Preliminary report: Evaluation of tissue ingrowth into experimental Replamineform vascular prostheses

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Vascular Surgery

Background:

• Arterial prostheses are crucial for vascular reconstruction.
• Developing biocompatible materials with optimal porosity remains a challenge.
• Sea urchin spines offer a unique natural model for porous biomaterials.

Purpose of the Study:

• To develop and evaluate a novel arterial prosthesis inspired by sea urchin spine microstructure.
• To assess the biocompatibility and tissue integration of the new prosthesis in a large animal model.

Main Methods:

• Fabrication of arterial prostheses (4 mm inside diameter) using bioelectric and segmented polyurethane with a 15-20 µm porous network.
• Surgical implantation of ten prostheses into the femoral and carotid arteries of dogs (27-35 kg).
• Histological analysis of explanted prostheses harvested at 3, 7, and 14 days to evaluate tissue ingrowth and patency.

Main Results:

• Eight out of ten prostheses remained widely patent at explantation.
• Significant tissue ingrowth, including fibroblastic and capillary penetration, was observed as early as day 3.
• Complete wall penetration (1 mm thickness) occurred by one week.
• Well-organized neointimal surfaces (50-100 µm) formed by two weeks.

Conclusions:

• The novel polyurethane-based arterial prosthesis, mimicking sea urchin spine porosity, shows excellent biocompatibility and promotes rapid tissue integration.
• This biomimetic approach offers a promising strategy for developing next-generation vascular grafts.
• The observed neointimal formation suggests potential for long-term patency and functional restoration.