Investigating the micro- and nanostructure of microfibrous biocompatible polyurethane scaffold by scanning probe nanotomography

This paper presents a study of three-dimensional micro- and nanosctucture of polyurethane dual scale biocompatible scaffold made by three-dimensional printing and electrospinning. The three-dimensional structure of the scaffold was analyzed by scanning probe nanotomography with use of an experimental setup combining an ultramicrotome and a scanning probe microscope. We performed a quantitative analysis of microporosity, nanoroughness, and three-dimensional morphology parameters of the scaffold. The electrospun scaffold consists of a network of microfibers with diameter ranging from 1.7 to 6.0 μm. The measured mean microfiber diameter is 3.54 ± 1.23 μm. The volume porosity of the electrospun scaffold is 72.5%, while mean surface area to volume ration is 0.28 μm–1 and mean nanoroughness of microfiber surface is 22.1 ± 3.0 nm. The quantitative characteristics of the micro- and nanostructure of elecrospun polyurethane matrices secure the high efficacy of its usage for increasing the biocompatibility of dual-scale hybrid bioengineered scaffolds for regenerative medicine tasks. The use of scanning probe nanotomography for analyzing threedimensional morphology characteristics and the topology of electrospun microfiber systems enables us to improve the efficiency of development of new bioengineered products.