title: Stromal-derived factor-1 alpha-loaded PLGA microspheres for stem cell recruitment.
abstract: OBJECTIVE
  Stromal-derived factor-1 alpha (SDF-1α) is a chemoattractant that has been investigated for treating various diseases, with the goal of recruiting endogenous stem cells to the site of injury. Biodegradable PLGA microspheres were investigated as a means to deliver SDF-1α in a sustained-release manner.
  
  
  METHODS
  We encapsulated SDF-1α into biodegradable poly(lactide-co-glycolide) (PLGA) microspheres using a double-emulsion solvent extraction/evaporation technique. We varied several formulation parameters, characterized the in vitro release profile of SDF-1α and the size and morphology of microspheres, and determined the bioactivity of the released SDF-1α of stimulating migration of mesenchymal stem cells (MSCs).
  
  
  RESULTS
  We found that microspheres fabricated using end-capped PLGA, BSA as an excipient, and low solvent volumes yielded a high encapsulation efficiency (>64%) and released SDF-1α over a >50-day timeframe. The released SDF-1α was bioactive and caused significant migration of MSCs throughout the duration of release from the microspheres.
  
  
  CONCLUSIONS
  We have identified several variables that led to successful encapsulation of SDF-1α into PLGA microspheres. We envision that SDF-lα-loaded microspheres may serve as injectable sources of sustained-release chemokine for promoting the recruitment of endogenous stem cells to the site of injury.
authors: Department of Biomedical Engineering, University of Minnesota, 7-105 Hasselmo Hall, 312 Church Street S. E., Minneapolis, MN 55455, USA.
authors: Daisy P
authors: DP
authors: Cross
authors: Chun
authors: C
authors: Wang
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