Probing the Role of Bone Lamellar Patterns through Collagen Microarchitecture Mapping, Numerical Modeling, and 3D‐Printing

Abstract

The fibrillar organization is crucial for the mechanics of osteonal bone and for its anisotropy. Different collagen fiber orientation (CFO) patterns are observed in bone and correlated to the main local loading, leading to the hypothesis that the fibers are preferentially aligned to bear specific loading types. A heterogeneous distribution of osteon morphotypes (OMs) is noticed in long bones, although the relationship between the OM spatial distribution and the local predominant loading is still unclear. This study aims to shed light on the reasons why Nature uses specific OMs in diverse stress‐dominated regions. A multimodal approach is adopted, including collagen fiber orientation mapping, numerical modeling of different OMs under tensile and compressive loading, and 3D‐printing of OM‐inspired samples, to unravel the relationship between different OMs and their mechanical behavior. Simulation results suggest a better performance of the vertical OM (VOM) under tensile loading and of the twisted OM (TOM) under compression, confirming earlier hypotheses. The outcomes of mechanical testing, conducted on 3D‐printed samples, highlight a possible buckling‐induced failure of fibers with preferential vertical orientation and provide evidence that OMs are stress‐tailored, opening new venues for the design of stress‐tuned bioinspired composites.

Optimized Hierarchical Structure and Chemical Gradients Promote the Biomechanical Functions of the Spike of Mantis Shrimps

“…The cracks penetrated the entire sample with the VFs, whereas the cracks in the sample with the TFs were mostly confined in the ML and presented a radial pattern similar to the cracks in the spike (Figure d). Specifically, the twisted fibers in the OL and IL delayed the structural failure and improved the mechanical performance of the samples. − …”

Design, manufacture, and testing of customized sterilizable respirator

“…Fig. 1 b shows the fast prototype of such a respirator with a polyjet multi-material 3D printer ( Grezzana et al, 2020 ; Qin et al, 2017 ; Xiang Gu et al, n.d. ). The 3D model was modified based on an open-source stereolithography file ( “MY FACE MASK: 3D printed face Mask with a replaceable filter,” n.d .…”

“…To balance the environmental issue and personal protection during the usage of respirators, one solution is to develop substituting fibrous network material that can provide similar protection but will not generate environmental issues in the long term. Natural materials including chitin, cellulose, hemicellulose, silk, collagen, keratin are found to have forms of various fibrous networks including mycelium (L. Yang et al, 2021 ), bamboo/wood/cotton fibers ( Cui et al, 2021 ), spider web/cocoon, basement membrane, and hair ( Buehler and Yung, 2009 ) that all have natural functions of filtration but can also be degraded within a more reasonable timeframe than plastics by microorganisms, causing no long-term issue to the environment ( Greer and Deshpande, 2019 ; Grezzana et al, 2020 ; Jones et al, 2020 ; Qin and Buehler, 2013 ; Shah et al, 2016 ). It is feasible to make fibrous membrane by using these biodegradable materials with an electro/melt spinning method and tailor the membrane into pieces of a desire shape to work as a changeable filter for the respirator.…”

Structural Mechanisms in Soft Fibrous Tissues: A Review

“…Based on Bancelin et al, 2015;Yang et al, 2015;Lynch et al, 2017. Zhang et al, 2019;Grezzana et al, 2020;Zorzetto et al, 2020). Nevertheless, using the same approach in soft fibrous tissues is more scarce.…”

“…For hard tissues, hierarchy is much frequently studied and mimicked. Moreover, and very notably, the nanoscale reinforcement is known to simultaneously favor the strength and toughness of materials (Evans, 1990; Launey and Ritchie, 2009), in particular bone (Gupta et al, 2005;Gupta et al, 2006;Launey and Ritchie, 2009;Libonati and Vergani, 2016;Grezzana et al, 2020). Therefore, combining nanoscale structures in higher levels constructs may provide valuable advantages.…”