Autologous Human Stromal Vascular Fraction Injection in Post- Burn Hypertrophic Scar: A Double-Blinded Placebo-Controlled ClinicalTrial

Background and Aim: Post-burn hypertrophic scar (HTS) is a commoncomplication of burn injury which results from the prolongedinflammatory response, and leads to cosmetic, functional, andpsychological complications. Adipose-derived stromal vascular fraction(SVF) contains heterogenous cells with regenerative, anti-inflammatoryand anti-fibrotic properties.Methods: In this phase I randomized placebo-controlled clinical trial,we aimed to evaluate the safety and potential efficacy of intra-dermalinjection of autologous SVF in HTS. We enrolled 20 patients whohad HTS for more than 1 year with Vancouver scar scale (VSS) of ≥4.In each patient, two 6 cm2 scar sites were randomly received 2 mL ofSVF (1×106 cells/cm2) or normal saline. Patients were followed till 4months post-transplantation. Our primary endpoint was the number andseverity of adverse events. Our secondary endpoints were alterations inVSS score, skin thickness (dermal and epidermal layers) measured usinghigh resonance ultrasound, patient self-assessment of HTS improvementbased on visual analog scale (VAS), and level of expression of TGF-βassessed by immunohistochemical assay. This study has been registeredwith IRCT.ir (identifier: IRCT2012070710201N1).Results: Safety evaluations showed no major and serious adverseevents in treated patients. The mean VSS scores of the treatment andplacebo sites before the injection were 8.0±1.2 and 7.3 ±1.6 whichrespectively decreased to 6.4±1.4 and 6.7±1.7 at 4 months following celltransplantation. The mean VAS at 4 months after cell transplantation inSVF and control groups was respectively 3.2±2.2 and 0.7±1.8. The meanskin thickness in SVF group decreased from 2.9±0.7 mm to 2.7±0.6 mm,while in the control group was respectively 2.8 ±0.7 mm and 2.8±0.8mm, before and 4 months after the treatment. The expression level ofTGF-β3 increased in SVF group skin biopsy specimens compared toplacebo group, 4 months after cell injection.Conclusion: In this study, we demonstrated safety and tolerability ofautologous SVF intra-dermal injection in HTS. Besides, our study resultsindicated the potential efficacy of SVF injection in HTS probably via theanti-inflammatory and regenerative properties of SVF cells. However, thisneeds to be confirmed performing further investigations.

کلیدواژه ها:

Stromal cells Burns Cicatrix ، Hypertrophic Regenerative medicine