ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Biological buffered saline solution as solvent in agar-carbomer hydrogel synthesis

Filippo Rossi, Giuseppe Perale, and Maurizio Masi

Dipartimento di Chimica, Materiali e Ingegneria Chimica “Giulio Natta”, Politecnico di Milano, Via Mancinelli 7, 20131 Milano, Italy

E-mail: giuseppe.perale@polimi.it

Abstract: The role of phosphate buffer saline solution (PBS) was investigated here as a solvent in the polycondensation synthesis of an injectable agar-carbomer based hydrogel, a promising new material specifically intended for regenerative medicine applications. The effects of PBS, with respect to standard distilled water (DW), were quantitatively assessed. Experiments were performed both from physico-chemical and biological points of view. Titration showed higher stability due to the presence of the buffer solution; ESEM analysis confirmed its distribution along the polymeric fibers and infrared spectroscopy showed the consequent anionic nature of the polymeric network. This electrostatic nature of the matrix was confirmed by mass equilibrium swelling data performed at different pH values of the swelling medium. A very relevant role of the solvent was observed also with respect to cell housing inside such hydrogels: living cell counts showed a high amount of cells surviving the latency period of encapsulation in hydrogel when PBS was applied while only very few survived in a deionized water based gel. Obtained data allowed a novel understanding of the causeeffect cascades of all observed phenomena which suggest the PBS fundamental role both in fine control of hydrogel preparation and in material tuning according to the specific needs of different target tissues; the latter being a feature of primary importance when applying hydrogels as cell carriers in regenerative medicine applications.

Keywords: hydrogels - phosphate buffered saline solution - cell housing - agar - carbomer

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-010-0052-4

Chemical Papers 64 (5) 573–578 (2010)