Collaborative Design of MgO/FeOx Nanosheets on Titanium: Combining Therapy with Regeneration

The repair of bone defects caused by osteosarcoma resection remains a clinical challenge because of the tumor recurrence and bacterial infection. Combining tumor and bacterial therapy with bone regeneration properties in bone implants is a promising strategy for the treatment of osteosarcoma. Here, a layer of MgO/FeO_x nanosheet is constructed on the Ti implant to prevent tumor recurrence and bacterial infection, while simultaneously accelerating bone formation. This MgO/FeO_x double metal oxide demonstrates good peroxidase activity to catalyze H₂ O₂ , which is rich in tumor microenvironment, to form reactive oxygen species (ROS), and shows good photothermal conversion capacity to produce photothermal effect, thus synergistically killing tumor cells and eliminating tumor tissue. In addition, it generates a local alkaline surface microenvironment to inhibit the energy metabolism of bacteria to enhance the photothermal antibacterial effect. Furthermore, benefiting from the generation of a Mg ion-containing alkaline microenvironment, this MgO/FeO_x film can promote the osteogenic differentiation of osteoblast and angiogenesis of vascular endothelial cells in vitro as well as accelerated bone formation in vivo. This study proposes a multifunctional platform for integrating tumor and bacterial therapy and bone regeneration, which has good application prospects for the treatment of osteosarcoma.

Complementary and Synergistic Design of Bi-Layered Double Hydroxides Modified Magnesium Alloy toward Multifunctional Orthopedic Implants

Magnesium (Mg)-based alloys have been regarded as promising implants for future clinic orthopedics, however, how to endow them with good anti-corrosion and biofunctions still remains a great challenge, especially for complicated bone diseases. Herein, three transition metals (M = Mn, Fe, and Co)-containing layered double hydroxides (LDH) (LDH-Mn, LDH-Fe, and LDH-Co) with similar M content are prepared on Mg alloy via a novel two-step method, then systematic characterizations and comparisons are conducted in detail. Results showed that LDH-Mn exhibited the best corrosion resistance, LDH-Mn and LDH-Co possessed excellent photothermal and enzymatic activities, LDH-Fe revealed better cytocompatibility and antibacterial properties, while LDH-Co demonstrated high cytotoxicity. Based on these results, an optimized bilayer LDH coating enriched with Fe and Mn (LDH-MnFe) from top to bottom have been designed for further in vitro and in vivo analysis. The top Fe-riched layer provided biocompatibility and antibacterial properties, while the bottom Mn-riced layer provided excellent anti-corrosion, photothermal and enzymatic effects. In addition, the released Mg, Fe, and Mn ions have a positive influence on angiogenesis and osteogenesis. Thus, the LDH-MnFe showed complementary and synergistic effects on anti-corrosion and multibiofunctions (antibacteria, antitumor, and osteogenesis). The present work offers a novel multifunctional Mg-based implant for treating bone diseases.

Mild pretreatment with Brønsted acidic deep eutectic solvents for fractionating β-O-4 linkage-rich lignin with high sunscreen performance and evaluation of enzymatic saccharification synergism

Herein, a mild fractionation method by employing polyol-based Brønsted acidic DESs (BDESs) was proposed to extract lignin with well-preserved β-O-4 substructures and to enhance fermentable sugar yields simultaneously. For ethylene glycol-oxalic acid (EG-OA), more than 53 % of lignin was obtained and superb carbohydrate digestibility (i.e., glucose and xylose yields were reached to 94.6 % and 87.7 %, respectively) was achieved after pretreatment. Remarkably, detailed structural studies revealed that the polyol was incorporated into lignin, which stabilized reactive carbocation intermediates formed during BDESs treatment and prevented undesired recondensation reactions. This lignin protection mechanism was shown to play a key role in enzymatic hydrolysis enhancement and lignin valorization. The resultant β-O-4 linkage-rich lignin fractions were attractive for natural sunscreen applications due to their lighter color and excellent UV-blocking performance. Overall, this work proposed a sustainable and economically practical lignin-first biorefinery approach that is beneficial for achieving comprehensive valorization of lignocellulose.

Structure, stability, antioxidant activity, and controlled-release of selenium nanoparticles decorated with lichenan from Usnea longissima

Selenium nanoparticles (SeNPs) have attracted widespread attention, but the poor water dispersibility restricted their applications seriously. Herein, Usnea longissima lichenan decorated selenium nanoparticles (L-SeNPs) were constructed. The formation, morphology, particle size, stability, physicochemical characteristics, and stabilization mechanism of L-SeNPs were investigated via TEM, SEM, AFM, EDX, DLS, UV-Vis, FT-IR, XPS, and XRD. The results indicated that the L-SeNPs displayed orange-red, amorphous, zero-valent, and uniform spherical nanoparticles with an average diameter of 96 nm. Due to the formation of CO⋯Se bonds or the hydrogen bonding interaction (OH⋯Se) between SeNPs and lichenan, L-SeNPs exhibited better heating and storage stability, which kept stable for more than one month at 25 °C in an aqueous solution. The decoration of the SeNPs surface with lichenan endowed the L-SeNPs with superior antioxidant capability, and their free radicals scavenging ability exhibited in a dose-dependent manner. Furthermore, L-SeNPs showed excellent selenium controlled-release performance. In simulated gastric liquids, selenium release kinetics from L-SeNPs followed the Linear superimposition model, which was governed by the polymeric network retardation of macromolecular, while in simulated intestinal liquids, it was well fitted to the Korsmeyer-Peppas model and followed a Fickian mechanism controlled by diffusion.

Novel 1,3,4-oxadiazole sulfonate/carboxylate flavonoid derivatives: synthesis and biological activity

BACKGROUND

With the long-term use of traditional bactericides and antiviral agents, drug resistance has become increasingly prominent, resulting in impaired crop growth and yields. Based on this, the introduction of small molecular active groups into natural products has become the direction of research for green pesticides.

RESULTS

In this study, novel 1,3,4-oxadiazole sulfonate/carboxylate flavonoid derivatives were explored. Among them, D4 exhibited good inhibitory effects on plant bacteria. It is worth mentioning that D4 (15 μg ml^-1 ) exhibited an excellent median effective concentration (EC₅₀ ) value against Xanthomonas oryzae pv. oryzae (Xoo), which was better than bismerthiazol (73 μg ml^-1 ) and thiodiazole copper (100 μg ml^-1 ). The EC₅₀ for D4 was much lower than the two positive controls (bismerthiazol, thiodiazole copper), making D4 more potent in this assay of bacterial growth inhibition. In addition, mechanism research using scanning electron microscopy revealed that D4 could cause deformation or rupture of the cell membranes of Xoo and Pseudomonas syringae pv. actinidiae. Moreover, D4 exhibited the best EC₅₀ for in vivo curative (132 μg ml^-1 ) and protective (101 μg ml^-1 ) activities against tobacco mosaic virus, which were more effective than ningnanmycin. Microscale thermophoresis data suggested that D4 [dissociation constant (K_d ) = 0.038 ± 0.011 μmol L^-1 ] exhibited a stronger binding capacity than the control agent ningnanmycin (K_d = 4.707 ± 2.176 μmol L^-1 ).

CONCLUSION

The biological activity data and mode of action demonstrated that D4 had the best antibacterial and antiviral effects. Compound D4 discovered in the current work may be a very promising agricultural drug. © 2022 Society of Chemical Industry.

Multifunctional hybrid hydrogel with transparency, conductivity, and self-adhesion for soft sensors using hemicellulose-decorated polypyrrole as a conductive matrix

Polymers with high conductivity and cross-linking ability are ideal materials for the preparation of conductive hydrogels for application in wearable electronic devices. However, the fabrication of conductive polymer-incorporated hydrogels with good synergistic properties remains a great challenge due to the hydrophobicity and opacity of conjugated π conductive polymers. In this study, a multifunctional hybrid hydrogel was prepared by incorporating hemicellulose-decorated polypyrrole (H/PPY), polyvinyl alcohol (PVA), and tannic acid (TA) into a polyacrylamide (PAM) network. The addition of excess ammonium persulfate (APS) in the process of gelation not only initiated the polymerization of PAM but also resulted in the change of the hydrogel from opaque to transparent by continuously breaking and reducing the size of the PPY particles. The hybrid hydrogel exhibited high transparency and conductivity, good adhesion ability and mechanical performance, and high resistance strain sensitivity and could accurately monitor the strain signals of the index finger and elbow flexion and pulse beat during rest and exercise, which has promising potential for use in wearable or implantable smart sensor devices, electronic skins, and artificial intelligence applications.

A SiO2 layer on PEO-treated Mg for enhanced corrosion resistance and bone regeneration

Magnesium (Mg) is a promising biodegradable metal for orthopedic applications, and plasma electrolytic oxidation (PEO) has been widely studied as a corrosion protection coating on Mg-based implants. However, the porous structures and easily formed cracks in fluid are disadvantageous for long-term corrosion protection. In this study, a SiO₂ layer was deposited on PEO-treated Mg to inhibit the formation of cracks on the PEO layer and prevent the permeation of corrosive fluid. The SiO₂ layer did not alter the surface morphology of the PEO layer but considerably enhanced its corrosion resistance. The in vitro culture of MC3T3-E1 cells demonstrated the good cytocompatibility and osteogenic induction ability of SiO₂-coated PEO-treated Mg, which could be attributed to Mg and Si ions released from the coating. The coating also favored the angiogenesis behaviors of HUVEC. Furthermore, with the continuous release of Mg and Si ions, the as-prepared implant showed a superior osseointegration ability in a rat bone implantation model. In summary, this newly designed Mg-based implant shows promising potential for orthopedic applications.

Triplex-forming oligonucleotides as an anti-gene technique for cancer therapy

Triplex-forming oligonucleotides (TFOs) can bind to the major groove of double-stranded DNA with high specificity and affinity and inhibit gene expression. Triplex-forming oligonucleotides have gained prominence because of their potential applications in antigene therapy. In particular, the target specificity of triplex-forming oligonucleotides combined with their ability to suppress oncogene expression has driven their development as anti-cancer agents. So far, triplex-forming oligonucleotides have not been used for clinical treatment and seem to be gradually snubbed in recent years. But triplex-forming oligonucleotides still represent an approach to down-regulate the expression of the target gene and a carrier of active substances. Therefore, in the present review, we will introduce the characteristics of triplex-forming oligonucleotides and their anti-cancer research progress. Then, we will discuss the challenges in their application.

Microbial network complexity drives non-linear shift in biodiversity-nutrient cycling in a saline urban reservoir

Aquatic biodiversity is important in mediating ecosystem functioning, contributing to ecosystem sustainability and human wellbeing. However, how microbial network complexity affects the biodiversity-nutrient cycling relationship in saline freshwater ecosystems remains underexplored. Using high-resolution time-series data, we examined the relationships between microeukaryotic-bacterial community network complexity, biodiversity and multi-nutrient cycling in an urban reservoir undergoing a freshwater salinization-desalinization cycle. We found that low microbial diversity enhanced ecosystem multi-nutrient cycling under high salinity stress. In addition, multi-nutrient cycling declined with increased network complexity. Further, we found a non-linear relationship between salinity-induced shifts in the complexity of the microbial network and biodiversity-nutrient cycling (BNC) relationship of keystone taxa, i.e. the strength of the BNC relationship first became weak and then strong with increased network complexity. Together, these results highlighted the significant insight that there is not always positive relationship between biodiversity/network complexity and multi-nutrient cycling, even between network complexity and BNC relationship in real-world ecosystems, suggesting that preserving microbial association is important in aquatic health managing and evaluating the freshwater salinization problem.

Surface modification of titanium with antibacterial porous N-halamine coating to prevent peri-implant infection

Peri-implant infection remains one of the greatest threats to orthopedics. The construction of bone implants with good antibacterial and osteogenic properties is beneficial for reducing the risk of implant-related infections and healing bone defects. In this study, N-halamine coating (namely N-Cl) was grafted onto alkali-heat treated titanium (Ti) using polydopamine to endow Ti-based orthopedic implants with strong bactericidal activity. Surface characterization revealed that the N-Cl coating has porous structure loaded with active chlorine (Cl⁺). The N-Cl coating also provided micro/nano-structured Ti surfaces with excellent antibacterial ability via transformation between N-H and N-Cl, and approximately 100% disinfection was achieved. Furthermore, the as-prepared N-Cl coating exhibited good biocompatibility and osteogenesis abilityin vitro. These results indicate that applying N-Cl coatings on Ti could prevent and treat peri-implant infections.

MOFs and MOF-Derived Materials for Antibacterial Application

Bacterial infections pose a serious threat to people's health. Efforts are being made to develop antibacterial agents that can inhibit bacterial growth, prevent biofilm formation, and kill bacteria. In recent years, materials based on metal organic frameworks (MOFs) have attracted significant attention for various antibacterial applications due to their high specific surface area, high enzyme-like activity, and continuous release of metal ions. This paper reviews the recent progress of MOFs as antibacterial agents, focusing on preparation methods, fundamental antibacterial mechanisms, and strategies to enhance their antibacterial effects. Finally, several prospects related to MOFs for antibacterial application are proposed, aiming to provide possible research directions in this field.

Black Mn-containing layered double hydroxide coated magnesium alloy for osteosarcoma therapy, bacteria killing, and bone regeneration

Osteosarcoma (OS) tissue resection with distinctive bactericidal activity, followed by regeneration of bone defects, is a highly demanded clinical treatment. Biodegradable Mg-based implants with desirable osteopromotive and superior mechanical properties to polymers and ceramics are promising new platforms for treating bone-related diseases. Integration of biodegradation control, osteosarcoma destruction, anti-bacteria, and bone defect regeneration abilities on Mg-based implants by applying biosafe and facile strategy is a promising and challenging topic. Here, a black Mn-containing layered double hydroxide (LDH) nanosheet-modified Mg-based implants was developed. Benefiting from the distinctive capabilities of the constructed black LDH film, including near-infrared optical absorption and reactive oxygen species (ROS) generation in a tumor-specific microenvironment, the tumor cells and tissue could be effectively eliminated. Concomitant bacteria could be killed by localized hyperthermia. Furthermore, the enhanced corrosion resistance and synergistic biofunctions of Mn and Mg ions of the constructed black LDH-modified Mg implants significantly facilitated cell adhesion, spreading and proliferation and osteogenic differentiation in vitro, and accelerated bone regeneration in vivo. This work offers a new platform and feasible strategy for OS therapeutics and bone defect regeneration, which broadens the biomedical application of Mg-based alloys.

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Black Mg–Mn(Ⅱ)-Mn(Ⅲ) LDH-engineered Mg-based bone implants were developed.

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The LDH film improved the corrosion resistance and biocompatibility of Mg implant.

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The LDH endowed the Mg alloy implants with superior photothermal/chemodynamic effects.

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The Mg-based implants had antitumor and bone defect regenerating properties.

Metallic Nanoparticle-Doped Oxide Semiconductor Film for Bone Tumor Suppression and Bone Regeneration

Bone implants with the photothermal effect are promising for the treatment of bone tumor defects. Noble metal-based photothermal nanoagents are widely studied for their stable photothermal effect, but they are expensive and difficult to directly grow on implant surfaces. In contrast, non-noble metal photothermal nanoagents are economical but unstable. Herein, to develop a stable and economical photothermal film on bone implants, a Ni nanoparticle-doped oxide semiconductor film was grown in situ on Nitinol via the reduction of Ni-Ti-layered double hydroxides. Ni nanoparticles remained stable in the NiTiO₃ structure even when immersed in fluid for 1 month, and thus, the film presented a reliable photothermal effect under near-infrared light irradiation. The film also showed excellent in vitro and in vivo antitumor performance. Moreover, the nanostructure on the film allowed bone differentiation of mouse embryo cells (C3H10T1/2), and the released Ni ions supported the angiogenesis behavior of human vein endothelial cells. Bone implantation experiments further showed the enhancement of osteointegration of the modified Nitinol implant in vivo. This novel multifunctional Nitinol bone implant design offers a promising strategy for the therapy of bone tumor-related defects.

A Unified Strategy to Fluorinated Nucleoside Analogues Via an Electrophilic Manifold

Herein, we present a strategy for the preparation of 3'-fluorinated nucleoside analogues via the aminocatalytic, electrophilic fluorination of readily accessible and bench-stable 2'-ketonucleosides. Initially developed to facilitate the manufacture of 3'-fluoroguanosine (3'-FG)─a substructure of anticancer therapeutic MK-1454─this strategy has been extended to the synthesis of a variety of 3'-fluoronucleosides. Finally, we demonstrate the utility of the 2'-ketonucleoside synthon as a platform for further diversification and suggest that this methodology should be broadly applicable to the discovery of novel nucleoside analogues.

IRONMAN peptide interacts with OsHRZ1 and OsHRZ2 to maintain Fe homeostasis in rice

IRONMAN (IMA) is a family of small peptides which positively regulate plant responses under Fe deficiency. However, the molecular mechanism by which OsIMA1 and OsIMA2 regulate Fe homeostasis in rice is unclear. Here, we reveal that OsIMA1 and OsIMA2 interact with the potential Fe sensors, OsHRZ1 (HAEMERYTHRIN MOTIF-CONTAINING REALLY INTERESTING NEW GENE (RING) AND ZINC-FINGER PROTEIN 1) and OsHRZ2. OsIMA1 and OsIMA2 contain a conserved 17 amino acid C-terminal region which is responsible for the interactions with OsHRZ1 and OsHRZ2. Plants overexpressing OsIMA1 (OsIMA1ox) show increased Fe concentration in seeds and reduced fertility, as observed in the hrz1-2 loss-of-function mutant plants. Moreover, the expression patterns of Fe deficiency inducible genes in the OsIMA1ox plants are the same as those in hrz1-2. Co-expression assays suggest that OsHRZ1 and OsHRZ2 promote the degradation of OsIMA1 proteins. As the interaction partners of OsHRZ1, the OsPRI (POSITIVE REGULATOR OF IRON HOMEOSTASIS) proteins also interact with OsHRZ2. The conserved C-terminal region of four OsPRIs contributes to the interactions with OsHRZ1 and OsHRZ2. An artificial IMA (aIMA) derived from the C-terminal of OsPRI1 can be also degraded by OsHRZ1. Moreover, aIMA overexpressing rice plants accumulate more Fe without reduction of fertility. This work establishes the link between OsIMAs and OsHRZs, and develops a new strategy for Fe fortification in rice.

Prognostic value of long-term antidiabetic and antihypertensive therapy in postoperative gastric cancer patients: the FIESTA study

Background

Gastric cancer is often comorbid with hypertension and diabetes mellitus and increases the mortality risk.

Materials and methods

We conducted this prospective cohort study to investigate antidiabetics and antihypertensives’ impact on gastric cancer survival. 3012 patients with gastric carcinoma undergoing radical gastrectomy were enrolled since January 2000 and followed up until July 2020.

Results

Hypertension and diabetes patients had worse survival than patients without hypertension and diabetes [median survival time (MST): 48 versus 112.5 months, p < 0.001 for hypertension, MST: 32.7 versus 183+ months, p < 0.001 for diabetes]. Compared to untreated patients, treated patients had better survival (MST: 109.7 months versus 39.1 months, p < 0.001 for antihypertensives, MST: 120.9 months versus 22.3 months, p < 0.001 for antidiabetics). Antihypertensives and antidiabetics were related to 42% (HR 0.58, 95% CI 0.47–0.73, p < 0.001) and 70% (HR 0.30, 95% CI 0.24–0.38, p < 0.001) reduced mortality risk relative to those without medications. metformin and Calcium channel blockers can better-improved prognosis compared to others (p = 0.00029 and p = 0.015).

Conclusion

Post-surgical gastric cancer patients could benefit substantially from anti-diabetes and antihypertensive therapy. Metformin and Calcium channel blockers may be superior to other medications.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02514-4.

Intracapsular approach used in laparoscopic duodenum-preserving total pancreatic head resection for pancreatic head benign or low-grade malignant tumors

PURPOSE

Laparoscopic duodenum-preserving total pancreatic head resection (LDPPHRt) is used for treating benign or low-grade malignant tumors of the pancreatic head. However, preservation of the duodenum and biliary tract integrity remains challenging. We present a new approach for LDPPHRt and evaluate its feasibility and safety.

METHODS

From April 2020 to December 2020, 30 patients successfully underwent LDPPHRt using the intracapsular approach in our center. Their medical records were reviewed for relevant clinical characteristics, pathologic findings, postoperative complications, and survival.

RESULTS

The median diameter of the lesions was 3.6 cm (range, 2.0-5.5 cm). The median operative time was 234.7 min (range, 195-310 min). The median blood loss was 66.7 ml (range, 20-250 ml). The morbidity rate was 26.7%, including POPF, hemorrhage, lymphatic leakage, wound infection, pulmonary infection, and delayed gastric emptying. Five patients developed pancreatic fistula type A, and two patients had type B, classified according to the International Study Group on Pancreatic Fistula. No biliary tract injury or duodenal leakage was observed. The median postoperative hospital stay was 11.5 days (range, 6-25), and the operative mortality rate was 0%.

CONCLUSION

The intracapsular approach is a feasible and safe surgical procedure in LDPPHRt for patients with benign or low-grade malignant tumors, especially those without severe pancreatic head fibrosis or peripancreatic adhesions.

Defect-Enriched ZnO/ZnS Heterostructures Derived from Hydrozincite Intermediates for Hydrogen Evolution under Visible Light

Introducing defect engineering into ZnO/ZnS heterojunction photocatalysts is an effective method to simultaneously improve their visible light performance and photocatalytic efficiency. Herein, a defect-enriched ZnO/ZnS heterostructure photocatalyst was synthesized through a hydrozincite [Zn₅ (OH)₆ (CO₃ )₂ ] intermediate-deriving reaction. The mechanism analysis showed that there were interstitial Zn and Zn vacancies in the hydrozincite-derived ZnO, while S vacancies and interstitial S and Zn vacancies were formed in ZnS components after calcination. These specific defect states endowed visible light response ability to both ZnO and ZnS components in the ZnO/ZnS photocatalysts. Under visible light irradiation, the photocatalytic hydrogen evolution rate of ZnO/ZnS reached 11.68 mmol h^-1  g^-1 , and under simulated sunlight irradiation, the best photocatalytic hydrogen evolution rate could reach 27.94 mmol h^-1  g^-1 , which was much higher than most previous reports. The analysis of energy band structure and photodeposition showed that the photocatalytic reduction sites were mainly on ZnS, and the photocatalytic reaction mainly followed the typical Z-type mechanism. This work presents a simple and low-cost method for the preparation of defects-enriched ZnO/ZnS-based photocatalytic materials with high photocatalytic activity and stability.