Insights and Recommendations on the Manuscript “Effectiveness of Secretome from Human Umbilical Cord Mesenchymal Stem Cells in Gel for Chronic Wounds” by Tan et al [Letter]

Dear editor

I have read the article titled “Effectiveness of Secretome from Human Umbilical Cord Mesenchymal Stem Cells in Gel (10% SM-hUCMSC Gel) for Chronic Wounds (Diabetic and Trophic Ulcer) – Phase 2 Clinical Trial” by Tan et al¹ with great interest. While the study presents valuable findings on the potential efficacy of secretome from human umbilical cord mesenchymal stem cells (SM-hUCMSC) in treating chronic wounds, I have some concerns that I would like to bring to your attention.

Firstly, the authors have combined two distinct wound types, diabetic foot ulcers and leprosy-related trophic ulcers. In the current study, more than 80% of the subjects were with leprosy wound, which has completely different pathological process than diabetic foot ulcers. This raises concerns about the appropriateness of combining these wound types for evaluating the intervention’s effectiveness since both wound types have the distinct pathophysiology and healing patterns.^2,3 Combining these wound types may introduce confounding factors and limit the generalizability of the findings.

Secondly, while the authors stated in the methods section that wound healing outcomes, beside wound size, would include the presence of granulation tissue growth, reduced edema, and reduced erythema, these variables were not reported in the results section. Reporting these outcomes would have provided a more comprehensive assessment of the wound healing process.

Furthermore, I would like to question the wound size measurement methodology. Table 3 shows that the standard deviations for wound length in Follow-up I and II are greater than the mean values, which seems unusual and raises concerns about the accuracy of the measurement technique employed.^4,5

Finally, the authors did not provide details on how the umbilical cord mesenchymal stem cells were obtained and screened for infectious diseases. This information is crucial to ensure the safety of the product used in the clinical trial. If this information was included in a previous Phase I trial, citing it would be beneficial for readers to understand the product preparation process and safety measures taken.

I kindly request the authors to address these concerns and provide clarifications or additional information to strengthen the validity and transparency of their findings. I hope these comments and concerns will be taken into consideration for improving the quality and transparency of the reported findings.