Chronic wounds that fail to heal over extended periods pose a significant financial burden on the healthcare system, underscoring the urgent need to enhance clinical treatments. Among the most promising approaches are stem cell-based therapies. Substantial evidence suggests that mesenchymal stem cells (MSCs) can facilitate the healing of chronic wounds in both animal models and preclinical studies, primarily through their paracrine actions. The bioactive factors and cytokines secreted by MSCs can be harvested in the form of conditioned medium. This medium has been processed into a lyophilized powder for clinical use. Patients with chronic wounds will recruited and divided into two groups: the control group will receive the commonly used fibroblast growth factor, while the experimental group was treated with the lyophilized powder. The study aims to assess the efficacy and safety of this Stem cell and exosome in treating chronic wounds (especially pilonidal sinus).

Pilonidal sinus disease (PSD) is an infectious or inflammatory condition beneath the skin at the peak of the gluteal cleft in the sacrococcygeal area. It is a chronic condition characterized by discharge, infection, and pain. Although it can occur during adolescence, it is most commonly seen in adult males, leading to a focus on adult treatments in research. Surgical treatment was first implemented by Anderson in 1847. Since then, various surgical and medical treatment options have been explored, yet there is no widely accepted standardized treatment. The ideal treatment should be simple, require a short hospital stay, have low recurrence rates, provide good cosmetic results, be cost-effective, cause minimal pain, and allow a quick return to social life, making the surgical approach contentious.

Maurice and Greenwood first reported the application of liquid phenol in 1964, initially under general anesthesia, later shifting to local anesthesia. Due to high recurrence rates with liquid phenol, Dogru and colleagues introduced the crystallized phenol (CP) procedure, a minimally invasive method now commonly used in adults.

Recent years have shown that stem cells and exosomes promote tissue healing and reduce inflammation. Known for their ability to differentiate into various cell types, stem cells, and exosomes play critical roles in intercellular communication, containing a variety of molecules. Their use in surgical fields has become popular as they speed up the post-operative healing process and reduce the risk of complications. Research in the literature supports that stem cells and exosomes accelerate wound healing (e.g., Nourian Dehkordi A, et al. 2019).

This study is based on two main premises: firstly, to identify the potential healing effects of stem cell and exosome applications in treating pilonidal sinus disease; and secondly, to comparatively assess the impact of these applications on surgical outcomes, specifically regarding surgery duration, complications, and the healing process. Comparing these two groups will help determine the value of stem cell and exosome applications in managing pilonidal sinus disease.

Inclusion Criteria:

• 0-18 years children.
• Patients with chronic non-healing wound and pilonidal sinus diseases.

Exclusion Criteria:

• Patients with epilepsia
• Patients with diabetes
• Patients with hypertension
• Patients with chronic other diseases.