DETERMINATION OF THE BINDING AND RELEASE PROFILE OF IMMOBILIZED INSULIN ON NAVICULA SALINICOLA NLA BIOSILICA

• Main Author: Azizah, Jasmine
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/87508
• Institution: Institut Teknologi Bandung

Diabetes is a chronic metabolic disease characterized by elevated blood glucose levels due to insufficient insulin production by the body. One of the treatment methods to control blood glucose levels is insulin therapy. As an alternative to relatively invasive insulin injections, the oral delivery method is currently being developed. The oral method offers advantages, including its similarity to the natural insulin absorption pathway in the body. However, several factors must be considered, such as pH changes along the digestive tract and digestive enzymes that may degrade insulin, resulting in low bioavailability. Therefore, a matrix is required to protect and deliver insulin orally. Diatoms are a type of unicellular microalgae with transparent biosilica shells that can serve as substitutes for synthetic silica as a drug delivery matrix. One type of diatom is Navicula salinicola NLA (NSN), which can be found in Indonesian waters. NSN has a boat-like shape and hierarchical nano-sized pores in its shell, making it suitable for use as an insulin delivery matrix. The aim of this study was to determine the adsorption and desorption capabilities of biosilica derived from NSN shells for insulin, as well as to examine the stability of immobilized insulin structure on NSN biosilica. The research steps included cultivating NSN diatoms, isolating NSN, binding insulin onto NSN biosilica, releasing insulin in vitro in simulated intestinal fluid (SIF), and characterizing the biosilica and biosilica-insulin complex. The characterization methods used were Scanning Electron Microscopy (SEM), Fourier-Transform Infrared (FTIR) spectroscopy, X-ray Fluorescence (XRF), UV-Vis spectrophotometry, and fluorescence spectrophotometry. Cultivation of NSN was successfully carried out using seawater medium (28 ppt salt solution), yielding a maximum cell count of 5,390,000 ± 74.96 cells/mL on the 12th day. Wet biomass harvesting was successfully conducted, producing 852.34 g of biomass with a productivity of 5.33 g/L culture. Isolation of biosilica from wet biomass resulted in 7.81 g of biosilica from 852.34 g of wet biomass. Based on experimental data fitting, the adsorption kinetics of insulin on biosilica followed pseudo first-order kinetics with an R² value of 0.99. In simulated intestinal fluid, insulin adsorbed onto biosilica was released up to 0.73 units (IU). Analysis of the emission spectrum of immobilized insulin showed a red shift in the emission peak due to adsorption on the biosilica surface.