Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 15.321
Filtrar
1.
Top Curr Chem (Cham) ; 378(2): 32, 2020 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-32146604

RESUMO

DNA hydrogels are crosslinked polymeric networks in which DNA is used as the backbone or the crosslinker. These hydrogels are novel biofunctional materials that possess the biological character of DNA and the framed structure of hydrogels. Compared with other kinds of hydrogels, DNA hydrogels exhibit not only high mechanical strength and controllable morphologies but also good recognition ability, designable responsiveness, and programmability. The DNA used in this type of hydrogel acts as a building block for self-assembly or as a responsive element due to its sequence recognition ability and switchable structural transitions, respectively. In this review, we describe recent developments in the field of DNA hydrogels and discuss the role played by DNA in these hydrogels. Various synthetic strategies for and a range of applications of DNA hydrogels are detailed.


Assuntos
DNA/química , Hidrogéis/química , DNA Polimerase Dirigida por DNA/metabolismo , Ligases/metabolismo , Luz , Nanotecnologia , Conformação de Ácido Nucleico , Hibridização de Ácido Nucleico
2.
J Environ Manage ; 261: 110225, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32148295

RESUMO

Concrete is significant for construction. A problem in application is the appearance of cracks that will damage its strength. An autogenous crack-healing mechanism based on bacteria receives increasing attention in recent years. The bacteria are able to form calcium carbonate (CaCO3) precipitations in suitable conditions to protect and reinforce the concrete. However, a large number of spores are crushed in aged specimens, resulting in a loss of viability. A new kind of hydrogel crosslinked by alginate, chitosan and calcium ions was introduced in this study. It was observed that the addition of chitosan improved the swelling properties of calcium alginate. Opposite pH response to calcium alginate was observed when the chitosan content in the solution reached 1.0%. With an addition of 1.0% chitosan in hydrogel beads, 10.28% increase of compressive strength and 13.79% increase of flexural strength to the control were observed. The results reveal self-healing properties of concretes. A healing crack of 4 cm length and 1 mm width was observed when using cement PO325, with the addition of bacterial spores (2.54-3.07 × 105/cm3 concrete) encapsulated by hydrogel containing no chitosan.


Assuntos
Quitosana , Hidrogéis , Bactérias , Carbonato de Cálcio , Materiais de Construção , Concentração de Íons de Hidrogênio
3.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 37(1): 179-184, 2020 Feb 25.
Artigo em Chinês | MEDLINE | ID: mdl-32096393

RESUMO

Decellularized extracellular matrix (dECM) has been widely used as a scaffold for regenerative medicine due to its high biomimetic and excellent biocompatibility. As a functional polymer material with high water content and controlled fluidity, hydrogel is very promising for some minimally invasive surgery in clinical practice. In recent years, with the rapid development of hydrogel theory and technology, dECM hydrogel has gradually become a research hotspot in the field of regenerative medicine. In this paper, the related researches in recent years are reviewed regarding the preparation of dECM hydrogel and its preclinical application. The future clinical use is also prospected.


Assuntos
Matriz Extracelular , Hidrogéis , Medicina Regenerativa , Engenharia Tecidual , Humanos , Tecidos Suporte
4.
J Agric Food Chem ; 68(10): 3050-3060, 2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-32069040

RESUMO

Industrial wastewater has brought great disaster to water bodies and soils and seriously affected the growth of crops. It is necessary to prepare a stable, effective, and sustainable treatment agent to control water pollution to obtain clean water. The adsorption effect of a lignosulfonate-lysine hydrogel (CLS-Lys adsorbent) on heavy metal ions (Cu2+ and Co2+) in water is studied. In the synthesis experiment, a response surface method is used to optimize the content of sodium lignosulfonate, lysine, initiator, and cross-linker. The CLS-Lys adsorbent is characterized by Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, thermal analysis, and zeta potential analysis. The performance of the CLS-Lys adsorbent under different influencing factors is studied. The kinetic and isothermal models of the CLS-Lys adsorbent are established. The results show that the main adsorption model of the CLS-Lys adsorbent is chemical adsorption, accompanied by electrostatic adsorption. These two ions have a competitive adsorption relationship, and when the two ions are present at the same time, they inhibit each other. In addition, the CLS-Lys adsorbent has good adsorption and analytical regeneration performance. It is an economic and effective adsorbent and has a broad application prospect.


Assuntos
Hidrogéis/química , Lignina/análogos & derivados , Lisina/química , Metais Pesados/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Adsorção , Hidrogéis/síntese química , Cinética , Lignina/química , Águas Residuárias/química , Purificação da Água/instrumentação
5.
J Agric Food Chem ; 68(9): 2696-2701, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32031789

RESUMO

All-cellulose composites are usually prepared by removing impurities and using a surface-selective dissolution approach, which detract significantly from their environment-friendly properties. In this paper, we report an environment-friendly approach to fabricate all-cellulose nanofiber composites from stack-up bacterial cellulose (BC) hydrogels via self-aggregation forces of the hydrogen bond by water-based processing. Structural and mechanical properties of BC-laminated composites have been investigated. The results indicated that BC composites possess the structure of all nanofibers, a tensile strength of 116 MPa, and a storage modulus of 25 GPa. Additionally, the interfacial shear strength and tensile strength of piece-hot-press BC demonstrate the strong self-aggregation forces of BC nanofibers. Thus, BC-laminated composites will be attractive in structural material.


Assuntos
Celulose/química , Gluconacetobacter xylinus/química , Hidrogéis/química , Nanofibras/química , Celulose/metabolismo , Gluconacetobacter xylinus/crescimento & desenvolvimento , Gluconacetobacter xylinus/metabolismo , Hidrogéis/metabolismo , Fenômenos Mecânicos , Resistência à Tração
6.
Chem Commun (Camb) ; 56(20): 3015-3018, 2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-32048648

RESUMO

The uncapped tripeptide DPhe-Phe-Leu acts as self-assembly template to yield supramolecular hydrogel biomaterials. As an example, self-assembling DPhe-Phe-Leu-Asp-Val contains the LDV bioadhesive motif for ß1 integrin activation. Hydrogels made of the two peptides successfully mimic fibronectin of the extracellular matrix and lead to high cell viability, adhesion, and spreading.


Assuntos
Hidrogéis/química , Imagem Óptica , Peptídeos/química , Adesão Celular , Sobrevivência Celular , Fibroblastos/química , Humanos , Substâncias Macromoleculares/química , Conformação Molecular , Tamanho da Partícula , Propriedades de Superfície
7.
Water Res ; 174: 115593, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32086133

RESUMO

The catalytic hydrogel membrane reactor (CHMR) is an interfacial membrane process that uses nano-sized catalysts for the hydrogenation of oxidized contaminants in drinking water. In this study, the CHMR was operated as a continuous-flow reactor using nitrite (NO2-) as a model contaminant and palladium (Pd) as a model catalyst. Using the overall bulk reaction rate for NO2- reduction as a metric for catalytic activity, we evaluated the effect of the hydrogen gas (H2) delivery method to the CHMR, the initial H2 and NO2- concentrations, Pd density in the hydrogel, and the presence of Pd-deactivating species. The chemical stability of the catalytic hydrogel was evaluated in the presence of aqueous cations (H+, Na+, Ca2+) and a mixture of ions in a hard groundwater. Delivering H2 to the CHMR lumens using a vented operation mode, where the reactor is sealed and the lumens are periodically flushed to the atmosphere, allowed for a combination of a high H2 consumption efficiency and catalytic activity. The overall reaction rate of NO2- was dependent on relative concentrations of H2 and NO2- at catalytic sites, which was governed by both the chemical reaction and mass transport rates. The intrinsic catalytic reaction rate was combined with a counter-diffusional mass transport component in a 1-D computational model to describe the CHMR. Common Pd-deactivating species [sulfite, bisulfide, natural organic matter] hindered the reaction rate, but the hydrogel afforded some protection from deactivation compared to a batch suspension. No chemical degradation of the hydrogel structure was observed for a model water (pH > 4, Na+, Ca2+) and a hard groundwater after 21 days of exposure, attesting to its stability under natural water conditions.


Assuntos
Hidrogéis , Nitritos , Catálise , Hidrogenação , Oxirredução , Paládio
8.
Beijing Da Xue Xue Bao Yi Xue Ban ; 52(1): 10-17, 2020 Feb 18.
Artigo em Chinês | MEDLINE | ID: mdl-32071457

RESUMO

OBJECTIVE: To prepare glycol-chitosan (GC)-based single/dual-network hydrogels with different composition ratios (GC31, DN3131 and DN6262) and to investigate the effects of hydrogel scaffolds on biological behavior of human dental pulp cell (hDPC) encapsulated. METHODS: GC-based single-network hydrogels (GC31) and GC-based dual-network hydrogels (DN3131, DN6262) with different composition ratios were prepared. The injectability was defined as the average time needed to expel a certain volume of hydrogel under a constant force. The degradation of the hydrogel was determined by the weight loss with time. The fracture stress was measured using a universal testing machine. The proliferation of hDPCs in hydrogels was detected using the cell counting kit-8 (CCK-8) method and CalceinAM/PI Live/Dead assay. After 14 days of odontoblastic induction, the expression of alkaline phosphatase (ALP), dentin sialophosphoprotein (DSPP) and dentin matrix protein-1 (DMP-1) was detected by real-time quantitative reverse transcription PCR (real-time RT-PCR) and the mineralized nodules was observed by Von Kossa staining. RESULTS: The injectability of all three groups of hydrogels was acceptable. The time of injection of GC31 was the shortest, and that of DN6262 was longer than DN3131 (P<0.05). The degradation rate of GC31 hydrogel in vitro was significantly faster than that of the dual-network hydrogel groups (P<0.05). There was no significant difference between DN3131 and DN6262 (P>0.05). The compressive resistance failure point of GC31 group was 1.10 kPa, while it was 7.33 kPa and 43.30 kPa for DN3131 and DN6262. The compressive strength of dual-network hydrogel was significantly enhanced compared with single-network hydrogel. hDPCs were in continuous proliferation in all the three groups, and the GC31 group showed a higher proliferation rate (P<0.05). The expression levels of DSPP, DMP-1 and ALP in the dual-network hydrogel groups (DN3131, DN6262) were significantly higher than that of GC31 after culturing for 14 days (P<0.05), there was no difference in the expression levels of DMP-1 and ALP between DN3131 and DN6262 (P>0.05); Von Kossa staining showed that more mineralization deposition and mass-shaped mineralized nodules formed in DN3131 and DN6262, while only light brown calcium deposition staining was observed in GC31 group, which was scattered in granular forms. CONCLUSION: GC-based single/dual network hydrogels with different composition ratios met the injectable requirements. GC31 group had a lower mechanical properties, in which hDPCs exhibited a higher proliferation rate. dual-network hydrogels had slower degradation rate and higher mechanical properties, in which hDPCs exhibited better odontoblastic differentiation potential and mineralization potential.


Assuntos
Polpa Dentária , Hidrogéis , Fosfatase Alcalina , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Quitosana , Humanos , Odontoblastos
10.
J Photochem Photobiol B ; 203: 111741, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31901721

RESUMO

Spinal cord injury (SCI) is a distressing injury and an irretrievable dramatic event that can debilitate victims for lifespan. Recovery and treatment of SCI is critical challenges for medicine, to overcome the hurdles stem cells and hydrogel scaffolds implantation is a boon for SCI recovery. In this regard, we reported the synthesis of Gold nanoparticles (Au NPs) loaded Agarose/Poly (N-isopropylacrylamide) (PNIPAM) as promising materials for SCI treatment. Herein, Au NPs was synthesized by well-established citrate reduction method and the prepared materials were characterised by UV-visible spectroscopy (UV-vis), Transmission electron microscopy (TEM), Fourier- transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), and EDAX analysis. The microscopic images showed an elliptical or ovoid porous structure nature of hydrogel, and successful and homogenous loading of photo plasmonic nanoparticles into the hydrogel structure. The in vitro cell viability and inflammation analyses data exhibited that prepared hydrogels have no toxic to the cells and displayed high anti-regenerative ability with bone marrow Mesenchymal stem cells (MSCs) and macrophages cells. The in vivo analysis study demonstrated that the treated materials with encapsulated MSCs have greater nerve tissue regeneration efficacy which was confirmed by the results of BBB scores. The hind limb locomotion of treated model animals was totally vanished after post-operational surgery. It's established that implanted nano-hydrogel materials combined with MSCs have quicker recovery of motor function after post-operative surgery, when compared to the other implanted animal groups.


Assuntos
Materiais Biocompatíveis/química , Hidrogéis/química , Transplante de Células-Tronco Mesenquimais , Nanopartículas Metálicas/química , Traumatismos da Medula Espinal/terapia , Bexiga Urinária/fisiopatologia , Resinas Acrílicas/química , Animais , Células da Medula Óssea/citologia , Ouro/química , Membro Posterior/fisiologia , Locomoção , Células-Tronco Mesenquimais/química , Células-Tronco Mesenquimais/citologia , Tecido Nervoso/fisiologia , Regeneração , Traumatismos da Medula Espinal/complicações , Traumatismos da Medula Espinal/patologia , Tecidos Suporte/química
11.
J Photochem Photobiol B ; 203: 111776, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31931388

RESUMO

Due to the emergence of antibiotic resistance, antimicrobial photodynamic therapy (aPDT) has recently been demonstrated as a promising alternative to antibiotics to treat wound infections caused by multidrug-resistant (MDR) pathogens. This study aimed to evaluate the bacterial killing efficiency of aPDT mediated by methylene blue (MB) loaded thermosensitive hydrogels against methicillin-resistant Staphylococcus aureus (MRSA). Box-Behnken Design method was employed to investigate the impacts of the polymer compositions, Poloxamer 407, Poloxamer 188 and Carbopol 934P, on the gelation temperature (Tsol-gel) and release rate of MB. The viscosity and in vitro bacterial killing efficiency of three selected formulations with Tsol-gel ranged 25-34 °C and MB release in 2 h (the incubation time used for aPDT experiment) ≥ 70%, were assessed. The viscosity was found to increase with increasing P407 content and increasing total gel concentration. In the in vitro aPDT experiment, all tested MB-hydrogels demonstrated >2.5 log10 colony forming unit (CFU) reduction against three clinical relevant MRSA strains. Interestingly, the bacterial reduction increased with decreasing amount of gel added (reduced MB concentration). This was possibly attributed to the increased viscosity at higher gel concentration reducing the diffusion rate of released MB towards bacterial cells leading to reduced aPDT efficiency. In summary, aPDT with the thermosensitive MB hydrogel formulations is a promising treatment strategy for wound infections.


Assuntos
Anti-Infecciosos/química , Hidrogéis/química , Azul de Metileno/química , Anti-Infecciosos/metabolismo , Anti-Infecciosos/farmacologia , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Luz , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Azul de Metileno/metabolismo , Azul de Metileno/farmacologia , Reologia , Temperatura Ambiente , Viscosidade
12.
J Biomed Nanotechnol ; 16(1): 40-53, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31996284

RESUMO

In recent decades, a large number of research studies have been conducted to improve the treatment strategy against epithelial ovarian cancer, but women in advanced stage still have poor outcomes. The development of advanced treatments must be continued to overcome the limitation. Docetaxel, a semi-synthetic product derived from the Pacific Taxus extract, has been studied for many years for its potent anticancer applications. Aiming to solve the problems of its highly lipophilicity, insolubility and adverse side effects, nanocarriers were applied. Relying on the integration of nanoparticles which had optimized sizes, shapes, and surface properties, the effect of docetaxel was enhanced. In this study, we designed a novel drug loaded gel-forming nanoparticle system (Doc-NMs-hydrogel composites), which acted as a sustained drug depot for docetaxel. Docetaxel was encapsulated into MPEG-PCL and then into blank thermosensitive hydrogel Pluronic F-127. Characterization showed that the prepared Doc-NMs had high drug loading (7%), minor particle size (37 nm), relatively good water solubility. Moreover, the cytotoxicity, apoptosis induction and the antitumor effects of Doc-NMs-hydrogel composites on mice abdominal SKOV-3 ovarian cancer model were investigated in vivo. Compared with other groups, at the same dosage, Doc-NMs-hydrogel composites show better apoptosis induction and cell growth inhibition. In conclusion, the prepared Doc-NMs-hydrogel composites enhanced anti-tumor activity by increasing local docetaxel concentration, maintaining stable and sustained drug release, prolonging drug retention time in tumors, and reducing toxicity to normal tissues. Doc-NMs-hydrogel composites might have great potential clinical application in anti-ovarian cancer activity.


Assuntos
Neoplasias Ovarianas , Animais , Antineoplásicos , Linhagem Celular Tumoral , Docetaxel , Portadores de Fármacos , Sistemas de Liberação de Medicamentos , Feminino , Humanos , Hidrogéis , Camundongos , Micelas , Nanopartículas , Taxoides
13.
Chem Soc Rev ; 49(2): 433-464, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31939475

RESUMO

Hydrogels are a unique class of polymeric materials that possess an interconnected porous network across various length scales from nano- to macroscopic dimensions and exhibit remarkable structure-derived properties, including high surface area, an accommodating matrix, inherent flexibility, controllable mechanical strength, and excellent biocompatibility. Strong and robust adhesion between hydrogels and substrates is highly desirable for their integration into and subsequent performance in biomedical devices and systems. However, the adhesive behavior of hydrogels is severely weakened by the large amount of water that interacts with the adhesive groups reducing the interfacial interactions. The challenges of developing tough hydrogel-solid interfaces and robust bonding in wet conditions are analogous to the adhesion problems solved by marine organisms. Inspired by mussel adhesion, a variety of catechol-functionalized adhesive hydrogels have been developed, opening a door for the design of multi-functional platforms. This review is structured to give a comprehensive overview of adhesive hydrogels starting with the fundamental challenges of underwater adhesion, followed by synthetic approaches and fabrication techniques, as well as characterization methods, and finally their practical applications in tissue repair and regeneration, antifouling and antimicrobial applications, drug delivery, and cell encapsulation and delivery. Insights on these topics will provide rational guidelines for using nature's blueprints to develop hydrogel materials with advanced functionalities and uncompromised adhesive properties.


Assuntos
Biomimética , Catecóis/química , Hidrogéis/química , Adesivos/química , Propriedades de Superfície
14.
Food Chem ; 313: 126095, 2020 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31923873

RESUMO

Core-shell hydrogel beads were successfully produced from soybean hull polysaccharides (SHP). Using electron microscopy, the beads were found to be spherical with smooth surfaces and have tight gel network internal structures. Fourier transform infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction were used to investigate the interaction between soy isoflavone and SHP in the gel beads mesh-like structure. Furthermore, the encapsulation efficiency and loading capacity of gel beads for soy isoflavone are 66.90% and 4.67%, respectively, and have the ability of pH-responsive release in vitro. Through the mathematical model of kinetics, we found that the release of soy isoflavone from gel beads showed Fickian diffusion in release media (pH 2.0 and 7.4), but showed non-Fickian diffusion at pH 4.0 and 6.8. This polymer can be extended to prepare more versatile delivery and controlled release system, appealing for food, pharmaceutical, biomedicine and cosmetics applications.


Assuntos
Hidrogéis/química , Isoflavonas/química , Polissacarídeos/química , Soja/metabolismo , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Concentração de Íons de Hidrogênio , Isoflavonas/metabolismo , Cinética
15.
AAPS PharmSciTech ; 21(2): 43, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31897806

RESUMO

Methicillin-resistant Staphylococcus aureus (MRSA) is considered a common colonizer of burn wound and accounts for high morbidity and mortality all across the globe. Systemic antibiotic therapy which is generally prescribed for these patients has a number of limitations. These include high drug dose, toxicity, and chances of development of drug resistance. However, local delivery of drug not only addresses these limitations but also provides better efficacy at the site of infection. In the present study, hydrogel preparations were developed for the topical delivery of moxifloxacin for the treatment of S. aureus-infected burn wound. Moxifloxacin was characterized by UV, FTIR, DSC, hot-stage microscopy, NMR, and HPLC and loaded into conventional and Boswellia-containing novel gels. Gels were characterized by visual examination, pH, UV spectroscopy, and release assays. In vivo studies showed that both gels were effective in eradicating the bacteria completely from the wound site when treatment was started during the early stage of infection. On the contrary, delayed treatment of planktonic and biofilm cells with novel gel showed better efficacy as compared with conventional gel in S. aureus-infected burn wound. Histopathological analysis also showed better skin healing efficacy of novel gel than conventional gel. Our results show that moxifloxacin can be efficiently used topically in the management of burn wound infections along with other antibacterial agents. Since biofilm-mediated infections are on the rise especially in chronic bacterial disease, therefore, a preparation containing antibiofilm agent-like Boswellia as one of the excipients would be more meaningful.


Assuntos
Antibacterianos/administração & dosagem , Antibacterianos/farmacologia , Anti-Infecciosos Locais/administração & dosagem , Anti-Infecciosos Locais/farmacologia , Biofilmes/efeitos dos fármacos , Queimaduras/complicações , Quitosana/química , Hidrogéis/química , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Infecção dos Ferimentos/tratamento farmacológico , Animais , Antibacterianos/química , Anti-Infecciosos Locais/química , Boswellia/química , Composição de Medicamentos , Géis , Staphylococcus aureus Resistente à Meticilina , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Moxifloxacina/administração & dosagem , Moxifloxacina/química , Moxifloxacina/uso terapêutico , Infecções Estafilocócicas/microbiologia , Infecção dos Ferimentos/microbiologia
16.
Chemphyschem ; 21(5): 406-414, 2020 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-31943647

RESUMO

Fluorescence dynamics of gold nanoclusters (Au9 and Au25 ) are studied in the complex and crowded environment of a triblock co-polymer (F127) hydrogel and inside cervical cancer cell, HeLa. In the hydrogel, spherical micelles of F127 remain immobilized with a hydrophobic core (PPO) and a hydrophilic corona (PEO) region. The fluorescence anisotropy decay suggests that the timescale of rotational relaxation in the hydrogel is similar to that in bulk water (viscosity ∼1 cP). From fluorescence correlation spectroscopy (FCS) it is inferred that the local viscosity in the hydrogel is 12 cP for Au9 and 18 cP for Au23 . These results indicate that gold nanoclusters (AuNCs) localize in the corona region of the hydrogel. Evidently, frictions against rotation and translation are different inside the gel. It is suggested that rotation of the AuNCs senses the immediate water-like "void" region while translation motion involves in-and-out movement of the AuNCs at the periphery of the gel. Finally, the gold nanoclusters are used for cell imaging and estimation of intracellular viscosity of HeLa cells.


Assuntos
Corantes Fluorescentes/química , Ouro/química , Hidrogéis/química , Nanopartículas Metálicas/química , Imagem Óptica , Polímeros/química , Anisotropia , Células HeLa , Humanos , Espectrometria de Fluorescência , Viscosidade
17.
Plast Reconstr Surg ; 145(2): 433-443, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31985637

RESUMO

BACKGROUND: This study explored the effect of a single local intraosseous application of a small dose of simvastatin on the wound healing process in type 1 diabetic rats and related mechanisms. METHODS: The authors chose the streptozotocin-induced type 1 diabetic rat to establish a full-thickness dermal wound using a 12-mm-diameter sterile disposable punch. The rats (n = 32) were divided randomly into four groups: (1) normal control rats, (2) type 1 diabetic rats with intraosseous injection of hydrogel vehicle, (3) type 1 diabetic rats with intraosseous injection of simvastatin (0.5 mg), and (4) type 1 diabetic rats with intragastric administration of simvastatin (20 mg/kg per day). Wound closure was followed by digital planimetry. Mobilization of endothelial progenitor cells into the circulatory system was studied using fluorescence-activated cell sorting. Neovascularization was analyzed with immunofluorescence histochemical staining. The relative levels of adiponectin and stromal cell-derived factor 1 (SDF-1) in serum, bone, and wound tissues were examined by enzyme-linked immunosorbent assay and Western blot. RESULTS: Diabetic rats exhibited impaired wound healing. Intraosseous administration of simvastatin accelerated wound healing beginning at day 4, and angiogenesis was more obvious than in the control group. Enzyme-linked immunosorbent assay revealed that adiponectin concentrations in the diabetic rats with intraosseous injection of hydrogel vehicle plus simvastatin 0.5-mg group were significantly higher compared with the diabetic rats with intraosseous injection of hydrogel vehicle group beginning at day 4. Intraosseous administration of simvastatin decreased the expression of adiponectin and SDF-1 in bone tissue but enhanced the expression of adiponectin in wounded skin. CONCLUSIONS: A single local intraosseous application of simvastatin promotes wound healing in type 1 diabetic rat. The underlying mechanisms may be attributed to the regulation of the adiponectin/SDF-1 pathway, which plays a pivotal role in endothelial progenitor cell mobilization and angiogenesis.


Assuntos
Indutores da Angiogênese/farmacocinética , Células Progenitoras Endoteliais/efeitos dos fármacos , Sinvastatina/farmacologia , Cicatrização/efeitos dos fármacos , Adiponectina/metabolismo , Animais , Quimiocina CXCL12/metabolismo , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 1/fisiopatologia , Combinação de Medicamentos , Hidrogéis , Injeções , Masculino , Neovascularização Fisiológica/efeitos dos fármacos , Poloxâmero/administração & dosagem , Ratos Sprague-Dawley , Sinvastatina/administração & dosagem , Pele/metabolismo
18.
Chem Commun (Camb) ; 56(7): 1085-1088, 2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31894779

RESUMO

We report an elastase-responsive, H2S-releasing hydrogel prepared by covalently crosslinking a mixture of carboxymethylcellulose and poly(ethylene glycol) with an elastase-degradable peptide functionalized with an H2S-releasing S-aroylthiooxime (SATO) unit. Addition of elastase triggered a gel-to-sol transition, which exposed SATOs, leading to more and longer H2S release compared to untriggered gels.


Assuntos
Carboximetilcelulose Sódica/farmacologia , Hidrogéis/farmacologia , Sulfeto de Hidrogênio/metabolismo , Elastase de Leucócito/metabolismo , Polietilenoglicóis/farmacologia , Animais , Carboximetilcelulose Sódica/síntese química , Carboximetilcelulose Sódica/metabolismo , Linhagem Celular , Doxorrubicina/toxicidade , Humanos , Hidrogéis/síntese química , Hidrogéis/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Oximas/síntese química , Oximas/metabolismo , Oximas/farmacologia , Polietilenoglicóis/síntese química , Polietilenoglicóis/metabolismo , Substâncias Protetoras/síntese química , Substâncias Protetoras/metabolismo , Substâncias Protetoras/farmacologia , Ratos
19.
J Agric Food Chem ; 68(6): 1536-1545, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-31961689

RESUMO

In this work, an electrical-driven release and migration glyphosate (EDRMG) was fabricated using a nanocomposite made up of attapulgite (ATP), glyphosate (Gly), and calcium alginate (CA). Therein, ATP-CA acted as a nanonetwork-structured carrier to efficiently load plenty of Gly to form porous ATP-Gly-CA hydrogel spheres (actually EDRMG-0.5) via a cross-linking reaction. The pores in EDRMG-0.5 hydrogel spheres were enlarged under an electric field because of the Coulomb force of the anionic CA polymer, and the release of negatively charged Gly from the spheres could be driven by the electric field force. Thus, EDRMG-0.5 exhibited a great electroresponsively controlled-release property, which was confirmed by a pot experiment. Importantly, the EDRMG-0.5 hydrogel spheres had fine biocompatibility on fish and mice, displaying good biosafety. This work provides a low cost and promising approach to control Gly release, deliver Gly precisely, and improve utilization efficiency, which might have a high application value.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Glicina/análogos & derivados , Herbicidas/química , /química , Alginatos/química , Animais , Portadores de Fármacos/química , Composição de Medicamentos , Sistemas de Liberação de Medicamentos/economia , Sistemas de Liberação de Medicamentos/instrumentação , Eletricidade , Peixes , Glicina/química , Hidrogéis/química , Compostos de Magnésio/química , Camundongos , Compostos de Silício/química
20.
Chemosphere ; 241: 125110, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31683441

RESUMO

Inorganic-organic composite hydrogels have attracted much attention in recent years. In this study, an amino-functionalized graphene/alginate double-network hydrogel (NH2-DN) with excellent mechanical and adsorption properties was successfully prepared. Triethylenetetramine (TETA) was used as a crosslinker which promotes random few-layer graphene sheets stacking and resulted in a reduced graphene oxide (rGO) network, containing mesopore and macropore structures on the hydrogel surface. Compared to single network hydrogel, enhanced thermal stability and mechanical properties were achieved in NH2-DN. The elasticity modulus was improved by approximately 3 times due to the formation of the double-network. More importantly, NH2-DN exhibited excellent adsorption properties for typical emerging contaminants (Cu2+ and ciprofloxacin (CIP)). Compared with that of an ordinary graphene/alginate single-network hydrogel (SN), the adsorption capacity of the NH2-DN for Cu2+ and CIP reached 153.91 mg g-1 and 301.36 mg g-1, respectively, which was increased by 130% and 182%, respectively. Adsorption isotherm and kinetic analyses reveal that the adsorption process of CIP onto the NH2-DN was dominated by chemical affinity. Adsorption properties were comprehensively examined, including the effects of the solid-liquid ratios, pH, and ionic strength. NH2-DN retained 94% of its adsorption capacity when the ionic strength was 0.5 mol L-1 and maintained at least 87% of its adsorption capacity in weak acidic and alkaline solutions. This novel amino-functionalized organic-inorganic hydrogel has great potential in environmental applications owing to its outstanding physicochemical, mechanical, and adsorption properties for emerging contaminants in wastewater.


Assuntos
Alginatos/química , Grafite/química , Hidrogéis/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Adsorção , Ciprofloxacino/química , Cobre/química , Cinética , Águas Residuárias/análise , Águas Residuárias/química , Poluentes Químicos da Água/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA