Poly(Ethylene Glycol)-b-Poly(D,L-Lactide) Nanoparticles as Potential Carriers for Anticancer Drug Oxaliplatin

Abstract

Nanoparticles based on biocompatible methoxy poly(ethylene glycol)-b-poly(D,L-lactide) (mPEG113-b-P(D,L)LAn) copolymers as potential vehicles for the anticancer agent oxaliplatin were prepared by a nanoprecipitation technique. It was demonstrated that an increase in the hydrophobic PLA block length from 62 to 173 monomer units leads to an increase of the size of nanoparticles from 32 to 56 nm. Small-angle X-ray scattering studies confirmed the “core-corona” structure of mPEG113-b-P(D,L)LAn nanoparticles and oxaliplatin loading. It was suggested that hydrophilic oxaliplatin is adsorbed on the core-corona interface of the nanoparticles during the nanoprecipitation process. The oxaliplatin loading content decreased from 3.8 to 1.5% wt./wt. (with initial loading of 5% wt./wt.) with increasing PLA block length. Thus, the highest loading content of the anticancer drug oxaliplatin with its encapsulation efficiency of 76% in mPEG113-b-P(D,L)LAn nanoparticles can be achieved for block copolymer with short hydrophobic block.

Nanoformulations of Drugs Based on Biodegradable Lactide Copolymers with Various Molecular Structures and Architectures

“…In [84] b-P(D,L)LA copolymers were prepared by the nanoprecipitation method and the effect of the stereochemical structure of the PLA block on their solubilizing ability in relation to the anticancer drug oxaliplatin, which is poorly soluble in water, was studied [85]. Under similar polymerization degrees of the hydrophobic PLA block, the content of oxaliplatin in PEG 113 -b-P(L)LA and PEG 113 -b-P(D,L)LA particles was 0.9 and 3.8 wt %, respectively (with the initial load of 5 wt %).…”

“…In addition, with an increase in the length of the P(D,L)LA block, its hydrophobicity increases, which can also prevent the effective encapsulation of a hydrophilic drug into the particles. In [85], the effect of the P(D,L)LA block length in PEG 113 -b-P(D,L)LA n copolymers on the content of the anticancer drug, oxaliplatin, in PEG 113 -b-P(D,L)LA n nanoparticles was studied. With an increase in the polymerization degree of the P(D,L)LA block n from 62 to 173 monomer units, the content of oxaliplatin in the particles decreased from 3.8 to 1.5 wt % (with the initial loading of the drug of 5 wt %).…”

The Role of Integrated Approach in the Determination of Nanoparticle Sizes in Dispersions

“…Secondly, polymeric NPs of the "core-corona" and "Janus" types can be studied by TEM only with the use of the selective contrasting procedure [15]. For example, to employ TEM for studying polymeric "core-corona" NPs, which are formed from amphiphilic block copolymers, such as poly(lactide)-block-poly(ethylene oxide) (PLA-b-PEO) [16,17], as well as hydrophobic PLGA copolymers in the presence of PVA as a hydrophilic stabilizer [18,19], toxic uranyl acetate is commonly used as a negative contrasting agent. In addition, when samples are dried at the stage of sample preparation, the stabilizing corona of particles collapses, and the D value determined for NPs by the TEM method turns out to be significantly lower than the value of their D h .…”

Polylactide-Based Materials: Synthesis and Biomedical Applications

“…This Special Issue presents the original research and reviews articles describing the synthesis and application of PLA-based materials. In this regard, Razuvaeva et al [ 1 ] reported the preparation of NPs composed of methoxy poly(ethylene glycol)- b -poly( d , l -lactide) copolymers loaded with the anticancer drug: oxaliplatin. The core–corona structure was obtained after the nanoprecipitation of copolymers.…”