scholarly journals Fabrication of Nanopores Polylactic Acid Microtubes by Core-Sheath Electrospinning for Capillary Vascularization

Biomimetics ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 15
Author(s):  
Yingge Zhou ◽  
Dilshan Sooriyaarachchi ◽  
George Z. Tan
Keyword(s):  
Polylactic Acid ◽  
Electrospinning Process ◽  
Medical Applications ◽  
Vascular Networks ◽  
The Core ◽  
Pump Rate ◽  
Core Solution ◽  
Substantial Progress ◽  
Vascular Channels ◽  
Fenestrated Capillary

There has been substantial progress in tissue engineering of biological substitutes for medical applications. One of the major challenges in development of complex tissues is the difficulty of creating vascular networks for engineered constructs. The diameter of current artificial vascular channels is usually at millimeter or submillimeter level, while human capillaries are about 5 to 10 µm in diameter. In this paper, a novel core-sheath electrospinning process was adopted to fabricate nanoporous microtubes to mimic the structure of fenestrated capillary vessels. A mixture of polylactic acid (PLA) and polyethylene glycol (PEO) was used as the sheath solution and PEO was used as the core solution. The microtubes were observed under a scanning electron microscope and the images were analyzed by ImageJ. The diameter of the microtubes ranged from 1–8 microns. The diameter of the nanopores ranged from 100 to 800 nm. The statistical analysis showed that the microtube diameter was significantly influenced by the PEO ratio in the sheath solution, pump rate, and the viscosity gradient between the sheath and the core solution. The electrospun microtubes with nanoscale pores highly resemble human fenestrated capillaries. Therefore, the nanoporous microtubes have great potential to support vascularization in engineered tissues.

Effects of Solution Viscosity on PLLA Porous Microtubes Fabricated by Core-Sheath Electrospinning

2021 ◽  
Author(s):  
Yingge Zhou ◽  
Imtiaz Qavi ◽  
George Z. Tan
Keyword(s):  
Lactic Acid ◽  
Product Development ◽  
Biomedical Applications ◽  
Viscosity Ratio ◽  
Tube Wall ◽  
Solution Viscosity ◽  
Outer Diameter ◽  
The Core ◽  
Core Solution ◽  
Fenestrated Capillary

Abstract Core-sheath electrospinning is a rapid microfabrication process for creating multi-layer polymer microfibers. This paper presents a process based on core-sheath electrospinning to fabricate poly(L-lactic acid) (PLLA) microtubes with nanopores on the tube wall. The morphology of the microtubes mimics human fenestrated capillary vessels. This study investigates the effects of the viscosities of the core and the sheath solutions on the microtube outer diameter and the nanopore size. The core solution shows a dominating influence on the microtube diameter. At the same core solution viscosity level, the microtube diameter is negatively correlated to the core-to-sheath viscosity ratio. The pore size is positively correlated to the microtube diameter. Understanding the effects of solution viscosity on microtube morphology is the prerequisite for process control and microtube product development for future biomedical applications.

scholarly journals Designing Biodegradable and Active Multilayer System by Assembling an Electrospun Polycaprolactone Mat Containing Quercetin and Nanocellulose between Polylactic Acid Films

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1288
Author(s):  
Carol López de Dicastillo ◽  
Luan Garrido ◽  
Eliezer Velásquez ◽  
Adrián Rojas ◽  
Rafael Gavara
Keyword(s):  
Antioxidant Activity ◽  
Thermal Treatment ◽  
Polylactic Acid ◽  
Active Compound ◽  
Cellulose Nanocrystals ◽  
Barrier Properties ◽  
Electrospinning Process ◽  
Multilayer Systems ◽  
Innovative Strategy ◽  
Packaged Foods

The design of multilayer systems is an innovative strategy to improve physical properties of biodegradable polymers and introduce functionality to the materials through the incorporation of an active compound into some of these layers. In this work, a trilayer film based on a sandwich of electrospun polycaprolactone (PCL) fibers (PCLé) containing quercetin (Q) and cellulose nanocrystals (CNC) between extruded polylactic acid (PLA) films was designed with the purpose of improving thermal and barrier properties and affording antioxidant activity to packaged foods. PCLé was successfully electrospun onto 70 µm-thick extruded PLA film followed by the assembling of a third 25 µm-thick commercial PLA film through hot pressing. Optical, morphological, thermal, and barrier properties were evaluated in order to study the effect of PCL layer and the addition of Q and CNC. Bilayer systems obtained after the electrospinning process of PCL onto PLA film were also evaluated. The release of quercetin from bi- and trilayer films to food simulants was also analyzed. Results evidenced that thermal treatment during thermo-compression melted PCL polymer and resulted in trilayer systems with barrier properties similar to single PLA film. Quercetin release from bi- and trilayer films followed a similar profile, but achieved highest value through the addition of CNC.

Solvent Assisted Coaxial-Electrospun Poly Methyl Methacrylate Polymer and Study of Resultant Fibers

2020 ◽  
Vol 18 (12) ◽  
pp. 905-909
Author(s):  
Arjun Satheesh ◽  
A. A. Alagiriswamy ◽  
S. Devanand ◽  
S. Nithiyanantham
Keyword(s):  
Methyl Methacrylate ◽  
Sem Analysis ◽  
Fiber Formation ◽  
Dimethyl Formamide ◽  
Poly Methyl Methacrylate ◽  
The Core ◽  
Pure Solvent ◽  
Core Solution ◽  
Polymer Dispersions

Electrospinning of dispersions with higher viscosity and limited flow may be carried out, based on the solvent assisted coaxial technique, where the flow of the core dispersion is supported by a free flowing sheath solvent. In the present work, the sheath solvents used are chloroform, toluene and dimethyl formamide and we discuss the fiber formation of Poly Methyl Methacrylate (PMMA) (dispersion-25 wt%). PMMA dispersed in chloroform is taken as the core solution and the sheath is pure solvent. The In-Situ effect of different sheath solvents in fiber formation at two different tip to collector distances are studied. The fibers formed are subjected to SEM analysis and the characteristics are analysed. The fiber formation of high viscos polymer dispersions makes the same materials subjectable to electrospinning and further 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°.

scholarly journals Fabrication and Characterization of Polylactic Acid Electrospun Scaffolds Modified with Multi-Walled Carbon Nanotubes and Hydroxyapatite Nanoparticles

Biomimetics ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 43
Author(s):  
Athanasios Kotrotsos ◽  
Prokopis Yiallouros ◽  
Vassilis Kostopoulos
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Polylactic Acid ◽  
Physical And Mechanical Properties ◽  
Polymeric Materials ◽  
Cost Effective ◽  
Electrospinning Process ◽  
Wide Range ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The solution electrospinning process (SEP) is a cost-effective technique in which a wide range of polymeric materials can be electrospun. Electrospun materials can also be easily modified during the solution preparation process (prior SEP). Based on this, the aim of the current work is the fabrication and nanomodification of scaffolds using SEP, and the investigation of their porosity and physical and mechanical properties. In this study, polylactic acid (PLA) was selected for scaffold fabrication, and further modified with multi-walled carbon nanotubes (MWCNTs) and hydroxyapatite (HAP) nanoparticles. After fabrication, porosity calculation and physical and mechanical characterization for all scaffold types were conducted. More precisely, the morphology of the fibers (in terms of fiber diameter), the surface properties (in terms of contact angle) and the mechanical properties under the tensile mode of the fabricated scaffolds have been investigated and further compared against pristine PLA scaffolds (without nanofillers). Finally, the scaffold with the optimal properties was proposed as the candidate material for potential future cell culturing.

Morphology Studies of Electrospun Lithium Iron Phosphate (LiFePO4)/Cellulose Acetate (CA) Fibers

2016 ◽  
Vol 694 ◽  
pp. 101-105
Author(s):  
M. Mohamad ◽  
M.F.Z. Abidin ◽  
Haslan Fadli Ahmad Marzuki ◽  
Abdullah Ahmad Nizam ◽  
Muhamad Hazri Othman ◽  
...  
Keyword(s):  
Cellulose Acetate ◽  
Lithium Iron Phosphate ◽  
Mixed Solvent ◽  
Iron Phosphate ◽  
Solution Concentration ◽  
Electrospinning Process ◽  
Solution Viscosity ◽  
Pump Rate ◽  
Preliminary Study ◽  
Needle Diameter

This work was carried out as a preliminary study of electrospun LiFePO4/CA fibers. Cellulose acetate (CA) and LiFePO4 solutions were prepared separately using mixed solvent of acetone and water, prior to the electrospinning process. Then, electrospinning parameters including solution concentration, distance tip to collector, pump rate, and needle diameter size were optimized. Brunauer Emmett Teller (BET) was used to determine the surface area of CA fibers. Viscosity of CA solution was obtained by viscometer. LiFePO4/CA fibers were stabilized and carbonized at different temperature. The surface morphology and microstructure of the obtained LiFePO4/ CA fibers were then characterized using scanning electron microscope (SEM). In this work, it is shown that different electrospinning parameter, solution concentration and solution viscosity gives different fibers diameter and distribution. Moreover, the stabilization and carbonization temperature of LiFePO4/CA fibers may also affect the fibers microstructure.

scholarly journals Effect of Solution Miscibility on the Morphology of Coaxial Electrospun Cellulose Acetate Nanofibers

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4419
Author(s):  
Ke Yan ◽  
Yao Le ◽  
Hu Mengen ◽  
Li Zhongbo ◽  
Huang Zhulin
Keyword(s):  
Cellulose Acetate ◽  
Shell Structure ◽  
Partial Solution ◽  
Electrospinning Process ◽  
Core Shell ◽  
Electrospinning Technique ◽  
Product Morphology ◽  
The Core ◽  
Core Shell Structure ◽  
Structural Characterizations

Coaxial electrospinning (co-electrospinning) technique has greatly expanded the universality of fabricating core-shell polymer nanofibers. However, the effect of solution miscibility on the morphology of co-electrospun products remains unclear. Herein, different cellulose acetate (CA) solutions with high solution miscibility but distinctly different electrospinnability were used to survey the effect of solution miscibility on the co-electrospinning process. The structural characterizations show that co-electrospun products are composed of nanofibers with and without the core-shell structure. This indicates that partial solution mixing occurred during the co-electrospinning process instead of absolute no-mixing or complete mixing. Importantly, the solution miscibility also shows a significant influence on the product morphology. In particular, the transformation from nanofibers to microparticles was realized with the increase of core-to-shell flow ratio during the co-electrospinning of core electrosprayable CA/dimethylacetamide (DMAc) solution and shell electrospinnable CA/acetone-DMAc (2/1, v/v) solution. Results show that the solution miscibility exerts a significant effect on not only the formation of core-shell structure but also the product morphology. This work provides a new insight for the in-depth understanding of the co-electrospinning process.

Sign in / Sign up

Export Citation Format

Share Document