Investigation of fibroblast and keratinocyte cell-scaffold interactions using a novel 3D cell culture system

In this study we investigated the influence of fibre diameter and interfibre space in 3D scaffolds on cellular behaviour of human dermal fibroblasts and a human keratinocyte cell line (HaCaT cell). Electrospun aligned poly L-lactic acid fibres (2-10 microm) were bound to form fibres with a broad range of diameters (2-120 microm) and then constructed in a specifically designed 3D cell culture system. Human dermal fibroblasts were introduced to one end of the free-standing fibres using a fibrin clot and encouraged to 'walk the plank'. Under these conditions it was observed that a minimum fibre diameter of 10 microm for fibroblast adhesion and migration arose. A thin layer of electrospun viscose rayon scaffold fibres (diameter 30-50 microm, pore size 50-300 microm) was also constructed in the 3D cell culture system. After introduction to the scaffold using cells contained within a fibrin clot, fibroblasts were observed to stratify and also elongate between fibres in order to occupy voids. An interfibre span of up to 200 microm was possible by a single fibroblast, but more commonly void distances were spanned by cellular multilayering. In contrast, HaCaT keratinocytes cultured under identical conditions using viscose rayon scaffolds occupied very much smaller void distances of 50-80 microm predominantly by stratification.