Topical application of a placental mesenchymal stem cell-embedded biomaterial hydrogel accelerates the repair of radiation-induced skin damage: a double-blind randomized phase II clinical trial.

Background: Radiation-induced skin injury (RSI) is a common complication of radiation therapy, that severely reduces the quality of life of patients, and there is currently no gold standard for treatment. Placental mesenchymal stem cells (PMSCs) have emerged as a promising therapeutic approach due to their regenerative and anti-inflammatory properties, and biomaterials can serve as cell scaffolds to prolong cell survival time. This study is the first to evaluate the safety and efficacy of the a topical application of PMSCs-embedded alginate hydrogel (PMSCs gel) in cancer patients suffering from RSI.

Materials and methods: This study was a double-blind, randomized, placebo-controlled phase II clinical trial conducted at Yunnan Cancer Hospital (Chinese Clinical Trial Registry, Approval Number: ChiCTR2400094739) involving participants with grade II or higher radiation-induced skin injuries. The participants were randomly assigned to either the PMSCs gel treatment group or the placebo control group and treated topically for six consecutive days. The primary outcomes included skin injury grade, pain assessment and wound healing rate, whereas the secondary outcomes focused on biomarker changes and quality of life assessments. Statistical analyses were performed using intention-to-treat (ITT) principles.

Results: This study included 66 patients, 23 males, and 43 females, with a mean radiation-induced skin injury area of 779 mm². Compared with the placebo control group, the PMSCs gel treatment group presented a faster overall recovery rate compared to the placebo control group, with statistically significant daily improvements from Day 1 to Day 6. Although there was no significant difference in the full healing rates between the groups, the PMSCs gel treatment significantly prevented further wound expansion from Day 2 to Day 6. Moreover, overall pain relief was greater in the PMSCs gel treatment group than in the control group.

Conclusions: Our study has demonstrated for the first time that PMSCs hydrogel have significant potential for accelerating the repair of radiation-induced skin damage and reducing skin pain.

Trial registration: This retrospectively registered Chinese Clinical Trial Registry identifier: ChiCTR2400094739 ( https://www.chictr.org.cn/bin/project/edit?pid=250420 ).