Sharif Digital Repository

Hydrogels are polymeric three-dimensional networks able to swell in the presence of an aqueous medium. Hydrogels from natural proteins and polysaccharides are ideal scaffolds for tissue engineering since they resemble the extracellular matrices of tissue comprised of various amino acids and sugar-based macromolecules.The biocompatible and biodegradable hydrogel scaffolds are promising materials for tissue engineering. Here, we report a new class of hydrogels derived from oxidized alginate (OA) and gelatin. The prepared oxidized alginate was shown to be efficient in crosslinking gelatin, leading to hydrogel formation. The effect of degree of oxidation and concentration of OA on the mechanical... 

In general, repair and regeneration of damaged tissues or lost organ is base definition of a technology named tissue engineering. Tissue engineering technology provides innovative path to achieve better medical treatment, including different methods which manipulate natural or synthetic biomaterials mimicking stem cells environmental condition inside the body, in order to facilitate desired cell expansion and differentiation. Recently, application of cell carriers in form of microcarriers which are injectable, biodegradable and biocompatible have attracted significant attention. Due to increasing effectiveness in animal cell culture.
The aim of this work was fabrication of... 

Significant advances in biotechnology have led to the emergence of a cost-effective way with less ethical issues to study disease, organ functions, tumors, and their response to drugs besides studying on animals. Microfluidic devices and organ on a chip (tumor on a chip) were introduced to remove those obstacles. Organ on a chip is a powerful tool for studying different types of tissues and simulating diseases, especially cancers, for biological and medical applications. Organ (tumor) on a chip is considered as a smaller scale of the real organ or tumor and it causes to the real-time study of tissues and their functions more accurately. In this study, to fabricate a droplet-based... 

Fabrication and characterization of different surface charged cellulose electrospun scaffolds including cellulose acetate, cellulose, carboxymethyl cellulose and quaternary ammonium cationic cellulose for biomedical applications have been reported in this research. We describe preparation of cellulosic nanofibers through the electrospinning following deacetylation cellulose acetate. Moreover, surface modification of electrospun cellulose nanofibers is carried out to obtain carboxymethyl cellulose and quaternized cellulose nanofibers, respectively. At last, the structural, morphological, mechanical, swelling, wettability and the cell culture properties of the scaffolds were analyzed and... 

Three sizes of silica nanoparticles (160±7, 450±10 and 600±25) were sythetized via template-removing method. The synthetized nanoparticles were functionalized with N-(2-aminoethyl)-3-aminopropyl trimethoxy-silane (EDS) to provide a positive charge on the surface of nanoparticles. BET analysis showed that the average pore diameter, surface area and pore volume of nanoparticles were 2.3 nm, 769 m2.g-1 and 0.44 cm3.g-1, respectively. showed that the Amine-functionalized silica nanoparticles were used to enhance the application of alginate polymer for 3D encapsulation of mammalian cells. Incorporating of silica nanoparticles can be suitable for the bead integrity and attachement of mammalian... 

Cancer is one of the most causes of mortality in the world. Leukemia is a type of cancer initiated by the rapid proliferation of blood cells including WBCs, RBCs, and Platelets, that classified into four general types of AML, ALL, CML, and CLL. The main treatment of leukemia is chemotherapy. Because of many problems that patients have with this treatment and not so good results of chemotherapy, we design a microfluidic chip that can perform personalized medicine treatment for leukemia patients.This microchip consists of two main parts, Concentration Gradient Generator (CGG), and cell culture. CGG system is a tree CGG with two inlets and four outlets, which makes a linear concentration of... 

According to today’s medicine progress, the need for improving the medical facilities have been increased. Within the human body, the biomolecules concentration gradient is regulating the cell functions. Biological processes such as immune response, wound healing, and cancer metastasis have been affected by the bimolecular concentration gradient. So understanding the cell behavior in the presence of a chemical gradient can improve the understanding from these biological processes, and also would help in medical researches. On the other hand, finding the appropriate dose of the drugs and in some cases finding the most effective drug is a clinical challenge that made a new field of research in... 

Nowadays, we are witnesses of deaths caused by cancer in large statistical amounts. Vast number of investigations are conducted for anticancer drug evaluation on human and animal cells using traditional two-dimensional and three-dimensional culturing platforms. However, most of them are not successful due to the lack of in-vivo relevant microenvironment in these platforms. One of the best cancer in-vitro cultures is the tumor spheroid which is a spherical cellular aggregation. By culturing these tumor spheroids in a microfluidic chip, it is possible to mimic the in-vivo microenvironment elements such as nutrient and metabolite gradients. Here we present a microfluidic device fabricated using...