A Novel Cryoprecipitate-Enriched PRP (Cryo-PRP) Gel with Enhanced Mechanical Strength and Regenerative Capacity Accelerates Enterocutaneous Fistula Healing

Zhang-Sheng Zhao^1*Zhen-Zhen Wang¹Hua Ye¹Xianlei Cai¹Bin Hu¹Qiu Han²You-Li Ma^1*

• ¹Ningbo Medical Centre Lihuili Hospital, Ningbo, China
• ²Chinese Academy of Sciences Ningbo Institute of Materials Technology and Engineering, Ningbo, China

Enterocutaneous fistula (ECF) presents a significant clinical challenge due to its complex pathophysiology, high recurrence rate, and limited non-surgical treatment options. While platelet-rich plasma (PRP) has shown potential in tissue regeneration, its limited mechanical strength restricts its application in high-output fistulas. To address this, we developed a cryoprecipitate-enriched PRP (Cryo-PRP) with elevated fibrinogen levels and improved gel stability. Cryo-PRP was prepared through cryoprecipitation of conventional PRP and characterized using scanning electron microscopy (SEM), fibrinogen quantification, and thromboelastography (TEG). Its therapeutic efficacy was evaluated in a rat ECF model by assessing wound closure, histological features, and expression of angiogenic and inflammatory markers. Cryo-PRP exhibited significantly higher fibrinogen concentration (5.26 ± 0.78 g/L vs. 2.58 ± 0.49 g/L, P < 0.001) and greater clot firmness (TEG-MA: 37.8 ± 2.2 mm vs. 28.7 ± 1.3 mm, P < 0.001) compared to standard PRP. SEM analysis showed a denser and more organized fibrin network in Cryo-PRP gels. In vivo, Cryo-PRP accelerated wound healing, promoted epithelialization, preserved crypt architecture, and reduced inflammation. Immunostaining demonstrated enhanced neovascularization (CD34), increased expression of regenerative markers (α-SMA, CD31, VEGF, PCNA), and downregulation of pro-inflammatory TNF-α. These findings highlight the superior mechanical and biological performance of Cryo-PRP, supporting its potential as a safe, autologous, and minimally invasive therapeutic option for ECF treatment.