Micropatterning Electrospun Scaffolds to Create Intrinsic Vascular Networks

Abstract

Sufficient vascularization is critical to sustaining viable tissue-engineered (TE) constructs after implantation. Despite significant progress, current approaches lack suturability, porosity, and biodegradability, which hinders rapid perfusion and remodeling in vivo. Consequently, TE vascular networks capable of direct anastomosis to host vasculature and immediate perfusion upon implantation still remain elusive. Here, a hybrid fabrication method is presented for micropatterning fibrous scaffolds that are suturable, porous, and biodegradable. Fused deposition modeling offers an inexpensive and automated approach to creating sacrificial templates with vascular-like branching. By electrospinning around these poly(vinyl alcohol) templates and dissolving them in water, microvascular patterns were transferred to fibrous scaffolds. Results indicated that these scaffolds have sufficient suture retention strength to permit direct anastomosis in future studies.Vascularization of these scaffolds is demonstrated by in vitro endothelialization and perfusion.

Tissue engineered vascular grafts: Origins, development, and current strategies for clinical application

“…Another area of recent interest has focused on modifying the manufacturing technique and the actual production of a graft for mechanical testing, with preliminary results showing three histologically distinct layers with distinct burst strength and suture retention profiles, hence setting the groundwork for manipulation of these individual layers for further refinement and manufacturing [58]. Finally, more preliminary work has again taken the advantage of the both the properties of biocompatible scaffolds and the multiple areas in the electrospinning process by utilizing fused deposition modeling to pattern the TEVG along a robust, high-suture retention-property scaffold for use in microvascular networks [59]. Electrospun TEVGs, however, have yet to be implanted in clinical trials.…”

Osteosarcoma growth on trabecular bone mimicking structures manufactured via laser direct write

“…This method has been demonstrated to produce both vili-shaped surface relief patterns and 3D woodpile-structured with internal porosity [20,21] . The use of a sacrificial scaffold has also been used in conjunction with electrospinning to produce microporous electrospun mats with internal channels to introduce a prototype vascular network in these scaffolds [22,23] . Recent studies reported on the use of layer-by-layer stereolithography for selectively photocuring Poly-HIPE emulsions to fabricate customised structures with both random microporosity and controlled macroporosity [11,13,24] .…”

Fabrication of scalable tissue engineering scaffolds with dual-pore microarchitecture by combining 3D printing and particle leaching

“…Recently, 3D printed poly(vinyl alcohol) (PVA) sacrificial moulds using 3D filament printer have been demonstrated to facilitate fabrication of porous polymeric scaffolds for various tissue engineering applications [23,24]. Ortega et al and Jeffries et al have proposed a new fabrication approach by encapsulating 3D printed single layered PVA channels using an inexpensive 3D filament printer in combination with electrospun nanofibers to create perfusable vascular networks [23,24].…”

“…Ortega et al and Jeffries et al have proposed a new fabrication approach by encapsulating 3D printed single layered PVA channels using an inexpensive 3D filament printer in combination with electrospun nanofibers to create perfusable vascular networks [23,24]. However, the fabricated scaffolds only comprised a single layer of channels, hence, they didn't generate a functional tissue/organ composed of multiple layers.…”