It is necessary to highlight here the inspiring effect of different pioneers of biomedical additive manufacturing and colleagues in the fields of tissue engineering, regenerative medicine and biofabrication. The idea of an accessible computer-aided design library of solutions for these fields is not novel. Seminal studies systematically investigated polyhedral shapes for scaffolds modeling, selected and classified the most suitable ones, implemented the first parametric library of scaffolding structures, demonstrated its utility for personalizing implants and validated it through rapid prototyping resources [1-2]. A study focusing on the interconnectivity of varied types of lattices to obtain complex-shape scaffolds was also conducted one decade ago [3]. More recently, the growing interest of additive manufacturing with high performance materials for lightweight design has led to the development of design charts for selection purposes [4-5], in which lattices, scaffolds and mechanical metamaterials are compared following Ashby graphs [6]. In this respect, the most systematic approach, combining computational modeling, simulations, prototyping and testing, has been probably carried out in recent years by Egan’s team, in connection to biomedical applications [7-9], focusing also on the modeling of tissue growth depending on scaffolds’ characteristics [10].

However, authors consider that some specific features of the newly presented open-source library of scaffolds are quite remarkable and may complement some of the aforementioned studies.

First, the presented library is designed for additive manufacturing considering most technologies applicable to scaffolds’ manufacturing; and provides specific designs for enhanced printability employing fused-deposition modeling, inkjet printing, poly-jet technology, selective laser sintering or melting, laser stereolithography, digital light processing, lithography-based ceramic manufacturing or two-photon polymerization, to cite some possibilities.

Second, the library counts with specific subsets of scaffolding geometries focused on multi-material and multi-scale or fractal-like solutions, taking into account the biomimetic and biomechanical solutions for complex tissue restorations normally require multi-material and multi-scale approaches, which have become also an essential trend in biomedical AMTs [11-13].

Third, the relevance of cell-material interactions and biointerfaces is considered [14-16] and subsets of test probes with design-controlled microtopographies and microtextured scaffolds are included in a related UBORA device (Open-source library of microtextured geometries for studying cell-material interactions).

Fourth, one of the main purposes of this open-source library is testing and pushing the current technological limits of AMTs and related printable materials, for which the dimensions of scaffolds and trusses and the incorporated microstructural and topographical details go beyond the common limits of AMTs and 3D printed scaffolds.

Fifth, FAIR data principles [17] have guided the implementation of the open-source library.

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