Characterization of rhodamine loaded PEG-g-PLA nanoparticles (NPs): Effect of poly(ethylene glycol) grafting density

Regulating the surface poly(ethylene glycol) density of polymeric nanoparticles and evaluating its role in drug delivery in vivo

“…4 Due to the technical hurdles in quantifying the extent of PEG densities, as well as in 5 regulating the surface PEG density while maintaining other nano-properties 6 unchanged, for polymeric self-assembled nanoparticles, there is only a small amount 7 of research on the relationship of surface PEG densities with their in vivo drug 8 delivery properties [19][20][21]. In order to achieve the aim of changing the surface PEG 9 densities of polymeric nanoparticles, researchers have usually incorporated 10 hydrophobic homopolymer into the relative block copolymer. For example, Gref et al 11 adjusted surface PEG densities by adding different masses of polylactide (PLA) into 12 poly(ethylene glycol)-block-polylactide (PEG-PLA) during nanoparticle preparations, 13 but this also caused significant particle size change [19].…”

“…Therefore, in the 4 study of surface PEG density of nanoparticles and its role in their in vivo behaviors, 5 other nano-properties should be kept identical to avoid unreliable conclusions. 6 To circumvent these challenges and gain improved systemic insight into the 7 relationship between surface PEG densities and their behaviors in biological 8 environments as well as their antitumor efficacy, in this study we developed a library 9 of polymeric nanoparticles with controllable surface PEG densities and sizes, by 10 combining PEG-PCL copolymer and PCL homopolymer in the preparations, from 11 which we selected a group of nanoparticles with varying surface PEG densities but 12 similar sizes in order to study the effect of surface PEG density on the in vivo fate of 13 nanoparticles in mice. The size of nanoparticles was controlled by regulating the mass 14 ratio of PCL homopolymer incorporated into PEG-PCL, and PEG density was also 15 judiciously modulated by changing the molecular weight of PEG-PCL and the molar 16 ratio of repeating units of PCL (CL) to that of PEG (EG).…”

“…The diblock copolymer of 7 monomethoxy poly(ethylene glycol) and poly(ε-caprolactone) (PEG-PCL) was 8 synthesized and characterized as previously reported [33]. PCL 3.5k homopolymer was 9 synthesized by ring-opening polymerization of ε-caprolactone with aluminum 10 isopropoxide as the initiator according to a previously reported method [34]. 11 N,N'-Diisopropylcarbodiimide (DIC), 4-dimethylaminopyridine (DMAP) and 12 Rhodamine B (RhoB) were purchased from Aladdin Industrial Inc. (China).…”

The Investigation on Polyion Complex Micelles Composed of Diammonium Glycyrrhizinate/Poly(Ethylene Glycol)–Glycidyltrimethylammonium Chloride-Grafted Polyasparthydrazide

“…Particles modified by PEG can improve the stability and prolong the circulation time in blood. PEG can shield the charge on particle surface and provide sufficient steric stabilization (16)(17)(18)(19)(20). The polyelectrolyte of PAHy-GTA and drugs may easily aggregate or combine with other molecules.…”

Preparação de nanopartículas poliméricas a partir de polímeros pré-formados: parte II

“…A agitação da emulsão é a etapa determinante para a obtenção das nanosferas e deve ser realizada antes da precipitação do polímero, de modo a serem obtidas gotículas de fase interna de dimensões coloidais. Por fim, promove-se a remoção do solvente orgânico, ocorrendo a precipitação do polímero na fase externa aquosa e consequente formação das nanosferas [10] . Os princípios ativos hidrossolúveis, para poderem ser incorporados por dispersão na fase orgânica, podem, em alternativa, ser dissolvidos numa fase aquosa, que, posteriormente, vai constituir a fase interna de uma emulsão múltipla A/O/A [11,12] .…”