DEVELOPMENT AND CHARACTERIZATION OF MOLECULARY-IMPRINTED POLYMER AND NANOCOMPOSITES AS SELECTIVE SORBENT CANDIDATE FOR SOFOSBUVIR ANALYSIS IN BLOOD PLASMA

• Main Author: Aprilia Wisnuwardhani, Hilda
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/80283
• Institution: Institut Teknologi Bandung

COVID-19 pandemic that occurred from 2020 until it was declared over in early 2023, has encouraged an increase in drug discovery and development which continues to be pursued. Currently, treatment for COVID-19 and other new diseases, especially diseases caused by viruses, is carried out using off-label drugs. There are sofosbuvir and remdesivir as examples. The use of off-label drugs requires rigorous monitoring. Therefore, selected bioanalytical methods are needed to monitor the therapeutic effects, bioavailability, and side effects of drugs. The absence of an official analysis method in the compendia is one of the challenges that arises. Another challenge in developing bioanalysis methods is that the sample preparation stage is associated with a complex biological matrix. Sorbents in the form of molecularly imprinted polymers (MIP) can be used at the bioanalytical sample preparation stage to separate analytes from the matrix. One form of composite sorbent is a combination of silver nanoparticles with MIP. In its application in bioanalysis, MIP and Ag@MIP can be followed by instrument analysis using the High-Performance Liquid Chromatography (HPLC) and Surface-enhanced Raman Scattering (SERS) methods. This research aims to produce MIP and Ag@MIP printed with sofosbuvir to separate sofosbuvir from blood plasma. The analytical method that has been developed is then validated to obtain a new analytical method for the analysis of sofosbuvir in blood plasma. The research began with an in silico study using Gaussian 09 software, calculating the binding and Gibbs free energy using the Density Functional Theory (DFT) B3LYP basis set 6-31G (d,p) method. The best functional monomer that has the best interaction with the sofosbuvir template was selected from the results of the in silico study. The effect of the solvent used in the MIP synthesis was optimized using the Polarizable Continuum Model (PCM) method using the same software. Molecular dynamics simulations were carried out using Gromacs 2016.3 to determine the best stoichiometric ratio between template, functional monomer and cross linker. The method used to synthesize MIP and Ag@MIP is non-covalent interaction, using bulk polymerization and precipitation methods. AgNPs were synthesized in situ from AgNO3 precursor using sodium borohydride as a reducing agent. The formation of AgNPs was analyzed using UV-Vis spectrophotometry by observing the absorption peak at a specific wavelength. NIP and Ag@NIP were also synthesized as a reference without templates. The template was removed from the imprinted polymer by sonication with acetonitrile. Morphological and microscopic characterization was carried out using SEM EDX, and XRD. Chemical characterization was carried out using FTIR method. The adsorption capacity of MIP and Ag@MIP was carried out by testing adsorption capability, adsorption kinetics, adsorption isotherm, adsorption selectivity and BET adsorption. Dispersive MISPE analysis conditions were optimized to obtain suitable conditions. The imprinted polymer selectivity test was tested for another drug compound that is also used in the treatment of COVID-19, i.e remdesivir. Reusability testing of dispersive MISPE was also conducted to determine how often the sorbents could be reused. Analyzing sofosbuvir in blood plasma begins with sample preparation using dispersive MISPE and Ag@MIP, then continues with detection using HPLC methods. The analytical methods to be validated include specificity, accuracy and precision. DFT test results show that MAA is the functional monomer that interacts best with SOF. This is characterized by binding energy and Gibbs free energy values of -79.583 kcal mol-1 and -66.627 kcal mol-1, respectively. Determination of the association constant showed that acetonitrile was the best solvent for the synthesis. The acetonitrile bond energy value of -9.38397 kcal mol-1 supports these results. Based on molecular dynamics simulations, the SOF to MAA complex ratio is 1:1, providing good results from the RDF parameters. The results of the Jobs plot analysis support this result. Polymers synthesized using the precipitation polymerization method (MIP A and MIP B) provide more homogeneous morphological characterization results. The adsorption capacity test proved this. The adsorption capacity values of MIP A and MIP B are 12,434 ± 0.599 mg/g and 13,957 ± 0.330 mg/g. This result is better than the adsorption ability of MIP C and D, namely 8.235 ± 1.466 mg/g and 7.733 ± 0.933 mg/g. The adsorption kinetics test results show that all the MIPs and Ag@MIPs produced follow the pseudo second-order kinetic model which is characterized by a correlation coefficient value close to one. The adsorption isotherm test results show that MIP A, B, C, D, and Ag@MIP follow the Langmuir isotherm adsorption model. The BET test results show that MIP A has the largest surface area, 162 m2 /g. The selectivity test results show that the polymers MIP A, B, C, D and Ag@MIP have better selectivity for SOF than their similar compound, RMD. The application results show that MIP A, B, C, D polymers are able to separate SOF from complex blood plasma matrices. MIP B has the best performance for extracting SOF for blood plasma matrices.