Novel biodegradable patch for atrial septal defect closure

Abstract

Since there are still occuring severe complications due to atrial septal defect (ASD) occluder, the development of a suitable ASD device is still in procuring. In the last years researcher focused on biodegradable devices. Accordingly, in this research a degradable occluding patch has been developed, to analyse the ability to solve existing complications. Therefore biodegradable patches were electrospun using medical grade polyurethane (PU) added with bioactive agents, chitosan nanoparticles (ChNP), collagen (Co) and heparin (Hep). The control patch was pure PU. ChNP were added to improve the mechanical properties and bolster the PU.The collagen is expected to provide an extracellular matrix improving cell adhesion and cell growth, serving as a biological sealant of the ASD. FTIR showed characteristic vibrations of active constituents and changes in the absorbance due to the ingredients. The contact angle analysis demonstrated no significance comparing control and composite patches. The mean values for the PU, PUChCo and coated PuChCo were found as 84.23° ± 1.06, 87.62° ± 3.73 and 90.42° ± 1.41 (p < 0.05). Moreover, the structure of the electrospun composite fibres were meticulously displayed through scanning electron microscopy. The decrease in nanofibre diameter (PU: 0445.7 nm to PUChCo: 0275.0 nm) between control and composite is due to a change of viscosity of the spinning solution after adding Co. The haemocompatible properties of the patches (PU, PUChCo, PUChCoHep) were inferred through in vitro tests, e.g. activated partial thromboplastin time (72.92 s, 70.77 s,103.33 s), prothrombin time (25.73 s, 29.4 s, 35.67 s) and haemolysis assay (3.64 %, 2.39 %, 2.12 %). In conclusion, the developed patch was observed to show desirable properties for an application in an ASD occlusion device.