Phase-transition characteristics of amphiphilic poly(2-ethyl-2-oxazoline)/poly(?-caprolactone) block copolymers in aqueous solutions

Kim, Chulhee; Lee, Sang Cheon; Kang, Sa-Ouk; Kwon, Ick Chan; Jeong, Seo Young

doi:10.1002/1099-0488(20000915)38:18<2400::aid-polb70>3.0.co;2-7

Cited by 35 publications

(22 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[17][18][19][20][21][22][23][24][25][26][27] Recently, we have reported on a block copolymer micelle system based on poly(2-ethyl-2-oxazoline) (PEtOz) as a hydrophilic block and poly(ε-caprolactone) (PCL) as a hydrophobic block. [28][29][30][31][32] The PEtOz-PCL micelle with a narrow size distribution was highly stable in aqueous conditions without any precipitation for several months and could be used as an efficient nanocarrier for delivery of hydrophobic anti-cancer drug, paclitaxel. 32 In addition, we showed that PEtOz-PCL block copolymer micelle can undergo reversible complexation with multifunctional carboxylic acids in aqueous phase via pH-responsive hydrogen bonding.…”

Section: Introductionsupporting

confidence: 79%

“…The synthesis and micellar characterization of the PEtOz-PCL block copolymer in Scheme I were carried out by following reference procedures. [28][29][30][31][32] The M n value of the block copolymer was 8,200 (M w /M n = 1.17), and the mean hydrodynamic diameter of the block copolymer micelles in aqueous solution, measured by DLS experiment was 26 nm (polydispersity factor, μ 2 /Γ 2 = 0.12) at 25 o C. For the dendritic building block, the PAMAM-4.5 with carboxyl surface was used to utilize the pH-responsive hydrogen bonding between the PEtOz shell of micelle and the carboxyl surface of the dendrimer.…”

Section: Resultsmentioning

confidence: 99%

“…32 In addition, we showed that PEtOz-PCL block copolymer micelle can undergo reversible complexation with multifunctional carboxylic acids in aqueous phase via pH-responsive hydrogen bonding. [28][29][30][31] The PEtOz outer shell of the micelle undergoes pH-responsive hydrogen bonding with poly(acrylic acid) or poly(methacrylic acid) in acidic aqueous solution. These complexes could be reversibly dispersed as micelles in basic aqueous solution due to breakage of hydrogen bonding between the PEtOz outer shell and the carboxyl group of poly(carboxylic acid)s.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Hydrogen-bonding induced alternating thin films of dendrimer and block copolymer micelle

Park

Rhue

et al. 2007

Macromol. Res.

Self Cite

View full text Add to dashboard Cite

The hydrogen-bonding induced alternating multilayer thin films of dendrimers and block copolymer micelles were demonstrated. The block copolymer micelles derived from amphiphilic poly(2-ethyl-2-oxazoline)-block-poly(ε-carprolactone) (PEtOz-PCL) in aqueous phase have a core-shell structure with a mean hydrodynamic diameter of 26 nm. The hydrogen bonding between the PEtOz outer shell of micelle and the carboxyl unit of poly(amidoamine) dendrimer of generation 4.5 (PAMAM-4.5G) at pH 3 was utilized as a driving force for the layerby-layer alternating deposition. The multilayer thin film was fabricated on the poly(methyl methacrylate) (PMMA) thin film spin-coated on silicon wafer or glass substrate by the alternate dipping of PEtOz-PCL micelles and PAMAM dendrimers in aqueous solution at pH 3. The formation of multilayer thin film was characterized by using ellipsometry, UV-vis spectroscopy, and atomic force microscopy. The PEtOz outer shell of PEtOz-PCL micelle provided the pH-responsive hydrogen bonding sites with peripheral carboxylic acids of PAMAM dendrimer. The multilayer thin film was reversibly removed after dipping in aqueous solution at pH ≥ 5.6 due to dissociation of the hydrogen bonding between PEtOz shell of PEtOz-PCL micelle and peripheral carboxyl units of PAMAM dendrimer.

show abstract

Section: Introductionsupporting

confidence: 79%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Hydrogen-bonding induced alternating thin films of dendrimer and block copolymer micelle

Park

Rhue

et al. 2007

Macromol. Res.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Thermoresponsive AB diblock, ABA triblock and multiblock copolymers based on poly(ε-caprolactone) (PCL) (A) and PEtOx (B) formed physically cross-linked micellar gels at low temperature and high concentration, as reported by Jeong et al [37,38]. Increasing the temperature induced a gel-sol transition followed by precipitation due to the collapse of the PEtOx chains.…”

Section: Thermoresponsive Poly(2-oxazoline)-based Hydrogelsmentioning

confidence: 99%

Bioinspired Poly(2-oxazoline)s

2011

View full text Add to dashboard Cite

Poly(2-oxazoline)s are regarded as pseudopeptides, thus bioinspired polymers, due to their structural relationship to polypeptides. Materials and solution properties can be tuned by varying the side-chain (hydrophilic-hydrophobic, chiral, bioorganic, etc.), opening the way to advanced stimulus-responsive materials and complex colloidal structures. The bioinspired -smart‖ solution and aggregation behavior of poly(2-oxazoline)s in aqueous environments are discussed in this review.

show abstract

“…Poly (2-ethyl-2-oxazoline) (PEtOz) is a water soluble, thermo-sensitive polyelectrolyte with good biocompatibility and biodegradability, which seem to be another attractive candidate for stimuli-sensitive block polymers [12,13]. Recently, several examples of PEtOz-containing block polymers have been described, in which the hydrophilic PEtOz unit was linked to poly(styrene) [14], hyaluronan [15] or polyesters (i.e., poly(L-lactide) and poly (ε-caprolactone)) [12,13,[16][17][18][19][20][21].…”

mentioning

confidence: 99%

Self-assembly and drug delivery behaviors of a novel thermo-sensitive block glycopolymer

et al. 2010

View full text Add to dashboard Cite

A novel thermo-sensitive block glycopolymer based on peracetylated maltoheptaose (AcMH) and poly(2-ethyl-2-oxazoline) (PEtOz) was synthesized for the first time and characterized by hydrogen nuclear magnetic resonance ( 1 H NMR) spectroscopy and gel permeation chromatograph (GPC) analyses. To obtain such a block polymer, the dihydroxyl poly(2-ethyl-2-oxazoline) homopolymer (OH-PEtOz-OH) was first synthesized by cationic ring-opening polymerization of 2-ethyl-2-oxazoline (EtOz), and then coupled with the peracetylated maltoheptaose having a free hydroxyl group at the reducing end (AcMH-OH) prepared from β-cyclodextrin. It was found that the obtained block polymer could self-assemble into nanosize spherical micelles with a distinct core-shell structure in aqueous solution triggered by its amphiphilic character without any organic solvent. The model drug indomethacin (IND) was efficiently loaded into the resultant polymeric micelles, which was confirmed by 1 H NMR spectra, transmission electron microscope (TEM) and dynamic light scattering (DLS) techniques. The release behavior of IND loaded micelles was well in response to the environmental temperature change. It is suggested that the resulting micelles might be a potential targeted carrier for drug delivery.amphiphilic block copolymer, oligosaccharide, poly(2-ethyl-2-oxazoline), self-assembly, drug delivery, thermo-sensitive Citation:Chen L Q, Zhang L M, Chen J J, et al. Self-assembly and drug delivery behaviors of a novel thermo-sensitive block glycopolymer.

show abstract

Phase-transition characteristics of amphiphilic poly(2-ethyl-2-oxazoline)/poly(?-caprolactone) block copolymers in aqueous solutions

Cited by 35 publications

References 30 publications

Hydrogen-bonding induced alternating thin films of dendrimer and block copolymer micelle

Hydrogen-bonding induced alternating thin films of dendrimer and block copolymer micelle

Bioinspired Poly(2-oxazoline)s

Self-assembly and drug delivery behaviors of a novel thermo-sensitive block glycopolymer

Contact Info

Product

Resources

About