Delivery of Human Adipose Stem Cells Spheroids into Lockyballs

PLoS One. 2016 Nov 9;11(11):e0166073. doi: 10.1371/journal.pone.0166073. eCollection 2016.

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.

MeSH terms

  • Adipose Tissue / cytology*
  • Adolescent
  • Adult
  • Cell Culture Techniques
  • Cells, Cultured
  • Core Binding Factor Alpha 1 Subunit / genetics
  • Elastic Modulus
  • Female
  • Gene Expression
  • Humans
  • Hydrogels / chemistry
  • Microscopy, Confocal
  • Microscopy, Electron, Scanning
  • Microscopy, Fluorescence
  • Middle Aged
  • Regenerative Medicine / methods
  • Reverse Transcriptase Polymerase Chain Reaction
  • SOX9 Transcription Factor / genetics
  • Sepharose / chemistry
  • Spheroids, Cellular / chemistry
  • Spheroids, Cellular / cytology
  • Spheroids, Cellular / transplantation*
  • Stem Cell Transplantation / methods
  • Stem Cells / cytology*
  • Stem Cells / metabolism
  • Stem Cells / ultrastructure
  • Tissue Engineering / methods
  • Tissue Scaffolds / chemistry*
  • Young Adult

Substances

  • Core Binding Factor Alpha 1 Subunit
  • Hydrogels
  • RUNX2 protein, human
  • SOX9 Transcription Factor
  • SOX9 protein, human
  • Sepharose

Grants and funding

This work was funded by CNPq—457541/2013-0—Chamada N° 47/2013 MCTI/CNPq/CT-Saúde/CT-Biotecnologia/MS/SCTIE/DECIT—Novas Terapias Portadoras de Futuro to JMG; European Research Council (Starting Grant-307701) to AO; CNPq Regenerative Medicine project 467643/2014-8 to JVLS; and Brazilian Institute of Biofabrication (INCT-BIOFABRIS) 08/57860-3 to JVLS.