Synthesis and characterization of pH/temperature-sensitive block copolymers via atom transfer radical polymerization

Kasala, Dayananda; Pi, Bong S.; Kim, Bong Sup; Park, Tae Gwan; Lee, Sang Soo

doi:10.1016/j.polymer.2006.11.040

Cited by 42 publications

(35 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Well-defined OSM-PCLA-PEG-PCLA-OSM pentablock copolymers were synthesized by atom transfer radial polymerization (ATRP). [79] The Br-PCLA-PEG- Reprinted with permission from ref. [75] .…”

Section: Ph/temperature-sensitive Block Copolymer Hydrogelsmentioning

confidence: 99%

Injectable Biodegradable Hydrogels

Nguyen

Lee

2010

Macromolecular Bioscience

Self Cite

416

343

View full text Add to dashboard Cite

Injectable biodegradable copolymer hydrogels, which exhibit a sol–gel phase transition in response to external stimuli, such as temperature changes or both pH and temperature (pH/temperature) alterations, have found a number of uses in biomedical and pharmaceutical applications, such as drug delivery, cell growth, and tissue engineering. These hydrogels can be used in simple pharmaceutical formulations that can be prepared by mixing the hydrogel with drugs, proteins, or cells. Such formulations are administered in a straightforward manner, through site‐specific control of release behavior, and the hydrogels are compatible with biological systems. This review will provide a summary of recent progress in biodegradable temperature‐sensitive polymers including polyesters, polyphosphazenes, polypeptides, and chitosan, and pH/temperature‐sensitive polymers such as sulfamethazine‐, poly(β‐amino ester)‐, poly(amino urethane)‐, and poly(amidoamine)‐based polymers. The advantages of pH/temperature‐sensitive polymers over simple temperature‐sensitive polymers are also discussed. A perspective on the future of injectable biodegradable hydrogels is offered.magnified image

show abstract

“…Well-defined OSM-PCLA-PEG-PCLA-OSM pentablock copolymers were synthesized by atom transfer radial polymerization (ATRP). [79] The Br-PCLA-PEG- Reprinted with permission from ref. [75] .…”

Section: Ph/temperature-sensitive Block Copolymer Hydrogelsmentioning

confidence: 99%

Injectable Biodegradable Hydrogels

Nguyen

Lee

2010

Macromolecular Bioscience

Self Cite

416

343

View full text Add to dashboard Cite

show abstract

“…The advent of atom transfer radical polymerization (ATRP) provides a new way to synthesize polymers with controlled molecular weight [5][6][7]. Numerous well-defined (co)polymers with the desired molecular weight and low polydispersity index (PDI <1.5) [8,9], (co)polymers with complex architectures [10][11][12][13], functional polymers and hybrid materials have been prepared by the ATRP technique [14][15][16]. Atom transfer radical polymerization (ATRP) also remains one of the most powerful, versatile, simplest, and least expensive polymerization techniques [17].…”

Section: Introductionmentioning

confidence: 99%

Effect of different ligands on the controlled polymerization of monodisperse polystyrene nanospheres by atom transfer radical polymerization in an aqueous emulsion

Tian¹,

Hu²,

Miao³

et al. 2012

Express Polym. Lett.

View full text Add to dashboard Cite

Abstract. Polystyrene nanospheres have been synthesized by atom transfer radical polymerization (ATRP) to control the molecular weight distribution in the aqueous system. The crucial factor in such a system is the ligand that adjusts the solubility of the catalyst in different phases to control the concentration of both the activator and the deactivator in reaction phase. The effect of different ligands including ethylenediamine, 1,10-phenanthroline (phen) and 4,4-dinonyl-2, 2-bipyridyl (dNbpy) on the catalytic solubility in the organic and aqueous phase has been investigated. The molecular weight distribution of polymer obtained in this way was analyzed by gel permeation chromatography (GPC). It showed that the obtained polymer particles presented a broad molecular weight distribution (polydispersity index 1.78) with ethylenediamine as the ligand, but the polymerization rate was high and conversion reached 96.8%. The molecular weight distribution of polystyrene was narrowest with dNbpy as ligand, but the conversion was lowest and only achieved to 69%. Possible reasons were the influence of the structure of three different ligands on the control of ATRP reaction. SEM and GPC indicated that the polystyrene nanospheres presented regular sphere with a diameter of about 120 nm and uniform molecular weight distribution, which possessed a significant potentials in drug carrier field.

show abstract

“…Here, an external stimulus triggers the formation or breakup of physical network junctions, which in turn leads to a reversible gel formation/ disintegration. [10][11][12][13][14][15][16][17][18] ''Smart'' hydrogels play an important role in biomedical applications like drug delivery and tissue engineering. [2,5,[19][20][21][22][23] They are further used in sensors, storage media, actuating systems, or microfluidic switches.…”

Section: Introductionmentioning

confidence: 99%

“…However, the number of physical hydrogels which are multiple stimuli-responsive is still limited. Dual responsive hydrogels, being responsive to pH and temperature, were realized based on poly(N,N-diethylacrylamide)-blockpoly(acrylic acid)-block-poly(N,N-diethylacrylamide) (PDEAAm-b-PAA-b-PDEAAm) ABA triblock copolymers, [16] ABCBA pentablock terpolymers, where A is a pH-sensitive poly(sulfamethazine methacrylate) block, B is poly(e-caprolactone) (PCL), and C is poly(ethylene oxide) (PEO), [11] and multiblock or star-shaped copolymers composed of PEO and poly-(amino urethane). [31,32] Alternatively, pHand temperature-responsive hydrogels can be constructed from PEO-block-poly-(L-glutamic acid) diblock copolymers utilizing host-guest interactions between PEO and a-cyclodextrin.…”

Section: Introductionmentioning

confidence: 99%

Temperature‐Dependent Gelation Behaviour of Double Responsive P2VP‐b‐PEO‐b‐P(GME‐co‐EGE) Triblock Terpolymers: A SANS Study

Karg

Reinicke

Lapp

et al. 2011

Macromolecular Symposia

View full text Add to dashboard Cite

Summary: Aqueous solutions of a double responsive P2VP 62 -b-PEO 452 -b-P(GME 36 -co-EGE 36 ) triblock terpolymer were investigated by means of small-angle neutron scattering (SANS) in order to derive information about structural changes going along with the temperature triggered gel-sol-gel transition at pH ¼ 7, and the sol-gel transition at pH ¼ 3.5, respectively, observed by rheology. SANS measurements on dilute samples at different pH and temperature confirmed the formation of core-shell-corona micelles under conditions, where only one of the outer blocks is insoluble. In addition, temperature-dependent scattering experiments were performed for higher volume fractions, that is, the concentration range where hydrogels were formed. This allowed us to identify the structural transitions, being responsible for the gel-sol-gel transition at pH ¼ 7, and the structure of the gel phase formed at low pH and elevated temperatures.

show abstract

Synthesis and characterization of pH/temperature-sensitive block copolymers via atom transfer radical polymerization

Cited by 42 publications

References 29 publications

Injectable Biodegradable Hydrogels

Injectable Biodegradable Hydrogels

Effect of different ligands on the controlled polymerization of monodisperse polystyrene nanospheres by atom transfer radical polymerization in an aqueous emulsion

Temperature‐Dependent Gelation Behaviour of Double Responsive P2VP‐b‐PEO‐b‐P(GME‐co‐EGE) Triblock Terpolymers: A SANS Study

Contact Info

Product

Resources

About