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Perovskite solar cells (PSCs) have emerged as one of the most promising and competitive photovoltaic technologies, and doctor-blading is a facile and robust deposition technique to efficiently fabricate PSCs in large scale, especially matching with roll-to-roll process. Herein, it demonstrates the encouraging results of one-step, antisolvent-free doctor-bladed methylammonium lead iodide (CH3 NH3 PbI3, MAPbI3 ) PSCs under a wide range of humidity from 45% to 82%. A synergy strategy of ionic-liquid methylammonium acetate (MAAc) and molecular phenylurea additives is developed to modulate the morphology and crystallization process of MAPbI3 perovskite film, leading to high-quality MAPbI3 perovskite film with large-size crystal, low defect density, and ultrasmooth surface. Impressive power conversion efficiency (PCE) of 20.34% is achieved for doctor-bladed PSCs under the humidity over 80% with a device structure of ITO/SnO2 /MAPbI3 /Spiro-OMeTAD/Ag. It is the highest PCEs for one-step solution-processed MAPbI3 PSCs without antisolvent assistance. The research provides a facile and robust large-scale deposition technique to fabricate highly efficient and stable PSCs under a wide range of humidity, even with the humidity over 80%.
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Flexible perovskite solar cells (f-PSCs) have been attracting tremendous attention due to their potentially commercial prospects in flexible energy system and mobile energy system. Reducing the energy barriers and charge extraction losses at the interfaces between perovskite and charge transport layers is essential to improve both efficiency and stability of f-PSCs. Herein, 4-trifluoromethylphenylethylamine iodide (CF3 PEAI) is introduced to form a 2D perovskite at the interface between perovskite and hole transport layer (HTL). It is found that the 2D perovskite plays a dual-functional role in aligning energy band between perovskite and HTL and passivating the traps in the 3D perovskite, thus reducing energy loss and charge carrier recombination at the interface, facilitating the hole transfer from perovskite to the Spiro-OMeTAD. Consequently, the photovoltaic performance of f-PSCs is significantly improved, leading to a power conversion efficiency (PCE) of 21.1% and a certified PCE of 20.5%. Furthermore, the long-term stability of f-PSCs is greatly improved through the protection of 2D perovskite layer to the underlying 3D perovskite. This work provides an excellent strategy to produce efficient and stable f-PSCs, which will accelerate their potential applications.
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Tumor-associated macrophages (TAMs) are pivotal effector cells in angiogenesis. Here, we tested whether CYP4X1 inhibition in TAMs by flavonoid CH625 prolongs survival and normalizes glioma vasculature. CH625 was selected against the CYP4X1 3D model by virtual screening and showed inhibitory activity on the CYP4X1 catalytic production of 14,15-EET-EA in the M2-polarized human peripheral blood mononuclear cells (IC50 = 16.5 µM). CH625 improved survival and reduced tumor burden in the C6 and GL261 glioma intracranial and subcutaneous model. In addition, CH625 normalized vasculature (evidenced by a decrease in microvessel density and HIF-1α expression and an increase in tumor perfusion, pericyte coverage, and efficacy of temozolomide therapy) accompanied with the decreased secretion of 14,15-EET-EA, VEGF, and TGF-ß in the TAMs. Furthermore, CH625 attenuated vascular abnormalization and immunosuppression induced by coimplantation of GL261 cells with CYP4X1high macrophages. In vitro TAM polarization away from the M2 phenotype by CH625 inhibited proliferation and migration of endothelial cells, enhanced pericyte migration and T cell proliferation, and decreased VEGF and TGF-ß production accompanied with the downregulation of CB2 and EGFR-dependent downstream STAT3 expression. These effects were reversed by overexpression of CYP4X1 and STAT3 or exogenous addition of 14,15-EET-EA, VEGF, TGF-ß, EGF, and CB2 inhibitor AM630. These results suggest that CYP4X1 inhibition in TAMs by CH625 prolongs survival and normalizes tumor vasculature in glioma via CB2 and EGFR-STAT3 axis and may serve as a novel therapeutic strategy for human glioma.
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Sistema Enzimático do Citocromo P-450/metabolismo , Flavonoides/farmacologia , Glioma/irrigação sanguínea , Macrófagos/efeitos dos fármacos , Neovascularização Patológica/imunologia , Receptor CB2 de Canabinoide/metabolismo , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Inibidores das Enzimas do Citocromo P-450/farmacologia , Regulação para Baixo/efeitos dos fármacos , Receptores ErbB/metabolismo , Glioma/patologia , Humanos , Macrófagos/metabolismo , Neovascularização Patológica/metabolismo , Fator de Transcrição STAT3/metabolismo , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Fator de Crescimento Transformador beta/biossínteseRESUMO
Fast dissolving oral film is a stamp-style, drug-loaded polymer film with rapid disintegration and dissolution. This new kind of drug delivery system requires effective taste masking technology. Suspension intermediate and liposome intermediate were prepared, respectively, for the formulation of two kinds of fast dissolving oral films with the aim of studying the effect of taste masking technology on the bioavailability of oral films. Loratadine was selected as the model drug. The surface pH of the films was close to neutral, avoiding oral mucosal irritation or side effects. The thickness of a 2 cm × 2 cm suspension oral film containing 10 mg of loratadine was 100 µm. Electron microscope analysis showed that liposomes were spherical before and after re-dissolution, and drugs with obvious bitterness could be masked by the encapsulation of liposomes. Dissolution of the two films was superior to that of the commercial tablets. Rat pharmacokinetic experiments showed that the oral bioavailability of the suspension film was significantly higher than that of the commercial tablets, and the relative bioavailability of the suspension film was 175%. Liposomal film produced a certain amount of improvement in bioavailability, but lower than that of the suspension film.
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Polímeros/química , Paladar/fisiologia , Administração Oral , Animais , Disponibilidade Biológica , Varredura Diferencial de Calorimetria , Concentração de Íons de Hidrogênio , Lipossomos , Loratadina/administração & dosagem , Loratadina/sangue , Loratadina/farmacocinética , Loratadina/farmacologia , Tamanho da Partícula , Ratos Sprague-Dawley , Espectroscopia de Infravermelho com Transformada de Fourier , Suspensões , Fatores de Tempo , Difração de Raios XRESUMO
Oxidative stress and infection are the main reasons for postponement of wound healing rate. They can potentially lead to serious inflammation and eventually lead to a longer and more painful recovery phase. Although wound dressings based on synthetic materials with antioxidative property have been proved to exhibit remarkable effect in controlling ROS level and improving wound healing, issues, such as high cost in raw materials, complicated procedures, usage of various toxic additives, and potential allergies, have significantly confined further clinical applications. In this study, a novel type of tissue engineering scaffold, based on tomatoes (Solanum lycopersicon) and gelatin methacryloyl (GelMA), was prepared via facile lyophilization and photo cross-link method (SL/GelMA). By taking advantages of various antioxidative components, such as carotenoids, flavonoids, phenolic acids, vitamin E, and vitamin C in tomatoes, SL/GelMA can effectively regulate ROS level, relieve the oxidative stress in wound bed, promote cell migration and angiogenesis, contribute to collagen deposition, and thus accelerate the rate of wound enclosure. Along with its high biocompatibility and low allergic potential, we believe that the food-derived wound dressing with facile preparation method, easy accessibility, and high cost-effectiveness can be translated for clinical treatments of various chronic wounds.
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Hidrogéis , Solanum lycopersicum , Hidrogéis/farmacologia , Espécies Reativas de Oxigênio , Cicatrização , Gelatina/farmacologia , Antioxidantes/farmacologiaRESUMO
Perovskite solar cells (PSCs) are being developed rapidly and exhibit greatly potential commercialization. Herein, it is found that the device performance can be improved by manipulating the migration of iodine ions via reverse-biasing, for example, at -0.4 V for 3 min in dark. Characterizations suggest that reverse bias can increase the charge recombination resistance, improve carrier transport, and enhance built-in electric field. Iodine ions including iodine interstitials in perovskites are confirmed to migrate and accumulate at the SnO2 /perovskite interface under reverse-basing, which fill iodine vacancies at the interface and interact with SnO2 . First-principles calculations suggest that the SnO2 /perovskite interface with less iodine vacancies has a stronger interaction and higher charge transfer, leading to larger built-in electric field and improved charge transport. Iodine ions that may pass through the SnO2 /perovskite interface are also confirmed to be able to interact with Sn4+ and passivate oxygen vacancies on the surface of SnO2 . Consequently, an efficiency of 23.48% with the open-circuit voltage (Voc ) of 1.16 V is achieved for PSCs with reverse-biasing, as compared with the initial efficiency of 22.13% with a Voc of 1.10 V. These results are of great significance to reveal the physics mechanism of PSCs under electric field.
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Food-derived materials possess inherent advantages in tissue engineering applications with appropriate biosafety, availability, and maneuverability. This work takes advantage of gelatin methacrylate (GelMa) to fabricate the tofu-incorporated hydrogels and systematically investigated the potential for bone regeneration. The results affirmed that tofu-incorporated hydrogel possessed porous architecture, satisfactory mechanical performance, and appropriate cytocompatibility. It is worth noting that little inflammation could be caused by the tofu/GelMa hydrogels, and the incorporated tofu powder could also promote the secretion of osteogenesis and immune-related cytokines in the early stage, resulting in improved bone regeneration during the 2-month implantation. All the results suggested that tofu/GelMa hydrogels possessed good potential for bone regeneration with low cost, satisfactory cytocompatibility, and excellent bioactivity.
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Hidrogéis , Alimentos de Soja , Materiais Biocompatíveis , Regeneração Óssea , GelatinaRESUMO
The past years have witnessed promising clinical feedback for anti-cancer immunotherapies, which have become one of the hot research topics; however, they are limited by poor delivery kinetics, narrow patient response profiles, and systemic side effects. To the best of our knowledge, the development of cancer is highly associated with the immune system, especially the tumor immune microenvironment (TIME). Based on the comprehensive understanding of the complexity and diversity of TIME, drug delivery strategies focused on the modulation of TIME can be of great significance for directing and improving cancer immunotherapy. This review highlights the TIME modulation in cancer immunotherapy and summarizes the versatile TIME modulation-based cancer immunotherapeutic strategies, medicative principles and accessory biotechniques for further clinical transformation. Remarkably, the recent advances of cancer immunotherapeutic drug delivery systems and future prospects of TIME modulation-based drug delivery systems for much more controlled and precise cancer immunotherapy will be emphatically discussed.
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Sistemas de Liberação de Medicamentos , Imunoterapia , Neoplasias/terapia , Microambiente Tumoral/imunologia , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacocinética , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Humanos , Fatores Imunológicos/antagonistas & inibidores , Imunomodulação , Nanopartículas/química , Neoplasias/imunologiaRESUMO
To overcome the low mechanical strength and difficult bonding of hydrogels to bones which are the major limitations of hydrogels used in bone-regeneration, a new type of calcium polyphosphate incorporated into bioinspired alginate/polyacrylic acid (CPP/PAA-Alg) hybrid double network (DN) hydrogel with both high strength and enhanced osseointergration was prepared by a two-step polymerization with alginate and polyacrylic acid for bone regeneration. The morphology, mechanical properties, swelling, biocompatibility, osseointegration and osteogenic ability of this CPP/PAA-Alg DN hydrogel were investigated. The results show that CPP/PAA-Alg DN hydrogel with highly porous microstructure possesses high water absorption capacity and highly strength properties which meet the requirements of bone repairing. The results of in vitro studies revealed that the CPP/PAA-Alg DN hydrogels can support the spread of cells and promote the cell proliferation. Animal studies demonstrated that the CPP incorporated would enhance the osseointegration of DN hydrogel with host bone at an early stage after implantation to accelerate the regeneration of bone. This research may provide a new way to develop biocompatible biomaterials with high mechanical strength and good osseointegration to meet the needs of bone regeneration.
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Materiais Biocompatíveis/química , Regeneração Óssea , Fosfatos de Cálcio/química , Hidrogéis/química , Osseointegração , Polifosfatos/química , Cinética , Fenômenos MecânicosRESUMO
Bone transplantations are still facing many serious challenges, hydrogel as a new kind of artificial bone substitutes has developed into a promising bone scaffold material. However, it is still a challenge to combine bioactive agents and hydrogel matrix to promote osteoinductivity. Herein, we developed a novel bioactive hydrogel based on arginine-based unsaturated poly (ester amide) (Arg-UPEA) and methacrylated hyaluronic acid (HA-MA) via photo-crosslinking. As the results indicated, we found that the introduction of Arg-UPEA into HA-MA hydrogels could finely modulate their compressive modulus, swelling level and porous structure. Besides, among groups of different feed ratio, groups of 10 % and 15 % of Arg-UPEA content effectively enhanced osteogenic differentiation in osteoblasts when compared with HA-MA hydrogel. Furthermore, better bone regeneration and expression of osteogenesis-related factors in vivo also verified the Arg-UPEA/HA-MA hybrid hydrogels as a promising scaffold material for bone tissue engineering.
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Substitutos Ósseos/química , Hidrogéis/química , Engenharia Tecidual , Alicerces Teciduais/química , Células 3T3 , Amidas/química , Amidas/farmacologia , Animais , Arginina/química , Arginina/farmacologia , Regeneração Óssea , Substitutos Ósseos/uso terapêutico , Osso e Ossos , Ácido Hialurônico/química , Ácido Hialurônico/farmacologia , Hidrogéis/uso terapêutico , Interações Hidrofóbicas e Hidrofílicas , Metacrilatos/química , Metacrilatos/farmacologia , Camundongos , Células NIH 3T3 , Osteogênese/fisiologia , Poliésteres/química , Poliésteres/farmacologia , Porosidade , Ratos Sprague-DawleyRESUMO
Epidemiologic studies show that the levels of air pollutants and particulate matter are positively associated with the morbidity and mortality of cardiovascular diseases. Here we demonstrate that the intratracheal instillation of multi-walled carbon nanotubes (MWCNTs), a standard fine particle, exacerbate doxorubicin (DOX)-induced cardiotoxicity in mice through altering gut microbiota and pulmonary and colonic macrophage phenotype. MWCNTs (25 µg/kg per day, 5 days a week for 3 weeks) promoted cardiotoxicity and apoptosis in the DOX (2 mg/kg, twice a week for 5 weeks)-treated C57BL/6 mice. MWCNTs exaggerated DOX-induced gut microbiota dysbiosis characterized by the increased abundances of Helicobacteraceae and Coriobacteriaceae. In addition, MWCNTs promoted DOX-induced M1-like polarization of colonic macrophages with an increase in TNF-α, IL-1ß and CC chemokine ligand 2 in peripheral blood. Importantly, treatment with the antibiotics attenuated MWCNTs plus DOX-induced apoptosis of cardiomyocytes and M1-like polarization of colonic macrophages. The fecal microbiota transplantation demonstrated that MWCNTs exaggerated DOX-induced cardiotoxicity with M1-like polarization of colonic macrophages. The conditioned medium from MWCNTs-treated pulmonary macrophages promoted DOX-induced gut microbiota dysbiosis and colonic macrophage polarization. Furthermore, the co-culture of macrophages and fecal bacteria promoted M1-like macrophage polarization and their production of TNF-α and IL-1ß, and thereby exacerbated the effects of MWCNTs. Moreover, IL-1ß and TNF-α blockade, either alone or in combination attenuated MWCNTs-exacerbated cardiotoxicity. In summary, MWCNTs exacerbate DOX-induced cardiotoxicity in mice through gut microbiota and pulmonary and colonic macrophage interaction. Our findings identify a novel mechanism of action of inhaled particle-driven cardiotoxicity.
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Antibióticos Antineoplásicos/toxicidade , Colo/efeitos dos fármacos , Doxorrubicina/toxicidade , Microbioma Gastrointestinal/efeitos dos fármacos , Cardiopatias/induzido quimicamente , Pulmão/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Nanotubos de Carbono/toxicidade , Animais , Antibacterianos/farmacologia , Apoptose/efeitos dos fármacos , Células Cultivadas , Quimiocina CCL2/sangue , Colo/imunologia , Colo/metabolismo , Colo/microbiologia , Disbiose , Fezes/microbiologia , Cardiopatias/sangue , Cardiopatias/imunologia , Cardiopatias/microbiologia , Interleucina-1beta/sangue , Pulmão/imunologia , Pulmão/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Fenótipo , Fator de Necrose Tumoral alfa/sangueRESUMO
Effective bone regeneration remains a challenge for bone-tissue engineering. In this study, we propose a new strategy to accelerate bone regeneration via a sustained supply of phosphorus without providing foreign calcium. Herein, a black phosphorus nanosheet (BPN)-based hydrogel platform was developed, and the BPNs were used to stably and mildly provide phosphorus. The hydrogel was fabricated by photo-crosslinking of gelatin methacrylamide, BPNs, and cationic arginine-based unsaturated poly(ester amide)s. This platform combines the following advantages: the hydrogel scaffold would keep BPNs inside, and the encapsulated BPNs can degrade into phosphorus ions and capture calcium ions to accelerate biomineralization in a bone defect. The introduction of BPNs helped to enhance the mechanical performance of hydrogels, photoresponsively release phosphate, and accelerate mineralization in vitro. Moreover, BPN-containing hydrogels improved osteogenic differentiation of human dental pulp stem cells via the bone morphogenic protein-runt-related transcription factor 2 pathway. In vivo results from a rabbit model of bone defects revealed that the BPNs helped to accelerate bone regeneration. All these results strongly suggest that the strategy of a sustained supply of calcium-free phosphorus and this BPN-containing hydrogel platform hold promise for effective bone regeneration.
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Regeneração Óssea/efeitos dos fármacos , Hidrogel de Polietilenoglicol-Dimetacrilato/administração & dosagem , Osteogênese/efeitos dos fármacos , Engenharia Tecidual , Animais , Cálcio/química , Diferenciação Celular/efeitos dos fármacos , Modelos Animais de Doenças , Gelatina/química , Humanos , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Fósforo/administração & dosagem , Fósforo/química , Coelhos , Alicerces Teciduais/químicaRESUMO
Thermal plastic polyurethanes (TPUs), serving as biomaterials, have become increasingly prevalent over time in many fields including artificial blood vessels, pericardial patches and other tissue engineering scaffolds by virtue of well adjustable performance. However, synthetic polyurethanes are, to some extent, inadequate for their cytocompatibility and biological activity owing to high hydrophobicity and lack of active groups. In this study, an amino-terminated bis(L-arginine) alkylene diester extender (L-Arg-8) was synthesized and Arg-based biodegradable poly(ester urea) urethanes (PEUUs) with different content of arginine groups were designed, synthesized and characterized in regard to the amelioration of the biodegradability, hydrophilicity and cytocompatibility of thermoplastic polyurethanes (TPUs) with PCL as soft segments. Biodegradability, hydrophilicity and positive surface charges increased after Arginine was introduced. As cytocompatibility was improved, PEUU materials A8-1.2 and A8-1.6 were proved to be suitable for human dental pulp stem cells (hDPSCs) to adhere, grow and proliferate on in vitro. These materials would unlock great potential for the use in tissue engineering and regeneration. Additionally, halloysite nanotubes (HNTs) were composited to PEUUs for further exploration to the applications in bone tissue. The addition of halloysite nanotubes further stimulated the osteogenic differentiation of human dental pulp stem cells in vitro. At the same time, a rat cranial defect model was built to assess effects of repair in vivo. Osteointegration and repair were promoted by patch-implanted groups. A8-1.2 6% HNTs showed the best repair. All the results indicated that Arg-based poly(ester urea) urethanes and the composites were conductive to bone repair.
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Osso e Ossos , Animais , Materiais Biocompatíveis , Humanos , Osteogênese , Poliésteres , Poliuretanos , Ratos , Engenharia Tecidual , Alicerces Teciduais , UreiaRESUMO
Designing biomimetic scaffolds that can provide an appropriate microenvironment in bone defects to accelerate bone regeneration may become the breach of bone tissue engineering. Herein, we present simple egg white (EW)-/eggshell (ES)-based biomimetic hybrid hydrogels to investigate their potential for promoted bone regeneration. The photopolymerized biomimetic hybrid hydrogels possessed porous structures, which may support cell growth. Remarkably, the addition of eggshells could benefit mechanical performance with good cytocompatibility. Moreover, biomimetic hybrid hydrogels could have effects on macrophages and regulate the osteogenic differentiation of human dental pulp stem cells, indicating their potential for enhanced bone regeneration. All of the results suggested that biomimetic hybrid scaffolds possess a promising prospect in bone tissue engineering with good bioactivity and low cost.
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To development biomimetic strategy for enhanced cancer therapy, the paclitaxel loaded egg white/sodium alginate nanoparticles were prepared by electronic spray method. Their appearance and particle size were observed by transmission electron microscope and particle size analyzer. The drug release behavior of nanoparticles was determined by high performance liquid chromatography (HPLC). The toxicity, morphology and interaction of nanoparticles to cells were studied by means of MTT, live/dead staining and laser scanning confocal microscopy. The results show that the nanoparticles have good particle size dispersion, regular morphology, good drug release performance, good biocompatibility and in vitro effective inhibition of CT26 colorectal cancer cells. These results demonstrated that the good biocompatibility of egg white coated sodium alginate nanoparticles and PTX loaded these nanoparticles would show potential application for cancer therapy.
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Alginatos/química , Antineoplásicos/química , Clara de Ovo/química , Nanopartículas/química , Paclitaxel/química , Alginatos/administração & dosagem , Animais , Antineoplásicos/administração & dosagem , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Liberação Controlada de Fármacos , Elétrons , Camundongos , Nanopartículas/administração & dosagem , Paclitaxel/administração & dosagemRESUMO
Gelatin methacryloyl (GelMA)-based biomaterials have been widely used in various biomedical applications due to their suitable biological properties and tuneable physical characteristics. In particular, GelMA can be used as a versatile matrix for bone tissue engineering scaffolds via various strategies to overcome major obstacles such as insufficient mechanical property and uncontrollable degradation. This review presents the research status of GelMA, its structure and function, GelMA-based biomaterials and the development of methods along with their existing challenges.
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The chemotherapeutic drug doxorubicin (DOX) provokes a dose-related cardiotoxicity. Thus, there is an urgent need to identify the underlying mechanisms and develop strategies to overcome them. Here we demonstrated that glabridin (GLA), an isoflavone from licorice root, prevents DOX-induced cardiotoxicity through gut microbiota modulation and colonic macrophage polarization in mice. GLA reduced DOX-induced leakage of myocardial enzymes including aminotransferase, creatine kinase, lactate dehydrogenase, and creatine kinase-MB. GLA downregulated pro-apoptotic proteins (Bax, cleaved-caspase 9 and cleaved-caspase 3) and upregulated anti-apoptotic proteins (HAX-1 and Bcl-2) in the cardiac tissues. In addition, GLA modulated DOX-induced dysbiosis of gut microbiota and thereby decreased the ratio of M1/M2 colonic macrophage, accompanied by the downregulated lipopolysaccharide (LPS) and upregulated butyrate in the feces and peripheral blood. The leakage of myocardial enzymes induced by the DOX was decreased by antibiotics treatment, but not altered by co-treatment with the GLA and antibiotics. The ratio of M1/M2 colonic macrophage and leakage of myocardial enzymes reduced by the GLA were greatly increased by the Desulfovibrio vulgaris or LPS but decreased by the butyrate. Depletion of the macrophage attenuated DOX-induced cardiotoxicity but failed to further affect the effects of GLA. Importantly, GLA decreased production of M1 cytokines (IL-1ß and TNF-α) but increased production of M2 cytokines (IL-10 and TGF-ß) in the colonic macrophage with the downregulation of NF-κB and the upregulation of STAT6. In summary, GLA prevents DOX-induced cardiotoxicity through gut microbiota modulation and colonic macrophage polarization, and may serve as a potential therapeutic strategy for the DOX-induced cardiotoxicity.
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To design and prepare a novel controlled release system for sustained release of two drugs. In this study, a double-layer microsphere was incorporated with strontium-doped calcium polyphosphate (SCPP) scaffold to facilitate bone regeneration and achieve skull repair. The double-layer microsphere combining tetracycline loaded sodium alginate and matrix metalloproteinase-2 (MMP-2) loaded chitosan was manufactured by electrospinning, which were further adhered to SCPP scaffold. The characteristics of microstructure were observed through scanning electron microscope. Loading efficiencies and the optimal ratio of microsphere of the obtained controlled release system were investigated. In addition, the cytotoxicity and the effects on osteoblast proliferation and expressions of osteogenesis-related factors were examined in vitro. Thereafter, the compound material with the controlled release system was implanted in the skull defect of rabbit to evaluate its properties of promoting bone regeneration. The results indicated that this novel controlled release system with SCPP scaffold and the double-layer microspheres loaded with tetracycline and MMP-2 could be a promising material for bones repair.
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Regeneração Óssea , Animais , Cálcio , Fosfatos de Cálcio , Metaloproteinase 2 da Matriz , Microesferas , Osteoblastos , Polifosfatos , Coelhos , EstrôncioRESUMO
Bone regeneration remains a clinical challenge with limited bone substitutes, urging for effective alternative strategies. Nanotubes, especially carbon nanotubes and titanium dioxide nanotubes, have been widely utilized for bone regeneration; however, their further applications were limited by the composition and degradability. As naturally occurring aluminosilicate nanoclay, halloysite nanotubes (HNTs), with good biocompatibility, functionality, and nanotubular structures, may be a promising platform for promoting bone regeneration. Herein, we presented a HNTs incorporated hydrogel and explored the potential bone tissue engineering applications of HNTs. The HNTs encapsulated hydrogel was simply fabricated by using the photopolymerization method with gelatin methacrylate (GelMA) and HNTs. The incorporation of HNTs led to an enhanced mechanical performance while maintaining a good cytocompatibility in vitro. The osteogenic activities of the HNTs incorporated platform have also been studied in vitro and in vivo. Remarkably, the addition of HNTs obviously upregulated the expression of osteogenic differentiation-related genes and concomitant protein of human dental pulp stem cells (hDPSCs) and therefore facilitated subsequent bone regeneration in calvarial defects of rats. Overall, the results obtained in this study highlight the bone regeneration capacity of HNTs, which may enhance current understanding of HNTs, and present a promising alternative strategy for bone regeneration.
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High-fat diet (HFD) promotes lung pre-metastatic niche formation and metastasis. Thus, there is an urgent need to identify the underlying mechanisms and develop strategies to overcome them. Here we demonstrate that glycyrrhizic acid (GA) prevents HFD-enhanced pre-metastatic niche formation and metastasis through gut microbiota. GA reduced HFD-enhanced myeloid-derived suppressor cell recruitment, pro-metastatic protein S100A8/A9 expression and metastasis burden of 4T1 breast cancer and B16F10 melanoma, accompanied by gut microbiota alteration and colonic macrophage polarization far away the M1-like phenotype. These parameters were greatly decreased by treatment with antibiotics, recolonization of Desulfovibrio vulgaris and Clostridium sordellii, and administration of lipopolysaccharide or deoxycholic acid. Macrophage depletion attenuated HFD-enhanced pre-metastatic niche formation and metastasis, but failed to further affect the effects of GA. Mechanistically, counteraction of HFD-enhanced gut microbiota dysbiosis by GA inhibited Gr-1+ myeloid cell migration and S100A8/A9 expression through decreasing the proportion of M1-like macrophages and their production of CCL2 and TNF-α in the colons via LPS/HMGB1/NF-κB signaling inactivation. Together, targeting the gut microbiota by GA to modulate colonic macrophages could be a novel strategy for the prevention of HFD-enhanced pre-metastatic niche formation and metastasis.