###### Abstract  
Recent progress in bioprinting has made possible the creation of complex 3D intestinal constructs, including vascularized villi. However, for their integration into functional units useful for experimentation or implantation, the next challenge is to endow them with a larger-scale, anatomically realistic vasculature. In general, the perfusion of bioprinted constructs has remained difficult, and the current solution is to provide them with mostly linear and simply branched channels. To address this limitation, here we demonstrated an image analysis-based workflow leading through computer-assisted design from anatomic images of rodent mesentery and colon to the actual printing of such patterns with paste and hydrogel bioinks. Moreover, we reverse-engineered the 2D intestinal image-derived designs into cylindrical objects, and 3D-printed them in a support hydrogel. These results open the path towards generation of more realistically vascularized tissue constructs for a variety of personalized medicine applications. 3D bioprinting; image analysis; vasculature; personalized; intestine; mesentery; FRESH bioprinting Article  
Design and Implementation of Anatomically Inspired Mesenteric and Intestinal Vascular Patterns for Personalized 3D Bioprinting  
[PERSON]; [PERSON]; [PERSON]; [PERSON] Design and Implementation of Anatomically Inspired Mesenteric and Intestinal 3D  
[PERSON]; [PERSON] Design and Implementation of Anatomically Inspired Mesenteric and Intestinal 3D  
In order to stay alive, any cell in animal tissues is located no further than about 200 \(\upmu\)m from a nearby capillary [11]. The microvascular networks are supplied by larger vessels distributed in space in a fractal manner [12], and composed of segments with increasingly complex cellular composition as the diameter of the vessels increases. Yet, the bioprinting of constructs with vascularization (and even more so with innervation) lags behind, although critical for their survival and function [13]. At least in part, this is due to the origination of bioprinting from the technology of additive manufacturing [14], which focuses on the objects' external shape with less consideration for their inner structure, which, in general, is supposed to be filled with more or less homogenously distributed materials, or with cells expected to perform self-assembling [15]. So far, most of the 'vascularization' of bioprinted constructs was provided by linear channels, occasionally lined by an endothelial layer [13]. Of note, simple vascular channels have been incorporated in the bioprinted model of the intestinal finger-like villi, fabricated using a collagen bioink alone [9], or, in an improved version, collagen supplemented with extracellular matrix from the small intestinal submuc [10]. The next step would be to connect these microvessels to blood supply networks with the structural properties of the intestinal vasculature and, desirably, also to mesenteric ones, preferably in a patient-personalized manner; however, to our knowledge such constructs have not been created yet. To address this limitation, we recently suggested to directly import, in the bioprinted models, anatomically realistic tissue-specific structures [16] and vascular patterns [17] derived from microscopic or macroscopic images, respectively. One of the conspicuous features of vascularization is the fractal organization of its branched architecture, with dimensions and cellular composition dependent of the branching order, also known as 'branch generation' [18]. Thus we asked whether it is possible to capture and transfer this refined structural information in the printed vascular patterns using a dedicated image analysis program called VESGEN 2D [17], and we showed its utility in printing such patterns extracted from human eye fundus [19]. Here we applied this same workflow specifically to intestinal (both colonic and mesenteric) vasculature.