Test methodMonitoring and modelling of oxygen transport through un-crosslinked and crosslinked gelatine gels

A non-invasive, luminescence quenching technique is developed for continuous monitoring of oxygen spatial-temporal concentration distribution in fully hydrated gelatine gels, intended for use as scaffolds in tissue engineering. Two mass transfer-diffusion models were used to simulate the unsteady-state oxygen mass transport in the system. Oxygen diffusion coefficient and mass transfer coefficient at the water-gel interface were determined for un-crosslinked gelatine, as well as gelatine crosslinked with 1 and 1.5% w/v glutaraldehyde. While crosslinking and increased concentration of the crosslinking agent reduced oxygen mass transfer across the gel surface, both factors increased the diffusion coefficient of oxygen in the bulk of the gel. Voids in the gelatine's microstructure, which were generated during the crosslinking process due to shrinkage and associated internal stresses, were associated with both increasing the diffusion coefficient within the gel, as well as inhomogeneous diffusion of oxygen within the gel.