16. - 18. 10. 2013, Brno, Czech Republic, EU WET ELECTROSPUN POLYCAPROLACTONE FIBROUS MATERIALS KOŠŤÁKOVÁ Eva, ŠEPS Michal, POKORNÝ Pavel, HORÁKOVÁ Jana, LUKÁŠ David Technical University of Liberec, Liberec, Czech Republic, EU, eva.kostakova@tul.cz, david.lukas@tul.cz Abstract Wet electrospinning technology uses a liquid collector instead of solid metal collector. The contribution describes a wet electrospinning technology for polycaprolactone bulky fibrous material. The materials are compared with fibrous layers electrospun onto metal plate collector and with materials electrospun from different solvent system into different liquid collectors systems. The final fibrous materials scanning electron images discovered dual structures of wet electrospun materials (combination of nanofibers and microfibers). The usage of these materials leads mainly to the tissue engineering, where the dual fiber diameter structure can offer better mechanical properties and bigger pores but still good cell adhesion. The initial in-vitro test of the best fibrous materials produced by wet electrospinning is introduced here too. Keywords: wet electrospinning, nanofibers, polycaprolactone 1. INTRODUCTION Wet electrospinning is a modification of well-known method for nanofibrous materials production – electrospinning. The modification is based on a usage of a liquid reservoir collector instead of solid mostly metallic collector. The first descriptions of such set up were focused to production of three dimensional nanofibrous scaffold 1, 2. The bulky nanofibrous materials by classical electrospinning method is not easy and can provided by special patterned collectors [3], usage of porogen particles in between nanofibers, usage of chemical blowing agents 4 etc. Wet electrospinning is relatively easy and effective method how to produce three dimensional (sponge like) materials without sophisticated machine devices and without special chemical additives in between or inside nanofibers. The main application of such materials is in tissue engineering. The presenting research is focused on polycaprolactone wet electrospinning with water/etanol mixtures as a liquid collector and its comparison with electrospinning onto plate metal collector. 2. MATERIALS AND METHODS Poly--caprolacone (PCL) with molecular weight M w =48,000 – 90,000 g/mol by Sigma Aldrich solved in chloroform/ethanol (9:1 by weight) mixture was solved for 24 hours at magnetic mixer. The final concentration of polymer in the solution was 15wt% Solution of PCL in chloroform only was used for comparison. When wet electrospinning method was applied, pure distilled water, pure ethanol and mixtures of water/ethanol (9:1; 8:2; 7:3; 6:4; 5:5; 4:6; 3:7; 2:8; 1:9, in the weight ratio in all cases) were used as a liquid collector. The electrospinning device consists of syringe ended by metal needle with internal diameter 0.9 mm connecting with a positive high voltage source (Spellman SL 150) and placed in the feeding device (KDScientific KDS-100) and a grounded collector based on a metal plate placed inside a reservoir with a collector liquid. Parameters of the electrospinning were found at the previous experiments: positive voltage 20 kV; distance between needle end and collector liquid level 100 mm; pool depth 10 mm; feeding velocity 7 ml/h. After electrospinning, the final samples were dried at laboratory temperature (20°C) and air humidity (60 % RH).