Sharif Digital Repository

Myocardial infarction is a major cause of death worldwide and remains a social and healthcare burden. Injectable hydrogels with the ability to locally deliver drugs or cells to the damaged area can revolutionize the treatment of heart diseases. Herein, we formulate a thermo-responsive and injectable hydrogel based on conjugated chitosan/poloxamers for cardiac repair. To tailor the mechanical properties and electrical signal transmission, gold nanoparticles (AuNPs) with an average diameter of 50 nm were physically bonded to oxidized bacterial nanocellulose fibers (OBC) and added to the thermosensitive hydrogel at the ratio of 1% w/v. The prepared hydrogels have a porous structure with open... 

Animal models and traditional cell cultures are essential tools for drug development. However, these platforms can show striking discrepancies in efficacy and side effects when compared to human trials. These differences can lengthen the drug development process and even lead to drug withdrawal from the market. The establishment of preclinical drug screening platforms that have higher relevancy to physiological conditions is desirable to facilitate drug development. Here, a heart-on-a-chip platform, incorporating microgrooves and electrical pulse stimulations to recapitulate the well-aligned structure and synchronous beating of cardiomyocytes (CMs) for drug screening, is reported. Each chip... 

Adult cardiomyocytes are terminally differentiated cells that result in minimal intrinsic potential for the heart to self-regenerate. The introduction of novel approaches in cardiac tissue engineering aims to repair damages from cardiovascular diseases. Recently, conductive biomaterials such as carbon- and gold-based nanomaterials, conductive polymers, and ceramics that have outstanding electrical conductivity, acceptable mechanical properties, and promoted cell-cell signaling transduction have attracted attention for use in cardiac tissue engineering. Nevertheless, comprehensive classification of conductive biomaterials from the perspective of cardiac cell function is a subject for... 

A proper self-regenerating capability is lacking in human cardiac tissue which along with the alarming rate of deaths associated with cardiovascular disorders makes tissue engineering critical. Novel approaches are now being investigated in order to speedily overcome the challenges in this path. Tissue engineering has been revolutionized by the advent of nanomaterials, and later by the application of carbon-based nanomaterials because of their exceptional variable functionality, conductivity, and mechanical properties. Electrically conductive biomaterials used as cell bearers provide the tissue with an appropriate microenvironment for the specific seeded cells as substrates for the sake of... 

High rates of mortality and morbidity stemming from cardiovascular diseases unveil extreme limitations in current therapies despite enormous advances in medical and pharmaceutical sciences. Following myocardial infarction (MI), parts of myocardium undergo irreversible remodeling and is substituted by a scar tissue which eventually leads to heart failure (HF). To address this issue, cardiac patches have been utilized to initiate myocardial regeneration. In this study, a porous cardiac patch is fabricated using a mixture of decellularized myocardium extracellular matrix (ECM) and chitosan (CS). Results of rheological measurements, SEM, biodegradation test, and MTT assay showed that the...