Emulsion-based control of electrospun fiber morphology

Abstract

The invention provides a fiber having different morphology and a method of making such fiber in a predictable manner. The method includes providing a first component including water, wherein the first component has a first evaporation rate, providing a second component including a polymer, wherein the second component has a second evaporation rate, provided that the second evaporation rate is higher than the first evaporation rate, combining the first component and the second component to make an emulsion, applying a force to the emulsion, and extruding the emulsion to make the fiber, wherein the fiber has an outer surface, an internal cavity and a diameter of at most 10 micrometers.

1 . A method of making a fiber, the method comprising: 
 providing a first component comprising water, wherein the first component has a first evaporation rate;    providing a second component comprising a polymer dissolved in a solvent, wherein the second component has a second evaporation rate, provided that the second evaporation rate is higher than the first evaporation rate;    combining the first component, the second component to make an emulsion;    applying a force to the emulsion; and    extruding the emulsion to make the fiber, wherein the fiber has an outer surface, an internal cavity and a diameter of at most 10 micrometers.    
   
   
       2 . The method of  claim 1 , wherein the first component comprises at most 20 vol. % of the emulsion.  
   
   
       3 . The method of  claim 1 , wherein the first component comprises from about 5 to about 20 vol. % of the emulsion.  
   
   
       4 . The method of  claim 1 , wherein the first component comprises from about 2 to 5 vol. % of the emulsion.  
   
   
       5 . The method of  claim 1 , wherein the second component comprises at least 80% of the emulsion.  
   
   
       6 . The method of  claim 1 , wherein the first component comprises glycerol and poly(vinyl alcohol).  
   
   
       7 . The method of  claim 1 , wherein the polymer is a member selected from the group consisting of poly(styrene), poly(urethane), poly(lactic acid), poly(glycolic acid), poly(ester), poly(alpha-hydroxy acid), poly(E-caprolactone), poly(dioxanone), poly(orthoester), poly(ether-ester), poly(lactone), poly(carbonate), poly(phosphazene), poly(phosphanate), poly(ether), poly(anhydride), mixtures thereof and copolymers thereof.  
   
   
       8 . The method of  claim 1 , wherein the solvent is a member selected from the group consisting of methylene chloride, chloroform, ether, hexane, pentane, petroleum ether, cresol, dichloroethane, ethyl acetate, methyl ethyl ketone, dioxane, propylene carbonate, and butyl acetate.  
   
   
       9 . The method of  claim 1 , further providing a third component, said third component is being a member selected from the group consisting of a biomolecule, a cell, a particle, and a gel.  
   
   
       10 . The method of  claim 9 , wherein the biomolecule is a member selected from the group consisting of a bioactive polypeptide, a polynucleotide coding for the bioactive polypeptide, a cell regulatory small molecule, a peptide, a protein, an oligonucleotide, a nucleic acid, a poly(saccharide), an adenoviral vector, a gene transfection vector, a drug, and a drug delivering agent.  
   
   
       11 . The method of  claim 9 , wherein the cell is a member selected from the group consisting of chondroblast, chondrocyte, fibroblast, an endothelial cell, osteoblast, osteocyte, an epithelial cell, an epidermal cell, a mesenchymal cell, a hemopoietic cell, an embryoid body, a stem cell, and dorsal root ganglia.  
   
   
       12 . The method of  claim 9 , wherein the particle is a colloidal particle or a solid particle.  
   
   
       13 . The method of  claim 12 , wherein the colloidal particle has a diameter of about 3 nm to about 10 micrometers and said colloidal nanoparticle is a member selected from the group consisting of a polymer, an oxide, a nitride, a carbide, calcium silicate, calcium phosphate, calcium carbonate, a carbonaceous material, a metal, and a semiconductor.  
   
   
       14 . The method of  claim 12 , wherein the solid particle has a diameter of about 3 nm to about 10 micrometers and said solid nanoparticle is a member selected from the group consisting of a polymer, an oxide, a nitride, a carbide, calcium silicate, calcium phosphate, calcium carbonate, a carbonaceous material, a metal, and a semiconductor.  
   
   
       15 . The method of  claim 9 , wherein the surfactant is a member selected from the group consisting of PLURONIC, polyvinyl alcohol, poly(sorbate), oleyl alcohol, glycerol ester, sorbitol, carboxy methoxy cellulose, sodium dodecyl sulfonate, sodium dodecyl benzene sulfonate, oleic acid, albumin, ova-albumin, lecithin, natural lipids, and synthetic lipids.  
   
   
       16 . The method of  claim 1 , wherein the emulsion comprises water, poly(lactic acid), poly(vinyl alcohol) and optionally a silicone oxide nanoparticle comprising a biomolecule.  
   
   
       17 . The method of  claim 1 , wherein the first component and the second component are provided at a ratio, wherein the ratio is adapted to affect morphology of the fiber.  
   
   
       18 . The method of  claim 17 , wherein the morphology is a member selected from the group consisting of flat fiber, round fiber, porous fiber and a combination thereof.  
   
   
       19 . A fiber manufactured by the method of  claim 1 .  
   
   
       20 . The fiber of  claim 19 , wherein the emulsion comprises water, poly(lactic acid), and optionally a nanoparticle comprising silicone oxide and the biomolecule.  
   
   
       21 . The fiber of  claim 19 , wherein the diameter is about 3 nm to 10 micrometers.  
   
   
       22 . In a method of making a fiber by electrospinning wherein the fiber is formed by extruding a fiber-forming medium from a vessel through an orifice under influence of a force, the improvement wherein the fiber-forming medium comprises an emulsion including (1) a first component comprising water, the first component is provided in an amount of at most 20 vol. %, and (2) a second component comprising a polymer, the second component is provided in an amount of at least 80 vol. %, on a condition that the first component has a first evaporation rate and the second component has a second evaporation rate and wherein the second evaporation rate is higher than the first evaporation rate.