Antibacterial effects of platelet-rich fibrin produced by horizontal centrifugation.

Platelet-rich fibrin (PRF) has been widely used owing to its ability to stimulate tissue regeneration. To date, few studies have described the antibacterial properties of PRF. Previously, PRF prepared by horizontal centrifugation (H-PRF) was shown to contain more immune cells than leukocyte- and platelet-rich fibrin (L-PRF). This study aimed to compare the antimicrobial effects of PRFs against Staphylococcus aureus and Escherichia coli in vitro and to determine whether the antibacterial effects correlated with the number of immune cells. Blood samples were obtained from eight healthy donors to prepare L-PRF and H-PRF. The sizes and weights of L-PRF and H-PRF were first evaluated, and their antibacterial effects against S. aureus and E. coli were then tested in vitro using the inhibition ring and plate-counting test methods. Flow-cytometric analysis of the cell components of L-PRF and H-PRF was also performed. No significant differences in size or weight were observed between the L-PRF and H-PRF groups. The H-PRF group contained more leukocytes than the L-PRF group. While both PRFs had notable antimicrobial activity against S. aureus and E. coli, H-PRF demonstrated a significantly better antibacterial effect than L-PRF. Furthermore, the antimicrobial ability of the PRF solid was less efficient than that of wet PRF. In conclusion, H-PRF exhibited better antibacterial activity than L-PRF, which might have been attributed to having more immune cells

The influence mechanism of industrial policies on Chinese companies' cross-border M&A decision-making

Abstract This study explored the potential links between Chinese industrial policy and cross-border mergers and acquisitions by Chinese firms from 2009 to 2019. Based on describing China's industrial strategy and evaluating the then-current situation of Chinese enterprises' cross-border mergers and acquisitions, this empirical study constructed a two-way fixed-effect panel model and an intermediate effect model to assess the mechanism of industrial policy's influence on Chinese enterprises' cross-border mergers and acquisitions decisions. The findings were as follows: (1) Industrial policy could promote the implementation of cross-border mergers and acquisitions of Chinese enterprises; (2) By easing financial restrictions, industrial policy could improve firms' access to capital and encourage cross-border mergers and acquisitions. (3) Industrial policies could promote the high political relevance of state-owned enterprises, thus promoting the success of transnational mergers and acquisitions of enterprises. Therefore, it was significant to promote the transformation of industrial policy from subsidy-oriented to performance-oriented and rationally evaluate the risks and benefits of M&A for enterprises to complete cross-border M&A

Dual functional monocytes modulate bactericidal and anti-inflammation process for severe osteomyelitis treatment

Osteomyelitis is an inflammatory bone disease caused by infection microorganisms which leads to progressive bone destruction and loss. Drug resistance and inflammatory damage make it urgent to develop new dual-functional therapies. Based on the powerful bactericidal effect of monocyte/macrophage cells by nature, a functional monocyte with programed anti-inflammatory ability is promising for osteomyelitis treatment. Herein, gold nanocage (GNC)-modified monocytes are developed which contain aspirin to realize the controlled antibacterial and anti-inflammatory process for bone infection treatment effectively. Aspirin@GNC-laden monocytes inherit the biological functions of origin monocytes such as chemotaxis to bacteria, differentiation potential, and phagocytic ability. The controlled release of aspirin from GNC has a beneficial effect on improving the rate and amount of bone regeneration after the anti-infection stage due to its ability to suppress the activity of natural immunity and induce osteoblast differentiation during the treatment of osteomyelitis. The present work described here is the first to utilize living monocytes to achieve a dual effect to antibacteria and anti-inflammation in a time-oriented and programed way, and provides an inspiration for future therapy based on this concept.</p

Correction to : Dual Functional Monocytes Modulate Bactericidal and Anti-Inflammation Process for Severe Osteomyelitis Treatment (Small, (2020), 16, 4, (1905185), 10.1002/smll.201905185)

Small 2020, 16, 1905185 In the originally published article, the description of Figure S2 was incorrect, and the wrong photos of the bacterial colony assay in Figure S4 were presented in the Supporting Information. S4 Figure (Figure presented.) Photo and quantitation of bacterial colony from infection tissue treated with PBS, GNC, As@GNC, monocyte and AsMon on macrophage depletion mouse 5 days after osteomyelitis induction. The Figure S2 caption should be: Figure S2. Temperature rise cycle of As@GNC under NIR irradiation (808 nm, 3.0 W cm −2) for 15 min followed by cooling. Figure S4 with the correct images of the “Monocyte” and “AsMon” groups are presented below. Neither of these changes affect the data, results or conclusions of this work. The authors apologize for any confusion this may have caused. </p

Construction of Cellular Substructure in Laser Powder Bed Fusion

Cellular substructure has been widely observed in the sample fabricated by laser powder bed fusion, while its growth direction and the crystallographic orientation have seldom been studied. This research tries to build a general model to construct the substructure from its two-dimensional morphology. All the three Bunge Euler angles to specify a unique growth direction are determined, and the crystallographic orientation corresponding to the growth direction is also obtained. Based on the crystallographic orientation, the substructure in the single track of austenitic stainless steel 316L is distinguished between the cell-like dendrite and the cell. It is found that, with the increase of scanning velocity, the substructure transits from cell-like dendrite to cell. When the power is 200 W, the critical growth rate of the transition in the single track can be around 0.31 ms&minus;1

Autologous versatile vesicles‐incorporated biomimetic extracellular matrix induces biomineralization

Restoring extracellular matrix (ECM) with supportive and osteoinductive abilities is of great significance for bone tissue regeneration. Current approaches involving cell‐based scaffolds or nanoparticle‐modified biomimic‐ECM have been met with additional biosafety concerns. Herein, the natural biomineralization process is first analyzed and is found that mesenchymal stem cells‐derived extracellular vesicles (EVs) from early and late stages of osteoinduction play different roles during the mineralization process. The functional EVs hierarchically with blood‐derived autohydrogel (AH) are then incorporated to form an osteoinductive biomimetic extracellular matrix (BECM). The alkaline phosphatase‐rich EVs are released from the outer layers to induce osteoblast differentiation during early stages. Thereafter, as the degradation of AH occurred, calcium/phosphorus (Ca/P)‐rich EVs are liberated to promote the nucleation of extracellular mineral crystals. Additionally, BECM contains considerable collagen fibrils that provide additional nucleation sites for crystallites deposition, thus reaching self‐mineralization in situ. In conclusion, this research provides a promising, versatile mineralization‐instructive platform to tackle the challenges faced in bone‐tissue engineering

Autologous Versatile Vesicles‐Incorporated Biomimetic Extracellular Matrix Induces Biomineralization

Restoring extracellular matrix (ECM) with supportive and osteoinductive abilities is of great significance for bone tissue regeneration. Current approaches involving cell‐based scaffolds or nanoparticle‐modified biomimic‐ECM have been met with additional biosafety concerns. Herein, the natural biomineralization process is first analyzed and is found that mesenchymal stem cells‐derived extracellular vesicles (EVs) from early and late stages of osteoinduction play different roles during the mineralization process. The functional EVs hierarchically with blood‐derived autohydrogel (AH) are then incorporated to form an osteoinductive biomimetic extracellular matrix (BECM). The alkaline phosphatase‐rich EVs are released from the outer layers to induce osteoblast differentiation during early stages. Thereafter, as the degradation of AH occurred, calcium/phosphorus (Ca/P)‐rich EVs are liberated to promote the nucleation of extracellular mineral crystals. Additionally, BECM contains considerable collagen fibrils that provide additional nucleation sites for crystallites deposition, thus reaching self‐mineralization in situ. In conclusion, this research provides a promising, versatile mineralization‐instructive platform to tackle the challenges faced in bone‐tissue engineering

Near-Infrared Light-Sensitive Nano Neuro-Immune Blocker Capsule Relieves Pain and Enhances the Innate Immune Response for Necrotizing Infection

Sensory neurons promote profound suppressive effects on neutrophils during Streptococcus pyogenes infection and contribute to the pathogenesis of necrotizing infection ("flesh-eating disease"). Thus, the development of new antibacterial agents for necrotizing infection is promising because of the clear streptococcal neuro-immune communication. Herein, based on the immune escape membrane exterior and competitive membrane functions of the glioma cell membrane, a novel nano neuro-immune blocker capsule was designed to prevent neuronal activation and improve neutrophil immune responses for necrotizing infection. These nano neuro-immune blockers could neutralize streptolysin S, suppress neuron pain conduction and calcitonin gene-related peptide release, and recruit neutrophils to the infection site, providing a strong therapeutic effect against necrotizing infection. Furthermore, nano neuro-immune blockers could serve as an effective inflammatory regulator and antibacterial agent via photothermal effects under near-infrared irradiation. In the Streptococcus pyogenes-induced necrotizing fasciitis mouse model, nano neuro-immune blockers showed significant therapeutic efficacy by ameliorating sensitivity to pain and promoting the antibacterial effect of neutrophils.</p

Dual-Wavelength Photosensitive Nano-in-Micro Scaffold Regulates Innate and Adaptive Immune Responses for Osteogenesis

The immune response of a biomaterial determines its osteoinductive effect. Although the mechanisms by which some immune cells promote regeneration have been revealed, the biomaterial-induced immune response is a dynamic process involving multiple cells. Currently, it is challenging to accurately regulate the innate and adaptive immune responses to promote osteoinduction in biomaterials. Herein, we investigated the roles of macrophages and dendritic cells (DCs) during the osteoinduction of biphasic calcium phosphate (BCP) scaffolds. We found that osteoinductive BCP directed M2 macrophage polarization and inhibited DC maturation, resulting in low T cell response and efficient osteogenesis. Accordingly, a dual-targeting nano-in-micro scaffold (BCP loaded with gold nanocage, BCP-GNC) was designed to regulate the immune responses of macrophages and DCs. Through a dual-wavelength photosensitive switch, BCP-GNC releases interleukin-4 in the early stage of osteoinduction to target M2 macrophages and then releases dexamethasone in the later stage to target immature DCs, creating a desirable inflammatory environment for osteogenesis. This study demonstrates that biomaterials developed to have specific regulatory capacities for immune cells can be used to control the early inflammatory responses of implanted materials and induce osteogenesis. [Figure not available: see fulltext.]</p

Fe3O4@TiO2‑laden neutrophils activate innate immunity via photosensitive reactive oxygen species release

Although a variety of advanced sterilization materials and treatments haveemerged, the complete elimination of bacterial infection, especially drug-resistantbacterial infection, remains an immense challenge. Here, we demonstrate the use ofneutrophils loaded with photocatalytic nanoparticles to reduce bacterial infection. Thismethod activates the immune system to achieve an anti-infection response. We preparedthe photocatalytic nanoparticle-laden neutrophils in vivo through neutrophilphagocytosis. The resulting loaded cells retained the cell membrane functionality ofthe source cell, as well as the complete immune cell function of neutrophils, particularlythe ability to recruit macrophages to the target area. Photocatalytic nanoparticle-ladenneutrophils can target infection sites and release reactive oxygen species to induce thesecretion of chemokines, leading to the targeted recruitment of macrophages andenhancing a powerful immune cascade. In a severe mouse infection model induced bypathogenic bacteria, small doses of photocatalytic nanoparticle-laden neutrophils showeda remarkable therapeutic effect by enhancing macrophage recruitment and the immune cascade