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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 303: 123190, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37499474

RESUMO

Gold (Au) nano-island arrays were deposited on the glass substrate to fabricate surface-enhanced Raman scattering (SERS) substrates by in-situ thermal evaporation (deposited and annealed samples at the same time). The optimal SERS intensity deposited by various thicknesses and in-situ annealing temperatures of Au nano-island arrays would be investigated. The biomolecules (adenine) were dropped on the well-designed SERS substrate for precise and quantitative SERS detection. The characterization of Au nano-island arrays SERS substrate would be evaluated by scanning electron microscope (SEM) and Raman spectroscopy. The results showed that the optimal deposition thickness and annealing temperature of Au nano-island arrays SERS substrate is about 14 nm and 200 °C respectively, which can construct the smallest interparticle spacing (W)/ particle diameter (D) ratio and the lowest reflection (%) and transmittance (%) to form the strongest SERS intensity. Moreover, finite-difference time-domain (FDTD) simulation of the electromagnetic field distributions on Au nano-island arrays displays the similar trend with the experimental results. The 14 nm deposition with 200 °C in-situ annealing temperature would display the highest density of hot-spots by FDTD simulation. The reproducible Au nano-island arrays SERS substrates with tunable surface roughness, W/D ratio, and lower reflection and transmittance show promising potential for SERS detection of biomolecules, bacteria, and viruses.

2.
J Nanosci Nanotechnol ; 12(6): 5066-70, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22905578

RESUMO

Novel amphipathic derivative of chitosan (carboxymethyl-hexanoyl chitosan, CHC) was made into mats of nanofibers (approximately 100 nm) via electrospinning. The resulting mats were further cross-linked with genipin. The morphology of CHC nanofibers was examined using a field emission scanning electron microscope (FESEM). The optimum parameters of CHC nanofiber was achieved when the CHC concentration was 4 wt% and electrospinning was conducted with a voltage of 20 kV over a distance of 10 cm. The characterizations of biocompatibility, hemocompatibility, and anti-bacterial activity of the nanofibers were also investigated. The results show that CHC nanofibers still preserved antibacterial activity and thrombogeneicity owing to those residual amino groups of chitosan and exhibit high biocompatibility for L929 fibroblast test. Thus CHC exhibited the potential to serve as a novel wound dressing and surgical implants application by these advanced features.


Assuntos
Fenômenos Fisiológicos Bacterianos/efeitos dos fármacos , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/farmacologia , Quitosana/química , Quitosana/farmacologia , Nanoestruturas/química , Próteses e Implantes , Antibacterianos/síntese química , Antibacterianos/farmacologia , Eletroquímica/métodos , Teste de Materiais , Nanoestruturas/administração & dosagem , Rotação
3.
Biomater Adv ; 139: 213008, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35882154

RESUMO

The use of microspheres for culturing adherent cells has been proven as an important method, allowing for obtaining adequate number of cells in limited space and volume of medium for the intended cell-based medical applications. However, the use of proteolytic enzymes for cell harvesting from the microsphere resulted in cell damage and loss of functionality. Therefore, in this study, we developed a novel redox/thermo-responsive dissolvable gelatin-based microsphere for successful cell proliferation and harvesting adequate high-quality cells using non-enzymatic cell detachment methods. Initially, a redox-induced dissolvable gelatin-based microsphere was successfully prepared using disulfide bonds as crosslinking agent, firmly stabilizing gelatin networks and forming a stable microsphere at physiological temperature. The optimized concentration of the crosslinking agent was 1.2 mM, which kept the microsphere stable for >120 h. The microsphere was then coated with PNIPAm-ALA copolymer via physical or chemical means, resulting in a positively charged thermosensitive surface. The positive charge derived from ALA in PNIPAm-ALA copolymer enhanced cell attachment, while the thermosensitive property of the copolymer enabled for temperature induced cell harvesting. When the temperature dropped below the LCST value of PNIPAm-ALA5 (33.4°C), the copolymer swelled and became more hydrophilic, allowing cells to be readily separated. The addition of reducing agents such as GSH, DTT and L-cysteine resulted in further cleavage of the disulfide bond in the microsphere and dissolution of the microsphere for complete cell detachment. Interestingly, cell attachment and proliferation were enhanced on microspheres coated with PNIPAm-ALA5 using diselenide as a crosslinking agent, and complete cell detachment was occurred within 15 min after adding 25 mM DTT followed by lowering the temperature (4°C). Therefore, the microsphere fabricated in this study was worthwhile for non-enzymatic cell detachment and has the potential to be used for cell expansion and harvesting adequate live cells of high quality and functionality for tissue engineering or cell therapy.


Assuntos
Gelatina , Polímeros , Dissulfetos , Gelatina/farmacologia , Microesferas , Oxirredução , Polímeros/química
4.
Spectrochim Acta A Mol Biomol Spectrosc ; 279: 121475, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-35696969

RESUMO

Thermo-responsive Raman-enhanced nanocapsules were successfully fabricated by Pluronic® F127 (F127) decorated with gold nanoparticles (AuNPs) for surface-enhanced Raman scattering (SERS) detection of biomolecules. F127 nanocapsules changes from hydrophilicity (swelling) to hydrophobicity (de-swelling) when the temperature increases from 15 °C to 37 °C, owing to the lower critical solution temperature (LCST) of F127 is about 26.5 °C. The size of nanocapsules would be enormous shrinking from 160 nm to 20 nm, resulting in a significant decrease in the distance between AuNPs to enhance hot spot effect, which increases the sensitivity of SERS detection. Based on the thermo-sensitive behavior, the ratio of AuNPs and F127 would be manipulated to find the optimal SERS enhancement effect. SERS nanocapsules can rapidly detect biomolecules (adenine and R6G) with limit of detection (LOD) lower than 10-6 M. In addition, the relatively difficult to detect clinical samples, carboxyl-terminal parathyroid hormone fragments (C-PTH), can also be measured by the thermo-responsive SERS nanocapsules developed in this work. It is expected the biomolecules can be adsorbed at low temperature (15 °C), as well as collected and concentrated at high temperature (37 °C) for SERS detection, to increase the sensitivity and stability of SERS detection.


Assuntos
Nanopartículas Metálicas , Nanocápsulas , Ouro , Poloxâmero , Polietilenos , Polipropilenos , Análise Espectral Raman/métodos
5.
Polymers (Basel) ; 14(12)2022 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-35746042

RESUMO

The flexible, anti-fouling, and bionic surface-enhanced Raman scattering (SERS) biochip, which has a Nepenthes peristome-like structure, was fabricated by photolithography, replicated technology, and thermal evaporation. The pattern of the bionic Nepenthes peristome-like structure was fabricated by two layers of photolithography with SU-8 photoresist. The bionic structure was then replicated by polydimethylsiloxane (PDMS) and grafting the zwitterion polymers (2-methacryloyloxyethyl phosphorylcholine, MPC) by atmospheric plasma polymerization (PDMS-PMPC). The phospholipid monomer of MPC immobilization plays an important role; it can not only improve hydrophilicity, anti-fouling and anti-bacterial properties, and biocompatibility, but it also allows for self-driving and unidirectional water delivery. Ag nanofilms (5 nm) were deposited on a PDMS (PDMS-Ag) substrate by thermal evaporation for SERS detection. Characterizations of the bionic SERS chips were measured by a scanning electron microscope (SEM), optical microscope (OM), X-ray photoelectron spectrometer (XPS), Fourier-transform infrared spectroscopy (FTIR), and contact angle (CA) testing. The results show that the superior anti-fouling capability of proteins and bacteria (E. coli) was found on the PDMS-PMPC substrate. Furthermore, the one-way liquid transfer capability of the bionic SERS chip was successfully demonstrated, which provides for the ability to separate samples during the flow channel, and which was detected by Raman spectroscopy. The SERS intensity (adenine, 10-4 M) of PDMS-Ag with a bionic structure is ~4 times higher than PDMS-Ag without a bionic structure, due to the multi-reflection of the 3D bionic structure. The high-sensitivity bionic SERS substrate, with its self-driving water capability, has potential for biomolecule separation and detection.

6.
Spectrochim Acta A Mol Biomol Spectrosc ; 281: 121578, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-35797953

RESUMO

In this study, the core-shell of Fe3O4-Au nanoparticles (NPs) were prepared by seeding AuNPs onto Fe3O4 NPs modified with poly-ethylenimine (PEI). Later, Fe3O4-Au NPs were attached to cationic poly(dimethyldiallylammonium chloride) (PDDA)-modified graphene oxide (GO) nanosheets through in situ self-assembly behaviors, termed as Fe3O4-Au@RGO nanocomposites, for surface-enhanced Raman scattering (SERS) detection and hyperthermia treatment of bacteria. The resulting Fe3O4-Au@RGO nanocomposites were evaluated systematically by transmission electron microscope, zeta potential, X-ray diffraction, X-ray photoelectron spectroscopy, and vibrating sample magnetometer. It revealed that the core-shell structured Fe3O4-Au NPs were dispersed homogeneously on the surface of the GO nanosheets. Furthermore, the rapid SERS detection for small biomolecules and bacteria was conducted by Raman spectroscopy. The results showed that the greatest SERS intensity was fne tuned at the weight ratio of Fe3O4-Au/RGO nanosheets was 20/1, displaying the optimal interparticle gap of AuNPs to induce the huge hot-spots effect. The magnetic inductive heating capability of Fe3O4-Au@RGO nanocomposites was produced under high frequency magnetic field exposure and can kill high than 90% of the bacteria at 10 min. Hence, the newly developed Fe3O4-Au@RGO nanocomposites were demonstrated to be viable for SERS detection of biomolecules and microbes and potential applications for magnetically capturing and hyperthermia treatment of bacteria.


Assuntos
Hipertermia Induzida , Nanopartículas Metálicas , Bactérias , Ouro/química , Grafite , Nanopartículas Metálicas/química , Análise Espectral Raman/métodos
7.
Colloids Surf B Biointerfaces ; 206: 111957, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34216853

RESUMO

Silicone hydrogel lenses were prepared by copolymerizing PDMS-PEGMA macromer (PGP) with various combinations of DMA, NVP, and PEGMA through UV initiated polymerization process. The resultant PGP macromer were characterized by gel permeation chromatography (GPC), and scanning electron microscope (SEM-EDS). Characterization of all the resultant co-polymers included Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), equilibrium water content (EWC), oxygen permeability (Dk), optical transparency, contact angle, mechanical properties, zeta potential, protein deposition, and cytotoxicity. The results show that higher content of hydrophilic polymers increased water uptake ability as well as improved hydrophilicity and modulus of silicone hydrogel lenses; however, oxygen permeability decreased with the decrease of PDMS content (145 barrers of PGP to 37 barrers of DP0). In addition, these silicone hydrogel lenses exhibited relatively optical transparency, anti-protein deposition, and non-cytotoxic according to an in vitro L929 fibroblast assay. Therefore, these silicone hydrogel polymers would be applicable for making contact lens.


Assuntos
Lentes de Contato Hidrofílicas , Lentes de Contato , Dimetilpolisiloxanos , Hidrogel de Polietilenoglicol-Dimetacrilato , Hidrogéis , Interações Hidrofóbicas e Hidrofílicas , Polímeros , Silicones
8.
Polymers (Basel) ; 12(6)2020 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-32531901

RESUMO

In this study, the epoxy powder was blended with graphene to improve its thermal conductivity and heat dissipation efficiency. The thermal conductivity of the graphene-loaded coating was increased by 167 folds. In addition, the emissivity of the graphene-loaded coating was 0.88. The epoxy powder was further coated on aluminum plate through powder coating process in order to study the effect on the performance of heat dissipation. In the case of natural convective heat transfer, the surface temperature of the graphene-loaded coated aluminum plate was 96.7 °C, which was 27.4 °C lower than that of bare aluminum plate (124.1 °C) at a heat flux of 16 W. In the case of forced convective heat transfer, the surface temperature decreased from 77.8 and 68.3 °C for a heat flux of 16 W. The decrease in temperature can be attributed to the thermal radiation. These results show that the addition of graphene nanoparticles in the coating can increase the emissivity of the aluminum plate and thus improving the heat dissipation.

9.
Polymers (Basel) ; 12(5)2020 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-32423074

RESUMO

In this study, silicone nanoparticles (SiNPs) were prepared from polydimethylsiloxane (PDMS) and tetraethyl orthosilicate (TEOS) via the sol-gel process. The resultant SiNPs were characterized by dynamic light scattering (DLS), transmission electron microscope (TEM), and scanning electron microscope (SEM). These SiNPs were then blended with 2-hydroxyethylmethacrylate (HEMA) and 1-vinyl-2-pyrrolidinone (NVP) before polymerizing into hydrogel contact lenses. All hydrogels were subject to characterization, including equilibrium water content (EWC), contact angle, and oxygen permeability (Dk). The average diameter of SiNPs was 330 nm. The results indicated that, with the increase of SiNPs content, the oxygen permeability increased, while the EWC was affected insignificantly. The maximum oxygen permeability attained was 71 barrer for HEMA-NVP lens containing 1.2 wt% of SiNPs with an EWC of 73%. These results demonstrate that by loading a small amount of SiNPs, the Dk of conventional hydrogel lenses can be improved greatly. This approach would be a new method to produce oxygen-permeable contact lenses.

10.
Colloids Surf B Biointerfaces ; 185: 110606, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31698265

RESUMO

This study demonstrated a novel injectable-thermoreversible hydrogel scaffold composing of PLuronic F127, carboxymethyl hexanoyl chitosan (CA) and glyoxal (Gx) for encapsulating human osteosarcoma MG-63 cells. The hydrogel was prepared by simply mixing CA, F127 and Gx. In so doing, this system exhibited short gelation time and higher gelation temperature. In addition, this hydrogel exhibited thermo-reversibility, that is, the hydrogel can liquefy at room temperature and revert to gel state at body temperature. The encapsulated cells in this hydrogel proliferated more than 400% in the 5-day incubation. Based on these results, these F127/CA/Gx hydrogels can be used to encapsulate cells for tissue engineering applications.


Assuntos
Células Imobilizadas/citologia , Quitosana/análogos & derivados , Hidrogéis/química , Injeções , Poloxâmero/química , Temperatura , Linhagem Celular Tumoral , Sobrevivência Celular , Quitosana/química , Glioxal/química , Humanos
11.
Polymers (Basel) ; 12(9)2020 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-32937918

RESUMO

This study presents a novel approach to increase the oxygen permeability of hydrogel by the addition of silica sol. Herein, 2-hydroxyethyl methacrylate (HEMA) was copolymerized with N-vinyl-2-pyrrolidone (NVP) after mixing with silica sol. The resultant hydrogel was subject to characterizations including Fourier-transform infrared (FTIR), equilibrium water content (EWC), contact angle, optical transmittance, oxygen permeability (Dk), tensile test, anti-deposition of proteins, and cytotoxicity. The results showed that with the increase of silica content, the Dk values and Young's moduli increased, the optical transmittance decreased slightly, whereas the EWC and contact angle, and protein deposition were not much affected. Moreover, the cytotoxicity of the resultant poly(HEMA-co-NVP)-SNPs indicated that the presence of silica sol was non-toxic and caused no effect to the growth of L929 cells. Thus, this approach increased the Dk of soft contact lenses without affecting their hydrophilicity.

12.
Nanomaterials (Basel) ; 10(4)2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-32260211

RESUMO

Magnetic reduced graphene oxide (MRGO) sheets were prepared by embedding Fe3O4 nanoparticles on polyvinylpyrrolidone (PVP) and poly(diallyldimethylammonium chloride) (PDDA)-modified graphene oxide (GO) sheets for bacteria capture and destruction under a high-frequency magnetic field (HFMF). The characteristics of MRGO sheets were evaluated systematically by transmission electron microscopy (TEM), scanning electron microscopy (SEM), zeta potential measurement, X-ray diffraction (XRD), vibrating sample magnetometry (VSM), and X-ray photoelectron spectroscopy (XPS). TEM observation revealed that magnetic nanoparticles (8-10 nm) were dispersed on MRGO sheets. VSM measurements confirmed the superparamagnetic characteristics of the MRGO sheets. Under HFMF exposure, the temperature of MRGO sheets increased from 25 to 42 °C. Furthermore, we investigated the capability of MRGO sheets to capture and destroy bacteria (Staphylococcus aureus). The results show that MRGO sheets could capture bacteria and kill them through an HFMF, showing a great potential in magnetic separation and antibacterial application.

13.
Polymers (Basel) ; 11(6)2019 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-31159172

RESUMO

In this study, silicone-based hydrogel contact lenses were prepared by the polymerization of 3-(methacryloyloxy)propyltris(trimethylsiloxy)silane (TRIS), N,N-dimethylacrylamide (DMA), 1-vinyl-2-pyrrolidinone (NVP), and 2-hydroxyethylmethacrylate (HEMA). The properties of silicone hydrogel lenses were analyzed based on the methods such as equilibrium water content, oxygen permeability, optical transparency, contact angle, mechanical test, protein adsorption, and cell toxicity. The results showed that the TRIS content in all formulations increased the oxygen permeability and decreased the equilibrium water content, while both DMA and NVP contributed the hydrophilicity of the hydrogels. The maximum value of oxygen permeability was 74.9 barrers, corresponding to an equilibrium water content of 44.5% as well as a contact angle of 82°. Moreover, L929 fibroblasts grew on all these hydrogels, suggesting non-cytotoxicity. In general, the silicone hydrogels in this work exhibited good oxygen permeability, stiffness, and optical transparency as well as anti-protein adsorption. Hence, these silicone hydrogel polymers would be feasible for making contact lens.

14.
Colloids Surf B Biointerfaces ; 173: 470-477, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30326363

RESUMO

To solve the thrombosis and restenosis problem in cardiovascular stent implantation for cardiovascular artery disease, chondroitin 6-sulfate (ChS) with heparin (HEP) have been used as drug carrier layers and alternatively covalently bonded on gold (Au)-dimercaptosuccinic acid (DMSA)-thiolized cardiovascular metallic (SUS316 L stainless steel, SS) stents. Sirolimus, a model drug, was encapsulated in the ChS-HEP alternative layers. The behavior of the drug in releasing and suppressing the growth of smooth-muscle cells (SMCs) was evaluated with 5-layer CHS-HEP coating on the SS stents. Moreover, hemocompatibility of blood clotting time and platelet adhesion was performed. The results showed that the 5-layer ChS-HEP-modified SS stents displayed the greatest hemocompatibility, showing prolonged blood clotting time of the activated partial thrombin time (> 500 s) and less platelet adhesion to reduce thrombosis. Furthermore, sirolimus can be released continuously for more than 40 days with the 5-layer ChS-HEP coating and is beneficial for inhibiting the growth of SMCs; however, it does not affect the proliferation of endothelial cells, which can avoid restenosis formation. Therefore, the multilayers of ChS-HEP grafted onto the Au-DMSA-cardiovascular SS stents provide high potential for use as drug eluting stents.


Assuntos
Sulfatos de Condroitina/química , Materiais Revestidos Biocompatíveis/química , Stents Farmacológicos , Ouro/química , Heparina/química , Sirolimo/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Materiais Revestidos Biocompatíveis/farmacologia , Composição de Medicamentos/métodos , Células Endoteliais da Veia Umbilical Humana/citologia , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/efeitos dos fármacos , Tempo de Tromboplastina Parcial , Adesividade Plaquetária/efeitos dos fármacos , Plasma Rico em Plaquetas , Sirolimo/química , Aço Inoxidável/química , Aço Inoxidável/farmacologia , Succímero/química
15.
Polymers (Basel) ; 11(9)2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31540544

RESUMO

In this study, a novel hemocompatible coating on stainless steel substrates was prepared by electrochemically copolymerizing 3,4-ethylenedioxythiophene (EDOT) with graphene oxide (GO), polystyrene sulfonate (PSS), or heparin (HEP) on SUS316L stainless steel, producing an anti-fouling (anti-protein adsorption and anti-platelet adhesion) surface to avoid the restenosis of blood vessels. The negative charges of GO, PSS, and HEP repel negatively charged proteins and platelets to achieve anti-fouling and anti-clotting. The results show that the anti-fouling capability of the poly(3,4-ethylenedioxythiophene) (PEDOT)/PSS coating is similar to that of the PEDOT/HEP coating. The anti-fouling capability of PEDOT/GO is higher than those of PEDOT/HEP and PEDOT/PSS. The reason for this is that GO exhibits negatively charged functional groups (COO-). The highest anti-fouling capability was found with the PEDOT/GO/HEP coating, indicating that electrochemical copolymerization of PEDOT with GO and HEP enhances the anti-fouling capability. Furthermore, the biocompatibility of the PEDOT coatings was tested with 3T3 cells for 1-5 days. The results show that all PEDOT composite coatings exhibited biocompatibility. The blood clotting time (APTT) of PEDOT/GO/HEP was prolonged to 225 s, much longer than the 40 s of pristine SUS316L stainless steel (the control), thus greatly improving the anti-blood-clotting capability of cardiovascular stents.

16.
Int J Pharm ; 346(1-2): 38-46, 2008 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-17662545

RESUMO

Aqueous mixture of beta-glucan and poly(vinyl alcohol) (PVA) was cast into films and dried at 110 degrees C without chemical crosslinking. The content of glucan in the film varied from 7% to 50%. The hydrophilicity of the resulting films was evaluated with swelling tests, wet area diffusion tests, and water vapor transmission tests. The swelling ratio, the wetting ratio, and the water vapor transmission rate increased with the glucan content. When contacting water, glucan was released, and the percent release of glucan increased with the glucan content. The addition of glucan made the film more ductile than pure PVA. The results of hemocompatibility test showed no significant effect on the activated partial thromboplastin time (APTT) and thrombin time (TT) and minor adsorption of human serum albumin (HSA). On observing the wound healing of rat skin, the healing time was shortened by 48% using PVA/glucan film comparing to cotton gauze. Therefore, a wound dressing made of PVA/glucan can greatly accelerate the healing without causing irritation.


Assuntos
Bandagens , Glucanos/química , Glucanos/farmacologia , Álcool de Polivinil/química , Cicatrização/efeitos dos fármacos , Adsorção , Animais , Sistemas de Liberação de Medicamentos , Glucanos/toxicidade , Cobaias , Humanos , Masculino , Tempo de Tromboplastina Parcial , Álcool de Polivinil/toxicidade , Ratos , Ratos Wistar , Albumina Sérica/química , Testes de Irritação da Pele , Resistência à Tração , Tempo de Trombina
17.
Colloids Surf B Biointerfaces ; 61(1): 43-52, 2008 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-17720460

RESUMO

A thin layer of gold was sputtered onto SUS316L stainless steel (SS) sheet. After thiolizing the Au layer with dimercaptosuccinic acid (DMSA), layers of chondroitin 6-sulfate (ChS) and heparin (HEP) were alternatively immobilized on the Au-treated SS. The resulting stent would be both anti-atherogenic and anti-thrombogenic. After repeating one to five cycles, one to five layers of polyelectrolyte complex (PEC) of ChS/HEP were successfully fabricated. A model drug, sirolimus, was loaded in the ChS/HEP layers. The SS-ChS-HEP surface was examined by X-ray photoelectron spectroscopy (XPS), contact angle, and atomic force microscopy (AFM) measurement. Biological tests including hemocompatibility, drug release pattern, and the inhibition of smooth muscle cell proliferation were also performed. The results show that the multilayer of ChS/HEP exhibits longer blood clotting time than pure SS substrates. Therefore, this biopolymer multilayer can avoid thrombosis on the stainless. The releasing rate of sirolimus can be controlled through the number of ChS/HEP PEC layers. With a five-layer coating, sirolimus can be released continuously for more than 20 days. Furthermore, the multilayer ChS/HEP loaded with sirolimus can suppress specifically to the growth of smooth muscle cells to avoid restenosis. This suggests that the PEC multilayer of ChS/HEP modified-SS could be applied in making drug-eluting stents.


Assuntos
Sulfatos de Condroitina/química , Stents Farmacológicos , Heparina/química , Aço Inoxidável/química , Absorciometria de Fóton , Testes de Coagulação Sanguínea , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Sulfatos de Condroitina/farmacologia , Endotélio Vascular/citologia , Desenho de Equipamento , Heparina/farmacologia , Humanos , Microscopia de Força Atômica , Sirolimo/química , Sirolimo/farmacologia , Succímero/química
18.
J Biomed Mater Res B Appl Biomater ; 83(1): 105-13, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17318824

RESUMO

The improvement of hydrophilicity and hemocompatibility of thermoplastic polyurethane (TPU) film was developed using surface modification of polyelectrolyte multilayers (PEMs) deposition. The polysaccharide PEMs included chitosan (CS, as a positive-charged agent) and dextran sulfate (DS, as a negative-charged and an antiadhesive agent) that were successfully prepared on the aminolyzed TPU film in a layer-by-layer (LBL) self-assembly manner. X-ray photoelectron spectroscopy (XPS), field-emission scanning electronic microscopy (FE-SEM), and atomic force microscopy (AFM) data will verify the progressive buildup of the PEMs film. The obtained results showed that the contact angle and Zeta-potential reached the steady value after four bilayers of coating, hence proving that the full coverage of coating with PEM layers was achieved. It could be found that the PEMs-deposited TPU films with DS as the outmost layer could resist the platelet adhesion and human plasma fibrinogen (HPF) adsorption, thereby prolonging effectively the blood coagulation times. Besides, the results of growth inhibition index (GI) of L929 fibroblast proliferation suggested that the as-fabricated TPU films were noncytotoxic. Overall results demonstrated that such an easy, valid, shape-independent, and noncytotoxic processing should be potential for the ion of TPU substrate in the application of hemodialysis or cardiovascular devices.


Assuntos
Materiais Revestidos Biocompatíveis/química , Plásticos/química , Adesividade Plaquetária , Poliuretanos/química , Linhagem Celular , Quitosana/química , Sulfato de Dextrana/química , Fibrinogênio/química , Humanos , Teste de Materiais , Estrutura Molecular , Diálise Renal , Propriedades de Superfície
19.
Colloids Surf B Biointerfaces ; 54(2): 222-9, 2007 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-17174535

RESUMO

The improvement of hydrophilicity and hemocompatibility of poly(tetramethylene adipate-co-terephthalate) (PTAT) membrane was developed via polyelectrolyte multilayers (PEMs) immobilization. The polysaccharide PEMs included chitosan (CS, as a positive-charged and antibacterial agent) and dextran sulfate (DS, as a negative-charged and anti-adhesive agent) were successfully prepared using the aminolyzed PTAT membrane in a layer-by-layer (LBL) self-assembly manner. The obtained results showed that the contact angle of as-modified PTAT membranes reached to the steady value after four bilayers of coating, hence suggesting that the full coverage was achieved. It could be found that the PTAT-PEMs membranes with DS as the outmost layer could resist the platelet adhesion and human plasma fibrinogen (HPF) adsorption, thereby prolonging effectively the blood coagulation times. According to L929 fibroblast cell growth inhibition index, the as-prepared PTAT membranes exhibited non-cytotoxic. Overall results demonstrated that such an easy, valid and shape-independent processing should be potential for surface modification of PTAT membrane in the application of hemodialysis devices.


Assuntos
Adipatos/química , Quitosana/química , Sulfato de Dextrana/química , Membranas Artificiais , Ácidos Ftálicos/química , Poliésteres/química , Ozônio
20.
Nanoscale Res Lett ; 12(1): 355, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28525950

RESUMO

Less targeted and limited solubility of hydrophobic-based drug are one of the serious obstacles in drug delivery system. Thus, new strategies to enhance the solubility of hydrophobic drug and controlled release behaviors would be developed. Herein, curcumin, a model of hydrophobic drug, has been loaded into PEGylated magnetic liposomes as a drug carrier platform for drug controlled release system. Inductive magnetic heating (hyperthermia)-stimulated drug release, in vitro cellular cytotoxicity assay of curcumin-loaded PEGylated magnetic liposomes and cellular internalization-induced by magnetic guidance would be investigated. The resultant of drug carriers could disperse homogeneously in aqueous solution, showing a superparamagnetic characteristic and could inductive magnetic heating with external high-frequency magnetic field (HFMF). In vitro curcumin release studies confirmed that the drug carriers exhibited no significant release at 37 °C, whereas exhibited rapid releasing at 45 °C. However, it would display enormous (three times higher) curcumin releasing under the HFMF exposure, compared with that without HFMF exposure at 45 °C. In vitro cytotoxicity test shows that curcumin-loaded PEGylated magnetic liposomes could efficiently kill MCF-7 cells in parallel with increasing curcumin concentration. Fluorescence microscopy observed that these drug carriers could internalize efficiently into the cellular compartment of MCF-7 cells. Thus, it would be anticipated that the novel hydrophobic drug-loaded PEGylated magnetic liposomes in combination with inductive magnetic heating are promising to apply in the combination of chemotherapy and thermotherapy for cancer therapy.

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