Fabrication and characterization of injectable hydrogels derived from decellularized skeletal and cardiac muscle

Abstract

Biomaterials, which can contain appropriate biomechanical and/or biochemical cues, are increasingly being investigated as potential scaffolds for tissue regeneration and/or repair for treating myocardial infarction, heart failure, and peripheral artery disease. Specifically, injectable hydrogels are touted for their minimally invasive delivery, ability to self-assemble in situ, and capacity to encourage host tissue regeneration. Here we present detailed methods for fabricating and characterizing decellularized injectable cardiac and skeletal muscle extracellular matrix (ECM) hydrogels. The ECM derived hydrogels have low cellular and DNA content, retain sulfated glycosaminoglycans and other extracellular matrix proteins such as collagen, gel at physiologic temperature and pH, and assume a nanofibrous architecture. These injectable hydrogels are amenable to minimally invasive, tissue specific biomaterial therapies for treating myocardial infarction and peripheral artery disease.

Biologic Scaffolds

“…Typically, hydrogels are derived by the gelation (i.e., a process of polymerization induced by physical -chemical agents) at 37˚C of a soluble form of the ECM, called pregel (Freytes et al 2008a). Preparation of a gel derived from UBM, colon (Keane et al 2015a), cardiac, and skeletal muscle ECMs (Ungerleider et al 2015), and demineralized bone (Sawkins et al 2013) has been described. ECM hydrogels from different source tissues have been shown to support in vitro cell growth of different cell types, including ECs, smooth muscle, myoblasts, cardiomyocytes (Freytes et al 2008a), cardiovascular progenitor cells (Williams et al 2015), and primary calvarial cells (Sawkins et al 2013).…”

Histological Evaluation of Decellularized Skeletal Muscle Tissue Using Two Different Decellularization Agents

“…Our idea to compare influence of Triton X-100 and SDS was based on studies (18)(19)(20) which used these two agents to prepare decellularized scaffolds. Both of these agents disrupt the cell membrane causing cell lysis by osmotic gradient.…”

Hydrogels for Cardiac Tissue Repair and Regeneration

“…It was reported that in USA, the myocardial infarction affects annually over 900,000 people and in the entire word approximately 50% of the people suffering myocardial infarction (MI) die within 5 years [2,3]. The main causes leading to congestive heart failure are represented by adverse remodeling of the left ventricle, loss of nonregenerative cardiomyocytes and myocardial infarction [3].…”

“…To solve these problems, biomaterials are increasingly investigated as potential scaffolds for cardiac tissue repair and/or regeneration. It was discovered that injectable hydrogels offers several advantages such as: ability to self-assemble in situ, minimally invasive delivery capacity (in comparison with other methods like in vitro engineered tissue or epicardial patch implantation) and capacity to encourage host tissue regeneration [2,4]. Also, these hydrogels possess the ability to mechanically stabilize the myocardial wall and modulate left ventricular remodeling alone or through delivery of therapies, like cells and growth factors and they can deliver cells directly into the infarcted wall ( Figure 1) [4,5].…”