22409

سنتز و مشخصه‌يابي نانوكامپوزيت آهن/سيليكا با كاربرد هايپرترميائي

كارشناسي ارشد

مهندسي پزشكي - بيومتريال

1398/10/25

دكتر مريم تاج آبادي - دكتر مرتضي تميزي فر

دكتر سيد محمد ميركاظمي

مواد و متالورژي

در اين پژوهش، نانوذرات‌مغناطيسي آهن صفرظرفيتي (Zerovalent iron nanoparticle) به روش احيا شيميائي سولفات آهن (FeSO4.7H2O) توسط عامل احيا NaBH4 سنتز شدند و پس از آن، جهت جلوگيري از اكسيد شدن، افزايش زيست‌سازگاري و بهبود امكان عاملدار كردن و بارگذاري دارو، پوششي از جنس سيليكا، توسط روش استوبر به وسيله پيش ماده TEOS (تترااتيل اورتوسيليكات) بر آنها اعمال شد. در ادامه جهت بررسي تاثير مقدار پيش‌ماده هاي FeSO4.7H2O و TEOS بر خواص نانوذرات، در شرايط سنتز ثابت، به وسيله نرم افزار طراحي آزمايش (Design expert) و متغير قرار دادن دو فاكتور مذكور، روند تغيير مشخصات و خواص مدنظر با تغيير فاكتورها، بررسي و مقدار بهينه محاسبه شد. براي مطالعه ريخت‌شناسي نانوذرات از ميكروسكوپ الكتروني روبشي نشر ميداني (FE-SEM) و ميكروسكوپ الكتروني عبوري TEM و جهت شناسايي فازي نانوذرات تهيه شده از روش هاي پراش پرتو ايكسXRD، ، طيف سنجي مادون قرمز تبديل فوريه (FT-IR) استفاده شده و همچنين براي محاسبه خواص مغناطيسي نانوذرات،‌از مغناطش سنج نمونه مرتعش(VSM) استفاده شده است. نتايج XRD و EDS نشان دهنده تشكيل فاز بلوري (Fe0) و نتايج FTIR نشان‌دهنده پيوندهاي مربوط به SiO2 و تشكيل آن در اطراف هسته آهن است. تصاوير TEM و FE-SEM نيز نشان مي‌دهد، ميانگين قطر هسته ذرات nm25/59 و نيز قطر ميانگين پوسته برابر nm87/9 است. همچنين بيشترين مغناطش اشباع در نمونه‌هاي طراحي آزمايش شده برابر با 119 emu/g بوده است. در بررسي كاربرد اين نانوذرات در فرآيند هايپرترميا تحت ميدان مغناطيسي متناوب، مقدار SLP (Specific Loss Power) بيشينه25/44 Watt/g و تغيير دماي 8/7 درجه‌سانتي‌گرادي در 4دقيقه ابتدايي برابر8 درجه‌سانتي‌گراد نشان داده شد. نتايج تست MTT مربوط به بررسي هاي زيستي نانوذرات در غلظت‌هاي متفاوت پس از سه روز در غلظت‌هاي كمتر ازµg/mL ‌250بيش از 80 درصد حيات سلولي نشان دادند و نانوذرات سنتز شده را از لحاظ زيست‌سازگاري براي كاربرد هايپرترميا تاييد كردند.

1399/07/14

Synthesis and characterization of nanocomposite Fe@SiO2 by hyperthermia application

10/5/2020 12:00:00 AM

Magnetic nanoparticles have numerous advantages in different fields and the major part of these applications are pertinent to medical field. Applications such as drug loading, drug delivery, MRI imaging, cells and macromolecules separation and cell purification, biosensors and treatment of cancerous tissue by means of heat production are among copious applications of nanoparticles in medicine. Hyperthermia is a method for cancerous tissue treatment in which the cancerous tissue is heated and this temperature increase will cause damage to cancerous cells in different ways. In this method magnetic nanoparticles are placed near cancer cells and an alternative magnetic field starts to produce and transfer heat to cancerous tissues and therefore increase the temperature of these cells. In this research, Zerovalent iron nanoparticles were synthesized with iron sulphate (FeSO4.7H2O) chemical reduction method with NaBH4 as reducer agent. Then, in order to prevent oxidation, increase biocompatibility and improve the possibility of drug delivery and drug loading, nanoparticles were covered by silica using Stober mechanism and with TEOS as a precursor. Some significant features of these nanoparticles are high saturated magnetization and also the ability to produce and transfer great amount of heat in Hypothermia process which are due to presence of Zerovalent iron and a good coverage with SiO2. After that, in order to examine the amount of NaBH4 and FeSO4 precursors effect on the nanoparticle’s feature, in constant synthesis situation and by using Design expert software and setting these two factors as variables, the process of characteristic variations with variation in factors was examined and optimum values was predicted. In order to identification and morphological study of synthesized nanoparticles, X Ray Diffraction (XRD), Field emission-Scanning Electron Microscopy (FE-SEM), Transmission Electron Microscopy (TEM), Fourier Transformation Infrared Spectroscopy (FT-IR) and Vibrating Sample Magnetometer (VSM) methods was used. XRD and EDS results confirm the formation of crystalline phase (Fe0) and FT-IR result shows the SiO2 bonds and its formation around magnetic cores. Likewise, TEM and FE-SEM images indicate that synthesized products are nanoparticles and these nanoparticles are coated. Also, the maximum value of saturated magnetization in designed samples were equal to 119 emu/g. In order to evaluate the application of these nanoparticles in Hyperthermia process, nanoparticles were dispersed in ethanol and a solution with concentration of 10 mg/mL was put in the Hyperthermia instrument with alternative magnetic field equal to 100 Oe and a current of 200 KHz. The maximum of SLP calculated to be 25.44 W/g and the temperature change in initial 4 minutes was 7/8ºC. Also, in order to examine biocompatibility of magnetic nanoparticles cell toxicity test (MTT) was used. According to MTT test results, after three days examination of different concentrations, only concentrations of 500 and 1000 µg/ml were a few toxic and therefore synthesized nanoparticles are biocompatible for using in hyperthermia.