Scaffolds design impacts fibroblasts in a 3D gingival model

Objectives: Cells grown on 3D scaffolds have begun to be used widely for specific tissue formation. Melt-electrowriting polycaprolactone (PCL) 3D printed scaffolds can be design to mimick natural extracellular matrix (ECM) structures. This structures may emulate gingival environment and become a reproducible gingiva connective tissue model. This study aims to understand the effects of pores size and architectural design on gingival fibroblasts functions and ECM secretion in a 3D PCL scaffolds using the melt electrowriting (MEW) technique.
Methods: Four homogeneous pore-sized (125, 250, 500, and 750 μm), one fiber offset (50/50%) and a three layered (250 μm bottom−500 μm middle−750 μm top) gradient pore-sized scaffolds were designed and printed with ∼10 μm diameter fibers. Human gingival fibroblasts (GF), from 3 different patients, were seeded and studied for 21 days. Viability, adhesion, proliferation were analysed. SEM imaging used to analyse the pore filling and fibroblasts spreading while confocal imaging used to analyse 3D reconstructions of major extracellular macromolecules.
Results: GF were able to grow on every scaffolds and no toxicity was observed. Cell attachment and proliferation showed better results on 250 μm, the offset and the gradient scaffold architectures. Indeed, ECM deposition-fibrillar collagen, fibronectin and collagen were more visible in heterogeneous designs after 14 days. ECM was able to fill the pores only in these scaffolds while on the other ones, ECM was limited along the fibres. These results were confirmed through SEM imaging.
Conclusions: This study compared the human gingival fibroblasts functions on 3D PCL models with different architectures. We demonstrated that scaffold design impacted gingival ECM deposition, localization, attachment and differentiation. The homogeneous 250 μm and the both heterogeneous scaffold designs showed advantageous architecture for cell proliferation and deposition. Thus, such in-vitro designs could be used to model and mimick gingival connective tissue.