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1.
Mar Pollut Bull ; 208: 116948, 2024 Sep 11.
Article de Anglais | MEDLINE | ID: mdl-39265311

RÉSUMÉ

Copper (Cu) is vital for macroalgae's functions, but high concentrations can be toxic. Rising CO2 levels affect algal growth and Cu bioavailability. In this study, the results reveal that at 5 °C, low Cu increased Ulva linza growth, while high Cu and elevated CO2 decreased growth. At 10 °C, low Cu and elevated CO2 enhanced growth, but high Cu did not have a significant impact. At 15 °C, high Cu reduced growth, but elevated CO2 offset this effect. Furthermore, under elevated CO2 conditions, the chloroplast structure of the algae appeared to be denser, accompanied by a large amount of starch granules, compared to low CO2 conditions. These results emphasize that lower temperatures, in conjunction with elevated CO2 concentration, could intensify the toxic effects of high Cu concentrations on thalli. However, at higher temperatures, elevated CO2 concentration appeared to be capable of mitigating the detrimental effects of heavy metals on algae.

2.
J Invest Dermatol ; 2024 Sep 07.
Article de Anglais | MEDLINE | ID: mdl-39182559

RÉSUMÉ

Systemic sclerosis is a typical fibrotic disease of unknown etiology that is characterized by abnormal fibroblast activation and excessive deposition of extracellular matrix. Unfortunately, effective therapeutic approaches are lacking. FGF21 plays a key role in mediating a variety of biological activities. However, its specific function in systemic sclerosis is unclear. In this study, we found that the expression of FGF21 was significantly downregulated in fibrotic skin tissue and in TGF-ß-stimulated fibroblasts. Furthermore, our studies demonstrated that treatment with recombinant FGF21 in the skin significantly alleviated bleomycin-induced and TBRI-activated fibrosis and inhibited the activation of fibroblasts, whereas skin fibrosis was exacerbated by deletion of FGF21. Mechanistically, FGF21 inhibits the activity of CK2α and promotes the degradation of GLI2. In conclusion, these results indicate that FGF21 attenuates skin fibrosis through the CK2α/GLI2 signaling pathway and therefore may be a potential therapeutic target for systemic sclerosis.

3.
Sci Adv ; 10(33): eado9479, 2024 Aug 16.
Article de Anglais | MEDLINE | ID: mdl-39141725

RÉSUMÉ

Current sprayable hydrogel masks lack the stepwise protection, cleansing, and nourishment of extensive wounds, leading to delayed healing with scarring. Here, we develop a sprayable biomimetic double wound mask (BDM) with rapid autophasing and hierarchical programming for scarless wound healing. The BDMs comprise hydrophobic poly (lactide-co-propylene glycol-co-lactide) dimethacrylate (PLD) as top layer and hydrophilic gelatin methacrylate (GelMA) hydrogel as bottom layer, enabling swift autophasing into bilayered structure. After photocrosslinking, BDMs rapidly solidify with strong interfacial bonding, robust tissue adhesion, and excellent joint adaptiveness. Upon implementation, the bottom GelMA layer could immediately release calcium ion for rapid hemostasis, while the top PLD layer could maintain a moist, breathable, and sterile environment. These traits synergistically suppress the inflammatory tumor necrosis factor-α pathway while coordinating the cyclic guanosine monophosphate/protein kinase G-Wnt/calcium ion signaling pathways to nourish angiogenesis. Collectively, our BDMs with self-regulated construction of bilayered structure could hierarchically program the healing progression with transformative potential for scarless wound healing.


Sujet(s)
Cicatrisation de plaie , Cicatrisation de plaie/effets des médicaments et des substances chimiques , Animaux , Hydrogels/composition chimique , Matériaux biomimétiques/composition chimique , Matériaux biomimétiques/pharmacologie , Cicatrice/métabolisme , Humains , Biomimétique/méthodes , Souris , Gélatine/composition chimique , Calcium/métabolisme
4.
Theriogenology ; 222: 22-30, 2024 Jul 01.
Article de Anglais | MEDLINE | ID: mdl-38615433

RÉSUMÉ

Primordial germ cells (PGCs) are the precursors of germ cells and play a crucial role in germline transmission. In chickens, PGCs can be cultured in vitro while maintaining their germline stem cell characteristics. The Deleted in Azoospermia-Like (DAZL) gene, which is highly expressed in PGCs, is essential for germ cell development. Here, through gene knockout experiments, we discovered that the loss of DAZL expression in chicken PGCs led to decreased proliferation and survival. By next employed techniques such as RIP-seq (RNA Binding Protein Immunoprecipitation) and Co-IP-MS/MS (Co-immunoprecipitation Mass Spectrometry), we identified genes directly regulated by DAZL or cooperating with DAZL at the transcriptomic and proteomic levels. DAZL was found to control genes related to germline development, pluripotency, and cell proliferation in PGCs. Additionally, we observed a significant overlap between RNAs and proteins that interact with both DAZL and DDX4, indicating their cooperation in the gene regulation network in chicken PGCs. Our research provides valuable insights into the function of the DAZL gene in germline cells.


Sujet(s)
Prolifération cellulaire , Poulets , DEAD-box RNA helicases , Cellules germinales , Protéines de liaison à l'ARN , Animaux , Protéines de liaison à l'ARN/métabolisme , Protéines de liaison à l'ARN/génétique , Poulets/génétique , Cellules germinales/métabolisme , DEAD-box RNA helicases/génétique , DEAD-box RNA helicases/métabolisme , Régulation de l'expression des gènes , Régulation de l'expression des gènes au cours du développement
5.
Int Immunopharmacol ; 132: 111970, 2024 May 10.
Article de Anglais | MEDLINE | ID: mdl-38608472

RÉSUMÉ

OBJECTIVES: As antibiotics become more prevalent, accuracy and safety are critical. Moxifloxacin (MXF) have been reported to have immunomodulatory effects on a variety of immune cells and even anti-proliferative and pro-apoptotic effects, but the mechanism of action is not fully clear. METHODS: Peripheral blood mononuclear cells (PBMC) from experimental groups of healthy adults (n = 3) were treated with MXF (10ug/ml) in vitro for 24 h. Single-cell sequencing was performed to investigate differences in the response of each immune cell to MXF. Flow cytometry determined differential gene expression in subsets of most damaged NK cells. Pseudo-time analysis identified drivers that influence MXF-stimulated cell differentiation. Detection of mitochondrial DNA and its involvement in the mitochondrial respiratory chain pathway clarifies the origin of MXF-induced stress injury. RESULTS: Moxifloxacin-environmental NK cells are markedly reduced: a new subset of NK cells emerges, and immediate-early-response genes in this subset indicate the presence of an early activation response. The inhibitory receptor-dominant subset shows enhanced activation, leading to increased expression of cytokines and chemokines. The near-mature subset showed greater cytotoxicity and the most pronounced cellular damage. CD56bright cells responded by antagonizing the regulation of activation and inhibitory signals, demonstrating a strong cleavage capacity. The severe depletion of mitochondrial genes was focused on apoptosis induced by the mitochondrial respiratory chain complex. CONCLUSION: NK cells exhibit heightened sensitivity to the MXF environment. Different NK subsets upregulate the expression of cytokines and chemokines through different activation pathways. Concurrently, MXF induces impairment of the mitochondrial oxidative phosphorylation system, culminating in apoptosis.


Sujet(s)
Apoptose , ADN mitochondrial , Cellules tueuses naturelles , Moxifloxacine , Moxifloxacine/pharmacologie , Humains , Apoptose/effets des médicaments et des substances chimiques , Cellules tueuses naturelles/immunologie , Cellules tueuses naturelles/effets des médicaments et des substances chimiques , Adulte , Cellules cultivées , Cytokines/métabolisme , Antibactériens/pharmacologie , Agranulocytes/effets des médicaments et des substances chimiques , Agranulocytes/immunologie , Mitochondries/effets des médicaments et des substances chimiques , Mitochondries/métabolisme , Mâle
6.
J Adv Res ; 2024 Apr 09.
Article de Anglais | MEDLINE | ID: mdl-38599281

RÉSUMÉ

INTRODUCTION: Sepsis, a systemic immune syndrome caused by severe trauma or infection, poses a substantial threat to the health of patients worldwide. The progression of sepsis is heavily influenced by septic liver injury, which is triggered by infection and cytokine storms, and has a significant impact on the tolerance and prognosis of septic patients. The objective of our study is to elucidate the biological role and molecular mechanism of fibroblast growth factor 21 (FGF21) in the process of sepsis. OBJECTIVES: This study was undertaken in an attempt to elucidate the function and molecular mechanism of FGF21 in therapy of sepsis. METHODS: Serum concentrations of FGF21 were measured in sepsis patients and septic mice. Liver injury was compared between mice FGF21 knockout (KO) mice and wildtype (WT) mice. To assess the therapeutic potential, recombinant human FGF21 was administered to septic mice. Furthermore, the molecular mechanism of FGF21 was investigated in mice with myeloid-cell specific HIF-1α overexpression mice (LyzM-CreDIO-HIF-1α) and myeloid-cell specific Atg7 knockout mice (Atg7△mye). RESULTS: Serum level of FGF21 was significantly increased in sepsis patients and septic mice. Through the use of recombinant human FGF21 (rhFGF21) and FGF21 KO mice, we found that FGF21 mitigated septic liver injury by inhibiting the initiation and propagation of inflammation. Treatment with rhFGF21 effectively suppressed the activation of proinflammatory macrophages by promoting macroautophagy/autophagy degradation of hypoxia-inducible factor-1α (HIF-1α). Importantly, the therapeutic effect of rhFGF21 against septic liver injury was nullified in LyzM-CreDIO-HIF-1α mice and Atg7△mye mice. CONCLUSIONS: Our findings demonstrate that FGF21 considerably suppresses inflammation upon septic liver injury through the autophagy/ HIF-1α axis.

7.
Respir Res ; 25(1): 108, 2024 Feb 28.
Article de Anglais | MEDLINE | ID: mdl-38419044

RÉSUMÉ

BACKGROUND: Acute lung injury (ALI) is a devastating clinical disorder with a high mortality rate, and there is an urgent need for more effective therapies. Fibroblast growth factor 18 (FGF18) has potent anti-inflammatory properties and therefore has become a focus of research for the treatment of lung injury. However, the precise role of FGF18 in the pathological process of ALI and the underlying mechanisms have not been fully elucidated. METHODS: A mouse model of ALI and human umbilical vein endothelial cells (HUVEC) stimulated with lipopolysaccharide (LPS) was established in vivo and in vitro. AAV-FGF18 and FGF18 proteins were used in C57BL/6J mice and HUVEC, respectively. Vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and p65 protein levels were determined by western blotting or immunofluorescent staining. Afterward, related inhibitors were used to explore the potential mechanism by which FGF18 relieves inflammation. RESULTS: In this study, we found that FGF18 was significantly upregulated in LPS-induced ALI mouse lung tissues and LPS-stimulated HUVECs. Furthermore, our studies demonstrated that overexpressing FGF18 in the lung or HUVEC could significantly alleviate LPS-induced lung injury and inhibit vascular leakage. CONCLUSIONS: Mechanically, FGF18 treatment dramatically inhibited the NF-κB signaling pathway both in vivo and in vitro. In conclusion, these results indicate that FGF18 attenuates lung injury, at least partially, via the NF-κB signaling pathway and therefore may be a potential therapeutic target for ALI.


Sujet(s)
Lésion pulmonaire aigüe , Facteurs de croissance fibroblastique , Sepsie , Souris , Humains , Animaux , Facteur de transcription NF-kappa B/métabolisme , Lipopolysaccharides/toxicité , Souris de lignée C57BL , Lésion pulmonaire aigüe/métabolisme , Poumon/métabolisme , Cellules endothéliales de la veine ombilicale humaine/métabolisme , Facteur de nécrose tumorale alpha/métabolisme , Sepsie/métabolisme
8.
FASEB J ; 38(2): e23410, 2024 01 31.
Article de Anglais | MEDLINE | ID: mdl-38193545

RÉSUMÉ

Skin wound healing is a complex and organized biological process, and the dermal fibroblasts play a crucial role. α-Catenin is known to be involved in regulating various cellular signals, and its role in wound healing remains unclear. Here, we have identified the pivotal role of the α-catenin/FAK/YAP signaling axis in the proliferation and migration of dermal fibroblasts, which contributes to the process of skin wound healing. Briefly, when α-catenin was knocked down specifically in dermal fibroblasts, the wound healing rate is significantly delayed. Moreover, interfering with α-catenin can impede the proliferation and migration of dermal fibroblasts both in vitro and in vivo. Mechanistically, the overexpression of α-catenin upregulates the nuclear accumulation of YAP and transcription of downstream target genes, resulting in enhanced the proliferation and migration of dermal fibroblasts. Furthermore, the FAK Tyr397 phosphorylation inhibitor blocked the promoting effects of α-catenin on YAP activation. Importantly, the continuous phosphorylation mutation of FAK Tyr397 reversed the retardatory effects of α-catenin knockdown on wound healing, by increasing the vitality of fibroblasts. Likewise, α-catenin/FAK was validated as a therapeutic target for wound healing in the db/db chronic trauma model. In summary, our findings have revealed a novel mechanism by which α-catenin facilitates the function of fibroblasts through the activity of the FAK/YAP signaling axis. These findings define a promising therapeutic strategy for accelerating the wound healing process.


Sujet(s)
Fibroblastes , Cicatrisation de plaie , alpha-Caténine/génétique , Mutation , Prolifération cellulaire
9.
FASEB J ; 37(9): e23135, 2023 09.
Article de Anglais | MEDLINE | ID: mdl-37594910

RÉSUMÉ

Diabetes is a chronic disease characterized by perturbed glucose and lipid metabolism, resulting in high blood glucose levels. Many complications induced by endothelial dysfunction can cause disability and even death of diabetic patients. Here, we found that the protein level of casein kinase 2α (CK2α) was increased in the endothelium of mice with type I diabetes (T1D) induced by streptozotocin (STZ) injection. Although a potential correlation between the protein level of CK2α and endothelial dysfunction in diabetes was established, the contribution of CK2α to the progression of endothelial dysfunction in diabetes remained largely unknown. By using CX4945 (a selective CK2α antagonist) and Si-csnk2a1 (small interfering RNA targeting CK2α), we found that inhibition of CK2α accelerated skin wound healing in T1D mice by promoting proliferation of endothelial cells. Administration of CX4945 or Si-csnk2a1 rescued the impaired Hedgehog signaling pathway in high glucose-treated human umbilical vein endothelial cells (HUVECs). Exploration of the underlying molecular mechanism revealed that the protective effect of CK2α inhibition on angiogenesis, which contributes to skin wound healing in diabetic mice, was blocked by administration of GANT61 (an inhibitor targeting the Hedgehog signaling pathway). Our findings establish CK2α as a regulator of endothelial dysfunction in diabetes and demonstrate that inhibition of CK2α accelerates skin wound healing in T1D mice by promoting endothelial cell proliferation via the Hedgehog signaling pathway.


Sujet(s)
Diabète expérimental , Diabète de type 1 , Humains , Animaux , Souris , Protéines Hedgehog , Casein Kinase II , Prolifération cellulaire , Glucose/pharmacologie , Cellules endothéliales de la veine ombilicale humaine , Cicatrisation de plaie
10.
Sensors (Basel) ; 23(2)2023 Jan 13.
Article de Anglais | MEDLINE | ID: mdl-36679750

RÉSUMÉ

(1) Background: Gamma cameras have wide applications in industry, including nuclear power plant monitoring, emergency response, and homeland security. The desirable properties of a gamma camera include small weight, good resolution, large field of view (FOV), and wide imageable source energy range. Compton cameras can have a 4π FOV but have limited sensitivity at low energy. Coded-aperture gamma cameras are operatable at a wide photon energy range but typically have a limited FOV and increased weight due to the thick heavy metal collimators and shielding. In our lab, we previously proposed a 4π-view gamma imaging approach with a 3D position-sensitive detector, with which each detector element acts as the collimator for other detector elements. We presented promising imaging performance for 99mTc, 18F, and 137Cs sources. However, the imaging performance for middle- and high-energy sources requires further improvement. (2) Methods: In this study, we present a new gamma camera design to achieve satisfactory imaging performance in a wide gamma energy range. The proposed gamma camera consists of interspaced bar-shaped GAGG (Ce) crystals and tungsten absorbers. The metal bars enhance collimation for high-energy gamma photons without sacrificing the FOV. We assembled a gamma camera prototype and conducted experiments to evaluate the gamma camera's performance for imaging 57Co, 137Cs, and 60Co point sources. (3) Results: Results show that the proposed gamma camera achieves a positioning accuracy of <3° for all gamma energies. It can clearly resolve two 137Cs point sources with 10° separation, two 57Co and two 60Co point sources with 20° separation, as well as a 2 × 3 137Cs point-source array with 20° separation. (4) Conclusions: We conclude that the proposed gamma camera design has comprehensive merits, including portability, 4π-view FOV, and good angular resolution across a wide energy range. The presented approach has promising potential in nuclear security applications.


Sujet(s)
Caméras à rayons gamma , Métaux lourds , Conception d'appareillage , Imagerie diagnostique
11.
Poult Sci ; 102(3): 102377, 2023 Mar.
Article de Anglais | MEDLINE | ID: mdl-36586387

RÉSUMÉ

In hens, egg production depends on the development of germ cells in the ovary. Germ cells are established before birth, and their number gradually decreases during their lifespan. Therefore, it is essential to determine the time points of massive germ cell loss and the underlying mechanism. In this study, a gene-edited chicken with mCherry fluorescence specifically expressed in the germline was generated by the integration of the mCherry gene into the 3'-end of the DAZL locus, which facilitated the isolation of germ cells from the gonads of DAZL-mCherry embryos or chicks and quantification using flow cytometry based on the observation of red fluorescence. The results demonstrated the dynamics of germ cell development from embryos at 17 d of hatching (dh) to chickens at 7 d post-hatch (dph) and revealed a substantial loss of germ cells in the late embryonic stage (18 -19 dh) and post-hatch period (2 -3 dph). Additionally, the number of germ cells in DAZL × Guangxi Ma chicken was significantly higher than that in DAZL × Lohmann Pink chicken at 19 dh and 3 dph (P < 0.05). Furthermore, the numbers of germ cells positively correlated with the body weight in DAZL × Lohmann Pink chicken. In conclusion, our results showed the dynamics of germ cell development in chicken ovaries during peri-hatch periods and indicated the time point of substantial germ cell loss. The results provide evidence for further exploration of the underlying mechanism and serve as a reference for chicken breeding and management.


Sujet(s)
Poulets , Édition de gène , Animaux , Femelle , Poulets/génétique , Édition de gène/médecine vétérinaire , Chine , Gonades , Cellules germinales
12.
Adv Healthc Mater ; 12(2): e2201220, 2023 01.
Article de Anglais | MEDLINE | ID: mdl-36330558

RÉSUMÉ

Hierarchical vasculature reconstruction is fundamental for tissue regeneration. The regeneration of functional vascular network requires a proper directional guidance, especially in case of large-size defects. To provide the "running track" for vasculature, a leaf-vein mimetic membrane using soft and elastic poly(lactide-co-propylene glycol-co-lactide) dimethacrylate is developed. Engraved with an interconnected and perfusable leaf-vein micropattern, the membrane can guide human umbilical vein endothelial cells (HUVECs) to form vasculature in vitro. In particular, the "running track" upregulates the angiogenesis-related gene expression and promotes the HUVECs to differentiate into tip cells and stalk cells via tuning vascular endothelial growth factor receptor 2 signaling transduction. As a proof of concept, its revascularization capability using a rat calvarial defect model in vivo is evaluated. The in vivo results demonstrate that the leaf-vein engraved membrane accelerates the formation and maturation of vasculature, leading to a hierarchical blood vessel network. With the superior pro-vasculature property, it is believed that the leaf-vein engraved membrane is not only an ideal candidate for the reconstruction of calvarial vasculature but also a promising solution for more complicated vasculature reconstruction, such as muscle, skin, and heart.


Sujet(s)
Matériaux biomimétiques , Cellules endothéliales de la veine ombilicale humaine , Néovascularisation physiologique , Veines , Animaux , Humains , Rats , Cellules endothéliales de la veine ombilicale humaine/métabolisme , Feuilles de plante , Cicatrisation de plaie , Matériaux biomimétiques/composition chimique , Matériaux biomimétiques/usage thérapeutique , Récepteur-2 au facteur croissance endothéliale vasculaire/métabolisme , Crâne/métabolisme , Crâne/anatomopathologie , Polyesters/composition chimique , Polyesters/usage thérapeutique
14.
Proc Natl Acad Sci U S A ; 119(41): e2206684119, 2022 10 11.
Article de Anglais | MEDLINE | ID: mdl-36191194

RÉSUMÉ

Leaf photosynthesis, coral mineralization, and trabecular bone growth depend on triply periodic minimal surfaces (TPMSs) with hyperboloidal structure on every surface point with varying Gaussian curvatures. However, translation of this structure into tissue-engineered bone grafts is challenging. This article reports the design and fabrication of high-resolution three-dimensional TPMS scaffolds embodying biomimicking hyperboloidal topography with different Gaussian curvatures, composed of body inherent ß-tricalcium phosphate, by stereolithography-based three-dimensional printing and sintering. The TPMS bone scaffolds show high porosity and interconnectivity. Notably, compared with conventional scaffolds, they can reduce stress concentration, leading to increased mechanical strength. They are also found to support the attachment, proliferation, osteogenic differentiation, and angiogenic paracrine function of human mesenchymal stem cells (hMSCs). Through transcriptomic analysis, we theorize that the hyperboloid structure induces cytoskeleton reorganization of hMSCs, expressing elongated morphology on the convex direction and strengthening the cytoskeletal contraction. The clinical therapeutic efficacy of the TPMS scaffolds assessed by rabbit femur defect and mouse subcutaneous implantation models demonstrate that the TPMS scaffolds augment new bone formation and neovascularization. In comparison with conventional scaffolds, our TPMS scaffolds successfully guide the cell fate toward osteogenesis through cell-level directional curvatures and demonstrate drastic yet quantifiable improvements in bone regeneration.


Sujet(s)
Ostéogenèse , Structures d'échafaudage tissulaires , Animaux , Régénération osseuse , Différenciation cellulaire , Humains , Souris , Porosité , Impression tridimensionnelle , Lapins , Ingénierie tissulaire/méthodes , Structures d'échafaudage tissulaires/composition chimique
15.
Poult Sci ; 101(12): 102174, 2022 Dec.
Article de Anglais | MEDLINE | ID: mdl-36240636

RÉSUMÉ

Advanced animal reproductive and breeding biotechnology has made it possible to alter traits or create new genetic resources by the direct knock-in or knock-out of target genes. Base editing technology can achieve single-base mutations without double-stranded DNA breaks, and is a promising tool for use in the genetic modification and breeding of livestock. However, the application of base editors (BEs) in chicken has not been optimized. We evaluated the efficacy of BE4max in chicken somatic cells (DF-1). The key element of BE4max, cytosine deaminase (APOBEC), was optimized for chicken. The base editing efficiency of the optimized chBE4max editor, compared with the original BE4max editor, was improved by 10.4% ± 4.6. By inhibiting the expression of the uracil DNA glycosylase-related gene methyl binding domain protein 4 (MBD4) by siRNA in chicken DF-1 cells, the editing efficiency was enhanced by 4.43% ± 1.4 compared to the control. These results suggest that this editor may have applications in poultry breeding studies.


Sujet(s)
Systèmes CRISPR-Cas , Poulets , Animaux , Poulets/génétique , Édition de gène/médecine vétérinaire , Édition de gène/méthodes , Mutation
16.
Appl Radiat Isot ; 186: 110256, 2022 Aug.
Article de Anglais | MEDLINE | ID: mdl-35533606

RÉSUMÉ

In single-photon emission computed tomography (SPECT), a micro-sized 99mTc source is routinely used for performance measurement, geometry calibration, and system matrix generation. Therefore, a micro-sized source is critical in nuclear instrument production and quality control. Standard methods can only produce a point source with a large size and low total activity, as they are limited by the concentration of the 99mTc solution. The absorption of 99mTc on ion exchange resins has been used; however, few studies have quantitatively evaluated the absorption process and optimized the source activity. This paper proposes a procedure for producing a micro-sized 99mTc resin source with a super-high concentration, as well as a method for the fast measurement of the point source time-activity curve (TAC). Experiments on two resin point sources with diameters of 0.681 mm and 0.326 mm were carried out. Two semi-empirical models, including the first kinetic model and the pseudo-second-order rate equation model, were used to fit TACs. The results show the first kinetic model fit better, which suggests an acquisition time of 2-4 h is needed for optimization. The verification experiment demonstrates a resin point source with a diameter of 0.35 mm and total activity of 10.6 mCi (i.e., 59.1 Ci/mL concentration) was produced.


Sujet(s)
Résines échangeuses d'ions , Tomographie par émission monophotonique , Calibrage , Tomographie par émission monophotonique/méthodes
17.
Small ; 18(36): e2200314, 2022 09.
Article de Anglais | MEDLINE | ID: mdl-35261154

RÉSUMÉ

Electrosprayed microspheres for bone regeneration are conventionally restricted by the lack of osteogenic modulation for both encapsulated stem cells and surrounding cells at the defect site. Here, sodium alginate microspheres encapsulating L-arginine doped hydroxyapatite nanoparticles (Arg/HA NPs) and bone mesenchymal stem cells (BMSCs) as regeneration-enhancer-element reservoirs (Arg/HA-SA@BMSC) for bone healing are electrosprayed. The Arg/HA NPs serve as a container of L-arginine and Ca2+ and the BMSCs inside the microspheres metabolize the released L-arginine into bioactive gas nitric oxide (NO) in the presence of Ca2+ to activate the nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) signaling pathway. Meanwhile, the generated NO diffuses out of the microspheres together with the Ca2+ and L-arginine as exterior enhancers to promote the osteogenesis-angiogenesis coupling of surrounding BMSCs and endothelial cells (ECs) at the bone defect site, generating an internal/external modulation loop between the encapsulated cells and surrounding native cells. It is demonstrated that such regeneration-enhancer-element reservoirs could effectively increase the bone tissue formation and neovasculature using rat calvarial defect models. It is envisioned that the microsphere system could streamline vascularized bone regeneration therapy as a high throughput, minimally invasive yet highly effective strategy to accelerate bone healing.


Sujet(s)
Cellules endothéliales , Ostéogenèse , Animaux , Arginine/pharmacologie , Régénération osseuse , Différenciation cellulaire , Durapatite , Microsphères , Monoxyde d'azote , Rats , Structures d'échafaudage tissulaires
18.
Mar Environ Res ; 170: 105447, 2021 Aug.
Article de Anglais | MEDLINE | ID: mdl-34438216

RÉSUMÉ

The toxicity of heavy metals to coastal organisms can be modulated by changes in pH due to progressive ocean acidification (OA). We investigated the combined impacts of copper and OA on different stages of the green macroalga Ulva linza, which is widely distributed in coastal waters, by growing the alga under the addition of Cu (control, 0.125 (medium, MCu), and 0.25 (high) µM, HCu) and elevated pCO2 of 1,000 µatm, predicted in the context of global change. The relative growth rates decreased significantly in both juvenile and adult thalli at HCu under OA conditions. The net photosynthetic and respiration rates, as well as the relative electron transfer rates for the adult thalli, also decreased under the combined impacts of HCu and OA, although no significant changes in the contents of photosynthetic pigments were detected. Our results suggest that Cu and OA act synergistically to reduce the growth and photosynthetic performance of U. linza, potentially prolonging its life cycle.


Sujet(s)
Ulva , Dioxyde de carbone , Cuivre/toxicité , Concentration en ions d'hydrogène , Océans et mers , Eau de mer
19.
Small ; 17(14): e2006598, 2021 04.
Article de Anglais | MEDLINE | ID: mdl-33705605

RÉSUMÉ

Current periosteal grafts have limitations related to low mechanical strength, tissue adhesiveness, and poor osteogenesis and angiogenesis potential. Here, a periosteum mimicking bone aid (PMBA) with similar structure and function to natural periosteum is developed by electrospinning photocrosslinkable methacrylated gelatin (GelMA), l-arginine-based unsaturated poly(ester amide) (Arg-UPEA), and methacrylated hydroxyapatite nanoparticles (nHAMA). Such combination of materials enhances the material mechanical strength, favors the tissue adhesion, and guarantees the sustained activation of nitric oxide-cyclic guanosine monophosphate (NO-cGMP) signaling pathway, with well-coordinated osteogenic-angiogenic coupling effect for accelerated bone regeneration. This work presents a proof-of-concept demonstration of thoroughly considering the progression of implant biomaterials: that is, the initial material components (i.e., GelMA, Arg-UPEA, and nHAMA) equip the scaffold with suitable structure and function, while its degradation products (i.e., Ca2+ and l-arginine) are involved in long-term mediation of physiological activities. It is envisioned that the strategy will inspire the design of high-performance bioscaffolds toward bone and periosteum tissue engineering.


Sujet(s)
Ostéogenèse , Périoste , Adhésifs , Biomimétique , Régénération osseuse , Ingénierie tissulaire , Structures d'échafaudage tissulaires
20.
Acta Biomater ; 124: 15-32, 2021 04 01.
Article de Anglais | MEDLINE | ID: mdl-33508510

RÉSUMÉ

Tendon adhesion formation describes the development of fibrotic tissue between the tendon and its surrounding tissues, which commonly occurs as a reaction to injury or surgery. Its impact on function and quality of life varies from negligible to severely disabling, depending on the affected area and extent of adhesion formed. Thus far, treatment options remain limited with prophylactic anti-inflammatory medications and revision surgeries constituting the only tools within the doctors' armamentarium - neither of which provides reliable outcomes. In this review, the authors aim to collate the current understanding of the pathophysiological mechanisms underlying tendon adhesion formation, highlighting the significant role ascribed to the inflammatory cascade in accelerating adhesion formation. The bulk of this article will then be dedicated to critically appraising different therapeutic structures like nanoparticles, hydrogels and fibrous membranes fabricated by various cutting-edge technologies for adhesion formation prophylaxis. Emphasis will be placed on the role of the fibrous membranes, their ability to act as drug delivery vehicles as well as the combination with other therapeutic structures (e.g., hydrogel or nanoparticles) or fabrication technologies (e.g., weaving or braiding). Finally, the authors will provide an opinion as to the future direction of the prevention of tendon adhesion formation in view of scaffold structure and function designs.


Sujet(s)
Qualité de vie , Tendons , Humains , Hydrogels , Technologie , Tendons/anatomopathologie , Adhérences tissulaires/anatomopathologie , Adhérences tissulaires/prévention et contrôle
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