Introducing Controlled Microporosity in Melt Electrowriting. Issue 6 (27th January 2023)

• Record Type: Journal Article
• Authors: Mueller, Kilian Maria Arthur; Unterrainer, Andreas; Rojas‐González, Diana Marcela; De‐Juan‐Pardo, Elena; Willner, Marian Sebastian; Herzen, Julia; Mela, Petra
• Is Part Of: Advanced materials technologies. Volume 8:Issue 6(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-01-27
• Subjects: cell infiltration -- mechanical anisotropy -- melt electrowriting -- pore morphology -- pore size -- randomized fibers -- tissue engineering; Materials science -- Periodicals; Technological innovations -- Periodicals; Materials science; Technological innovations; Periodicals; 620.1105
• DOI: 10.1002/admt.202201158
• Languages: English
• ISSNs: 2365-709X

Abstract

Abstract: Melt electrowriting (MEW) enables the electric field‐assisted digital fabrication of precisely defined scaffold architectures of micron‐sized fibers. However, charge accumulation and consequent disruption of the precoded pattern by fiber bridging prevents controlled printing at small interfiber distances. This, together with the periodical layer stacking characteristic for additive manufacturing, typically results in scaffolds with channel‐like macroporosity, which need to be combined with other biofabrication techniques to achieve the desired microporosity for cellular infiltration. Therefore, a design strategy is devised to introduce controlled interconnected microporosity directly in MEW scaffolds by an algorithm that creates arrays of bridging‐free parallel fibers, angularly shifted from layer to layer and starting at a random point to avoid periodical fiber stacking, and hence channel‐like pores while defining micropores. This work hypothesizes that pore size can be controlled, decoupled from fiber diameter, and the mechanical properties, including anisotropy ratio, can be tuned. The authors demonstrate this while leveraging the platform for both flat and seamless tubular scaffolds and characterize them via micro‐computed tomography and tensile loading. Lastly, successful cell ingrowth into the micropores and extracellular matrix formation are shown. This platform enables microporous scaffolds entirely via MEW that can be tailored to the architectural and mechanical requirements of the target tissues. Abstract : This work introduces controlled microporosity to fibrous scaffolds fabricated via melt electrowriting. A software platform enables the multifaceted design of both flat and seamless tubular scaffold architectures that can be independently controlled in terms of their fiber diameter, pore size, and shape, as well as their structural anisotropy, while enabling efficient cell infiltration.