Physico-chemical properties and degradability of non-woven hyaluronan benzylic esters as tissue engineering scaffolds

The development of biocompatible materials which can be processed into three-dimensional scaffolds and the design of appropriate configurations in order to enable the cellular infiltration and proliferation is a major issue in the tissue engineering. The hyaluronan total benzyl ester (Hyaff (R) 11) has been found to be suitable substrate to grow a variety of cell types. Since structural, physical, chemical and biological data can help for tailoring appropriate scaffold for tissue engineering, information on chemicophysical properties on degradability of hyaluronan total benzyl ester non-woven has been obtained. The thermal analysis, the evaluation of the surface chemical composition, the morphology, the mechanical behaviour and the swelling tests were carried out on these materials. The hyaluronan total benzyl ester non-woven showed a thermal stability up to 220 degreesC and the surface composition differed from that of the bulk for C-O and C-C contribution. No contaminant were detected. The non-woven swelled in culture medium. Moreover the mechanical tests showed that when submitted to a press treatment, the samples have best mechanical properties. The pressed Hyaff (R) 11 non-woven undergoes degradation when exposed to DMEM. The frying and breaking of the fibres, a decrease of the mechanical properties and a molecular weight loss have been observed. First, the ester bond of the Hyaff (R) 11 non-woven is hydrolysed and the benzylic alcohol is released and the low molecular weight values indicate that a cleavage of the polymer is promoted by the components of the culture medium. After 11 days, some fragments, constituted by hyaluronic acid with a molecular weight of 23,000 Da became soluble in the medium. No oligomer was detected.