A review of developments in electrospinning technology: New opportunities for the design of artificial tissue structures

Purpose: As a technology for the production of micro- and nanostructured scaffold materials, electrospinning has gained widespread acceptance in the medical research community over the last decade. The process generates a non-woven fiber mat consisting of one continuous filament with diameters ranging from the micron to the nanometer range. Because of its similarity to the filamentous microenvironment in native tissues, it is most often used as scaffold material in tissue engineering applications. This similarity promotes a more positive cell response to the generated fibers than to bulk material alone. However, because current electrospinning equipment does not yet fully utilize the potential of the process technology, the reproducibility of the scaffold structure is often limited. It is thus the goal of this review to describe the current state of electrospinning process technology with respect to the design of artificial tissue structures. Method: This review is based on a comprehensive examination conducted in 2007 and 2008 of patents filed with the European Patent Organization and other scientific publications. Results: It describes selected technical developments in electrospinning related to the production of non-woven fiber scaffolds and their implications in the design of artificial tissue structures. Specifically, it describes techniques for the production of aligned fiber structures, multilayered, multiscaled and multifiber scaffolds, fiber modification and functionalization, and useful advances in process control. It also presents technical sketches showing in detail how to implement the techniques presented into electrospinning equipment setups. Finally, it discusses remaining limitations that pertain to the design of scaffold materials.