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1.
Int J Mol Sci ; 22(23)2021 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-34884873

RESUMO

The bioavailability of the antihypertensive drug valsartan can be enhanced by various microencapsulation methods. In the present investigation, valsartan-loaded polymeric nanoparticles were manufactured from Eudragit® RLPO using an emulsion-solvent evaporation method. Polyvinyl alcohol (PVA) was found to be a suitable stabilizer for the nanoparticles, resulting in a monodisperse colloid system ranging in size between 148 nm and 162 nm. Additionally, a high encapsulation efficiency (96.4%) was observed. However, due to the quaternary ammonium groups of Eudragit® RLPO, the stabilization of the dispersion could be achieved in the absence of PVA as well. The nanoparticles were reduced in size (by 22%) and exhibited similar encapsulation efficiencies (96.4%). This more cost-effective and sustainable production method reduces the use of excipients and their expected emission into the environment. The drug release from valsartan-loaded nanoparticles was evaluated in a two-stage biorelevant dissolution set-up, leading to the rapid dissolution of valsartan in a simulated intestinal medium. In silico simulations using a model validated previously indicate a potential dose reduction of 60-70% compared to existing drug products. This further reduces the expected emission of the ecotoxic compound into the environment.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Nanopartículas/química , Ácidos Polimetacrílicos/química , Valsartana/química , Valsartana/farmacocinética , Anti-Hipertensivos/química , Anti-Hipertensivos/farmacocinética , Liberação Controlada de Fármacos , Excipientes/química , Suco Gástrico , Humanos , Tamanho da Partícula , Álcool de Polivinil/síntese química
2.
Cell Mol Biol (Noisy-le-grand) ; 67(1): 58-63, 2021 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-34817367

RESUMO

Hyaluronic acid (HA) is one of the most attractive natural polymers employed in biomaterials with biological applications. This polysaccharide is found in different tissues of the body because it is a natural component of the extracellular matrix; furthermore, it has crucial functions in cell growth, migration, and differentiation. Since its biological characteristics, HA has been utilized for the new biomaterial's development for tissue engineering, such as hydrogels. These hydrophilic macromolecular networks have gained significant attention due to their unique properties, making them potential candidates to be applied in biomedical fields. Different mechanisms to obtain hydrogels have been described. However, the research of new non-toxic methods has been growing in recent years. In this study, we prepared a new hydrogel of HA and polyvinyl alcohol by the cost-effective technique of cross-linking by gamma irradiation. The hydrogel was elaborated for the first time and was characterized by several methods such as Fourier Transform Infrared Spectroscopy, Differential Scanning Calorimetry, Thermogravimetric Analysis, and Scanning Electron Microscopy. Likewise, we evaluated the cytotoxicity of the biomaterial and its influence on cell migration in human fibroblasts. Furthermore, we provide preliminary evidence of the wound closure effect in a cellular wound model. The novel hydrogel offers an increase of HA stability with the potential to expand the useful life of HA in its different medical applications.


Assuntos
Materiais Biocompatíveis/efeitos da radiação , Raios gama , Ácido Hialurônico/efeitos da radiação , Polímeros/efeitos da radiação , Álcool de Polivinil/efeitos da radiação , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/farmacologia , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Humanos , Ácido Hialurônico/síntese química , Ácido Hialurônico/ultraestrutura , Microscopia Eletrônica de Varredura , Modelos Químicos , Estrutura Molecular , Polímeros/síntese química , Polímeros/farmacologia , Álcool de Polivinil/síntese química , Álcool de Polivinil/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Engenharia Tecidual/métodos
3.
Sci Rep ; 11(1): 11404, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34075116

RESUMO

A series of ZnO and ZnO/poly(vinyl alcohol) (PVA) catalysts were prepared using sol-gel method. An X-ray diffraction analysis confirmed the existence of the wurtzite ZnO phase, and scanning electron microscopy (SEM) observation revealed the formation of spherical ZnO and ZnO/PVA nanoparticles. The decomposition of methylene blue (MB) and methyl orange (MO) induced by the synthesized pure ZnO and ZnO/PVA nanoparticles was studied under ultraviolet-visible irradiation. Among the catalysts evaluated, ZnO/5PVA was the most active in the decomposition of MB, whereas ZnO/7PVA was the most active catalyst in the decomposition of MO. Moreover, an investigation of the biological activity of pure ZnO and ZnO/PVA indicated that ZnO/5PVA exhibited the best performance in lowering the glucose level in diabetic rats.


Assuntos
Hipoglicemiantes/síntese química , Hipoglicemiantes/farmacologia , Luz , Nanopartículas/química , Álcool de Polivinil/síntese química , Óxido de Zinco/síntese química , Ácidos , Animais , Glicemia/metabolismo , Catálise/efeitos da radiação , Azul de Metileno/química , Azul de Metileno/efeitos da radiação , Álcool de Polivinil/farmacologia , Ratos , Espectrofotometria Ultravioleta , Temperatura , Difração de Raios X , Óxido de Zinco/farmacologia
4.
Int J Mol Sci ; 22(8)2021 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-33918892

RESUMO

Various hydrogel systems have been developed as biomaterial inks for bioprinting, including natural and synthetic polymers. However, the available biomaterial inks, which allow printability, cell viability, and user-defined customization, remains limited. Incorporation of biological extracellular matrix materials into tunable synthetic polymers can merge the benefits of both systems towards versatile materials for biofabrication. The aim of this study was to develop novel, cell compatible dual-component biomaterial inks and bioinks based on poly(vinyl alcohol) (PVA) and solubilized decellularized cartilage matrix (SDCM) hydrogels that can be utilized for cartilage bioprinting. In a first approach, PVA was modified with amine groups (PVA-A), and mixed with SDCM. The printability of the PVA-A/SDCM formulations cross-linked by genipin was evaluated. On the second approach, the PVA was functionalized with cis-5-norbornene-endo-2,3-dicarboxylic anhydride (PVA-Nb) to allow an ultrafast light-curing thiol-ene cross-linking. Comprehensive experiments were conducted to evaluate the influence of the SDCM ratio in mechanical properties, water uptake, swelling, cell viability, and printability of the PVA-based formulations. The studies performed with the PVA-A/SDCM formulations cross-linked by genipin showed printability, but poor shape retention due to slow cross-linking kinetics. On the other hand, the PVA-Nb/SDCM showed good printability. The results showed that incorporation of SDCM into PVA-Nb reduces the compression modulus, enhance cell viability, and bioprintability and modulate the swelling ratio of the resulted hydrogels. Results indicated that PVA-Nb hydrogels containing SDCM could be considered as versatile bioinks for cartilage bioprinting.


Assuntos
Materiais Biocompatíveis , Bioimpressão , Álcool de Polivinil , Impressão Tridimensional , Engenharia Tecidual , Alicerces Teciduais , Animais , Bioimpressão/métodos , Matriz Óssea , Cartilagem/química , Bovinos , Técnicas de Cultura de Células , Técnicas de Química Sintética , Reagentes de Ligações Cruzadas , Matriz Extracelular , Hidrogéis/química , Ressonância Magnética Nuclear Biomolecular , Álcool de Polivinil/síntese química , Álcool de Polivinil/química
5.
Carbohydr Polym ; 263: 117993, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33858580

RESUMO

For skin contact medical devices, realizing a strong contact with skin is essential to precisely detect human biological information and enable human-machine interaction. In this study, we aimed to fabricate and characterize an inclusion complex film (ICF) for skin adhesion using α-cyclodextrin (α-CD) and nonanyl group-modified PVA (C9-PVA) under wet conditions. Based on the water insolubility of C9-PVA and the inclusion ability of α-CD for alkyl groups, α-CD/C9-PVA ICF was prepared. Among the prepared ICFs, α-CD/2.5C9-PVA (w/w = 0.5) ICF showed the highest bonding strength and T-peeling strength to porcine skin. Furthermore, α-CD/2.5C9-PVA (w/w = 0.5) ICF had better water vapor transmission rate than that of commercial tapes. In addition, the ion permeability test revealed that α-CD/2.5C9-PVA (w/w = 0.5) ICF exhibited excellent Na and Cl ion permeability. These results demonstrated that the multi-functional α-CD/2.5C9-PVA (w/w = 0.5) ICF can be a promising adhesive for skin contact medical devices.


Assuntos
Adesivos/química , Álcool de Polivinil/química , Pele , alfa-Ciclodextrinas/química , Adesivos/síntese química , Animais , Íons/metabolismo , Permeabilidade , Platina/química , Álcool de Polivinil/análogos & derivados , Álcool de Polivinil/síntese química , Proteínas/metabolismo , Solução Salina/química , Suínos , Tecnologia Farmacêutica/métodos , Água/química
6.
Carbohydr Polym ; 261: 117875, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33766362

RESUMO

Hydrogels are three-dimensional polymeric networks capable of absorbing large amounts of water or biological fluids with the properties resembling natural living tissues. Herein, polyvinyl alcohol (PVA)/N-succinyl chitosan (NSCS)/lincomycin hydrogels for wound dressing were prepared by the freezing/thawing method, then characterized by FTIR, SEM, and TGA. The compression strength, swelling behavior, water retention capacity, antibacterial activity, drug release and cytotoxicity were systematically investigated. The results showed that the introduction of NSCS remarkably enhanced the swelling capacity, leading to the maximum swelling ratio of 19.68 g/g in deionized water. The optimal compression strength of 0.75 MPa was achieved with 30 % NSCS content.Additionally, the incorporation of lincomycin brought a remarkable antibacterial activity against both Escherichia coli and Staphylococcus aureus. Specifically, 77.71 % of Staphylococcus aureus was inhibited with 75 µg/mL lincomycin, while the MTT assay demonstrated the nontoxic nature of the composite hydrogels. In summary, this PVA/NSCS/lincomycin hydrogel showed promising potential for wound dressing.


Assuntos
Curativos Hidrocoloides , Quitosana/química , Lincomicina/administração & dosagem , Álcool de Polivinil/química , Cicatrização/efeitos dos fármacos , Antibacterianos/química , Antibacterianos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Quitosana/síntese química , Quitosana/farmacologia , Liberação Controlada de Fármacos , Células HaCaT , Humanos , Lincomicina/química , Lincomicina/farmacocinética , Teste de Materiais , Testes de Sensibilidade Microbiana , Álcool de Polivinil/síntese química , Álcool de Polivinil/farmacologia
7.
AAPS PharmSciTech ; 22(3): 109, 2021 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-33718994

RESUMO

Hydrogel wound dressings are highly effective in the therapy of wounds. Yet, most of them do not contain any active ingredient that could accelerate healing. The aim of this study was to prepare hydrophilic active dressings loaded with an anti-inflammatory compound - trans-resveratrol (RSV) of hydrophobic properties. A special attention was paid to select such a technological strategy that could both reduce the risk of irritation at the application site and ensure the homogeneity of the final hydrogel. RSV dissolved in Labrasol was combined with an aqueous sol of poly(vinyl) alcohol (PVA), containing propylene glycol (PG) as a plasticizer. This sol was transformed into a gel under six consecutive cycles of freezing (-80 °C) and thawing (RT). White, uniform and elastic membranes were successfully produced. Their critical features, namely microstructure, mechanical properties, water uptake and RSV release were studied using SEM, DSC, MRI, texture analyser and Franz-diffusion cells. The cryogels made of 8 % of PVA showed optimal tensile strength (0.22 MPa) and elasticity (0.082 MPa). The application of MRI enabled to elucidate mass transport related phenomena in this complex system at the molecular (detection of PG, confinement effects related to pore size) as well as at the macro level (swelling). The controlled release of RSV from membranes was observed for 48 h with mean dissolution time of 18 h and dissolution efficiency of 35 %. All in all, these cryogels could be considered as a promising new active wound dressings.


Assuntos
Criogéis/síntese química , Álcool de Polivinil/síntese química , Resveratrol/síntese química , Cicatrização , Antioxidantes/administração & dosagem , Antioxidantes/síntese química , Antioxidantes/farmacocinética , Curativos Hidrocoloides , Criogéis/administração & dosagem , Criogéis/farmacocinética , Álcool de Polivinil/administração & dosagem , Álcool de Polivinil/farmacocinética , Resveratrol/administração & dosagem , Resveratrol/farmacocinética , Resistência à Tração/efeitos dos fármacos , Resistência à Tração/fisiologia , Cicatrização/efeitos dos fármacos , Cicatrização/fisiologia
8.
J Biomed Mater Res A ; 109(7): 1160-1172, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-32985092

RESUMO

Novel poly(vinyl alcohol)/chondroitin sulfate (PVA/CS) composite hydrogels containing hydroxyapatite (HA) or Sr-doped HA (HASr) particles were synthesized by a freeze/thaw method and characterized aiming towards biomedical applications. HA and HASr were synthesized by a wet-precipitation method and added to the composite hydrogels in fractions up to 15 wt%. Physical-chemical characterizations of particles and hydrogels included scanning electron microscopy, energy-dispersive spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, thermogravimetry, porosity, compressive strength/elastic modulus, swelling degree, and cell viability. Particles were irregular in shape and appeared to have narrow size variation. The thermal behavior of composite hydrogels was altered compared to the control (bare) hydrogel. All hydrogels exhibited high porosity. HA/HASr particles reduced total porosity without reducing pore size. The mechanical strength was improved as the fraction of HA or HASr was increased. HASr particles led to a faster water uptake but did not interfere with the total hydrogel swelling capacity. In cell viability essay, increased cell growth (above 120%) was observed in all groups including the control hydrogel, suggesting a bioactive effect. In conclusion, PVA/CS hydrogels containing HA or HASr particles were successfully synthesized and showed promising morphological, mechanical, and swelling properties, which are particularly required for scaffolding.


Assuntos
Materiais Biocompatíveis/química , Sulfatos de Condroitina/química , Durapatita/química , Álcool de Polivinil/química , Estrôncio/química , Materiais Biocompatíveis/síntese química , Sulfatos de Condroitina/síntese química , Força Compressiva , Durapatita/síntese química , Módulo de Elasticidade , Álcool de Polivinil/síntese química , Porosidade , Termogravimetria
9.
Carbohydr Polym ; 254: 117427, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33357904

RESUMO

This paper reports a strategy for preparing polyether polyols from corn starch, with (i) a mixture of polyethylene glycol 400 and glycerin (7:3, w/w) as the liquefying solvent and (ii) a spent-coffee-derived solid-acid catalyst (SC-SAC) (1:10, w/w, SC-SAC/starch) at 433 K for 1.5 h, under which conditions the liquefaction yield exceeded 99 %. The SC-SAC was prepared via hydrothermal carbonization at 453 K for 12 h, followed by sulfonation with H2SO4 at 343 K for 10 h. The liquefied starch product (SLP) was then used to plasticize poly(vinyl alcohol) (PVA) films with various mixing ratios. The optimal 0.4 SLP/PVA blend film exhibited good mechanical properties (tensile strength 38.07 MPa, elongation at break 1199 %), good transparency, and excellent flexibility. The results highlight the possibility of using SLP/PVA films in the development of degradable packaging materials.


Assuntos
Café/química , Extratos Vegetais/química , Plastificantes/química , Polímeros/química , Álcool de Polivinil/síntese química , Amido/química , Zea mays/química , Biocatálise , Plásticos Biodegradáveis/química , Glicerol/química , Maleabilidade , Polietilenoglicóis/química , Embalagem de Produtos/métodos , Solventes/química , Resistência à Tração
10.
J Mater Chem B ; 8(48): 11010-11020, 2020 12 23.
Artigo em Inglês | MEDLINE | ID: mdl-33188676

RESUMO

Conductive hydrogels are capturing intensive attention for versatile applications in flexible wearable devices on account of their unique combination of softness, stretchability, conductivity and biocompatibility. However, most of the hydrogel sensors can only serve as single-type sensors to detect strain or pressure, accompanied by a limited detection range. Moreover, the poor anti-freezing performance is also a serious problem to be addressed for their practical applications. Herein, a multi-model, large range and anti-freezing hydrogel sensor was constructed from a high-mechanical and ionic conductive multi-crosslinked poly(vinyl alcohol) (M-PVA) hydrogel, which was prepared via incorporating chain entanglement interaction and complexation between Fe3+ ions and hydroxyl groups into the microcrystalline network through immersion treatment in Fe2(SO4)3 solution. The three reversible and reconstructable crosslinks within the M-PVA hydrogel worked in tandem to achieve ultra-stretchability (1120%), supercompressibility (98%), high toughness, fast self-recoverability and excellent fatigue resistance. Meanwhile, the introduction of Fe3+ and SO42- ions endowed the M-PVA hydrogel with good ionic conductivity and remarkable anti-freezing properties (-50 °C), which benefited the M-PVA hydrogel to act as a freezing-tolerant dressing. The assembled multi-model hydrogel sensor can sensitively and stably detect large range elongation (∼900%), compression (∼70%), bend and pressure (up to 4.60 MPa) concurrently, as well as various human activities including speaking, finger bending and treading behavior. Notably, the hydrogel sensor was capable of maintaining excellent mechanical flexibility and sensitive sensing capacity at low temperature. The M-PVA hydrogel is a promising flexible sensing material for versatile applications in ionic skin, motion recognition and intelligent wearable devices.


Assuntos
Congelamento/efeitos adversos , Movimento (Física) , Álcool de Polivinil/síntese química , Dispositivos Eletrônicos Vestíveis , Animais , Humanos , Masculino , Ratos , Ratos Sprague-Dawley , Estresse Mecânico
11.
J Mater Chem B ; 8(46): 10549-10558, 2020 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-33125024

RESUMO

Conductive hydrogel-based epidermal strain sensors can generate repeatable electrical changes upon mechanical deformations for indication of the skin's physiological condition. However, this remains challenging for many conductive hydrogel sensors due to biomechanical mismatch with skin tissues and an unstable resistance variation response, resulting in non-conformable deformations with the epidermis and dermis, and consequently generating inaccurate monitoring of human movements. Herein, a conductive hydrogel that highly matches the skin is fabricated from dynamically hydrogen-bonded nanocrystallites of polydopamine-modified reduced graphene oxide (PDA-rGO) nanosheets composited with polyvinyl alcohol, namely the PDA-rGO/PVA hydrogel. PDA-rGO provides a large number of dynamic hydrogen-bonding interactions in the hydrogel, resulting in a skin-matching modulus (78 kPa) and stretchability. Moreover, the resultant hydrogel possesses excellent cytocompatibility and conductivity (0.87 S m-1), high sensitivity (gauge factor of compression: 20) at low strain and outstanding linearity at high strain as well as a stable resistance variation response. These desirable properties enable the application of the PDA-rGO/PVA hydrogel as a skin-friendly wearable sensor for real-time and accurate detection of both large-scale joint movements and tiny physiological signals, including the bending and relaxing of fingers, the wrist, elbow and knee joints, and wrist pulse and swallowing. Moreover, this hydrogel is integrated into a 2D sensor array that monitors strains or pressures in two dimensions, which is promising for electronic skin, biosensors, human-machine interfaces, and wearable electronic devices.


Assuntos
Grafite/química , Hidrogéis/química , Monitorização Fisiológica/métodos , Movimento/fisiologia , Álcool de Polivinil/química , Dispositivos Eletrônicos Vestíveis , Animais , Materiais Biomiméticos/síntese química , Materiais Biomiméticos/química , Materiais Biomiméticos/toxicidade , Força Compressiva , Deglutição , Condutividade Elétrica , Grafite/síntese química , Grafite/toxicidade , Humanos , Hidrogéis/síntese química , Hidrogéis/toxicidade , Indóis/síntese química , Indóis/química , Indóis/toxicidade , Células-Tronco Mesenquimais/efeitos dos fármacos , Monitorização Fisiológica/instrumentação , Polímeros/síntese química , Polímeros/química , Polímeros/toxicidade , Álcool de Polivinil/síntese química , Álcool de Polivinil/toxicidade , Ratos , Estresse Mecânico
12.
Int J Biol Macromol ; 165(Pt A): 902-917, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33011256

RESUMO

Polypropylene (PP) meshes are the most widely used as hernioplasty prostheses. As far as hernia repair is concerned, bacterial contamination and tissue adhesion would be the clinical issues. Moreover, an optimal mesh should assist the healing process of hernia defect and avoid undesired prosthesis displacements. In this present study, the commercial hernia mesh was modified to solve the mentioned problems. Accordingly, a new bi-functional PP mesh with anti-adhesion and antibacterial properties on the front and adhesion properties (reduce undesired displacements) on the backside was prepared. The backside of PP mesh was coated with polycaprolactone (PCL) nanofibers modified by mussel-inspired L-3,4-dihydroxyphenylalanine (L-DOPA) bioadhesive. The front side was composed of two different nanofibrous mats, including hybrid and two-layered mats with different antibacterial properties, drug release, and biodegradation behavior, which were based on PCL nanofibers and biomacromolecule carboxyethyl-chitosan (CECS)/polyvinyl alcohol (PVA) nanofibers containing different ofloxacin amounts. The anti-adhesion, antibacterial, and biocompatibility studies were done through in-vitro experiments. The results revealed that DOPA coated PCL/PP/hybrid meshes containing ofloxacin below 20 wt% possessed proper cell viability, AdMSCs adhesion prevention, and excellent antibacterial efficiency. Moreover, DOPA modifications not only enhanced the surface properties of the PP mesh but also improved cell adhesion, spreading, and proliferation.


Assuntos
Quitosana/química , Hérnia/tratamento farmacológico , Nanofibras/química , Ofloxacino/química , Animais , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Quitosana/síntese química , Quitosana/farmacologia , Di-Hidroxifenilalanina/química , Di-Hidroxifenilalanina/farmacologia , Hérnia/patologia , Herniorrafia/métodos , Humanos , Camundongos , Ofloxacino/farmacologia , Poliésteres/química , Poliésteres/farmacologia , Polipropilenos/química , Polipropilenos/farmacologia , Álcool de Polivinil/síntese química , Álcool de Polivinil/química , Próteses e Implantes
13.
Int J Biol Macromol ; 163: 2236-2247, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32931835

RESUMO

Nanocomposite hydrogel film was prepared from Polyvinyl alcohol [PVA], Corn Starch [CS], Linseed oil polyol [LP], and silver nanoparticles [NP]. LP was prepared by epoxidation and hydration of Linseed oil [LO]. IR and NMR supported the insertion of hydroxyl groups in LP by epoxide ring opening reaction at epoxidized LO. Silver NP were biosynthesized using aqueous leaves' extract from locally grown Ocimum forsskaolii Benth [LEO] plant. FTIR, XRD, UV and TEM confirmed the synthesis of NP (size 30 to 39 nm). Transparent and foldable hydrogel film resulted by blending the constituents (PVA, CS, LP and NP), crosslinking by glutaraldehyde, at room temperature, and showed expansion in water, different pH solutions, biodegradation and good antibacterial and antifungal activity against tested microbes. Linseed polyol influenced the structure, morphology, hydrophilicity, improved swelling ability and thermal stability and accelerated biodegradation of hydrogel films. NP were well adhered to LP globules that were embedded in PVA/CS matrix as strung set of beads (LP globules) decorated with black pearls (spherical NP). Silver NP conferred antimicrobial behavior to hydrogel film as observed by antimicrobial screening on different microbes. The results were encouraging and showed that such hydrogel films may find prospective applications in antimicrobial packaging.


Assuntos
Antibacterianos/química , Nanopartículas Metálicas/química , Polímeros/química , Álcool de Polivinil/química , Antibacterianos/síntese química , Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Linho/química , Óleo de Semente do Linho , Nanocompostos/química , Polímeros/síntese química , Álcool de Polivinil/síntese química , Álcool de Polivinil/farmacologia , Prata/química , Amido/química , Zea mays/química
14.
Dalton Trans ; 49(32): 11226-11237, 2020 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-32756631

RESUMO

There are still some key problems in the process of the flame retardant treatment of poly vinyl alcohol (PVA): poor compatibility, deteriorating mechanical properties and potential toxicity to human health and environment. To solve these issues, a green and eco-friendly bio-based polyelectrolyte complex (PEC) formed by chitosan and phytic acid was designed to enhance the flame retardant and mechanical properties of PVA by a facile ultrasonic-assisted solution blending method. Moreover, the mechanical and flame retardant properties could be regulated by varying the ratio of each component in the PEC. Thermogravimetric analysis (TGA) indicated that after the introduction of PEC, PVA/PEC composites maintained better thermal stability and char formation ability. Besides, when the addition of PEC reached 20 wt%, the limited oxygen index (LOI) value of cured PVA increased from 18% to 25.9%, 30.8% and 35.6% for PVA/20(2 : 1) PEC, PVA/20(1 : 2) PEC and PVA/20(1 : 8) PEC, respectively. Moreover, UL-94 V-0 rating was achieved except for the PVA/20(2 : 1) PEC. Compared with pure PVA, the peak heat release rate (pHRR) and the total heat release (THR) of PVA/20(1 : 8) PEC demonstrated a sharp decrease by 69.9% and 45.5%, respectively, in the microscale combustion calorimeter measurements (MCC). These results indicate that PEC can endow PVA with excellent flame retardancy. Furthermore, the microscopic investigations on char residues of all samples by scanning electron microscopy, Fourier transform infrared spectra and Raman spectroscopy revealed the possible flame retardant mechanisms in condensed and gaseous phases. In addition, PVA/PEC composites have better mechanical properties owing to their harder backbones of chitosan, formation of phosphonate bonds and the PVA molecular chain movement blocked by PEC. As a result, the facile processing technology and eco-friendly flame retardants are expected to be applied in practice.


Assuntos
Quitosana/química , Ácido Fítico/química , Polieletrólitos/síntese química , Álcool de Polivinil/síntese química , Calorimetria , Estrutura Molecular , Tamanho da Partícula , Polieletrólitos/química , Álcool de Polivinil/química , Espectroscopia de Infravermelho com Transformada de Fourier
15.
J Mater Chem B ; 8(19): 4340-4356, 2020 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-32363370

RESUMO

One of the long-standing challenges in materials science involves synthesizing biomaterials that recapitulate important features of native biological tissues. Even though, the number of available biomaterials at the moment are virtually limitless, few of them has unlocked all the secrets of the human body by mimicking the combinatorial-like material properties of our tissues and organs. Inspired by the human body, we have developed a polymeric gum, which combines stretchability, toughness, strength, flexibility, and self-healing. It also exhibits a high bioactivity that can target and eliminate bacterial infections fast and reliably. Notably, this material is moldable into almost any complex shape, and therefore suitable as a building block for wearables designed to conform directly with the curved and personalized anatomy of patients. It also exhibits excellent drug retention and release capacity, which altogether makes it suitable for applications in personalized wearable drug-delivery devices.


Assuntos
Materiais Biocompatíveis/farmacologia , Sistemas de Liberação de Medicamentos , Álcool de Polivinil/farmacologia , Taninos/farmacologia , Dispositivos Eletrônicos Vestíveis , Cicatrização/efeitos dos fármacos , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Humanos , Teste de Materiais , Estrutura Molecular , Tamanho da Partícula , Álcool de Polivinil/síntese química , Álcool de Polivinil/química , Propriedades de Superfície , Taninos/síntese química , Taninos/química
16.
17.
Macromol Rapid Commun ; 41(10): e2000038, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32285525

RESUMO

Streoregular poly(vinyl alcohol) is hard to obtain because vinyl alcohol is unstable relative to its tautomer acetaldehyde, and the monomer precursor vinyl ester is poisonous to the coordination catalyst. Herein, the coordination polymerization of 2-vinyl-2,1-borazanaphthalene (BN2VN) is reported by the linked or unlinked half-sandwich ligands attached scandium precursors ((FluSiMe3 )Sc(CH2 SiMe3 )2 (THF) (THF = tetrahydrofuran, 1), (FluCH2 CH2 -NHC-R)Sc(CH2 SiMe3 )2 (THF) (R = mesityl 2, i Pr 3, Me 4), and (FluCH2 Py)Sc(CH2 SiMe3 )2 (5) for the first time. Among these precursors, complex 5 converts 600 equivalents of BN2VN into polymer within 5 min to reach an activity as high as 8.99 × 105 g molSc -1 h-1 . The resultant products show excellent syndiotacticity and melting temperatures above 300 °C, which can be transferred to syndiotactic poly(vinyl alcohol) with 90% rr triad content by postpolymerization oxidation.


Assuntos
Naftalenos/química , Álcool de Polivinil/síntese química , Complexos de Coordenação/química , Estrutura Molecular , Polimerização , Álcool de Polivinil/química , Escândio/química , Estereoisomerismo
18.
J Sep Sci ; 43(11): 2105-2114, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32135026

RESUMO

Cell membrane chromatography is a powerful tool for screening active components from complex matrices. New cell membrane carriers need to be developed to increase the coverage of cell membranes on the surface of stationary phases, thereby improving cell membrane chromatographic retention. In this work, we prepared polyvinyl alcohol-poly dimethyl diallyl ammonium chloride modified silica gel as a cell membrane carrier. Osteoblast cell was used as cell membrane source, which was widely used to evaluate the osteogenic activity of drugs. The new cell membrane chromatographic stationary phase was used to screen anti-osteoporosis components in Liuwei Dihuang decoction-containing serum. The chemical structures of the new modified materials were characterized by scanning electronic microscopy, Fourier transform infrared spectroscopy, and elemental analysis characterization. Compared with the common cell membrane column, the cell membrane coverage of this modified material was increased by 30%, and thus provided a stronger retention effect in positive drugs. Nineteen metabolites in rat serum samples were retained on the cell membrane chromatography and identified by ultra-high-performance liquid chromatography/time-of-flight mass spectrometry. Among those, four components (morroniside, catalpol, loganin, and acteoside) were selected for in vitro pharmacodynamics validation. They significantly increased the osteoblast proliferation. The new modified material was successfully applied to screen anti-osteoporosis components from Liuwei Dihuang Decoction-containing serum.


Assuntos
Membrana Celular/efeitos dos fármacos , Medicamentos de Ervas Chinesas/farmacologia , Osteoporose/tratamento farmacológico , Extratos Vegetais/farmacologia , Álcool de Polivinil/química , Administração Oral , Animais , Membrana Celular/química , Proliferação de Células/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Medicamentos de Ervas Chinesas/administração & dosagem , Medicamentos de Ervas Chinesas/análise , Medicamentos de Ervas Chinesas/química , Espectrometria de Massas , Medicina Tradicional Chinesa , Osteoblastos/efeitos dos fármacos , Extratos Vegetais/administração & dosagem , Extratos Vegetais/sangue , Álcool de Polivinil/síntese química , Ratos
19.
Colloids Surf B Biointerfaces ; 188: 110777, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32004905

RESUMO

Hydrogel-based cleaning of paper artworks is an increasingly widespread process in the cultural heritage field. However, the search for tuned (compatible, highly retentive and not perishable) hydrogels is a challenging open question. In this paper, a complete characterization of chemical hydrogels based on polyvinyl alcohol (PVA) crosslinked with telechelic PVA and their remarkable performances as gels for cleaning paper artworks are reported. The rheological properties, porosity, water content of these gels were determined and analyzed as a function of the components concentration during synthesis. Due mechanical and retentive properties, the reported gels are optimum candidates for paper cleaning applications. The efficacy of these PVA-based gels has been demonstrated applying them on the surface of the sheets of several paper artworks, and characterizing the samples before and after the cleaning process by means of a multidisciplinary approach involving spectroscopic and chromatographic tests.


Assuntos
Materiais Biocompatíveis/química , Álcool de Polivinil/química , Materiais Biocompatíveis/síntese química , Concentração de Íons de Hidrogênio , Teste de Materiais , Tamanho da Partícula , Álcool de Polivinil/síntese química , Propriedades de Superfície
20.
Int J Biol Macromol ; 149: 1262-1274, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32044364

RESUMO

Limitation of antibacterial activity, low water vapour, oxygen permeation and mechanical strength are the disadvantages of existing wound dressings. The present research is focused on synthesis of Polyvinyl alcohol (PVA) and Chitosan (CH) hydrogels using freeze thaw process. The formation of AgNPs and PVA/CH hydrogels was confirmed by UV spectroscopy, particle size, morphology, spectral analysis, swelling studies, and in-vitro drug release studies. The particle size of AgNPs was found to be in the range of 20-35 nm with an intense peak at 430 nm. The results of spectral peaks showed that PVA/CH blend maintains characteristics peak of -OH and -NH in the spectrum with higher intensity. The morphology and tensile strength of hydrogels showed a wrinkled surface with an increase in force and extension values from 0.49 to 11.15 N and 45 to 129 mm, respectively. A controlled release of 84.3% (28 h) of Ocimum sanctum extract was noticed from hydrogel discs which scavenges 69.2% of free radicals as compared to raw extract 82.5% (16 h) which scavenges 63.1% of free radicals, respectively. The results of zone of inhibition (ZOI) against gram +ve and gram -ve bacteria was found to be 9.3 mm and 6.3 mm, respectively.


Assuntos
Antibacterianos/síntese química , Antibacterianos/farmacologia , Quitosana/síntese química , Reagentes de Ligações Cruzadas/química , Nanopartículas Metálicas/química , Álcool de Polivinil/síntese química , Álcool de Polivinil/farmacologia , Prata/farmacologia , Liberação Controlada de Fármacos , Escherichia coli/efeitos dos fármacos , Sequestradores de Radicais Livres/farmacologia , Nanopartículas Metálicas/ultraestrutura , Testes de Sensibilidade Microbiana , Ocimum sanctum/química , Tamanho da Partícula , Espectrofotometria Atômica , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus/efeitos dos fármacos , Eletricidade Estática , Vapor , Estresse Mecânico , Termogravimetria
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