Inkjet Fabrication of Composite Particles with Solid Inclusions for Drug Delivery and Catalytic Reactions

Inkjet fabrication of composite particles with solid inclusions for drug delivery and catalytic reactions

Dohnal J., Štěpánek F.

Institute of Chemical Technology, Department of Chemical Engineering

Laboratory of Chemical Robotics

Tel: +420 220 443 046, email: dohnalj@vscht.cz

Calcium alginate is very often used for the encapsulation of living cells or enzymes for bioapplications ^[1,2,3]. An active substance (living cells, enzymes or catalyst particles) can be dispersed or dissolved in the starting sodium alginate solution and subsequently encapsulated in the beads by calcium ions.

Alginate beads can be prepared by different techniques from simple dropping of alginate solution to a calcium pool to precipitation in a microfliudic device. We use inkjet printing in this work. This technique can generate small microdroplets of a liquid with viscosity of up to 25 mPas with a diameter from 40 to 80 μm. Stable dispersions are possible to printing and this work uses it for their aims.

The aim of this work is preparation of composite microparticles from calcium alginate with inner inclusion for artificially started control release of active substances or for fabrication of alginate beads with inner solid inclusions or catalysts which can be used as microreactors for artificially started reaction. 1% (w/w) of sodium alginate solutions with model particles from TiO₂ or composite SiO₂/Fe₃O₄ particles was used as inner inclusions. Release kinetics of model substances (from hollow SiO₂/Fe₃O₄ particles) or catalytic properties (inclusions from TiO2) was investigated.

Figure  SEQ Figure \* ARABIC 1: Calcium alginate beads from dispersion of TiO₂ in alginate solution with concentration 1,95 (A), 3,9 (B) 5,85 (C) and 7,8 (D) vol. % of inner solids.

1)       Anal, A. K.; Stevens, W. F. Chitosan-alginate multilayer beads for controlled release of ampicillin. Int. J. Pharm. 2005, 290, 45–54.

2)       Murua, A.; et al. Cell microencapsilation technology: Towards clinical application. J. Controlled Release 2008, 132, 76–83.

3)       Morch, Ý. A; et al. Effect of Ca²⁺, Ba²⁺ and Sr²⁺ on Alginate Microbeads. Biomacromolecules 2006, 7, 1471–1480.