Synthesis and characterization of poly‐α,β‐[N‐(2‐hydroxyethyl)‐L‐aspartamide]‐g‐poly(L‐lactide) biodegradable copolymers as drug carriers

Abstract

A series of biodegradable amphiphilic graft polymers were successfully synthesized by grafting poly(L-lactide) (PLLA) sequences onto a water-soluble polymer poly-alpha,beta-[N-(2-hydroxyethyl)-L-aspartamide] (PHEA) backbone. We established the feasibility of preparing these novel graft polymers by the ring-opening polymerization initiated by the macroinitiator PHEA bearing hydroxyl groups without adding any catalyst. The successful grafting of PLLA sequences onto the PHEA backbone was verified by combined size exclusion chromatography (SEC) and multiangle laser light scattering (MALLS) analysis. The chemical structures of graft polymers were characterized by FTIR and (1)H NMR. The critical micelle concentration (CMC) of the graft polymer was determined by fluorescence probe technique using pyrene. By controlling the feed ratio of the macroinitiator to the monomer, graft polymers with different branch lengths can be obtained. Using the 3-(4,5 dimethylthiozol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay, the graft copolymer has been proved to have low cytotoxicity. Based on the amphiphilicity of the graft copolymers, nanoparticular drug delivery systems were prepared by the direct dissolution method and the dialysis method. The anticancer drug Tegafur was encapsulated into polymeric nanoparticles, and in vitro drug release behavior was investigated. Transmission electron microscopy (TEM) images demonstrate that these nanoparticles are regularly spherical in shape. The particle size and distribution of the nanoparticles were measured.

Poly-α,β-(N-(2-hydroxyethyl)-L-aspartamide)-g-poly(1,3-trimethylene carbonate) amphiphilic graft co-polymer as a potential drug carrier

“…This is due to the micellization of the amphiphilic PHEA-g-PTMC in water. A similar phenomenon was observed for other amphiphilic co-polymers with PHEA as backbones [15,16].…”

“…As we can find from Table 1, the molecular weight M w of PHEA-2 is much lower than PHEA, indicating the degradation occurred during the heating. Generally the backbone secession during the ring-opening polymerization does not affect the composition of the resultant co-polymer [15]. However, the degradation of backbone ultimately leads to a lower M w of the resulting graft polymer.…”

Formulation and Evaluation of Isorhamnetin Loaded Poly Lactic-Co-Glycolic Acid Nanoparticles

“…Numerous encapsulation techniques have already been developed to prepare particulate sustained drug release systems, some of the commonly reported methods of preparing NPs from biodegradable polymers include emulsion solvent evaporation [13], monomer polymerization [14], nanoprecipitation [15], cross-flow filtration [16] or emulsion-diffusion technique [17], and the salting out method. However, the selection of a particular technique of encapsulation is typically determined by the solubility characteristics of the drug [18].…”

Preparation and Characterization of Poly (D,L-Lactide-co-Glycolide) (PLGA) Nanoparticles Loaded with Linamarin for Controlled Drug Release

“…[1][2][3] Among the different polymers, biodegradable polymers are the most widely used in medical applications. [4,5] Delivery systems based on biodegradable polymers are capable of improving drug stability, bioavailability, transport, release, and targeting properties, thus enhancing drug efficacy [6,7] Polyesters, poly lactic acid (PLA), poly (glycolic acid) (PGA), and poly (lactic-co-glycolic acid) (PLGA), are the most investigated biodegradable polymers [1,[8][9][10] for delivery of proteins and antigens, [2,11] peptides, [12,13] and plasmid DNA. [4,14] Polyesters are biocompatible [15][16][17] and biodegradable [18,19] due to hydrolytic cleavage of their ester bonds, [20][21][22] although some have considered the possibility of enzyme catalytic degradation.…”