Self-Assembly of Cetyl Linear Polyethylenimine To Give Micelles, Vesicles, and Dense Nanoparticles

Wang, Wei; Qu, Xiaozhong; Gray, Alexander I.; Tetley, Laurence; Uchegbu, Ijeoma F.

doi:10.1021/ma049042o

Cited by 60 publications

(109 citation statements)

References 23 publications

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“…The morphology of the nanoparticles produced from amphiphilic block/graft copolymers can be varied by changing the composition of the hydrophobic and hydrophilic blocks on the polymer chains. [2][3][4] Recently, many studies have focused on self-assembled biodegradable nanoparticles for biomedical and pharmaceutical applications. The commonly used biodegradable polymers are aliphatic polyesters, such as poly(lactic acid) (PLA), poly(glycolic acid) (PGA), poly( -caprolactone) (PCL), and their copolymers.…”

Section: Introductionmentioning

confidence: 99%

Hydrolytic and Enzymatic Degradation of Nanoparticles Based on Amphiphilic Poly(γ-glutamic acid)-graft-l-Phenylalanine Copolymers

et al. 2005

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Amphiphilic graft copolymers consisting of poly(gamma-glutamic acid) (gamma-PGA) as the hydrophilic backbone and L-phenylalanine ethylester (L-PAE) as the hydrophobic side chain were synthesized by grafting L-PAE to gamma-PGA. The nanoparticles were prepared by a precipitation method, and about 200 nm-sized nanoparticles were obtained due to their amphiphilic properties. The hydrolytic and enzymatic degradation of these gamma-PGA nanoparticles was studied by gel permeation chromatography (GPC), scanning electron microscopy (SEM), dynamic light scattering (DLS) and (1)H NMR measurements. The hydrolysis ratio of gamma-PGA and these hydrophobic derivatives was found to decrease upon increasing the hydrophobicity of the gamma-PGA derivates. The pH had an effect on the hydrolytic degradation of the polymer. The hydrolysis of the polymer could be accelerated by alkaline conditions. The degradation of the gamma-PGA backbone by gamma-glutamyl transpeptidase (gamma-GTP) resulted in a dramatic change in nanoparticle morphology. With increasing time, the gamma-PGA nanoparticles began to decrease in size and finally disappeared completely. Moreover, the gamma-PGA nanoparticles were degraded by four different enzymes (Pronase E, protease, cathepsin B and lipase) with different degradation patterns. The enzymatic degradation of the nanoparticles occurred via the hydrolysis of gamma-PGA as the main chain and L-PAE as the side chain. In the case of the enzymatic degradation of gamma-PGA nanoparticles with Pronase E, the size of the nanoparticles increased during the initial degradation stage and decreased gradually when the degradation time was extended. Nanoparticles composed of biodegradable amphiphilic gamma-PGA with reactive function groups can undergo further modification and are expected to have a variety of potential pharmaceutical and biomedical applications, such as drug and vaccine carriers.

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Section: Introductionmentioning

confidence: 99%

Hydrolytic and Enzymatic Degradation of Nanoparticles Based on Amphiphilic Poly(γ-glutamic acid)-graft-l-Phenylalanine Copolymers

et al. 2005

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“…The association of the lipid molecules with the hydrophobic chains of the HPMA copolymer-PGE 1 conjugate apparently resulted in a change of the microenvironment and reduced access of enzymes to the ester bond. Similarly, Uchegbu and coworkers found that cholesterol improved the attraction between hydrophobic chains of cetyl linear polyethylenimine (38).…”

Section: Attachment Of Hydrophobic Grafts Into the Hpma Copolymer Conmentioning

confidence: 87%

Stability in Plasmas of Various Species of HPMA Copolymer–PGE1 Conjugates

et al. 2007

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“…16 The self assembly of polymers into vesicles is governed by similar constraints and as such, the hydrophobic-lipophilic balance of polymers determines whether a polymer will self assemble into vesicles in a similar manner as is found in liposomes and niosomes. 18,24 There are also some polymer specific factors which impact on vesicle forming ability. For example, the degree of polymerization is critical to vesicle forming ability, and generally very high degrees of polymerization prevent vesicle formation.…”

Section: Polymer Self Assemblymentioning

confidence: 99%