(403d) Inkjet Printing and Spraying of Composite Calcium Alginate Particles with Solid Inner Inclusions

InkJet printing and spraying of composite calcium
alginate particles with solid inner inclusions

Dohnal J., ?tìpánek 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 filled by TiO₂
particles for photocatalysis respectively Fe₃O₄
particles which are able to concentrate by magnetic field in current location.
For massive production of these composite particles spray drying nozzle was
used and this work compare process limitation and differences between InkJet
and Spray nozzle in respect to quality of final product.

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.