Encapsulation of Nanoparticle Fe3O4 With Phospholipid And Dimethylaminobenzyl-Chitosan As Protein ?-Amyloid Contrast Agent

• Main Author: Pura, Megantara
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/33459
• Institution: Institut Teknologi Bandung

Alzheimer is a disease that slowly destroys memory and cognitive ability. There are 46 million Alzheimer patient around the world with 22 million of them in Asia, and the amount of Alzheimer’s patients are expected to increase fourfold at year 2050. Magnetic Resonance Imaging (MRI), with help of contrast agent is capable of early detection of this disease. However, enzyme ligand that is used for MRI media contrast is neurotoxic. On the other hand, research on PET contrast agent uses dimethylaminobenzyl ligand, which is able to interact with Amyloid protein and biocompatible. The strategy of this research is to design magnetite-based MRI contrast coated with dimethylaminobenzyl-chitosan as its ligand. Synthesis of magnetite nanoparticle used co-precipitation method with oleic acid as its surfactant, while the encapsulant used chitosan modified with 4-N,N dimethylaminobenzaldehyde. Encapsulation process was done by dispersion of nanoparticle in acetone, then added with modified chitosan solution. Ultrasound processor was used for mixture homogenization. Interaction test between modified chitosan and beta-sheet protein was also done, in order to calculate dissociation constant between those materials. UV-Vis result showed new peak at 353 nm on modified chitosan spectrum compared with normal chitosan, proved that chitosan was modified with dimethylaminobenzaldehyde. FTIR spectrum of encapsulated nanoparticles shows strong spectrum of iron oxide and 1,4 disubstituted benzene. XRD analysis shows that the nanoparticle formed is D-Magnetite with crystal size 13 + 4 nm. Lastly TEM image shows dark colored spheres inside a membrane. The size of dark colored sphere is 12 + 4 nm, which is in range of crystal size from XRD analysis, proving that the dark spheres are magnetite. Radius of gyration from modified chitosan is 6 nm, which is close to the thickness of the membrane, proved that the modified chitosan is encapsulating the magnetite. Dissociation constant of the modified chitosan is in 10-3 order, which is in range of interaction between enzyme and its substrate, showing potential of the modified chitosan as alternative ligand of Amyloid protein.