Implantation of Stromal Vascular Fraction Progenitors at Bone Fracture Sites: From a Rat Model to a First-in-Man Study


Saxer F., Scherberich A., Todorov A., Studer P., Miot S., Schreiner S., ...More

STEM CELLS, vol.34, no.12, pp.2956-2966, 2016 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 34 Issue: 12
  • Publication Date: 2016
  • Doi Number: 10.1002/stem.2478
  • Journal Name: STEM CELLS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.2956-2966
  • Keywords: Adipose tissue, Cellular therapy, Osteoporotic fracture, Bone repair, Mesenchymal stromal cells, MESENCHYMAL STEM-CELLS, HUMAN ADIPOSE-TISSUE, VASCULOGENIC GRAFTS, OSTEOGENIC GRAFTS, ILIAC CREST, DIFFERENTIATION, REGENERATION, DEFECTS, OSTEOPOROSIS, CAPACITY
  • Dokuz Eylül University Affiliated: Yes

Abstract

Stromal Vascular Fraction (SVF) cells freshly isolated from adipose tissue include osteogenicand vascular-progenitors, yet their relevance in bone fracture healing is currently unknown. Here, we investigated whether human SVF cells directly contribute to the repair of experimental fractures in nude rats, and explored the feasibility/safety of their clinical use for augmentation of upper arm fractures in elderly individuals. Human SVF cells were loaded onto ceramic granules within fibrin gel and implanted in critical nude rat femoral fractures after locking-plate osteosynthesis, with cell-free grafts as control. After 8 weeks, only SVF-treated fractures did not fail mechanically and displayed formation of ossicles at the repair site, with vascular and bone structures formed by human cells. The same materials combined with autologous SVF cells were then used to treat low-energy proximal humeral fractures in 8 patients (64-84 years old) along with standard open reduction and internal fixation. Graft manufacturing and implantation were compatible with intraoperative settings and led to no adverse reactions, thereby verifying feasibility/safety. Biopsies of the repair tissue after up to 12 months, upon plate revision or removal, demonstrated formation of bone ossicles, structurally disconnected and morphologically distinct from osteoconducted bone, suggesting the osteogenic nature of implanted SVF cells. We demonstrate that SVF cells, without expansion or exogenous priming, can spontaneously form bone tissue and vessel structures within a fracture-microenvironment. The gained clinical insights into the biological functionality of the grafts, combined with their facile, intra-operative manufacturing modality, warrant further tests of effectiveness in larger, controlled trials.