Bioinspired Growth of Mineralized Tissue

Abstract

578

Embryonic‐Like Mineralized Extracellular Matrix/Stem Cell Microspheroids as a Bone Graft Substitute

“…Optimum bone grafts, including autografts, should possess osteoconductivity, to allow bone‐forming cells to attach, bone ingrowth, and osteoinductivity, which requires the presence of bioactive cells to induce bone regeneration . In this study, MECS comprising mineralized ECM and embedded BMMSCs showed enhanced intrinsic osteoconductivity and osteoinductivity revealed by the in vitro and in vivo experiments, and therefore could be considered as a synthetic alternative to autografts.…”

“…When BMMSCs were cultured in the mineralizing medium containing polyaspartic acid and calcium and phosphate ions, the self‐produced ECM could be mineralized, leading to larger sized solid MECS with a diameter of 246.67 ± 15.28 µm. From scanning electron microscopy (SEM) images of surface morphology, the CS showed a flat and smooth cellular morphology, while nano‐hydroxyapatites (nHAs, 377 ± 59 nm) were mainly deposited around collagen filaments secreted by the BMMSCs; cells were embedded in the MECS, recapitulating the early stage of intramembranous ossification ( Figure a) . Cross‐section of MECS further showed more collagen filaments and direct cell–cell communication via filaments (Figure S2, Supporting Information).…”

“…The native extracellular matrix (ECM) produced by mesenchymal precursors is a complex entity composed of structural proteins (primarily collagen), proteoglycans, and specialized multi‐adhesive proteins . During skeletal development, the collagen‐based ECM serves as a temporary matrix for mineralized tissue deposition, and also acts as a reservoir for many signaling molecules modulating cell activities such as intracellular communication, growth and differentiation .…”

“…During embryonic bone development, mesenchymal precursor cell‐derived osteoblasts form compact aggregates accompanied by secretion and mineralization of collagen‐rich ECM, leading to osteoblasts being embedded in the mineralized matrix. The mineralized matrix provides mechanical support for osteoblasts and promote differentiation of osteoblasts to osteocytes, which play a critical role in bone remodeling and repair processes . Therefore, from the perspective of biomimetic design, an ideal bone graft would meet the following requirements: i) mimic native ECM to provide a physiological environment for cell accommodation, ii) fabricate 3D cell‐embedded micromolds to improve intercellular crosstalk, and iii) provide sufficient mechanical strength and stiffness to support osteoblast proliferation and differentiation .…”