Morphological features of platelet-rich plasma on acellular vascular scaffolds

Materials for small-caliber vascular stents are deficient, with acellular vascular scaffold (AVS) being a promising solution. Platelet-rich plasma (PRP) sourced from the recipient augments the biocompatibility of vascular graft materials. Through integration of PRP onto AVS materials, our goal is to bolster AVS biocompatibility within the body, elevate the M2/M1 macrophage ratio toward graft materials for low degradation rate, and foster robust heparin attachment onto the surface of AVS materials. We aimed to examine the morphological features of PRP on AVS using electron microscopy.

Hydrophilicity testing of the material gauged alterations in water absorption post-PRP integration. Hematoxylin and eosin staining was used to assess decellularization levels. The collagen and elastin degradation rates in AVS after subcutaneous transplantation in rats were tracked. Immunofluorescence staining was used to determine the relative abundance of M1 and M2 macrophages. Heparin staining, heparin quantification, platelet adhesion, and whole-blood clotting experiments were performed to probe heparin adsorption onto the material.

The presence of a plasma protein network in the outer membrane layer of AVS was evident. PRP enhanced the water absorption rate of AVS, and freeze-drying had no effect on the suture tension of AVS. The ambient storage temperature of this extracellular matrix material was -80°C. Following PRP addition, heparin staining showed a deeper coloration. The heparin release curve was smoother in the PRP group. Additionally, in the experimental group with PRP, a lower number of platelets adhered after heparin addition, and these blood clots had the least weight.

PRP can increase the M2/M1 ratio in AVS subcutaneously transplanted into rats, decelerating the degradation rate of collagen and elastin. Furthermore, PRP can enhance heparin attachment to the AVS, leading to a more gradual heparin release rate.