scholarly journals Emulsion Electrospinning as an Approach to Fabricate PLGA/Chitosan Nanofibers for Biomedical Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Fatemeh Ajalloueian ◽  
Hossein Tavanai ◽  
Jöns Hilborn ◽  
Olivier Donzel-Gargand ◽  
Klaus Leifer ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Composite Scaffold ◽  
Electrospun Nanofibers ◽  
Electrospinning Process ◽  
Culture Studies ◽  
Angle Measurements ◽  
Transmission Electron ◽  
Contact Angle Measurements ◽  
Fibroblast Attachment ◽  
Tissue Reconstruction

Novel nanofibers from blends of polylactic-co-glycolic acid (PLGA) and chitosan have been produced through an emulsion electrospinning process. The spinning solution employed polyvinyl alcohol (PVA) as the emulsifier. PVA was extracted from the electrospun nanofibers, resulting in a final scaffold consisting of a blend of PLGA and chitosan. The fraction of chitosan in the final electrospun mat was adjusted from 0 to 33%. Analyses by scanning and transmission electron microscopy show uniform nanofibers with homogenous distribution of PLGA and chitosan in their cross section. Infrared spectroscopy verifies that electrospun mats contain both PLGA and chitosan. Moreover, contact angle measurements show that the electrospun PLGA/chitosan mats are more hydrophilic than electrospun mats of pure PLGA. Tensile strengths of 4.94 MPa and 4.21 MPa for PLGA/chitosan in dry and wet conditions, respectively, illustrate that the polyblend mats of PLGA/chitosan are strong enough for many biomedical applications. Cell culture studies suggest that PLGA/chitosan nanofibers promote fibroblast attachment and proliferation compared to PLGA membranes. It can be assumed that the nanofibrous composite scaffold of PLGA/chitosan could be potentially used for skin tissue reconstruction.

scholarly journals Surface Modification of the Alloy Ti-7.5Mo by Anodization for Biomedical Applications

2016 ◽  
Vol 869 ◽  
pp. 913-917 ◽  
Author(s):  
Ana Lucia do Amaral Escada ◽  
Javier Andres Muñoz Chaves ◽  
Ana Paula Rosifini Alves Claro
Keyword(s):  
Contact Angle ◽  
Electron Microscope ◽  
Biomedical Applications ◽  
Anatase Phase ◽  
Ammonium Fluoride ◽  
X Ray ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Simple Surface ◽  
Scanning Electron

The purpose of this study was to evaluate the TiO2 nanotubes growth and the variation in its diameter to improve the surface properties of Ti-7.5Mo to use for biomedical applications. For the nanotubes TiO2 growth, the samples were anodized in glycerol and ammonium fluoride and divided according to the anodizing potential at 5V to 10V and 24 hour time. The surfaces were examined by scanning electron microscope (SEM), X-ray analysis (XRD) and contact angle measurements. The average tube diameter, ranging in size from 13 to 23 nm, was found to increase with increasing anodizing voltage. It was also observed a decrease in contact angle in accordance with the increase in the anodizing potential. The X-ray analysis showed the presence of anatase phase in samples whose potential was 10V and this condition represents a simple surface treatment for Ti-7.5Mo alloy that has high potential for biomedical applications.

Non-woven Membranes Electrospun from Polylactic Acid Incorporating Silver Nanoparticles as Biocide

2012 ◽  
Vol 1376 ◽  
Author(s):  
Haydee Vargas-Villagran ◽  
Elvia Teran-Salgado ◽  
Maraolina Dominguez-Diaz ◽  
Osvaldo Flores ◽  
Bernardo Campillo ◽  
...  
Keyword(s):  
Contact Angle ◽  
Silver Nanoparticles ◽  
Polylactic Acid ◽  
Chloroform Solution ◽  
Average Diameter ◽  
Electrospinning Process ◽  
Water Contact ◽  
X Ray Scattering ◽  
Angle Measurements ◽  
Contact Angle Measurements

ABSTRACTIn this research, we describe the electrospinning processing of polylactic acid (PLA) and the influence of silver nanoparticles on the morphology and microstructure of produced non woven membranes thus produced. The PLA was electrospun from a chloroform solution and a filamentary and granular morphology was obtained, the filaments having an average diameter of 1.25 μm, When silver nanoparticles (of ca. 12 nm size) were incorporated, the filaments diameter was reduced to an average of 0.65 μm, and the density of beads was also reduced. The membranes were rather amorphous, as revealed by X-ray scattering, presumably due to the quenching process associated with the electrospinning process. Water contact angle measurements showed that silver nanoparticles induced significant hidrophobicity in the membranes as neat PLA membrane had a contact angle of 54° and PLA/Ag membrane exhibited an angle of 115°.

Surface-modified halloysite nanotubes as fillers applied in reinforcing the performance of polytetrafluoroethylene

Clay Minerals ◽  
2018 ◽  
Vol 53 (4) ◽  
pp. 643-656 ◽  
Author(s):  
Zhi-Lin Cheng ◽  
Xing-Yu Chang ◽  
Zan Liu ◽  
Dun-Zhong Qin
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Sodium Dodecyl ◽  
Halloysite Nanotubes ◽  
Angle Measurements ◽  
Transmission Electron ◽  
Contact Angle Measurements ◽  
Ftir Spectrometry ◽  
Surface Modified ◽  
Scanning Electron

ABSTRACTIn order to improve the dispersibility of halloysite nanotubes (HNTs) in polytetrafluoroethylene (PTFE), the modification of HNT surfaces was studied with three types of modifiers (polymethyl methacrylate [PMMA], sodium dodecyl sulfate [SDS] and carboxylic acid). The modified HNTs were characterized by Fourier-transform infrared (FTIR) spectrometry, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and contact angle measurements. The HNTs were used to reinforce the mechanical properties of PTFE. The mechanical results indicated that the tensile strength of the modified HNT-filled PTFE nanocomposites (F-HNT/PTFE) improved to an acceptable degree and Young's modulus increased significantly. The tribological results showed that the wear rate of F-HNT/PTFE decreased by 21–82 and 9–40 times compared to pure PTFE and the pristine F-HNT/PTFE, respectively.

Hydrophobization of Kraft-type Cellulose and Microfiber Cellulose Obtained from Soybean Husk in Ultrasonic Field

2019 ◽  
Vol 13 (2) ◽  
pp. 151-159
Author(s):  
Blanca I.M. Mejia ◽  
Oxana V. Kharissova ◽  
Boris I. Kharisov
Keyword(s):  
Electron Microscopy ◽  
Tensile Strength ◽  
Sio2 Nanoparticles ◽  
Ultrasonic Field ◽  
Homogeneous Distribution ◽  
Silicon Dioxide Nanoparticles ◽  
Angle Measurements ◽  
Transmission Electron ◽  
Contact Angle Measurements ◽  
20 Nm

Background: The addition of nanoparticles to cellulose paper can improve its mechanical strength, chemical stability, biocompatibility and hydrophobic properties. Silica nanoparticles are known to be inert, hydrophobic, biocompatible, biodegradable and have a good distribution in being deposited on surfaces. The main characteristics of 20 nm SiO2 nanoparticles are good chemical and thermal stability with a melting point of 1610-1728°3C, a boiling point of 2230°C with a purity of 99.5%. Objective: To carry out the hydrophobization of paper based on Kraft cellulose and on cellulose obtained from soybean husk with 20-nm size SiO2 nanoparticles and to study hydrophobicity, morphology and topography of the prepared composites. Methods: The ground and roasted soybean husk was treated with a NaOH, washed and dried. Hydrophobization of paper was carried in aqueous medium by SiO2 addition in weight ratios “paper-SiO2” of 0.01-0.05 wt.%, stirring, filtration and drying. The obtained cellulose sheet composites were characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), FTIRspectroscopy, Mullen proofs of hydrophobicity, and contact angle measurements. Results: The mechanical properties of paper nanocomposites (tensile strength and compression) increased considerably by varying the concentrations. The tensile strength increased by 41-46% and the compressive strength increased by 55-56%. The existence of fiber nanofoils, good adhesion of 20-nm SiO2 nanoparticles to the paper surface, and their homogeneous distribution were observed. Conclusion: Cellulose was successfully obtained from soybean husk, applying the alkaline-based extraction method. A good reinforcement of cellulose fibers is observed due to the outstanding characteristics of the silicon dioxide nanoparticles.

Studying Effects of Bias Voltage on Properties, Wettability and Platelet Adhered Behavior of DLC Films Prepared By DC-MFCVAD

2007 ◽  
Vol 353-358 ◽  
pp. 2203-2206
Author(s):  
Feng Wen ◽  
Nan Huang ◽  
Yong Xiang Leng ◽  
Zhi Li ◽  
Yang Cao
Keyword(s):  
Bias Voltage ◽  
Biomedical Applications ◽  
Vacuum Arc ◽  
X Ray ◽  
Magnetic Filter ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Vacuum Arc Deposition ◽  
Scratch Tests ◽  
Arc Deposition

Diamond-Like carbon (DLC) films were prepared under different bias voltage by direct current magnetic filter cathode vacuum arc deposition (DC-MFCVAD). Bias voltages changed from 0 to -200 V. The study intends to investigate the effect on the properties of DLC films for biomedical applications. X-ray photoelectron spectrum (XPS) was used to investigate composition of the films. Nano-scratch tests were used to characterize effects of bias voltage to adhesion. Furthermore, the wettability of the DLC films was investigated by contact angle measurements using four common liquids. Finally, platelet adhesion experiments were done to evaluate the interaction of blood with DLC films. The results showed that the adhesion, wettability and hemo-compatibility of DLC films were affected by bias voltage.

scholarly journals The Effect of Titanium Dioxide Surface Modification on the Dispersion, Morphology, and Mechanical Properties of Recycled PP/PET/TiO2 PBNANOs

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1692 ◽  
Author(s):  
Eider Matxinandiarena ◽  
Agurtzane Múgica ◽  
Manuela Zubitur ◽  
Cristina Yus ◽  
Víctor Sebastián ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Tio2 Nanoparticles ◽  
Crystallization Rate ◽  
Pet Bottles ◽  
Hydrophobically Modified ◽  
Angle Measurements ◽  
Transmission Electron ◽  
Titanium Dioxide Surface ◽  
Contact Angle Measurements ◽  
Pet Crystallization

Titanium dioxide (TiO2) nanoparticles have recently appeared in PET waste because of the introduction of opaque PET bottles. We prepare polymer blend nanocomposites (PBNANOs) by adding hydrophilic (hphi), hydrophobic (hpho), and hydrophobically modified (hphoM) titanium dioxide (TiO2) nanoparticles to 80rPP/20rPET recycled blends. Contact angle measurements show that the degree of hydrophilicity of TiO2 decreases in the order hphi > hpho > hphoM. A reduction of rPET droplet size occurs with the addition of TiO2 nanoparticles. The hydrophilic/hydrophobic balance controls the nanoparticles location. Transmission electron microscopy (TEM_ shows that hphi TiO2 preferentially locates inside the PET droplets and hpho at both the interface and PP matrix. HphoM also locates within the PP matrix and at the interface, but large loadings (12%) can completely cover the surfaces of the droplets forming a physical barrier that avoids coalescence, leading to the formation of smaller droplets. A good correlation is found between the crystallization rate of PET (determined by DSC) and nanoparticles location, where hphi TiO2 induces the highest PET crystallization rate. PET lamellar morphology (revealed by TEM) is also dependent on particle location. The mechanical behavior improves in the elastic regime with TiO2 addition, but the plastic deformation of the material is limited and strongly depends on the type of TiO2 employed.

scholarly journals Preparation of Lutein-Loaded PVA/Sodium Alginate Nanofibers and Investigation of Its Release Behavior

Pharmaceutics ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 449 ◽  
Author(s):  
Xinxu Han ◽  
Peipei Huo ◽  
Zhongfeng Ding ◽  
Parveen Kumar ◽  
Bo Liu
Keyword(s):  
Sodium Alginate ◽  
Biomedical Applications ◽  
Room Temperature ◽  
Cross Linking ◽  
Release Mechanism ◽  
Disintegration Time ◽  
X Ray ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Before And After

This investigation aims to study the characteristics and release properties of lutein-loaded polyvinyl alcohol/sodium alginate (PVA/SA) nanofibers prepared by electrospinning. In order to increase PVA/SA nanofibers’ water-resistant ability for potential biomedical applications, the electrospun PVA/SA nanofibers were cross-linked with a mixture of glutaraldehyde and saturated boric acid solution at room temperature. The nanofibers were characterized using scanning electron microscopy (SEM) and X-ray diffractometer (XRD). Disintegration time and contact angle measurements testified the hydrophilicity change of the nanofibers before and after cross-linking. The lutein release from the nanofibers after cross-linking was measured by an ultraviolet absorption spectrophotometer, which showed sustained release up to 48 h and followed anomalous (non-Fickian) release mechanism as indicated by diffusion exponent value obtained from the Korsmeyer–Peppas equation. The results indicated that the prepared lutein-loaded PVA/SA nanofibers have great potential as a controlled release system.

scholarly journals Biomedical Applications of Electrospun Nanofibers: Drug and Nanoparticle Delivery

Pharmaceutics ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 5 ◽  
Author(s):  
Rajan Bhattarai ◽  
Rinda Bachu ◽  
Sai Boddu ◽  
Sarit Bhaduri
Keyword(s):  
Anticancer Agents ◽  
Biomedical Applications ◽  
Electrospun Nanofibers ◽  
Electrospinning Process ◽  
Ease Of Use ◽  
Solution Flow Rate ◽  
Electrospun Fibers ◽  
Polymeric Solution ◽  
Active Moiety ◽  
Multiple Drugs

The electrospinning process has gained popularity due to its ease of use, simplicity and diverse applications. The properties of electrospun fibers can be controlled by modifying either process variables (e.g., applied voltage, solution flow rate, and distance between charged capillary and collector) or polymeric solution properties (e.g., concentration, molecular weight, viscosity, surface tension, solvent volatility, conductivity, and surface charge density). However, many variables affecting electrospinning are interdependent. An optimized electrospinning process is one in which these parameters remain constant and continuously produce nanofibers consistent in physicochemical properties. In addition, nozzle configurations, such as single nozzle, coaxial, multi-jet electrospinning, have an impact on the fiber characteristics. The polymeric solution could be aqueous, a polymeric melt or an emulsion, which in turn leads to different types of nanofiber formation. Nanofiber properties can also be modified by polarity inversion and by varying the collector design. The active moiety is incorporated into polymeric fibers by blending, surface modification or emulsion formation. The nanofibers can be further modified to deliver multiple drugs, and multilayer polymer coating allows sustained release of the incorporated active moiety. Electrospun nanofibers prepared from polymers are used to deliver antibiotic and anticancer agents, DNA, RNA, proteins and growth factors. This review provides a compilation of studies involving the use of electrospun fibers in biomedical applications with emphasis on nanoparticle-impregnated nanofibers.

PREPARATION AND PROPERTIES OF NANOCOMPOSITE FROM NR AND NATURAL NA+-MONTMORILLONITE

2020 ◽  
Vol 93 (2) ◽  
pp. 286-296
Author(s):  
N. T. Thuong ◽  
N. P. D. Linh ◽  
C. H. Ha ◽  
P. T. Nghia ◽  
S. Kawahara
Keyword(s):  
Electron Microscopy ◽  
Tensile Testing ◽  
Testing Machine ◽  
Nanocomposite Materials ◽  
Water Soluble ◽  
Tensile Testing Machine ◽  
Angle Measurements ◽  
Transmission Electron ◽  
Contact Angle Measurements ◽  
High Ammonia

ABSTRACT NR/Na+-montmorillonite (NR/Na+-MMT) nanocomposites were prepared through mixing in the latex stage. NR/Na+-MMT nanocomposites with various amounts of Na+-MMT were fabricated using three types of NR latexes: fresh NR (FNR), high ammonia NR, and deproteinized NR latex. The Na+-MMT and NR latexes were characterized by particle size distribution and Fourier transform infrared spectroscopy analyses. The nanocomposite materials were then analyzed by scanning electron microscopy, transmission electron microscopy, and contact angle measurements. The mechanical properties of the resulting products were measured by tensile testing machine. The composite prepared from FNR gave the best tensile strength at 3 phr MMT loading. The outstanding properties are proposed to be due to the contribution of the water-soluble compounds present in FNR that possess similar hydrophilicity to Na+-MMT.

Medical Applications of Functional Electrospun Nanofibers - A Review

2017 ◽  
Vol 752 ◽  
pp. 132-138 ◽  
Author(s):  
Liliana Rozemarie Manea ◽  
Alexandru Popa ◽  
Andrei Petru Bertea
Keyword(s):  
Tissue Engineering ◽  
Biomedical Applications ◽  
Review Paper ◽  
Electrospun Nanofibers ◽  
Electrospinning Process ◽  
Polymer Materials ◽  
Medical Applications ◽  
Medical Field ◽  
Future Directions ◽  
Early 21St Century

Electrospinning is one of the most extensively used technique in the early 21st century, due to its adaptability and potential for applications in various domains. Electrospun nanofibers are used in many fields, for example nanoelectronics, optical devices, protective clothing, sound absorption, nano membranes and many biomedical applications. This review paper provides a summary of the electrospinning process, polymer solution and work parameters that influence the nanofibers manufacture, focusing on subjects related to electrospun nanofibers that are used for medical applications such as: wound healing, artificial skin, selective separation, immobilization of active agents and molecules, scaffold for tissue engineering, nervous system and bone tissue engineering, drug delivery. New groups of polymer materials and new generations of composite and nanostructural materials and their new applicability in the medical field are reviewed. The paper ends with perspectives and future directions for design, manufacture and utilization electrospun nanofibers for medical applications.

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