Perivascular sirolimus-delivery system.

Area of Science:

• Biomaterials Science
• Vascular Surgery
• Pharmacology

Background:

• Autologous vein grafts are crucial for vascular repair but prone to intimal hyperplasia and restenosis due to histological differences from arteries.
• Restenosis significantly compromises the long-term patency and efficacy of vascular grafts.

Purpose of the Study:

• To develop and evaluate a novel perivascular sirolimus-delivery system for controlled drug release.
• To investigate the efficacy of sirolimus-releasing meshes in preventing vascular smooth muscle cell proliferation in vitro.

Main Methods:

• Two types of polyester meshes (Mesh I and Mesh II) were coated with a sirolimus-loaded copolymer (purasorb).
• Mesh II featured a dual-layer coating for potentially more controlled drug release.
• In vitro studies assessed drug release kinetics, vascular smooth muscle cell proliferation, and cell viability over 14 days.

Main Results:

• Mesh I released sirolimus over 6 weeks, while Mesh II released over 4 weeks.
• Mesh II demonstrated more homogeneous sirolimus release without an initial burst effect.
• Both meshes effectively inhibited rat vascular smooth muscle cell proliferation and maintained cell viability.
• Mesh II exhibited a steeper cumulative release curve at later time points compared to Mesh I.

Conclusions:

• The developed sirolimus-eluting perivascular meshes are effective in inhibiting vascular smooth muscle cell proliferation in vitro.
• These novel devices show significant potential for preventing autologous graft restenosis.
• Further investigation is warranted to assess their in vivo efficacy and clinical applicability.