“Tree‐Shaped” Copolymers Based on Poly(ethylene glycol) and Atactic or Isotactic Polylactides: Synthesis and Characterization

Izzo, Lorella; Pappalardo, Daniela

doi:10.1002/macp.201000347

Cited by 20 publications

(25 citation statements)

References 49 publications

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“…Copolymers were synthesized according to literature in a slightly modified procedure . PEG methyl ether was placed in the round bottomed flask and dried under vacuum for few hours at 40°C.…”

Section: Methodsmentioning

confidence: 99%

Thermodynamic compatibility of actives encapsulated into PEG‐PLA nanoparticles: In Silico predictions and experimental verification

et al. 2016

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Achieving optimal solubility of active substances in polymeric carriers is of fundamental importance for a number of industrial applications, including targeted drug delivery within the growing field of nanomedicine. However, its experimental optimization using a trial-and-error approach is cumbersome and time-consuming. Here, an approach based on molecular dynamics (MD) simulations and the Flory-Huggins theory is proposed for rapid prediction of thermodynamic compatibility between active species and copolymers comprising hydrophilic and hydrophobic segments. In contrast to similar methods, our approach offers high computational efficiency by employing MD simulations that avoid explicit consideration of the actual copolymer chains. The accuracy of the method is demonstrated for compatibility predictions between pyrene and nile red as model dyes as well as indomethacin as model drug and copolymers containing blocks of poly(ethylene glycol) and poly(lactic acid) in different ratios. The results of the simulations are directly verified by comparison with the observed encapsulation efficiency of nanoparticles prepared by nanoprecipitation. © 2016 Wiley Periodicals, Inc.

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Section: Methodsmentioning

confidence: 99%

Thermodynamic compatibility of actives encapsulated into PEG‐PLA nanoparticles: In Silico predictions and experimental verification

et al. 2016

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“…The copolymers used in this work were synthesized according to the procedures reported in the literature [19] by using a PEG/LA ratio (w/w) of 1/2.…”

Section: Synthesis Of Mpeg-(pla)n Copolymersmentioning

confidence: 99%

“…To overcome limitations of polymer coatings containing PSs, we report here a spraycoating system based on degradable polymer micelles made of poly(ethylene glycol)monomethylether-co-polylactide branched copolymers of the general structure mPEG-(PLA)n (MnmPEG = 5 kDa, n = 1, 2, or 4), releasing a PS. The same copolymers were previously obtained in both micro-and nanometric formulations and previously described also as drug delivery systems [19][20][21]. The photoactive molecule was chosen among the 4,4difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) dyes family, which are characterized to be strongly UV-absorbing and to have high quantum efficiencies of fluorescence.…”

Section: Introductionmentioning

confidence: 99%

Bodipy-Loaded Micelles Based on Polylactide as Surface Coating for Photodynamic Control of Staphylococcus aureus

et al. 2021

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Decontaminating coating systems (DCSs) represent a challenge against pathogenic bacteria that may colonize hospital surfaces, causing several important infections. In this respect, surface coatings comprising photosensitizers (PSs) are promising but still controversial for several limitations. PSs act through a mechanism of antimicrobial photodynamic inactivation (aPDI) due to formation of reactive oxygen species (ROS) after light irradiation. However, ROS are partially deactivated during their diffusion through a coating matrix; moreover, coatings should allow oxygen penetration that in contact with the activated PS would generate 1O2, an active specie against bacteria. In the attempt to circumvent such constraints, we report a spray DCS made of micelles loaded with a PS belonging to the BODIPY family (2,6-diiodo-1,3,5,7-tetramethyl-8-(2,6-dichlorophenyl)-4,4′-difluoroboradiazaindacene) that is released in a controlled manner and then activated outside the coating. For this aim, we synthesized several amphiphilic copolymers (mPEG–(PLA)n), which form micelles, and established the most stable supramolecular system in terms of critical micelle concentration (CMC) and ∆Gf values. We found that micelles obtained from mPEG–(PLLA)2 were the most thermodynamically stable and able to release BODIPY in a relatively short period of time (about 80% in 6 h). Interestingly, the BODIPY released showed excellent activity against Staphylococcus aureus even at micromolar concentrations.

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“…Thanks to improved synthetic approaches, it has nowadays become possible to generate weak polyelectrolytes with structures differing from the standard linear one such as treelike, starlike, or brushes. The change in geometrical disposition and, hence, local density of ionizable monomers compared with linear species should obviously impact on the electrolytic properties of the macromolecules, so that the behavior with respect to global or local ionization, conformations in solution, the thermodynamics of confinement, as well as the relative distribution of ions and ionized polymers may be markedly affected, as it neatly emerges titrating starlike poly(acrylic acid) (PAA), poly(dimethylamino ethyl methacrylate) (PDMAEMA), and poly(diethyl amino ethyl methacrylate) .…”

Section: Introductionmentioning

confidence: 99%

Absorbed weak polyelectrolytes: Impact of confinement, topology, and chemically specific interactions on ionization, conformation free energy, counterion condensation, and absorption equilibrium

Tagliabue

Izzo

Mella

2019

J Polym Sci B Polym Phys

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Absorption of weak polyelectrolytes impacts on properties such as ionization, conformations, and counterion (CI) condensation that are important in several areas of applied and fundamental science. We used a weak polyelectrolyte model and Monte Carlo simulations to investigate how the mentioned properties depend on pH or the size of a spherical cavity (SC) permeable to CIs but not to polyelectrolytes; the latter have either linear or starlike topologies and may be allowed to form charged hydrogen bonds (c H-bonds) between ionized and neutral monomers. Average ionization decreases upon increasing the number of arms at a constant number of monomers; it instead increases with the arm length in large SC due to CI screening. The way SC size, c H-bonds, and pH values interrelate to define ionization is instead more complicate due to arm pairing or clustering when c H-bonds are possible. These induce oscillations in the arm local ionization and impact on both monomer and CI distributions in the complete simulation cell in a way that also depends on polymer topology. The impact of ionization on the confinement free energy is also estimated; this highlighted that c H-bonding may enhance absorption compared with neutral chains.

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“Tree‐Shaped” Copolymers Based on Poly(ethylene glycol) and Atactic or Isotactic Polylactides: Synthesis and Characterization

Cited by 20 publications

References 49 publications

Thermodynamic compatibility of actives encapsulated into PEG‐PLA nanoparticles: In Silico predictions and experimental verification

Thermodynamic compatibility of actives encapsulated into PEG‐PLA nanoparticles: In Silico predictions and experimental verification

Bodipy-Loaded Micelles Based on Polylactide as Surface Coating for Photodynamic Control of Staphylococcus aureus

Absorbed weak polyelectrolytes: Impact of confinement, topology, and chemically specific interactions on ionization, conformation free energy, counterion condensation, and absorption equilibrium

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