International Journal of Pharmaceutical Research 2011, Volume 3, Issue 2, 20-26. ISSN 0975-2366 Research Article Folate – Galactose – targeted delivery of fluoresceine isothiocyanate as a drug model prepared by FOL-PEG-g-PEI-GAL conjugate as a novel carrier S.Ghiamkazemi 1, 2, 3 , M.Hajiabedin 6 , A.Amanzadeh 5 , T.Amini 7 , R.Dinarvand 1, 2 , M.Amini 3, 4 , M.Rafiee-Tehrani 1, 2* 1 Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran, Iran 2 Department of Pharmaceutics, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran 3 Department of Medicinal Chemistry, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran 4 Drug Design and Development Research Center, Tehran University of Medical Sciences, Tehran, Iran 5 National Cell Bank of Iran (NCBI), Pasteur Institute of Iran, Tehran, Iran 6 Pharmaceutical Sciences Branch, Faculty of Pharmacy, Islamic Azad University, Tehran, Iran 7 Nobleceuticals Ltd, Birmingham, United Kingdom *Corresponding author: E-mail: rafitehr@sina.tums.ac.ir, Tel: 0098- 021-88009440, Fax: 0098- 021-88026734 Received: 15/09/2010, Revised: 25/11/2010, Accepted: 10/12/2010 ABSTRACT Polyethylenimine (PEI) is a well-known cationic polymer that has gained recent attention as a transfection and trans- duction agent. However; it is extremely cytotoxic in many cell lines because of its high surface charge (about +40 mV), non- biodegradability and non-biocompatibility. Other drawbacks of this polymer include, low duration of expression, non- specific cell uptake and instability in blood circulation. To enhance Polyethyleneimine biocompatibility, the graft pegylated copolymer was synthesized. To target cancer liver cells, two targeting ligands folic acid and galactose (lactobionic acid) were attached with graft Pegylated copolymer to increase specifically the entrance of this new targeted copolymer to cancer liver cells, because the folic acid and lactobionic acid receptors are over expressed only on human hepatocyte carcinoma. The composition of this new conjugated copolymer was characterized using 1 H-NMR spectra. Its molecular weight and zeta potential were compared to polyethyleneimine. To study the entrance of this targeted carrier to human hepatocyte carcinoma (HepG2), fluoresceine isothiocyanate (FITC) as a model drug was conjugated to this novel carrier and the emission of green fluorescent was determined from three cell lines (HEK293, KB and HepG2) and compared with fluoresceine isothiocyanate alone. The conjugated copolymer showed no cytotoxicity and targeted cultured HepG2 cells more effectively than KB and HEK 293 cell lines because of its two targeting moieties. In conclusion, the results indicate that the novel biocompatible copolymer can be considered as a useful carrier for targeted drug delivery to liver cancer cells. KEYWORDS: Polyethylenimine, FOL-PEG-g-PEI-GAL, targeted drug delivery, fluoresceine isothiocyanate, pegylation, HEK293 and KB and HepG2 cell lines. INTRODUCTION In recent years, there has been an enormous interesting the formulation of a targeted carrier for a specific popula- tion of cells, either locally or systematically. The targeted drug delivery system can be achieved by either non- polymeric or polymeric carrier methods [1-3]. Novel drug delivery by non-polymeric carriers has been studied for years; however, the broad use of this system is affected by the limited size of material delivered, cytotoxicity and no targeting interaction to certain cells [2, 3]. Therefore, polymeric drug delivery carriers have be- come a promising alternative since the carriers could be synthesized with higher purity and quality degree and less immunogenic response than the viral and lipidic carriers for drug targeting [3-5]. An ideal carrier for drug delivery needs to be inert while in circulation and should release its payload at the target site resulting in an efficient transduc- tion of the cells. This carrier should have sufficiently small size and stability and minimal aggregation in blood, in or- der to efficiently enter target cells. For achieving to this proper carrier, Cationic lipids and biodegradable polymers have been synthesized to react with drugs and promote efficient intracellular delivery [4, 5]. Among the cationic polymers, polyethylenimine has emerged to be one of the most popular reagents for trans- duction of cells in culture. However, its application in vivo has been limited due to multiple cationic charges on its surface and consequent difficulties in targeting therapeutic sites, high zeta-potential, non-biodegradability and non- biocompatibility in serum media [4, 5]. It also has low sta- bility and short circulation time in blood stream. Therefore, efficient, less toxic and biodegradable polycation drug car- riers are highly desirable for therapeutic drug delivery. To achieve this goal, in this study, polyethylenimine (PEI) was modified with polyethylene glycol. So, PEG-g- PEI copolymer was prepared to enhance the biodegradabil- ity and stability in serum media. To target cancer liver cells and to increase the trans- duction efficiency to this cell lines, pegylated PEI was conjugated with two targeting ligands (galactose and folic acid). The asialoglycoprotein receptor (ASGP-R) is known to be present only on hepatocytes at a high density of 500,000 receptors per cell [6, 8- 9] and targeted systems via the (AGSP-R) is one of the effective drug delivery systems into the liver in vivo [7,10-12]. The compounds like galac- tose, manose, arabinose will be able to recognize the asi- aloglycoprotein receptors on the surface of paranchymal hepatocyte [9- 11]. So, this hepatocyte-specific receptor recognizes and interacts with galactose ligand on the PEG- g-PEI-GAL. 20 | IJPR | April-June