3D-printable nitric oxide-releasing absorbable stents

• Grant number: 24/08081-4
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: July 01, 2024
• End date: June 30, 2026
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Agreement: Netherlands Organisation for Scientific Research (NWO)
• Principal Investigator: Marcelo Ganzarolli de Oliveira
• Grantee: Rayane da Silva Vale
• Host Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 22/14645-2 - Nitric oxide releasing hydrogels and vascular prosthesis for cardiovascular applications, AP.TEM

Abstract

The main scientific and innovation challenge of this project is the development of totally absorbable intracoronary nitric oxide (NO)-releasing stents, composed polyesters, and polymeric blends involving poly(lactic acid) and poly(caprolactone). The materials to be developed will associate the property of complete bioabsorption of the stent, with localized release of NO, which, in turn, may exert antithrombotic, antiproliferative and pro-endothelial actions. The project involves the development of methodologies for the synthesis of photocrosslinkable polyesters, the formation of polyester blends, the manufacture of intracoronary stents by 3D printing and electrospinning, the evaluation and modulation of the mechanical properties, hydrolytic degradation and NO release of the stents, as well as their bio and hemocompatibility. The same photocrosslinkable resins may also be used for the coating of metallic stents in a parallel approach. Stents obtained by 3D printing and electrospinning will be manually mounted on angioplasty balloons. The morphology of the stents will be characterized by SEM before and after expansion to evaluate the preservation of the mesh structure. The wettability of the polyester surfaces before and after NO release will be evaluated by contact angle measurements. Mechanical tests will be performed using a texturometer. As goals, it is intended to obtain stents that possess sufficient flexibility for expansion and arterial implantation and sufficient radial strength to sustain the artery wall after expansion on the balloon. Hydrolytic degradation tests of the stents will be carried out under accelerated conditions by gravimetric monitoring. The evolution of the surface morphology during degradation will be evaluated by SEM and EDS. The kinetics of NO release from the stents will be characterized by chemiluminescence using a NO analyzer. It is expected to obtain both fully polymeric NO-releasing stents and coated NO-releasing stents capable of being expanded in balloon catheter for deployment. The project will involve collaboration with Prof. Andrei Sposito of the Faculty of Medical Sciences at UNICAMP. The electrospinning technology will be explored to manufacture porous stents in collaboration with Dr. Ana Millas at the 3D Biotechnology Solutions - 3DBS company in Campinas, SP.