Injectable soft-tissue augmentation by tissue engineering and regenerative medicine with human mesenchymal stromal cells, platelet-rich plasma and hyaluronic acid scaffolds

Background aimsThe aim of this study was to evaluate the possibility of soft-tissue augmentation adopting tissue engineering and regenerative medicine (TERM) technology for a longer duration of injected implants.MethodsTERM is the combination and re-organization of three types of injection materials to regenerate organs and tissues: (i) living cells, including cultured human mesenchymal stromal cells (hMSCs) and human fibroblasts (hFibro); (ii) scaffolds of hyaluronic acid (HA); and (iii) growth factors of platelet-rich plasma (PRP). The experimental combinations were as follows: HA, HA/hFibro, HA/hMSCs, HA/PRP, HA/PRP/hFibro and HA/PRP/hMSCs. These were injected intradermally into immunodeficient rats and evaluated by histologic analysis, percentage of original volume and maintenance volume.ResultsThe percentage of original volume values at 14 days were 0.02 ± 0.01% (HA), 0.20 ± 0.03% (HA/hFibro), 0.50 ± 0.02% (HA/hMSCs), 11.66 ± 1.81% (HA/PRP), 24.36 ± 8.97% (HA/PRP/hFibro) and 28.04 ± 4.11% (HA/PRP/hMSCs), respectively. There were significant differences between groups with and without PRP. Regarding maintenance volume values, HA/PRP, HA/PRP/hFibro and HA/PRP/hMSCs from 7 to 14 days were also higher, at 46.25 ± 1.21%, 78.39 ± 2.90% and 88.81 ± 5.97%, respectively. HA/PRP/hMSCs groups maintained the shape and dimensions of the injected implant, indicating that the injected cells produced type I collagen.ConclusionsThe findings suggest that a soft tissue-engineered procedure with MSCs may be useful for longer lasting soft-tissue augmentation.