3D printed patch of sequential sustained-release of dual growth factors for angiogenesis in Moyamoya disease

Abstract

Moyamoya disease is a rare, progressive cerebrovascular disorder caused by blocked arteries at the base of the brain. Traditionally, surgery (mainly classified as direct revascularization and indirect revascularization) is typical way for curing this disease. For children, who hold a large majority of the patient group, could only do indirect vascularization because of their weak vessel. However, indirect revascularization needs more than a couple of months to improve symptom. Here, we developed a 3D printed patch of sequential sustained release of growth factors (from VEGF to HGF) that can promote angiogenesis to shorten the symptom improvement time. We produced a novel hybrid bioink, a mixture of vascular-tissue-derived extracellular matrix (VdECM) and methacrylated hyaluronic acid (HAMA) by dual crosslinking (chemical (Michael addition) and thermal crosslinking). Delicate 3 layered disk type patch is fabricated by 3D bioprinting technique. New bioink mixed with VEGF and HGF were used to print outer and inner layers, respectively. The hybrid bioink has high modulus, up to 1.4 MPa. We optimized 3D bioprinting condition, and vitrification process. After vitrification, patch yields high mechanical strength, flexibility and easy handling property, increasing transplantation efficiency at surgery. We validated sequential and sustained release properties of patch by ELISA for VEGF and HGF. The patch enhances the human brain microvascular endothelial cells proliferation by releasing growth factors, in vitro. In conclusion, the patch could be used for therapeutic angiogenesis in Moyamoya disease. These outcomes suggest that the patch could be widely applied for various ischemic diseases, and cerebral vascular diseases.