Systematic review on spheroids from adipose‐derived stem cells: Spontaneous or artefact state?

Abstract

Three‐dimensional (3D) cell cultures represent the spontaneous state of stem cells with specific gene and protein molecular expression that are more alike the in vivo condition. In vitro two‐dimensional (2D) cell adhesion cultures are still commonly employed for various cellular studies such as movement, proliferation and differentiation phenomena; this procedure is standardized and amply used in laboratories, however their representing the original tissue has recently been subject to questioning. Cell cultures in 2D require a support/substrate (flasks, multiwells, etc.) and use of fetal bovine serum as an adjuvant that stimulates adhesion that most likely leads to cellular aging. A 3D environment stimulates cells to grow in suspended aggregates that are defined as “spheroids.” In particular, adipose stem cells (ASCs) are traditionally observed in adhesion conditions, but a recent and vast literature offers many strategies that obtain 3D cell spheroids. These cells seem to possess a greater ability in maintaining their stemness and differentiate towards all mesenchymal lineages, as demonstrated in in vitro and in vivo studies compared to adhesion cultures. To date, standardized procedures that form ASC spheroids have not yet been established. This systematic review carries out an in‐depth analysis of the 76 articles produced over the past 10 years and discusses the similarities and differences in materials, techniques, and purposes to standardize the methods aimed at obtaining ASC spheroids as already described for 2D cultures.

Twenty years of islet-on-a-chip: microfluidic tools for dissecting islet metabolism and function

“…This includes stem-cell-derived 3D aggregates, spheroids derived from adipose stem cells, liver cells, and lung spheroids, among many others. These microfluidic platforms offer immobilization for imaging, a customizable controlled microenvironment, and the possibility of detecting secreted metabolites such as VEGF from adipose derived stem cell spheroids 104 or albumin from liver spheroids. 105 However, it is important to note that islet-on-a-chip devices designed for detecting secreted metabolites are tailored based on the reaction kinetics of the tracer molecule and antibody.…”

Self‐Healing Hydrogel Containing Decellularized Liver Matrix and Endothelial Cell‐Covered Hepatocyte Spheroids for Rescue of Injured Hepatocytes

“…[ 31 ] Additionally, an elevated secretion of VEGF was observed in the spheroids under lower oxygen conditions compared to higher oxygen conditions. [ 32 ] Since the inner necrotic zone of spheroids contains cells that are senescent/apoptotic due to limited nutrients and oxygen influx (hypoxia), [ 33 ] the finding indicates that VEGF is more abundantly secreted inside hepatocyte spheroids, thereby inducing the migration of HUVECs from the exterior.…”

Advancements in culture technology of adipose-derived stromal/stem cells: implications for diabetes and its complications

“…Existing techniques for ASC culture can be categorized into scaffold-free and scaffold systems (26,99). The conventional scaffold-free culture techniques, such as the use of low adhesion plates, hanging drops, and spinner flasks, have been shown to impact the viability and stemness of ASCs.…”

“…Furthermore, threedimensional (3D) cultured cells are studied to prolong the lifespan of transplanted cells and enhance their pro-healing functions in unfavorable environments (22)(23)(24)(25). Recent literature provides numerous strategies for obtaining 3D cultured ASCs (26). These cells possess enhanced abilities to maintain their stemness and display multilineage plasticity compared to cells cultured in adhesion (26).…”

“…Recent literature provides numerous strategies for obtaining 3D cultured ASCs (26). These cells possess enhanced abilities to maintain their stemness and display multilineage plasticity compared to cells cultured in adhesion (26). Moreover, 3D cells more closely mirror biological processes compared to cells cultured in traditional monolayers, driving the need for the development of 3D culture, including spheroids, organoids, organ-on-a-chip models, and bioprinting (27)(28)(29).…”