Assessing keloid treatment efficacy: a comparison of intralesional umbilical-cord mesenchymal stem cells, their conditioned medium, and triamcinolone acetonide injection through macroscopic and microscopic examination

Background: Current keloid treatment involves intralesional injection of triamcinolone acetonide (TA), which, despite its usage, is associated with high recurrence rates and adverse effects. Mesenchymal stem cells (MSCs) exhibit potent proliferative abilities and can curb fibroblast activity and proliferation within keloids. It is now known that umbilical cord mesenchymal stem cells (UC-MSCs) have been shown to have greater proliferative potential than bone marrow-derived MSCs (BM-MSCs), and other advantages of UC-MSCs include being easily accessible and less immunogenic. To assess the viability of administering umbilical cord MSC (UC-MSC) and its conditioned medium (UC-CM) via intralesional injection compared to TA in reducing macroscopic keloid volume and type 1:3 collagen ratio. Methods: This randomized controlled trial enrolled twenty-four keloid patients by consecutive sampling. Eligible patients were required to have keloids on the chest, back, abdomen, or extremities. Patients with hypertrophic scars, a history of kidney failure, hypertension, blood disorders, malignancy, pregnancy, breastfeeding, or keloid treatment were excluded. Sociodemographic data, keloid size, and tissue biopsies were collected during scheduled visits. Bivariate analyses applied were considered significant at a p-value of <0.05. Results: The study revealed that the most significant decrease in macroscopic volume occurred within the UC-MSC group, followed by the UC-CM group, and then the TA group (UC-MSC: 50.24% ± 3.58%; UC-CM: 43.97% ± 3.04%; TA: 33.53% ± 2.64; p = 0.004. The UC-CM group exhibited the most substantial decrease in the type 1:3 collagen ratios (4.80±0.26), with UC-MSC (4.60(4.15-8.05)) and TA (3.96(1.63-4.14)) following in sequence (p=0.002). Conclusion: The findings of this study indicate that the use of UC-MSC and UC-CM exhibits promising superiority over TA in terms of reducing macroscopic keloid volume and type 1:3 collagen ratio.