepatocellular carcinoma (HCC) HepG2 cells and the possible involvement of c-fos protein in this process. METHODS: Human HCC HepG2 cells were divided into three groups treated respectively with PGE2, a combination of PGE2 and c-fos antisense oligodeoxynucleotide (ASO), and PGE2 plus c-fos sense oligodeoxynucleotide (SO). The expression of VEGF mRNA in HepG2 cells after different treatments was detected by reverse transcriptase-polymerase chain reaction (RT-PCR). The relative expression level of VEGF mRNA in HepG2 cells in each group was measured. RESULTS: Administration of PGE2 resulted in an increased expression of c-fos and VEGF mRNA in HepG2 cells. The relative expression level of c-fos mRNA reached the peak at 3 h (68.4+/-4.7%) after PGE2 treatment, which was significantly higher than that at 0 h (20.6+/-1.7%, P<0.01). Whereas, the highest expression level of VEGF mRNA was observed at 6 h (100.5+/-6.1%) after PGE2 treatment, which was significantly higher than that at 0 h (33.2+/-2.4%, P<0.01). C-fos ASO significantly reduced PGE2-induced VEGF mRNA expression in HepG2 cells. CONCLUSION: PGE2 increases the expression and secretion of VEGF in HCC cells by activating the transcription factor c-fos, promotes the angiogenesis of HCC and plays an important role in the pathogenesis of liver cancer.