Implantable patch of oxidized nanofibrillated cellulose and lysozyme amyloid nanofibrils for the regeneration of infarcted myocardium tissue and local delivery of RNA-loaded nanoparticles.

Biopolymeric implantable patches are popular scaffolds for myocardial regeneration applications. Besides being biocompatible, they can be tailored to have required properties and functionalities for this application. Recently, fibrillar biobased nanostructures proved to be valuable in the development of functional biomaterials for tissue regeneration applications. Here, periodate-oxidized nanofibrillated cellulose (OxNFC) was blended with lysozyme amyloid nanofibrils (LNFs) to prepare a self-crosslinkable patch for myocardial implantation. The OxNFC:LNFs patch showed superior wet mechanical properties (60 MPa for Young's modulus, and 1.5 MPa for tensile stress at tensile strength), antioxidant activity (70% scavenging activity under 24 h), and bioresorbability ratio (80% under 91 d), when compared to the patches composed solely of NFC or OxNFC. These improvements are achieved while preserving the morphology, required thermal stability for sterilization, and biocompatibility towards rat cardiomyoblast (H9c2) cells. Additionally, both OxNFC and OxNFC:LNFs patches reveal the ability to act as efficient vehicles to deliver spermine (Sp) modified acetalated dextran nanoparticles (Sp-AcDEX NPs), loaded with small interfering RNA (siRNA), with 80% of delivery after 5 d. This study highlights the value of simply blending OxNFC and LNFs, synergistically combining their key properties and functionalities, resulting in a biopolymeric patch that comprises valuable characteristics for myocardial regeneration applications. This article is protected by copyright. All rights reserved.