Sharif Digital Repository

Methods that has been used for articular defects are faced with many limitations, so new therapies based on tissue engineering were taken into consideration in recent years. However, tissue engineering also encounters challenges regarding optimal scaffold construction and suitable cell source selection. Mature harvested chondrocytes are limited in number and may lose their chondrogenic potential in several cultures, leading to dedifferentiation. In addition, using stem cells also presents unique challenges associated with them, among which hypertrophic differentiation is the most substantial problem. Choosing the appropriate biomaterial similar to the cartilage structure with sufficient... 

Platelet Rich Plasma (PRP) is a blood-derived product containing concentrate of platelets, which are a rich source of autologous growth factors. PRP injection has been used clinically as a therapeutic method for cartilage repair. However, clinical efficiency of this method is unpredictable, maybe as a result of burst release of growth factors then fail cell-stimulating potential as most biomolecules are cleaned before they can exert a therapeutic effect. The aim of this project was to prepare a suitable scaffold for PRP delivery to regenerate cartilage injuries. In order to resemble polysaccharide-protein nature of the cartilaginous extracellular matrix, in this study, we developed an... 

Three-dimensional cell culture and forming multicellular aggregates is superior over traditional monolayer approaches due to better mimicking in vivo conditions and hence functions of a tissue. A considerable amount of attention has been devoted to devising efficient methods for the rapid formation of uniform sized multicellular aggregates. Restoring cartilage to healthy state is difficult due to low cell density and hence low regenerative capacity. Currently used platforms are not compatible with clinical translation and require dedicated handling of trained personnel. However, when engineering and implanting cell microaggregates in a higher concentration, new cartilage is efficiently... 

Beta cells are responsible for secreting insulin to maintain normoglycaemia throughout the individual’s life. Type 1 Diabetes Mellitus (T1DM) is a metabolic disorder characterized by an autoimmune response that promotes the destruction of beta-cells within the pancreatic islets, resulting in lifelong inadequate insulin secretion. Encapsulating beta cells inside a semipermeable membrane to protect encapsulated cells from direct contact with the host immune system, is a new way to treat type 1 diabetes without the need for long-term immunosuppression. . In this case, the semipermeable membrane surrounds the cells and allows oxygen, nutrients, and cell products to penetrate bilaterally while... 

Mammalian cardiac tissue lacks the ability to effectively self-regenerate following severe damage. The application of external therapeutic agents with strong mechanical properties is needed to restore its function. Even though conventional therapies have several challenges and limitations, injectable hydrogels, with minimally invasive, can significantly improve cardiac tissue regeneration. Extracellular matrices are the most appropriate biomaterials for synthesizing cardiac scaffolds. The human amniotic membrane obtained from the amniotic sac is a readily available, abundant, and inexpensive candidate that has been successfully utilized for the clinical treatment of cardiac diseases.... 

Nerve damage is one of the factors affecting the quality of life of patients. The nervous system does not have the ability to repair large injuries, and autologous transplantation, which is the standard treatment method for nerve injuries, is faced with a shortage of donors and a decrease in the function of the donor site. Tissue engineering hydrogels, due to their similarity to the natural tissue of the stomatal body, are a hope for the repair of nerve tissue. In this research, an injectable, minimally invasive and temperature-sensitive hydrogel based on chitosan-etaglycerophosphate-sodium hydrogen carbonate salt or trisodium phosphate salt containing aligned nanofibers made of gelatin and... 

Osteoarthritis has always been one of the most common diseases in middle age because it causes severe pain and inflammation in the joints of the body. Cartilage tissue does not have the ability to repair itself. For this reason, fabricating and designing the most efficient, least-expensive, and most convenient methods for the treatment of cartilage defects is always an important issue. Today, there are surgical and injectable methods to relieve pain and initiate the body's natural healing response. But due to the many disadvantages and limitations of these methods, tissue engineering science has turned to modifying these methods or providing new methods. One of these methods is the use of... 

Growth factors play an important role in tissue repair and regeneration including articular cartilage tissue. Direct injection of growth factor is a common practice in clinics. However, it has been shown that this method is not very effective and, in some cases, induces some side effects. Moreover, incorporation of this valuable signals in systems where they are quickly released and washed out is not effective as well. Thereby the aim of this study was to design and fabricate an efficient system to effectively deliver growth factors for cartilage tissue engineering. The designed system is an injectable, in situ forming hydrogel, based on hyaluronic acid (HA) as a biocompatible and attractive...