Adipose-Derived Stem Cells in Bone Tissue Engineering: Useful Tools with New Applications

Abstract

Adipose stem cells (ASCs) are a crucial element in bone tissue engineering (BTE). They are easy to harvest and isolate, and they are available in significative quantities, thus offering a feasible and valid alternative to other sources of mesenchymal stem cells (MSCs), like bone marrow. Together with an advantageous proliferative and differentiative profile, they also offer a high paracrine activity through the secretion of several bioactive molecules (such as growth factors and miRNAs) via a sustained exosomal release which can exert efficient conditioning on the surrounding microenvironment. BTE relies on three key elements: (1) scaffold, (2) osteoprogenitor cells, and (3) bioactive factors. These elements have been thoroughly investigated over the years. The use of ASCs has offered significative new advancements in the efficacy of each of these elements. Notably, the phenotypic study of ASCs allowed discovering cell subpopulations, which have enhanced osteogenic and vasculogenic capacity. ASCs favored a better vascularization and integration of the scaffolds, while improvements in scaffolds' materials and design tried to exploit the osteogenic features of ASCs, thus reducing the need for external bioactive factors. At the same time, ASCs proved to be an incredible source of bioactive, proosteogenic factors that are released through their abundant exosome secretion. ASC exosomes can exert significant paracrine effects in the surroundings, even in the absence of the primary cells. These paracrine signals recruit progenitor cells from the host tissues and enhance regeneration. In this review, we will focus on the recent discoveries which have involved the use of ASCs in BTE. In particular, we are going to analyze the different ASCs' subpopulations, the interaction between ASCs and scaffolds, and the bioactive factors which are secreted by ASCs or can induce their osteogenic commitment. All these advancements are ultimately intended for a faster translational and clinical application of BTE.

Adipose Tissue-Derived Stem Cells: The Biologic Basis and Future Directions for Tissue Engineering

“…Several materials with the ability to mimic the ECM have been investigated for scaffold production, potentiating the effects of ASCs. These materials range from decellularized tissue matrices to inorganic ceramics, such as bioceramics with application in hard tissue replacement orthodontic; polymers- natural proteins, polysaccharides with applications in connective and hard tissues, decellularized living tissues/organs and drug delivery; polymers synthetic degradable with application in implants and non-degradable for orthopedic implants; metals for orthopedic and dental application; composites with orthopedic and dental application [ 43 , 44 , 45 ].…”

Polymer-Bioactive Glass Composite Filaments for 3D Scaffold Manufacturing by Fused Deposition Modeling: Fabrication and Characterization

“…Their main advantage is their potential for osteogenic differentiation in comparison to e.g., MG-63 cells which are arrested in pre-osteoblastic state (Czekanska et al, 2012 ). The potential of adipose-derived stem cells (ASC) for bone engineering has been recently highlighted (Vishnubalaji et al, 2012 ; Bhattacharya et al, 2016 ; Iaquinta et al, 2019 ; Storti et al, 2019 ) and ASC have been applied on biomaterial scaffolds as a potential critical size defect treatment strategy (Du et al, 2018 ). The high availability of ASC from body lipoaspirates (Yang et al, 2019 ) combined with the potential for osteogenic differentiation (Zhang et al, 2015 ) and defect reconstruction (Mesimäki et al, 2009 ; Yoshida et al, 2019 ; Zang et al, 2019 ) in vivo renders ASC excellent candidates to study the osteoinductive properties of biomaterials, with promising implications towards clinical translation (Barba et al, 2017 ).…”

Promotion of Hair Growth by Conditioned Medium from Extracellular Matrix/Stromal Vascular Fraction Gel in C57BL/6 Mice

“…Using the patient's own stem cells to regenerate hair growth is a promising alternative therapeutic strategy [3]. Adipose-derived stem cells (ADSCs) are mesenchymal stem cells within the stromal vascular fraction (SVF) of subcutaneous adipose tissue, which have been extensively researched and have been applied in tissue engineering and regenerative medicine [4,5]. Furthermore, the field of ADSC-based regenerative medicine has now expanded to include the treatment of hair loss.…”