Delivery of Human Adipose Stem Cells Spheroids into Lockyballs

Abstract

Adipose stem cells (ASCs) spheroids show enhanced regenerative effects compared to single cells. Also, spheroids have been recently introduced as building blocks in directed self-assembly strategy. Recent efforts aim to improve long-term cell retention and integration by the use of microencapsulation delivery systems that can rapidly integrate in the implantation site. Interlockable solid synthetic microscaffolds, so called lockyballs, were recently designed with hooks and loops to enhance cell retention and integration at the implantation site as well as to support spheroids aggregation after transplantation. Here we present an efficient methodology for human ASCs spheroids biofabrication and lockyballs cellularization using micro-molded non-adhesive agarose hydrogel. Lockyballs were produced using two-photon polymerization with an estimated mechanical strength. The Young’s modulus was calculated at level 0.1362 +/-0.009 MPa. Interlocking in vitro test demonstrates high level of loading induced interlockability of fabricated lockyballs. Diameter measurements and elongation coefficient calculation revealed that human ASCs spheroids biofabricated in resections of micro-molded non-adhesive hydrogel had a more regular size distribution and shape than spheroids biofabricated in hanging drops. Cellularization of lockyballs using human ASCs spheroids did not alter the level of cells viability (p › 0,999) and gene fold expression for SOX-9 and RUNX2 (p › 0,195). The biofabrication of ASCs spheroids into lockyballs represents an innovative strategy in regenerative medicine, which combines solid scaffold-based and directed self-assembly approaches, fostering opportunities for rapid in situ biofabrication of 3D building-blocks.

Combining Stem Cells and Biomaterial Scaffolds for Constructing Tissues and Cell Delivery

“…This figure was reproduced under a Attribution 4.0 International (CC BY 4.0). Figure taken from[135].…”

Tailored Melt Electrowritten Scaffolds for the Generation of Sheet‐Like Tissue Constructs from Multicellular Spheroids

“…The latter are considered an important building block in biofabrication and have been proposed as larger, assembled structures. These approaches include using bioprinting‐assisted spheroid fusion, microneedle‐based (Kenzan) spheroid assembly, caging within 2PP‐fabricated “lockyballs” and spheroids combined with direct polymer melt deposition …”

Adult Stem Cells Spheroids to Optimize Cell Colonization in Scaffolds for Cartilage and Bone Tissue Engineering

“…ASC spheroids were formed inside lockyballs showing high aggregation capacity in vitro, maintaining master gene expression for chondrogenesis and osteogenesis. This methodology represents an innovative strategy for tissue engineering, since the resulting tissue construct shows a larger area of cells (spheroids) than material and could represent a building-block [ 83 ].…”