The properties of chitosan films can be modified by changing the solvent type, attributing to the different interaction patterns between chitosan and acids. However, little is known about how these ...interactions affect the structure and properties of chitosan films. In this work, the influence of acid type on the structure and properties of chitosan films was studied by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). FTIR spectra showed that the ionic interactions and hydrogen bonding could occur between chitosan and acid ions. Structural analysis revealed that chitosan was partially crystalline in hydrochloric and acetic acid films, whereas it was amorphous in lactic and citric acid films. DSC result indicated that the glass transition temperature of chitosan was much lower in citric acid film with low water content than in all the other films, suggesting that the citrate ions interacted more strongly with chitosan. A melting transition appeared in hydrochloric and acetic acid films. In addition, the tensile strength of these films decreased with an increase in the volume of acid. These observations indicate that the choice of a proper solvent for chitosan may be desirable for certain special applications.
•Interactions between chitosan and acids ions depend on the nature of acids.•Both Tg and Tm of chitosan can be observed in hydrochloric and acetic acid films.•Citrate ions play a major role in the plasticization of chitosan films.•Film structure and properties can be modified by changing the solvent type.
Circularly polarized luminescence (CPL) materials have received increasing attention in recent years. Amongst various CPL materials, circularly polarized phosphorescence (CPP) materials featuring ...long life‐time represent a novel research frontier and exhibit promising applications in various fields. Herein, the state‐of‐the‐art advances of CPP materials are systematically summarized, as classified into transition metal complexes, organic small molecules, polymers, and organic/inorganic hybrid materials. Besides, the recent applications of CPP materials in organic light‐emitting diodes and encryption display are also summarized. Furthermore, the current challenges and future perspectives are put forward. It is expected that this review will offer more inspirations for the future rational design of advanced CPP materials, thus further promoting their future practical applications.
This review summarizes the state‐of‐the‐art research progress of circularly polarized phosphorescent (CPP) materials, and the emerging categories such as transition metal complexes, organic small molecules, polymers, and organic/inorganic hybrid materials are also reviewed. The applications in organic light‐emitting diodes and encryption displays are also summarized. Challenges and perspectives for achieving high‐performance CPP materials are proposed.
Chirality is pivotal in nature which attracts wide research interests from all disciplines and creating chiral matter is one of the central themes for chemists and material scientists. Despite of ...significant efforts, a simple, cost-effective and general method that can produce different kinds of chiral metamaterials with high regularity and tailorability is still demanding but greatly missing. Here, we introduce polarization-directed growth of spiral nanostructures via vector beams, which is simple, tailorable and generally applicable to both plasmonic and dielectric materials. The self-aligned near field enhances the photochemical growth along the polarization, which is crucial for the oriented growth. The obtained plasmonic chiral nanostructures present prominent optical activity with a g-factor up to 0.4, which can be tuned by adjusting the spirality of the vector beams. These spiral plasmonic nanostructures can be used for the sensing of different chiral enantiomers. The dielectric chiral metasurfaces can also be formed in arrays of sub-mm scale, which exhibit a g-factor over 0.1. However, photoluminescence of chiral cadmium sulfide presents a very weak luminescence g-factor with the excitation of linearly polarized light. A number of applications can be envisioned with these chiral nanostructures such as chiral sensing, chiral separation and chiral information storage.
Cooperative adaptive cruise control (CACC) systems have the potential to increase traffic throughput by allowing smaller headway between vehicles and moving vehicles safely in a platoon at a ...harmonized speed. CACC systems have been attracting significant attention from both academia and industry since connectivity between vehicles will become mandatory for new vehicles in the USA in the near future. In this paper, we review three basic and important aspects of CACC systems: communications, driver characteristics, and controls to identify the most challenging issues for their real-world deployment. Different routing protocols that support the data communication requirements between vehicles in the CACC platoon are reviewed. Promising and suitable protocols are identified. Driver characteristics related issues, such as how to keep drivers engaged in driving tasks during CACC operations, are discussed. To achieve mass acceptance, the control design needs to depict real-world traffic variability such as communication effects, driver behavior, and traffic composition. Thus, this paper also discusses the issues that existing CACC control modules face when considering close to ideal driving conditions.
Adipose tissue-derived stem cells (ADSCs) have been shown to enhance wound healing via their paracrine function. Exosomes, as one of the most important paracrine factors, play an essential role in ...this process. However, the concrete mechanisms that underlie this effect are poorly understood. In this study, we aim to explore the potential roles and molecular mechanisms of exosomes derived from ADSCs in cutaneous wound healing.
Normal human skin fibroblasts and ADSCs were isolated from patient skin and adipose tissues. ADSCs were characterized by using flow cytometric analysis and adipogenic and osteogenic differentiation assays. Exosomes were purified from human ADSCs by differential ultracentrifugation and identified by electron microscopy, nanoparticle tracking, fluorescence confocal microscopy and western blotting. Fibroblasts were treated with different concentrations of exosomes, and the synthesis of collagen was analyzed by western blotting; the levels of growth factors were analyzed by real-time quantitative PCR (RT-PCR) and ELISA; and the proliferation and migration abilities of fibroblasts were analyzed by real-time cell analysis, CCK-8 assays and scratch assays. A mouse model with a full-thickness incision wound was used to evaluate the effect of ADSC-derived exosomes on wound healing. The level of p-Akt/Akt was analyzed by western blotting. Ly294002, a phosphatidylinositol 3-kinases (PI3K) inhibitor, was used to identify the underlying mechanisms by which ADSC-derived exosomes promote wound healing.
ADSC-derived exosomes were taken up by the fibroblasts, which showed significant, dose-dependent increases in cell proliferation and migration compared to the behavior of cells without exosome treatment. More importantly, both the mRNA and protein levels of type I collagen (Col 1), type III collagen (Col 3), MMP1, bFGF, and TGF-β1 were increased in fibroblasts after stimulation with exosomes. Furthermore, exosomes significantly accelerated wound healing in vivo and increased the level of p-Akt/Akt in vitro. However, Ly294002 alleviated these exosome-induced changes, suggesting that exosomes from ADSCs could promote and optimize collagen deposition in vitro and in vivo and further promote wound healing via the PI3K/Akt signaling pathway.
This study demonstrates that ADSC-derived exosomes can promote fibroblast proliferation and migration and optimize collagen deposition via the PI3K/Akt signaling pathway to further accelerate wound healing. Our results suggest that ADSCs likely facilitate wound healing via the release of exosomes, and the PI3K/Akt pathway may play a role in this process. Our data also suggest that the clinical application of ADSC-derived exosomes may shed new light on the use of cell-free therapy to accelerate full-thickness skin wound healing and attenuate scar formation.
Schematic diagram shows how the wound healing effect of ADSC-Exos is mediated by the activation of the PI3K/Akt signaling pathways. Display omitted
•ADSC-Exos are internalized into HDFs and regulate their biological behaviors and functions.•ADSC-Exos play an important role in accelerating wound healing via activating PI3K/Akt signaling pathway.•ADSC-Exos may serve as a cell-free therapy for the potential clinical treatment of wound healing.
Hypertrophic scar (HS) is a fibro-proliferative disorder of dermis after burn or trauma and usually leads to esthetic disfiguration and functionary impairment for patients. Emerging evidences ...demonstrated ADSC-Exo could alleviate the visceral fibrosis, but little attention had been paid to its role in skin fibrosis. In the study, we would explore the effect of ADSC-Exo on HS and investigated the exact mechanism underlying the properties.
ADSC-Exo were isolated, identified, and internalized by HS-derived fibroblasts (HSFs). The effect of ADSC-Exo on the proliferation and migration of HSFs were detected by flow cytometry and Ki67 immunofluorescence staining, or scratch and trans-wells assays, respectively. RT-PCR, immunoblotting, immunofluorescence, and immunohistochemistry staining were used to evaluate the expression of IL-17RA, Col1, Col3, α-SMA, SIP1, and p-Smad2/p-Smad3 in HSFs stimulated with ADSC-Exo, miR-192-5p mimics, or inhibitors, IL-17RA siRNA and their negative controls. Digital morphology, H&E, Masson's trichrome staining, and immunohistochemistry staining were performed to measure the effect of ADSC-Exo and Lv-IL-17RA shRNA on excisional wound of BALB/c mice.
The verified ADSC-Exo effectively inhibited the proliferation and migration of HSFs, decreased the expression of Col1, Col3, α-SMA, IL-17RA, and p-Smad2/p-Smad3 and increased the levels of SIP1 in HSFs. Besides, the mice in ADSC-Exo-treated group demonstrated faster wound healing and less collagen deposition. Furthermore, miR-192-5p was highly expressed in ADSC-Exo and ADSC-Exosomal miR-192-5p ameliorated hypertrophic scar fibrosis. Meanwhile, miR-192-5p targeted the expression of IL-17RA to decrease the pro-fibrotic proteins levels. Moreover, IL-17RA was overexpressed in HS and HSFs, and knockdown IL-17RA alleviated the expression of Col1, Col3, α-SMA, and p-Smad2/p-Smad3 and increased the expression of SIP1 in HSFs. Most importantly, IL-17RA silence also facilitated wound healing, attenuated collagen production, and modulated Smad pathway in HSFs.
This study illustrated ADSC-Exo attenuated the deposition of collagen, the trans-differentiation of fibroblasts-to-myofibroblasts, and the formation of hypertrophic scar by in vitro and in vivo experiments. ADSC-Exosomal miR-192-5p targeted IL-17RA to regulate Smad pathway in hypertrophic scar fibrosis. ADSC-Exo could be a promising therapeutic strategy for clinical treatment of hypertrophic scar and the anti-fibrotic properties could be achieved by miR-192-5p/IL-17RA/Smad axis.
Sepsis is a fatal disease with a high rate of morbidity and mortality, during which acute lung injury is the earliest and most serious complication. Injury of pulmonary microvascular endothelial ...cells (PMVECs) induced by excessive inflammation plays an important role in sepsis acute lung injury. This study is meant to explore the protective effect and mechanism of ADSCs exosomes on excessive inflammation PMVECs injury.
We successfully isolated ADSCs exosomes, the characteristic of which were confirmed. ADSCs exosomes reduced excessive inflammatory response induced ROS accumulation and cell injury in PMVECs. Besides, ADSCs exosomes inhibited excessive inflammatory response induced ferroptosis while upregulated expression of GPX4 in PMVECs. And further GPX4 inhibition experiments revealed that ADSCs exosomes alleviated inflammatory response induced ferroptosis via upregulating GPX4. Meanwhile, ADSCs exosomes could increase the expression and nucleus translocation of Nrf2, while decrease the expression of Keap1. miRNA analysis and further inhibition experiments verified that specific delivery of miR-125b-5p by ADSCs exosomes inhibited Keap1 and alleviated ferroptosis. In CLP induced sepsis model, ADSCs exosomes could relieve the lung tissue injury and reduced the death rate. Besides, ADSCs exosomes alleviated oxidative stress injury and ferroptosis of lung tissue, while remarkably increase expression of Nrf2 and GPX4.
Collectively, we illustrated a novel potentially therapeutic mechanism that miR-125b-5p in ADSCs exosomes could alleviate the inflammation induced PMVECs ferroptosis in sepsis induced acute lung injury via regulating Keap1/Nrf2/GPX4 expression, hence improve the acute lung injury in sepsis.
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Objective
Whether periodontitis increases the risk of diabetic microangiopathy remains controversial. The present meta‐analysis aims to investigate the relationship between periodontitis and diabetic ...microangiopathy in patients with type 2 diabetes mellitus.
Methods
PubMed, EMBASE, Web of Science, the Cochrane Library, CNKI, and WanFang data were searched without language restrictions. The methodological quality of the studies included was assessed using Newcastle‐Ottawa Scale method, and meta‐analysis was performed by Review Manager 5.3. Odds ratio (OR) and 95% confidence interval (CI) were used to assess the risk of periodontitis for diabetic microangiopathy among patients with type 2 diabetes.
Results
Thirteen cross‐sectional studies, covering 10 570 participants, were included in the present meta‐analysis. The results demonstrated that periodontitis was associated with increased risk of type 2 diabetic microangiopathy (OR: 2.43, 95% CI: 1.65–3.56), diabetic retinopathy (OR: 4.33, 95% CI: 2.19–8.55), and diabetic nephropathy (OR: 1.75, 95% CI: 1.07–2.85), while periodontitis was not associated with diabetic neuropathy (OR: 0.99, 95% CI: 0.19–5.12). Subgroup analysis among the studies in Asian (OR: 3.06, 95% CI: 1.94–4.84) and North American (OR: 1.42, 95% CI: 1.08–1.86) populations confirmed the existed association between periodontitis and type 2 diabetic microangiopathy. The relationship still existed in groups with sample size larger than 500 (OR: 1.77, 95% CI: 1.34–2.34) and smaller than 500 (OR: 3.33, 95% CI: 1.38–8.03). A sensitivity analysis confirmed the stability of the results by excluding moderate quality studies or removing articles one after the other.
Conclusion
Current evidences have proved that periodontitis is associated with increased risk of diabetic microangiopathy in patients with type 2 diabetes mellitus. This conclusion may provide useful evidence for correlated clinical researches.
PROSPERO registration number CRD42021247773.
Chiral sensing of single molecules is vital for the understanding of chirality and their applications in biomedicine. However, current technologies face severe limitations in achieving ...single-molecule sensitivity. Here we overcome these limitations by designing a tunable chiral supramolecular plasmonic system made of helical oligoamide sequences (OS) and nanoparticle-on-mirror (NPoM) resonator, which works across the classical and quantum regimes. Our design enhances the chiral sensitivity in the quantum tunnelling regime despite of the reduced local E-field, which is due to the strong Coulomb interactions between the chiral OSs and the achiral NPoMs and the additional enhancement from tunnelling electrons. A minimum of four molecules per single-Au particle can be detected, which allows for the detection of an enantiomeric excess within a monolayer, manifesting great potential for the chiral sensing of single molecules.
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