Electrospinning of polycarbonate urethane biomaterials

Abstract

Polycarbonate urethane (PCU) nano-fibers were fabricated via electrospinning using N,N- dimethylformamide (DMF) and tetrahydrofuran (THF) as the mixed solvent. The effect of volume ratios of DMF and THF in the mixed solvent on the fiber structures was investigated. The results show that nano-fibers with a narrow diameter distribution and a few defects were obtained when mixed solvent with the appropriate volume ratio of DMF and THF as 1∶1. When the proportion of DMF was more than 75% in the mixed solvent, it was easy to form many beaded fibers. The applied voltage in the electrospinning process has a significant influence on the morphology of fibers. When the electric voltage was set between 22 and 32 kV, the average diameters of the fibers were found between 420 and 570 nm. Scanning electron microscopy (SEM) images showed that fiber diameter and structural morphology of the electrospun PCU membranes are a function of the polymer solution concentration. When the concentration of PCU solution was 6.0 wt-%, a beaded-fiber microstructure was obtained. With increasing the concentration of PCU solutions above 6.0 wt-%, beaded fiber decreased and finally disappeared. However, when the PCU concentration was over 14.0 wt-%, the average diameter of fibers became large, closed to 2 μm, because of the high solution viscosity. The average diameter of nanofibers increased linearly with increasing the volume flow rate of the PCU solution (10.0 wt-%) when the applied voltage was 24 kV. The results show that the morphology of PCU fibers could be controlled by electrospinning parameters, such as solution concentration, electric voltage and flow rate.

Key words： electrospinning; polycarbonate urethane; process parameter; average diameter; morphology

Acknowledgments

This work has been financially supported by Program for New Century Excellent Talents in University “NCET,” NCET-07-0596, Ministry of Education ofChina, by the International Cooperation from Ministry of Science and Technology of China (Grant No. 2008DFA51170), and by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry.

References

1 Huang Z M, Zhang Y Z, Kotaki M, Ramakrishna S. A review on polymer nanofibers by electrospinning and their applications in nanocomposites. Composites Science and Technology, 2003, 63(15): 2223–2253

2 Park H S, Park Y O. Filtration properties of electrospun ultrafine fiber webs. Korean Journal of Chemical Engineering, 2005, 22(1): 165–172

3 Huang L, Nagapudi K, Apkarian R P, Chaikof E L. Engineered collagen-PEO nanofibers and fabrics. J Biomater Sci Polym Ed, 2001, 12(9): 979–993

4 Wang X, Drew C, Lee S H, Senecal K J, Kumar J, Samuelson L A. Electrospun nanofibrous membranes for highly sensitive optical sensors. Nano Letters, 2002, 2(11): 1273–1275

5 Li W J, Laurencin C T, Caterson E J, Tuan R S, Ko F K. Electrospun nanofibrous structure: a novel scaffold for tissue engineering. Journal of Biomedical Materials Research, 2002, 60(4): 613–621

6 He Q, Cui Y, Ai S, Tian Y, Li J. Self-assembly of composite nanotubes and their applications. Current Opinion in Colloid & Interface Science, 2009, 14(2): 115–125

7 Buttafoco L, Kolkman N G, Engbers-Buijtenhuijs P, Poot A A, Dijkstra P J, Vermes I, Feijen J. Electrospinning of collagen and elastin for tissue engineering applications. Biomaterials, 2006, 27(5): 724–734

8 Sun B, Duan B, Yuan X. Preparation of core/shell PVP/PLA ultrafine fibers by coaxial electrospinning. Journal of Applied Polymer Science, 2006, 102(1): 39–45

9 Yang F, Both S K, Yang X, Walboomers X F, Jansen J A. Development of an electrospun nano-apatite/PCL composite membrane for GTR/GBR application. Acta Biomaterialia, 2009, 5(9): 3295–3304

10 Duling R R, Dupaix R B, Katsube N, Lannutti J. Mechanical characterization of electrospun polycaprolactone (PCL): a potential scaffold for tissue engineering. Journal of Biomechanical Engineering, 2008, 130(1): 011006–011018

11 Duan Y Y, Jia J, Wang S H, Yan W, Jin L, Wang Z Y. Preparation of antimicrobial poly(ϵ-caprolactone) electrospun nanofibers containing silver-loaded zirconium phosphate nanoparticles. Journal of Applied Polymer Science, 2007, 106(2): 1208–1214

12 You Y, Min B M, Lee S J, Lee T S, Park W H. In vitro degradation behavior of electrospun polyglycolide, polylactide, and poly(lactide-co-glycolide). Journal of Applied Polymer Science, 2005, 95(2): 193–200

13 Sell S A, Bowlin G L. Creating small diameter bioresorbable vascular grafts through electrospinning. Journal of Materials Chemistry, 2008, 18(3): 260–263

14 Ulrich H. Introduction to Industrial Polymers. New York: Hanser Publishers, 1993

15 Okoshi T, Soldani G, Goddard M, Galletti P M. Very small-diameter polyurethane vascular prostheses with rapid endothelialization for coronary artery bypass grafting. J Thorac Cardiovasc Surg, 1993, 105(5): 791–795

16 Lee S. Multifunctionality of layered fabric systems based on electrospun polyurethane/zinc oxide nanocomposite fibers. Journal of Applied Polymer Science, 2009, 114(6): 3652–3658

17 Peng P, Chen Y Z, Gao Y F, Yu J, Guo Z X. Phase morphology and mechanical properties of the electrospun polyoxymethylene/polyurethane blend fiber mats. Journal of Polymer Science. Part B, Polymer Physics, 2009, 47(19): 1853–1859

18 Cha D I, Kim H Y, Lee K H, Jung Y C, Cho J W, Chun B C. Electrospun nonwovens of shape-memory polyurethane block copolymers. Journal of Applied Polymer Science, 2005, 96(2): 460–465

19 Guan J J, Fujimoto K L, Sacks M S, Wagner W R. Preparation and characterization of highly porous, biodegradable polyurethane scaffolds for soft tissue applications. Biomaterials, 2005, 26(18): 3961–3971

20 McKee M G, Park T, Unal S, Yilgor I, Long T E. Electrospinning of linear and highly branched segmented poly(urethane urea)s. Polymer, 2005, 46(7): 2011–2015

21 Marois Y, Pâris E, Zhang Z, Doillon C J, King M W, Guidoin R G. Vascugraft^® microporous polyesterurethane arterial prosthesis as a thoraco-abdominal bypass in dogs. Biomaterials, 1996, 17(13): 1289–1300

22 Doi K, Matsuda T. Significance of porosity and compliance of microporous, polyurethane-based microarterial vessel on neoarterial wall regeneration. Journal of Biomedical Materials Research. Part A, 1997, 37(4): 573–584

23 Demir M M, Yilgor I, Yilgor E, Erman B. Electrospinning of polyurethane fibers. Polymer, 2002, 43(11): 3303–3309

24 Chen S, Hou H, Hu P, Wendorff J H, Greiner A, Agarwal S. Polymeric Nanosprings by Bicomponent Electrospinning. Macromolecular Materials and Engineering, 2009, 294(4): 265–271

25 Badami A S, Kreke M R, Thompson M S, Riffle J S, Goldstein A S. Effect of fiber diameter on spreading, proliferation, and differentiation of osteoblastic cells on electrospun poly(lactic acid) substrates. Biomaterials, 2006, 27(4): 596–606

26 Lowery J L, Datta N, Rutledge G C. Effect of fiber diameter, pore size and seeding method on growth of human dermal fibroblasts in electrospun poly(ϵ-caprolactone) fibrous mats. Biomaterials, 2010, 31(3): 491–504

27 Pinchuk L. A review of the biostability and carcinogenicity of polyurethanes in medicine and the new generation of ‘biostable’ polyurethanes. Journal of Biomaterials Science. Polymer Edition, 1995, 6(3): 225–267

28 Thomas V, Kumari T V, Jayabalan M. In vitro studies on the effect of physical cross-linking on the biological performance of aliphatic poly(urethane urea) for blood contact applications. Biomacromolecules, 2001, 2(2): 588–596

29 Zhang Z, Marois Y, Guidoin R G, Bull P, Marois M, How T, Laroche G, King M W. Vascugraft^® polyurethane arterial prosthesis as femoro-popliteal and femoro-peroneal bypasses in humans: pathological, structural and chemical analyses of four excised grafts. Biomaterials, 1997, 18(2): 113–124

30 Yarin A L. Free Liquid Jets and Films: Hydrodynamics and Rheology. New York: Longman, 1993

31 Yuan X, Zhang Y, Dong C, Sheng J. Morphology of ultrafine polysulfone fibers prepared by electrospinning. Polymer International, 2004, 53(11): 1704–1710

32 Chang K H, Lin H L. Electrospin of polysulfone in N,N’-dimethyl acetamide solutions. Journal of Polymer Research, 2009, 16(6): 611–622

33 Lee J S, Choi K H, Ghim H D, Kim S S, Chun D H, Kim H Y, Lyoo W S. Role of molecular weight of atactic poly(vinyl alcohol) (PVA) in the structure and properties of PVA nanofabric prepared by electrospinning. Journal of Applied Polymer Science, 2004, 93(4): 1638–1646

34 Zong X, Kim K, Fang D, Ran S, Hsiao B S, Chu B. Structure and process relationship of electrospun bioabsorbable nanofiber membranes. Polymer, 2002, 43(16): 4403–4412

35 Shenoy S L, Bates W D, Frisch H L, Wnek G E. Role of chain entanglements on fiber formation during electrospinning of polymer solutions: good solvent, non-specific polymer-polymer interaction limit. Polymer, 2005, 46(10): 3372–3384

36 Deitzel J M, Kleinmeyer J, Harris D, Tan N C B. The effect of processing variables on the morphology of electrospun nanofibers and textiles. Polymer, 2001, 42(1): 261–272

37 Fong H, Chun I, Reneker D H. Beaded nanofibers formed during electrospinning. Polymer, 1999, 40(16): 4585–4592

38 Nasir M, Matsumoto H, Danno T, Minagawa M, Irisawa T, Shioya M, Tanioka A. Control of diameter, morphology, and structure of PVDF nanofiber fabricated by electrospray deposition. Journal of Polymer Science. Part B, Polymer Physics, 2006, 44(5): 779–786

39 Tsai P P, Schreuder-Gibson H, Gibson P.Different electrostatic methods for making electret filters. Journal of Electrostatics, 2002, 54(3-4): 333–341