Authors' reply

摘要

In our phase 2 trial, we found that cell therapy with a combination of growth-arrested neonatal keratinocytes and fibroblasts, without the need for a distinct tissue construct, significantly reduced wound size and led to greater complete closure in patients with refractory venous leg ulcers, with the optimum dose being 0.5xl06 cells/mL given every 14 days. Cell viability is one of several manufacturing release criteria for the product. After freezing, thawing, and transit through the spray device, about 80% of the cells retain viability (data on file). We agree with Guo-You Zhang and colleagues that viability is likely to be crucial for the success of the therapy.Regarding a representative figure, we felt it was important for our paper to provide all of the data for all groups tested, and we did not include a specific figure forthe identified optimum dose.