1 e-Polymers 2012, no. 087 http://www.e-polymers.org ISSN 1618-7229 Synthesis and characterization of an amphiphilic methoxy poly(l-lactide)-block-poly(glycidylmethacrylate) copolymer as a drug nanocarrier Massoumeh Bagheri, * Forough Motirasoul * Chemistry Department, Science Faculty, Azarbaijan Shahid Madani University, P.O. Box: 53714-161, 5375171379,Tabriz, Iran; fax: (+98)(412) 4327541; e-mail: massoumehbagheri@yahoo.com (Received: 19 April, 2012; published: 31 December, 2012) Abstract: Present research is a preliminary report on the amphiphilic diblock copolymer (mPLA-b-PGMA) comprising hydrophobic methoxy poly(L-lactide) (mPLA) and hydrophilic poly(glycidyl methacrylate) (PGMA) segments was used as a promising drug carrier. Diblock copolymer was synthesized via ring opening polymerization (ROP) and atom transfer radical polymerization (ATRP) methods. Methanol first initiated ROP of L-lactide in the presence of tin(II)bis(2-ethylhexanoate) (Sn(oct) 2 ) as a catalyst. The resulting monohydroxyl-terminated polylactic acid (mPLA) was subsequently converted to a bromine-ended macroinitiator (mPLA–Br) by esterification with 2-bromisobutyryl bromide. The copolymer mPLA-b-PGMA was synthesized in a subsequent ATRP of GMA. The obtained polymers were characterized by means of 1 H NMR, FTIR, DSC and TGA. The copolymer mPLA-b- PGMA self-assembled into nanoscale micelles in aqueous solutions, as investigated by transmission electron microscopy (TEM) and dynamic light scattering (DLS). The TEM image of polymeric micelles showed that the micelles were spherical in shape and that their diameters were in the range of 80-140 nm. Then by using the naproxen as a hydrophobic model drug, the drug-loaded micelles with 81.18 % loading efficiency and 16.24 % loading capacity were prepared. Moreover, in vitro release study of naproxen was performed using dialysis bag in phosphate-buffered solution at 37°C and pH at 7.4. Accordingly, these polymeric micelles may provide as an effective drug carrier for controlled drug release. Introduction Recently, nanoparticles made from biodegradable polymers have widely attracted great interest due to their advantages over conventional therapeutic strategies [1]. Types of such nanoparticles include polymeric micelles, liposomes and polymer based- nanoparticles. They can potentially provide benefits such as increased therapeutic effect, prolonged bioactivity, controlled release rate, and finally decreased administration frequency and thereby increasing patient compliance [2]. Polymeric micelles have attracted much attention as a nanosized drug carrier in drug delivery system [3, 4]. Recently, polymeric micelles as carriers of hydrophobic drugs have drawn increasing research interests, due to their various advantages in drug delivery applications [5, 6]. Amphiphilic block copolymers can self-assemble into nanoscale micelle-like structures with a hydrophobic core and a hydrophilic shell due to the intra- and/or intermolecular interactions of hydrophobic segments in aqueous solutions [7, 8]. The core–shell architecture of the micelles is essential for their utility in drug delivery. In