#TITLE_ALTERNATIVE#

• Main Author: AGUS SYAMSUR RIJAL NIM: 30712007 , MUH.
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/29065
• Institution: Institut Teknologi Bandung

Multi Drug Resistance (MDR) is a problem in cancer therapy. The main cause of <br /> <br /> resistance is the over expression of P-glycoprotein (P-gp) and its activity to cause <br /> <br /> efflux of anticancer drugs. To overcome this problem, it is necessary to use MDR <br /> <br /> inhibitors to suppress P-gp activity so that anticancer compounds can be <br /> <br /> efficiently delivered. The development of nanocarrier for anticancer can provide <br /> <br /> passive target following the Enhanced Permeation and Retention (EPR) effect so <br /> <br /> that the drug will accumulate in the tumor tissue and will be expected to decrease <br /> <br /> its toxicity in normal tissue. Some polymers/excipients include poloxamer, <br /> <br /> polyethylene glycol (PEG), D-&#945;-tocopheryl polyethylene glycol 1000 succinate <br /> <br /> (TPGS), Cremophor EL, Solutol HS-15, Brij-35, Peceol® (glyceryl monooleate) <br /> <br /> and dendrimer have been studied could inhibit the activity of P-gp through <br /> <br /> different mechanisms but not yet known the mechanism and polymer that are most <br /> <br /> potential in inhibiting P-gp activity. It is therefore necessary to do screening study <br /> <br /> of P-gp inhibitory activity of mechanisms pathways and potent polymer in the <br /> <br /> form of nanoparticles through in vitro testing of cancer cell cultures. The purpose <br /> <br /> of this study was to investigate the most potent inhibition of P-gp activity from <br /> <br /> nanocarriers from various types of polymers/excipient as well as to produce more <br /> <br /> effective anticancer nanocarrier preparations and overcoming drug resistance by <br /> <br /> inhibiting P-gp activity. <br /> <br /> The study begins with the optimization of blank nanocarrier formation for four <br /> <br /> selected polymers ie. Synperonic PE / P84 (P84), TPGS, glyceryl monooleate <br /> <br /> (GMO) and PAMAM dendrimer G5 (PG5). The P84 and TPGS polymeric micelle <br /> <br /> nanoparticles were prepared by a thin-film hydration method of 1-10% <br /> <br /> concentration resulting in a 24-34 nm and 21-27 nm particle size range with a <br /> <br /> polydispersity index of 0.17-0.45 and 0.24-0.43. The GMO nanoparticle was <br /> <br /> prepared in liquid crystal dispersion in water or cubosomal nanoparticles. The <br /> <br /> preparation of nanoparticles was performed by ultrasonication (2.5 minutes) of <br /> <br /> GMO solution in ethanol with Poloxamer 407 (P407) in aqueous phase obtained <br /> <br /> optimum formula at 1% GMO concentration with P407 1% as stabilizer with size <br /> <br /> 108,7 nm. PG5 is a dendritic molecule that has a three-dimensional structure with <br /> <br /> an inner cavity. PG5 has a diameter of 5.4 nm. Further optimization was to <br /> <br /> prepare nanoparticles using docetaxel (DTX) as drug model gives DTX <br /> <br /> entrapment efficiency results for P84-DTX, TPGS-DTX, GMO-DTX and PG5- <br /> <br /> DTX nanoparticles 58,78 ± 2.03, 91,56 ± 7.30, 74.19 and 5.87% respectively. <br /> <br /> Characterization with photon correlation spectroscopy (PCS) for the optimized <br /> <br /> formula of each excipient resulted in a particle size of 21.8 ± 4.2, 29.0 ± 0.8, <br /> <br /> 113,8 and 14.69±2.7 nm, respectively. The potential zeta was -9.06 to +22.78 mV. <br /> <br /> The morphology of each of the nanoparticle shows a spherical shape except the <br /> <br /> DTX-GMO nanoparticles that have a cubic shape tendency. <br /> <br /> In vitro cytotoxicity test in MCF7 cells by MTT method showed that P84-DTX, <br /> <br /> TPGS-DTX, GMO-DTX and PG5-DTX nanoparticles could increase the <br /> <br /> cytotoxicity of DTX 2,8; 10.8; 8.4 and 2.4 times, respectively compared to control <br /> <br /> DTX cytotoxicity. <br /> <br /> The development of MCF7 cells resistant to DTX was done by stepwise increased <br /> <br /> of DTX exposure yielding MCF7 resistant (MCF7/R) cells with IC50 value 4.7 <br /> <br /> times higher and having P-gp expression three times higher than IC50 of MCF7 <br /> <br /> parent cell. Furthermore, it is used for in vitro cancer resistance study related to <br /> <br /> the increased of P-gp expression. <br /> <br /> Visualization of P-gp expression by immunocytochemistry assay showed that <br /> <br /> treatment with P84, TPGS and PG5 nanocarrier were qualitatively decreased the <br /> <br /> number of MFC7/R cells expressing P-gp. While in the quantification test of P-gp <br /> <br /> expression using flowcytometry method,only treatment with GMO nanocarrier <br /> <br /> has been able to significantly decrease the P-gp levels. <br /> <br /> The decrease of P-gp activity by each nanocarrier was determined by multidrug <br /> <br /> resistance assay by determining the uptake of calcein-AM compound into MCF7 <br /> <br /> and MCF7/R cells. The test results showed no change in the uptake calcein-AM in <br /> <br /> MCF7 cells while in MCF7/R cells treated with GMO, PG5, P84 and TPGS <br /> <br /> nanocarrier can increase uptake calcein-AM significantly, indicating that the <br /> <br /> nanocarrier able to decrease P-gp expression. The test results also show that <br /> <br /> GMO nanocarrier have the best ability to decrease P-gp expression. <br /> <br /> At the end of this study we have produced a DTX-GMO cubosome that has a size <br /> <br /> of 100 nm, better cytotoxicity potential and can decrease P-gp expression so that <br /> <br /> it can be developed as a nanocarrier to overcome resistance to cancer therapy. <br />