Sharif Digital Repository

Polycaprolactone (PCL) scaffolds and its composites containing bioactive glass particles (45S5) and TiO2 nanostructures with pre-defined and controlled external and internal architecture were prepared via an indirect three-dimensional (3D) printing process. The scaffolds had an interconnected structure with macro- (400-500 μm) and micro- (~25 μm) pores. Bioactivity, mechanical behavior and kinetics of tissue growth in 3D scaffolds were studied. The size effect of biogactive glass particles (6 μm, 250 nm, <100 nm) and morphology of titania nanostructures (spherical, tube, leaf-like, and flower-like particles) were elaborated. The biogactive glass particles with different sizes were prepared... 

In the past decades, electrospinning has been widely used for the production of micro/nanofibers. In spite of the simplicity and effectivity of the conventional electrospinning for fabricating nanofibers, compact structure and small pores of the nanofibers hinder the efficient penetration of analytes during the extraction process. In order to overcome this issue, an applicable strategy called wet electrospinnig has been employed to enlarge the pore size of the electrospun scaffolds. By applying this technique, a collector was placed at the bottom of a solvent bath and highly porous foam from polyamide nanofibers was produced immediately after freeze-drying (3D electrospinning).... 

Nowadays, tissue engineering and stem cells-based therapies have outlined a promising prospect in neural networks regeneration. But it usually requires biocompatible and conductive scaffolds for culturing neural stem cells and directing their differentiation toward the neurons. Graphene due to its unique physical and chemical properties has attracted much interest in tissue engineering. For this purpose, in this study biocompatible graphene oxide foams have been used for neural stem cell culturing. For the first time, graphene oxide foam were fabricated by precipitation of chemically exfoliated graphene oxide sheets in an aqueous suspension onto the PET substrate at ~80 oC under UV... 

Tissue engineering aims to produce artificial tissues and organs to treat the damaged part, by implant in body of patients, is an important issue in research and development. In cases that tissue damage is sever or due to genetic defects or congenital disease, tissue in the body are not fully formed, tissue engineering can be used to regenerate, repair or replace organs or tissues. Cell culture on the scaffold and put it in the bioreactor is a critical step in the formation of tissues or organs. Among various bioreactors, perfusion bioreactor due to increase of convection in the structure of cell-scaffold is widely used. Enhancement of convection increases shear stress on the cells that is... 

The aim of this study is the fabrication of 3D porous PCL scaffolds contain core-shell fibers for cartilage tissue engineering. The novel fabrication method is co-axial wet electrospinning simultaneously. These tablets like scaffolds have superior porosity and pore sizes for cell culturing and cell-cell interaction as they have good mechanical properties for cartilage tissue engineering in comparison to 2D electrospun scaffolds. The structure of these 3D scaffolds is mimicking the ECM of cartilage. This study presents the coaxial electrospinning of PCL nanofibers encapsulated with bovine serum albumin and platelet rich plasma for demonstration of controlled release and bioactivity retention,... 

Herein, we successfully prepared two types of hydrogels, alginate-beta-cyclodextrin based hydrogel and alginate without beta-cyclodextrin hydrogel in order to use in cartilage tissue engineering. At first, sodium alginate was modified with beta-cyclodextrin ring due to incorporate the kartogenin (KGN) differentiating drug in the hydrogel structure. For confirming the correctness of the modification reactions, H-NMR spectroscopy was used. In the presence of phenolized-ECM, alginic acid, modified alginate with beta cyclodextrin, HRP, H2O2, calcium carbonate, and glucono-delta-lactone (GDL), ECM-alginate-IPN and ECM-modified-alginate-IPN hydrogels were synthesized. Then, the KGN was loaded on... 

The aim of this dissertation is to investigate and determine the optimal composition of hydrogels that can meet the needs of stem cells for the growth and proliferation of mesenchymal stem cells. In this research, firstly, unfunctionalized and functionalized mesoporous silica nanoparticles (with an average diameter of approximately 90 nm), were synthesized. Scanning electron microscopy and zeta potential measurement were utilized to study their morphology and surface charge. Then, graphene oxide nanosheets were synthesized. Field emission electron microscopy, zeta potential measurement and Fourier transform infrared spectrum analysis were used to examine their morphology, surface charge and...