Zahra Alyani Nezhad; Ghazale Geraily; Fatemeh Hataminia; Somayeh Gholami; Seyed Mohammad Mahdi Abtahi; Hossien Ghanbari
Abstract
Introduction: External radiotherapy is the most common method of radiotherapy which the most important problem associated with is that there is no difference between healthy and tumor tissues in dose absorption. One way to differentiate the dose sensitivity is to use metal-based nanoparticles. Bismuth ...
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Introduction: External radiotherapy is the most common method of radiotherapy which the most important problem associated with is that there is no difference between healthy and tumor tissues in dose absorption. One way to differentiate the dose sensitivity is to use metal-based nanoparticles. Bismuth oxide nanoparticles are good candidates for cancer radiotherapy. In this study, we investigated the dose enhancement effect of the synthesized spherical Bi2O3 NPs in 6MV external radiotherapy. Material and methods: Bi2O3 were synthesized and GENIPIN gel dosimeter was produced and divided into two equal portions, one part to fill vials containing pure gel and the other part to be added to a specified amount of nanoparticles to give a concentration of 0.1Mm. Then, the irradiation of the pure gel and gel vials containing the NPs was performed one day after manufacture by a 6MV external radiotherapy device. Gel readout was performed using spectrophotometer and absorption-dose curves were achieved. Results: results show that spherical Bi2O3 NPs cause a decrease in GENIPIN absorbance range compared to gel without NPs. The slope of the absorbance-dose curve in presence of NPs is 0.038 which is more than this slop in the pure gel (0.029) which indicates a DEF of 1.31 in the usage of these NPs in the tumor. Conclusion: we can conclude that by applying these spherical Bi2O3 NPs, dose absorption of the tumor will increase up to 31% which means the efficacy of radiotherapy can be maintained by lower applied dose to the tumor and healthy cells.
Saman Firoozi; Mohammad Ali Derakhshan; Roya Karimi; Ali Rashti; Babak Negahdari; Reza Faridi Majidi; Samaneh Mashaghi; Hossien Ghanbari
Abstract
Objective(s): Tissue engineering represents a new approach to solve the current complications of the heart valve replacements by offering viable valve prosthesis with growth and remodeling capability. In this project, electrospinning and dip coating techniques were used to fabricate heart valve constructs ...
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Objective(s): Tissue engineering represents a new approach to solve the current complications of the heart valve replacements by offering viable valve prosthesis with growth and remodeling capability. In this project, electrospinning and dip coating techniques were used to fabricate heart valve constructs from medical grade polyurethane (PU). Methods: First, a mold of tricuspid valve was dip coated in a PU solution, except for its valvular parts. Then, PU nanofibers were electrospun on the dip coated mold to form the valves. The morphology and diameter of nanofibers were investigated by SEM and contact angle measurements were done to evaluate the wettability of scaffolds. Thereafter, a tensile tester machine was used to assess mechanical properties of nanofibrous scaffolds. Then, the HUVEC cell line was cultured on the surface of scaffolds. Results: The SEM images showed the proper nanofibrous structure of the prepared scaffolds. Also, the obtained structure demonstrated appropriate tensile properties. Based on direct and indirect MTT, DAPI staining and SEM results, nanofibers were biocompatible and cells attached to the surface of the scaffolds, properly. Conclusions: This study demonstrated polyurethane-based nanofibrous scaffolds for engineering artificial heart valve. The presented scaffold provides temporary support for cells prior to generation of extracellular matrix (ECM).
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