BIOSILICA CYCLOTELLA SRIATA TBI AS A MATRIX FOR INSULIN DELIVERY

• Main Author: Afritama, Atika
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/85284
• Institution: Institut Teknologi Bandung

Insulin plays a crucial role in regulating blood sugar levels. Therefore, insulin is used as a therapy for diabetic patients, which is commonly administered through injection. As an alternative for relatively invasive injection method, oral delivery of insulin recently has gained attention. One of the major challenges in the oral delivery of insulin is the degradation of its structure as it passes through the gastrointestinal tract. In this study, we developed a biosilica matrix derived from Cyclotella striata TBI as a carrier for insulin. Biosilica was isolated from Cyclotella striata TBI, characterized using BET, FTIR, XRF, and SEM, and tested for its insulin adsorption capacity. Cyclotella striata TBI cells were cultivated with an initial density of 227,000 cells/mL and increased sevenfold over twelve days, with a biomass productivity of 833 mg L–1 culture d–1. The yield of biosilica from Cyclotella striata TBI biomass was 1%. Biosilica derived from Cyclotella striata TBI exhibited a petri dish-like morphology with hierarchical pores having a diameter of 9.24 µm. The surface area of the biosilica was 130.64 m2/g, with an average total pore volume of 0.289 mL/g and an average pore diameter of 4.43 nm. Biosilica characteristics were identified by the presence of Si–O–Si stretching symmetries at wave numbers of 795 and 1900 cm-1. According to XRF analysis, Cyclotella striata TBI biosilica consisted of 100% SiO2.The surface of biosilica was successfully modified with amine groups that indicated by the appearance of an amine peak at wave number of 1600 cm- 1. Pure biosilica (SiO2) and modified biosilica (Si-APTES) adsorb insulin follow a pseudo first order kinetic adsorption model. The insulin adsorption isotherm model on SiO2 follows the Sips model (maximum adsorption capacity is 35.9 mg insulin per gram of biosilica), whereas insulin adsorption on Si-APTES follows the Langmuir model (maximum adsorption capacity is 65.3 mg insulin per gram of modified biosilica). The adsorption capacities at equilibrium for SiO2 versus Si-APTES show no significant difference. Furthermore, the release (desorption) of insulin in simulated intestinal fluid reaches 40% within 10 hours. The secondary structure of desorbed insulin shows no significant difference compared to secondary structure of standard insulin.