Placental Stem Cell Hydrogel Shows Promise in Phase II Trial for Radiation-Induced Skin Injuries
Key Insights
A double-blind, randomized phase II clinical trial demonstrated that placental mesenchymal stem cell (PMSC) hydrogel significantly accelerated wound healing and reduced pain in cancer (search) patients with radiation-induced skin injuries (search) compared to placebo treatment.
The study enrolled 66 patients with grade II or higher radiation-induced skin injuries (search), with the treatment group showing statistically significant improvements in wound healing rates and prevention of wound expansion from day 2 onwards (P < 0.05).
PMSC gel treatment resulted in elevated TGF-β1 (search) levels (P = 0.05) and greater pain reduction compared to controls (P = 0.0399), suggesting the therapy works through anti-inflammatory and tissue regeneration mechanisms.
Cancer (search) patients undergoing radiotherapy face a significant challenge: approximately 85-95% develop varying degrees of radiation-induced skin injuries (search) (RSI) that can severely impact their quality of life and potentially interrupt treatment. A new phase II clinical trial has demonstrated that a novel hydrogel embedded with placental mesenchymal stem cells (PMSCs) offers promising therapeutic benefits for these debilitating side effects.
The double-blind, randomized, placebo-controlled trial, conducted at Yunnan Cancer Hospital (search) and registered under ChiCTR2400094739, enrolled 66 patients with grade II or higher radiation-induced skin injuries (search) according to RTOG/EORTC criteria. Participants were randomized 2:1 to receive either PMSC hydrogel (search) (44 patients) or placebo gel (22 patients) applied topically once daily for six consecutive days.
Significant Wound Healing Improvements
The primary outcomes revealed substantial benefits for patients receiving PMSC gel treatment. By day 6, the treatment group demonstrated significantly faster overall wound healing rates compared to controls (P < 0.001). Notably, 36 patients in the treatment group experienced wound size reduction, while only 8 experienced wound expansion. In contrast, the control group showed equal numbers of patients with wound reduction and expansion (11 each).
Starting from day 2, the PMSC gel group showed statistically significant advantages in preventing wound progression, with P values less than 0.05 maintained through day 6. This consistent benefit suggests the therapy's ability to halt injury advancement, a critical factor in radiation-induced skin damage management.
The Radiation-Induced Skin Reaction Assessment Scale (RISRAS) scores further supported these findings. While both groups showed improvements over the treatment period, the PMSC gel group demonstrated significantly greater alleviation of skin injury severity compared to controls (P = 0.001).
Pain Relief and Biomarker Changes
Pain assessment using the Numeric Rating Scale revealed another significant advantage for PMSC gel treatment. Both groups experienced pain reduction, but the treatment group showed substantially greater improvement (P < 0.001) compared to the modest reduction in controls (P = 0.0003). The between-group comparison favored the treatment group with statistical significance (P = 0.0399).
Laboratory evaluations identified TGF-β1 (search) as the only biomarker showing significant elevation in the treatment group (P = 0.05), while other inflammatory markers including TNF-α (search), IL-6, and IL-10 remained unchanged. This selective biomarker response suggests PMSC gel promotes healing through specific regenerative pathways rather than broad inflammatory modulation.
Quality of Life Outcomes
Despite the significant improvements in wound healing and pain, quality of life assessments using the EORTC QLQ-C30 Version 3.0 questionnaire showed no statistically significant differences between groups. Functional, symptom, and overall scores remained stable in both groups throughout the six-day treatment period, with no significant interaction between treatment allocation and time.
Treatment Mechanism and Safety
The PMSC hydrogel (search) contained 1.0 × 10^6 viable cells per application, suspended in a sodium alginate matrix and applied to cover approximately 15 cm² of wound area. The stem cells, derived from full-term cesarean deliveries with informed consent, were characterized by high expression of CD73 (search), CD90 (search), and CD105 (search) markers and low expression of CD34, CD45, and HLA-DR.
The study's safety profile appeared favorable, with no serious adverse events directly attributed to PMSC gel treatment reported. The therapy's localized application approach minimizes systemic exposure while delivering regenerative factors directly to the injury site.
Clinical Implications
Univariate logistic regression analysis confirmed that PMSC gel treatment was significantly more effective than placebo in promoting healing of radiation-induced skin injuries (search) by day 6 (P < 0.001), with no other factors showing notable effects on healing outcomes.
The researchers noted that radiation-induced skin injuries (search) are characterized by latency, progression, and persistence, making them particularly challenging to treat. Current management lacks a gold standard approach, highlighting the clinical need for effective interventions like PMSC gel therapy.
Study Limitations and Future Directions
The investigators acknowledged several limitations, including the relatively small sample size, short follow-up period, and single-center design. The lack of quality of life improvements may reflect the brief observation window or the insensitivity of standardized instruments to capture localized symptom changes.
The research team emphasized the need for larger, multicenter phase III trials with extended follow-up periods and comprehensive biomarker analyses to validate these promising initial findings. Future studies should also incorporate injury-specific quality of life metrics to better capture treatment benefits beyond the current standardized assessments.