Sharif Digital Repository

Recently, decellularized amniotic membrane-derived hydrogels (DAMHs) have received significant attention for wound care, ocular surface reconstruction, and chondral healing. Despite the advantages of DAMHs for tissue engineering (TE), the loss of structural components during the decellularization process mitigates their mechanical strength and thus limits their practical application. Herein, we present a method for the surface modification of two-dimensional nanosilicates (laponite) as a rheological modifier to tailor the properties of DAMHs. Results show that after introducing nanosilicates, severe aggregation of the nanoparticles occurs, owing to the shielding effect of ions on the surface... 

Endothelial cell migration is a crucial step in the process of new blood vessel formation - a necessary process to maintain cell viability inside thick tissue constructs. Here, we report a new method for maintaining cell viability and inducing cell migration using a perfused microfluidic platform based on collagen gel and a gradient hydrogel sheet. Due to the helpful role of the extracellular matrix components in cell viability, we developed a hydrogel sheet from decellularized tissue (DT) of the bovine heart and chitosan (CS). The results showed that hydrogel sheets with an optimum weight ratio of CS/DT = 2 possess a porosity of around 75%, a mechanical strength of 23 kPa, and display cell... 

Myocardial infarction (MI) causes a high mortality rate in the world every year. Myocardial tissue engineering using extracellular matrix-derived substrate and cytocompatible biopolymers is a promising approach for treating MI. Besides, injectable porous microspheres are developing engineer constructs to use as dual-purpose microcarriers for cell culture and injectable scaffolds in trivial invasiveness for tissue implantation. This study aimed to fabricate porous microcarriers composed of myocardial extracellular matrix and chitosan using an electrospraying technique. The effect of electrospraying parameters, including extracellular matrix/chitosan ratio and voltage, on MCs diameter was... 

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... 

Cartilage is an avascular tissue with limited self-repair ability. Since the methods for treatment of cartilage defects have not been effective, new therapies based on tissue engineering are considered over the recent years. In this study, human cartilage tissue was decellularized and porous injectable microcarriers (MCs) composed of acellular extracellular matrix (ECM) of cartilage tissue and chitosan (CS), with different ECM weight ratios, were fabricated by electrospraying technique to be used in the treatment of articular cartilage defects. Various properties of ECM/CS MCs such as microstructure, mechanical strength, water uptake behaviour, and biodegradability rate were investigated.... 

The employment of tissue engineering scaffolds in the reconstruction of the damaged bone tissues has shown remarkable promise since they significantly facilitate the healing process. Fabrication of highly porous biocompatible scaffolds with sufficient mechanical strength is still challenging. In this regard, polymers have been widely utilized to construct three-dimensional (3D) porous scaffolds due to their excellent processability and biocompatibility. However, insufficient mechanical strength and inappropriate degradation rate of the monophasic polymer scaffolds in the bone regeneration process, as the main challenges, limit their extensive clinical application. The incorporation of... 

Injectable hydrogels which mimic the physicochemical and electromechanical properties of cardiac tissue is advantageous for cardiac tissue engineering. Here, a newly-developed in situ forming double-network hydrogel derived from biological macromolecules (oxidized alginate (OA) and myocardial extracellular matrix (ECM)) with improved mechanical properties and electrical conductivity was optimized. 3-(2-aminoethyl amino) propyltrimethoxysilane (APTMS)-functionalized reduced graphene oxide (Amine-rGO) was added to this system with varied concentrations to promote electromechanical properties of the hydrogel. Alginate was partially oxidized with an oxidation degree of 5% and the resulting OA... 

There are limitations in current medications of articular cartilage injuries. Although injectable bioactive hydrogels are promising options, they have decreased biomechanical performance. Researchers should consider many factors when providing solutions to overcome these challenges. In this study, we created an injectable composite hydrogel from chitosan and human acellular cartilage extracellular matrix (ECM) particles. In order to enhance its mechanical properties, we reinforced this hydrogel with microporous microspheres composed of the same materials as the structural building blocks of the scaffold. Articular cartilage from human donors was decellularized by a combination of physical,...