Nano-Biomaterials
Mohammad Nazari; Razieh Solgi; Ghazale Graily; Seyed Rabi Mahdavi; Alireza Shirazi
Volume 12, Issue 1 , June 2018, , Pages 11-23
Abstract
In clinical studies, it is difficult to determine the temperature distribution throughout both tumor and normal tissue during hyperthermia treatment, since temperatures are sampled at only a limited number of locations with conventional sensors. Simulation studies can help physicians understand better ...
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In clinical studies, it is difficult to determine the temperature distribution throughout both tumor and normal tissue during hyperthermia treatment, since temperatures are sampled at only a limited number of locations with conventional sensors. Simulation studies can help physicians understand better the effects of the treatment. In this study, three 2D tumor models are built in the COMSOL software environment based on the images of nano-particle distributions in sliced PC3, DU145 and LAPC4 tumors. The images are pre-processed in MATLAB before being imported into COMSOL. A uniform distribution model is added as a control group. Temperature distribution, maximum temperature, time to reach steady state, CEM43, iso-effective dose and heat flux at tumor-tissue boundary are analyzed to evaluate the effect of the nano-particle distribution on hyperthermia treatment. The results indicate that a more concentrated nano-particle distribution is better in damaging diseased tissue than the uniform distribution under high heating power. A more uniform distribution is better than the concentrated distribution under low heating power. For concentrated nano-particle distributions, the location where the nano-particles are concentrated influences tissue damage: a more centered one has a better effect. Tumor tissue is more likely to be defective.
Nanobiotechnology / Bionanotechnology / Nanobiology
Mah Monir Karimzade; Ladan Rashidi; Fariba Ganji; Mitra Ahmadi; Sattar Tahmasebi Enferadi
Volume 8, Issue 4 , February 2015, , Pages 385-398
Abstract
The aim of this research is the preparation of a system based on mesoporous silica nanoparticles (MSN) for delivery of Rivastigmine hydrogen tartrate and investigating of the system cytotoxicity, with or without drugs, on the human brain neuroblastoma cells (SY5Y). Rivastigmine is a hydrophilic and a ...
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The aim of this research is the preparation of a system based on mesoporous silica nanoparticles (MSN) for delivery of Rivastigmine hydrogen tartrate and investigating of the system cytotoxicity, with or without drugs, on the human brain neuroblastoma cells (SY5Y). Rivastigmine is a hydrophilic and a hydrophobic drug which is used for treatment of Alzimerʾs disease. In this study MSN were synthesized and characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, x-ray diffraction, N2 adsorption isotherms, and z-potential analysis. Results showed that all MSN were spherical with the same structure. The mean size of nanoparticles was 100±13 nm and the mean diameter of pores was 2.15 nm. The loading capacity and efficiency of rivastigmine hydrogen tartrate were obtained 20.88, and 25%, respectively. Release of rivastigmine from nanoparticles in the simulated gastric and body fluid during 24 h were obtained 70.5 and 79.6%, respectively, which was shown the slightly fast release of rivastigmine in simulated gastric fluid. The cytotoxicity effect of nanoparticles with and without rivastigmine was done by MTT assay on SY5Y cell lines. Results showed that the in vitro rivastigmine release from the nanoparticles containing of it exhibited the more treatment property as free rivastigmine on SY5Y.
Nano-Biomaterials
Sahar Rezaei; Nader Riahi Alam
Volume 8, Issue 2 , June 2014, , Pages 151-158
Abstract
Detection of tumors at an early stage is important for the diagnosis of cancer. Therefore, to detect cancer cells it is necessary to distinguish between metastases from normal cells at an early stage. Due to the large size and coverage necessary to prevent chemical reactions of the current contrast agents ...
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Detection of tumors at an early stage is important for the diagnosis of cancer. Therefore, to detect cancer cells it is necessary to distinguish between metastases from normal cells at an early stage. Due to the large size and coverage necessary to prevent chemical reactions of the current contrast agents in the body, they are just applicable to the extracellular space. Due to the small size of nanoparticles in comparison to cells, it is possible for them to enter the cells. Therefore, these materials are used for molecular imaging. In this paper, variations in the external magnetic field (Tesla) due to magnetic nanoparticles in homogeneous tissue were studied by the finite element method. For this purpose, a simulation was performed in the presence of magnetic nanoparticles and without it. By the finite element method, conversion of differential and integral governing equations to simple and solvable equations that are numerically stable was made possible. The results obtained indicate that the external magnetic field is intensified by the presence of magnetic nanoparticles.
Nano-Biomaterials
Shekufe Borhan; Saeed Hesaraki
Volume 6, Issue 3 , June 2012, , Pages 163-168
Abstract
Bioactive glasses with different compositions have been extensively used as substitute for defective bones. Injectable biomaterial is important in clinical applications that involve defects with limited accessibility or when using minimally invasive surgical techniques. In this study bioactive glass ...
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Bioactive glasses with different compositions have been extensively used as substitute for defective bones. Injectable biomaterial is important in clinical applications that involve defects with limited accessibility or when using minimally invasive surgical techniques. In this study bioactive glass nano-powder was synthesized by acid-base catalyzed sol-gel process and used as solid phase of injectable non-setting pastes. Morphological characteristics of powder were found by TEM. To prepare paste the powder was mixed with hyaluronic acid and polyvinyl alcohol solutions. Stability of pastes was determined by soaking in simulated body fluid. Rheological behaviours of paste in both rotation and oscillation modes were also measured. The results showed that particle size of glass powder was 20-30 nm. According to rheometry, these nano composites exhibited non-Newtonian shear thinning behaviour. By adding polyvinyl alcohol more stable paste with increased hysteresis loop area is obtained. The oscillatory tests revealed that these pastes were viscoelastic with more elastic character. The biocomposite can potentially be used as bioactive paste for the treatment of hard and even soft tissues.
Biomechanics of Bone / Bone Biomechanics
Hoda Salemi; Ali Asghar Behnamghader; Mohammad Reza Baghaban Eslaminejad; Mohammad Ataei
Volume 6, Issue 4 , June 2012, , Pages 249-255
Abstract
Collagen and Hydroxyapatite (HA) nanoparticles are significant constituent of the natural bone. In this study, the effect of collagen on the morphological and phase characteristics of calcium phosphate nanoparticles was investigated. The synthesis reaction was initiated by mixing H3PO4 as phosphorous ...
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Collagen and Hydroxyapatite (HA) nanoparticles are significant constituent of the natural bone. In this study, the effect of collagen on the morphological and phase characteristics of calcium phosphate nanoparticles was investigated. The synthesis reaction was initiated by mixing H3PO4 as phosphorous source and CaCl2 as calcium source in presence of Collagen Type 1. Collagen concentration in suspension and Ca to P ratio was 1% and 1.67 respectively. The morphology and structure of samples (with collagen and without collagen), heat treated at 600 0C were characterized by X-Ray diffraction (XRD), Fourier transformation infrared (FTIR) and Scanning electron microscopy (SEM). More fine and flake-like shape particles were observed in the SEM images of sample synthesized in the presence of collagen compared to the control sample which was constituted of larger granular particles. The XRD results revealed the powders were composed of hydroxyapatite and octacalcium phosphate and the sample synthesized in the presence of collagen was less crystalline. The amide bands of collagen and P-O and OH characteristic peaks were identified in FT-IR spectra.
Nano-Biomaterials
Zeynab Fereshteh; Mohammad Hossein Fathi; Reza Mozaffarinia
Volume 6, Issue 3 , June 2012, , Pages 177-193
Abstract
The aim of this study was to prepare and characterize the novel poly (ε-caprolactone) / Mg-doped fluorapatite nanoparticles (PCL / nMg-FA) composite scaffolds by electrospinning method. The optimized composite was achieved by changing of electrospinning parameters such as solvent, polymer concentration, ...
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The aim of this study was to prepare and characterize the novel poly (ε-caprolactone) / Mg-doped fluorapatite nanoparticles (PCL / nMg-FA) composite scaffolds by electrospinning method. The optimized composite was achieved by changing of electrospinning parameters such as solvent, polymer concentration, applied voltage, nozzle to collector distance and content of ceramic. It was shown that the diameter size of fibers decreased by adjusting the viscosity and conductivity solution. Optimal samples were studied with transmission electron microscopy (TEM), scanning electron microscope (SEM), X-ray diffraction (XRD), energy dispersive X-ray (EDX) and thermogravimetric analysis (TGA). According to TEM and the X-ray maps of the scaffolds, Mg-FA particles were homogeneously dispersed into the nanofibers without any agglomeration. It is noteworthy that was not any surfactant in this study. Also results of XRD show no chemical reactions between polymeric solution components. Mechanical properties of the scaffolds were also evaluated. Results showed that tensional strength of scaffolds and also thermal stability increased by increasing the weight ratio of nanoparticles up to 5 wt. %.
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.
Targeted Drug Delivery / Smart Drug Delivery / Drug Targeting
Seyede Sara Shafiei; Mehran Solati Hashjin; Mehrnaz Salarian
Volume 3, Issue 2 , June 2009, , Pages 119-125
Abstract
Layered double hydroxides (LDHs) are layered solid materials having positively charged layers. A variety of negatively charged biomolecules can be hybridized with LDHs to evolve into bio-LDH Nano hybrids, including vitamins, drugs and DNA strands as well as simple organic acids. In this research, Mg-Al-LDH ...
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Layered double hydroxides (LDHs) are layered solid materials having positively charged layers. A variety of negatively charged biomolecules can be hybridized with LDHs to evolve into bio-LDH Nano hybrids, including vitamins, drugs and DNA strands as well as simple organic acids. In this research, Mg-Al-LDH containing drug was synthesized by coprecipitation and anion exchange methods. The LDH structure was characterized by X-Ray Diffraction XRD, FTIR, SEM and STA techniques. The in vitro release profile of nano hybrids was analyzed by UV spectrophotometer. It was concluded that the present biocompatible hydrotalcite-like compound can be an excellent host material for encapsulating Ibuprofen and can play a role as a delivery vehicle for a controlled release.
Nano-Biomaterials
Rouzbeh Kazemzadeh; Ali Asghar Behnamghader; Saeed Hesaraki; Fateme Hazrati
Volume 3, Issue 2 , June 2009, , Pages 127-133
Abstract
Magnesium-contained Hydroxyapatite Nano powder was synthesized by wet chemical method using calcium nitrate tetra hydrate, magnesium nitrate hexa hydrate and di ammonium hydrogen phosphate in the presence of Glutamic acid. According to thermal analysis (STA) findings the samples were calcinated at specific ...
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Magnesium-contained Hydroxyapatite Nano powder was synthesized by wet chemical method using calcium nitrate tetra hydrate, magnesium nitrate hexa hydrate and di ammonium hydrogen phosphate in the presence of Glutamic acid. According to thermal analysis (STA) findings the samples were calcinated at specific temperatures and characterized by XRD, FTIR and TEM analysis. XRD results showed the that b-TCP ((Ca1-xMgx)3(PO4)2) was the dominant phase at 920°C. No characteristic peaks of hydroxyapatite were observed at that temperature. In contrast, the sample which was synthesized in the absence of Glutamic acid, contained both hydroxyapatite and b-TCP phase. The Findings showed a rapid decline in degree of crystallinity at 90°C with presence of Glutamic acid in reaction media. Transmission electron microscopy (TEM) observations on heat treated samples at 480°C revealed that using Glutamic acid has noticeable effect on crystallite size instead of its growth orientation. Dimensions of biomimetic nanoparticles as observed by TEM were 150x60nm and in the witness sample was 500x150nm. According to Scherrer formula for crystallite size, the size of the witness sample was calculated about 40nm. However, because of low degree of crystallinity it was impossible to calculate the size of Glutamic contained samples.
Nano-Biomaterials
Babak Farsadzadeh; Ali Asghar Behnamghader; Sedighe Joughedust
Volume 3, Issue 2 , June 2009, , Pages 151-160
Abstract
In this study hydroxyapatite (HA), flour-hydroxyapatite (FHA) and fluorapatite (FA) nanopowders synthesized by sol-gel route. Theses powders are used as biocompatible materials for bone replacement and teeth restoration. Ammonium fluoride (NH4F MERK), calcium nitrate [Ca(NO3)2,4H2O MERK] and triethyl ...
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In this study hydroxyapatite (HA), flour-hydroxyapatite (FHA) and fluorapatite (FA) nanopowders synthesized by sol-gel route. Theses powders are used as biocompatible materials for bone replacement and teeth restoration. Ammonium fluoride (NH4F MERK), calcium nitrate [Ca(NO3)2,4H2O MERK] and triethyl phosphite [TEP, (C2H5O) 3P MERK)] were used as F, Ca and P precursors respectively. Triethyl phosphite was first hydrolyzed in ethanol with a small amount of distilled water. To prepare FHA and FA, an appropriate amount of the NH4F powder was added directly to TEP solution. The appropriate amounts of TEP solution was added dropwise to the calcium nitrate solution to yield a stoichiometric ratio of Ca/P=1.67. The resulted solution stirred for 1 h and aged at 25°C for 24 h and 40°C for 72h afterward. After oven drying at 80°C, the powder samples were heat-treated at 550°C for 1 h in air. Microstructural characteristics, powder morphology, chemical structure and phase analysis and in vitro study were performed by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), Fourier Transform Infra-Red (FTIR), Zetasizer instrument and cell culture method. Fluoride-substituted hydroxyapatite powders (FHA) and Fluor apatite (FA) were successfully fabricated via a sol–gel technique with the incorporation of different levels of fluoride ions. Nearly complete substitution of the OH¯ by F¯ occurred with heat treatment, which was confirmed by FTIR analysis. The particle size distribution of powders evaluated by a zeta-sizer instrument was 100-160nm. The XRD results showed that the crystal size of powders is 20-50nm. The phase stability and crystallinity were different depending on the level of fluoride substitution. Moreover, the crystallinity and crystallite size of the powders increased with fluoride substitution. These improvements in the crystallization and phase stability of the apatite structure, resulting from the fluoride substitution via the sol– gel process, suggest enhanced performance of the FHA powders. The cellular response to the HA, FHA and FA powder was assessed by an in vitro culture method using fibroblastic L929 cells. After culturing for 3 days, the results showed that the number of cells increased with increasing fluoride substitution.
Nano-Biomaterials
Babak Mostaghasi; Mohammad Hossein Fathi; Mahmoud Sheikh Zeinaddin; Sabihe Soleimanianzad
Volume 1, Issue 2 , June 2007, , Pages 137-146
Abstract
Hydroxyapatite (HA) is a well known candidate for many applications in dentistry and medicine such as bone replacement and regeneration and coatings for medical implants. Nano-crystalline HA exhibits improved mechanical properties and biocompatibility. To optimize the benefits of nano-sized precursors, ...
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Hydroxyapatite (HA) is a well known candidate for many applications in dentistry and medicine such as bone replacement and regeneration and coatings for medical implants. Nano-crystalline HA exhibits improved mechanical properties and biocompatibility. To optimize the benefits of nano-sized precursors, the particles must be of a uniform shape and size and have minimum degree of agglomeration. The aim of this study was to synthesize of nano-crystalline HA via the biomineralization route. For this purpose, an Iranian strain of Serratia (Serratia marcescens PTCC 1187) was utilized for the synthesis of nano-crystalline HA. The strain was cultivated. Then the pellet of S. marcescens PTCC 1187 was separated and exposed to Glycerol 2-phosphate and Calcium chloride. After 14 days of incubation at 37oC, the white precipitated material was separated. After drying and calcination at 600oC the powder was characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and fourier transform infrared spectroscopy (FTIR) techniques. The results showed that nano-structured HA powder was synthesized and the crystallinity of the powder was relatively high according to the standard. The particles of the powder were single crystal with the size of 25-30 nm. Moreover, the shape and size of the particles were relatively uniform and the agglomeration was lower comparing to the conventional methods. This powder could be used in the regeneration of bone defects, fabrication of medical, dental implants and also as a vector for pharmaceuticals and biological materials such as the genes.
