Human Adipose-Derived Stem Cell-Conditioned Medium Promotes Vascularization of Nanostructured Scaffold Transplanted into Nude Mice

Several studies have been conducted on the interaction between three-dimensional scaffoldsand mesenchymal stem cells for the regeneration of damaged tissues. Considering that stem cellsdo not survive for sufficient time to directly sustain tissue regeneration, it is essential to developcell-free systems to be applied in regenerative medicine. In this work, by in vivo experiments, weestablished that a collagen-nanostructured scaffold, loaded with a culture medium conditioned withmesenchymal stem cells derived from adipose tissue (hASC-CM), exerts a synergic positive effecton angiogenesis, fundamental in tissue regeneration. To this aim, we engrafted athymic BALB-Cnude mice with four different combinations: scaffold alone; scaffold with hASCs; scaffold withhASC crude protein extract; scaffold with hASC-CM. After their removal, we verified the presence ofblood vessels by optical microscopy and confirmed the vascularization evaluating, by real-time PCR,several vascular growth factors: CD31, CD34, CD105, ANGPT1, ANGPT2, and CDH5. Our resultsshowed that blood vessels were absent in the scaffold grafted alone, while all the other systemsappeared vascularized, a finding supported by the over-expression of CD31 and CDH5 mRNA. Inconclusion, our data sustain the capability of hASC-CM to be used as a therapeutic cell-free approachfor damaged tissue regeneration.