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Investigation on Effect of Additives on the Synthesis of Mesoporous Silica Nano Particles for Drug Delivery Applications

Askari, Majid | 2015

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 56211 (07)
  4. University: Sharif University of Technology
  5. Department: Materials Science and Engineering
  6. Advisor(s): Nemati, Ali; Akbari, Hmid; Khoobi Shourkaei, Mahdi
  7. Abstract:
  8. In recent years, the use of mesoporous silica nanoparticles as carriers of biological agents has increased. The use of nanometer dimensions in intra-body applications not only hides the particles from the view of macrophages and the body's immune system, but also causes the particles to enter the cells more easily through endocytosis. Template removal method is the most common method in the synthesis of mesoporous silica. In this method, the orderly arrangement of pattern-forming molecules is used to form pores. Until now, various types of organic materials have been used as pattern materials. The main goal is the synthesis of nanoparticles with the largest size of holes and the largest effective surface area and volume of holes. Tannic acid is a natural polyphenol that has proven antioxidant and prooxidant properties. In addition, recently, reports have been published about its anti-cancer properties. In this project, in the first step, tannic acid was used as a new template material for the synthesis of mesoporous silica particles. Samples were synthesized in the presence of different amounts of tannic acid, and the optimal amount of tannic acid was obtained to reach mesoporous nanoparticles with the largest pore size and the largest effective surface area and volume. In the next step, the effect of adding hydrochloric acid (HCl) and reducing the pH of the environment on the properties and characteristics of the final mesoporous material was investigated. The methods of washing with water and calcination were used and confirmed as methods of removing the pattern from the pores. At the end, the amount of tannic acid loaded on the structure during synthesis was obtained and compared with the amount loaded on the calcined particles. The release process of tannic acid from each of the two samples was also investigated. In order to examine the synthesized structures from tests such as: dynamic light scattering (DLS), nitrogen absorption and desorption, X-ray diffraction (XRD), simultaneous thermal test (SDA), infrared spectroscopy (FTIR), visible and ultraviolet spectroscopy. (UV/Vis. Spec.) and scanning and transmission electron microscopes (SEM and TEM) were used. The results showed that tannic acid has the ability to be used as a template material in the synthesis of mesoporous silica, and in the condition that tannic acid is dissolved in water to near saturation concentration, the resulting sample has the best characteristics in terms of effective surface area (634 m^2/gr), the volume of pores is (0.51^cm3⁄gr) and the size and order of pores is (3.7 nm). Adding hydrochloric acid to the synthesis medium also has a constructive effect on the pattern formation in the water medium and improves the properties of the synthesized mesoporous nanoparticles. The loading of tannic acid during synthesis on the optimal sample was 25.32% by weight and the loading of tannic acid on the calcined particles was 14.3% by weight. Examining the release process of tannic acid from each of the structures also showed that in both types of loading, an explosive release occurs at the beginning. In Edema, the release of tannic acid from a sample loaded in situ is slower than the sample loaded after removing the template due to the trapping of tannic acid in the holes and structure of the material during synthesis
  9. Keywords:
  10. Mesoporous Silica Nanoparticles ; Template Removing ; Tannic Acid ; Drug Delivery ; Nano Sized ; Template Agent

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