Nano-Biomaterials
Melika Iloukhani; Mohammad Rabiee; Mahvash Oskoui; Fathollah Moztarzadeh; Mahdis Shayan
Volume 5, Issue 3 , June 2011, , Pages 193-204
Abstract
In recent years, nanoparticles have attracted considerable attention due to their special optical, chemical, and electrical properties. Developments of nanoparticles synthesis methods for producing materials with precise size and morphology have been considered recently. Among these methods, biosynthesis ...
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In recent years, nanoparticles have attracted considerable attention due to their special optical, chemical, and electrical properties. Developments of nanoparticles synthesis methods for producing materials with precise size and morphology have been considered recently. Among these methods, biosynthesis has a special position for its high compatibility with environment. The use of microorganism in nanotechnology is one of the important aspects of this issue. In this survey we have used Escherichia coli 35218 to Cadmium Sulfide nanoparticles synthesis. First, appropriate time of cadmium ions addition and their maximum concentrations were determined that they dont inhibit bacterial growth. Then we studied intra and extracellular biosynthesis. According to this survey, this strain wasn't able to produce cadmium sulfide nanoparticles intracellulary but also these nanoparticles were extracellulary synthesized in the medium supplemented with L-cysteine. Formation of CdS nanoparticles, their morphologies and fluorescence properties were determined with WDX, SEM and fluorescence microscopy.
Maryam Parviz; Mohammad Rabiee; Mohammad Ali Shokrgozar; Fathollah Moztarzadeh; Farzad Yousefi Gharebaghi; Mahdis Shayan; Mohammad Reza Tahriri
Volume 3, Issue 2 , June 2009, , Pages 89-97
Abstract
A great deal of attention has been drawn to the colloidal chemistry based semiconductor nanocrysallites, also known as quantum dots (QDs). Because of the strong quantum confinement, quantum dots have unique size-dependent optical properties, which are much more superior to the conventional organic fluorescence ...
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A great deal of attention has been drawn to the colloidal chemistry based semiconductor nanocrysallites, also known as quantum dots (QDs). Because of the strong quantum confinement, quantum dots have unique size-dependent optical properties, which are much more superior to the conventional organic fluorescence materials. In addition, strong chemical resistant makes inorganic semiconductor QDs an ideal candidate for next-generation of bio-labels and other biomedical applications. This study presents a synthesize method of high quality biocompatible CdSe QDs in aqueous solution by using gelatin as inhibitor. A thin ZnS layer was grown on CdSe QDs, forming a CdSe/ZnS core/shell structure, to improve the photoluminescence. The optical properties of the QDs were characterized by photoluminescence spectra. The stability of CdSe/ZnS QDs in aqueous solution has been improved with capping in mercaptosuccinic acid (MSA) groups. PAGE test results show that carboxylic groups of MSA have interacted with NH2 agent of CD20 antibodies. We evaluate the in vitro efficiency of the luminescence of the bioconjugated QDs to kill Raji cells. Raji cells have anti-CD20 which can especially connect to CD20-QDs. In conclusion, we found that CD20-CdSe/ZnS bioconjugated QDs with different concentration 50-250 µg/mL which have been exited at 400nm in 2h intervals can result in Raji cells death. This study shows the potential of CdSe/ZnS for cancer treatment.
Biomechanics of Bone / Bone Biomechanics
Mahmoud Azami; Fathollah Moztarzadeh; Mohammad Rabiee
Volume 3, Issue 4 , June 2009, , Pages 275-284
Abstract
During past decade, using biomimetic approaches has received much attention by scientists in the field of tissue substitutes preparation. These approaches have been employed for synthesis of bone tissue engineering scaffolds in the case of either materials or synthesis methods. In this study, an apatite ...
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During past decade, using biomimetic approaches has received much attention by scientists in the field of tissue substitutes preparation. These approaches have been employed for synthesis of bone tissue engineering scaffolds in the case of either materials or synthesis methods. In this study, an apatite phase has been synthesized within gelatin hydrogel in biomimetic condition. The obtained composite hydrogel has changed to a porous scaffold with the application of freeze drying technique in order to be used in bone tissue engineering. To characterize the chemical composition and crystal structure of the synthesized precipitate within hydrogel, FTIR, XRD and TEM analysis were used. Surface morphology and porous structure of the scaffold were studied with SEM. SEM analysis was also used to investigate the quality of cultured osteoblast cells activity. Results approved formation of an apatite phase within gelatin hydrogel in biomimetic condition with crystallite size ranging between 7-10 nm. Porosity percentage of the obtained nanocomposite scaffold was about 82% with pores sizes in the range of 100-350μm. Young’s elastic modulus of the scaffold was comparable with that of the spongy bone. The osteoblast cells cultured on the scaffold showed adhesion, immigration and extracellular matrix excretion on the scaffold internal surfaces. Thus, obtained results indicated the potential ability of the prepared biomimetic bone tissue engineering scaffold to be used in bone tissue repair process.
