Block sequence affects thermosensitivity and nano-assembly: PEG-l-PA-dl-PA and PEG-dl-PA-l-PA block copolymers

Park, Soo Hyun; Choi, Bo Gyu; Moon, Hye Sung; Cho, So-Hye; Jeong, Byeongmoon

doi:10.1039/c1sm05505d

Cited by 39 publications

(31 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Only in the case of the ACB one, upon increasing the temperature, was a random coil formed instead. 70 Due to the effect of the stereochemistry a comparison of this study with the previous ones on ABC, BAC and ACB is not feasible.…”

Section: Effect Of the Sequence Of The Blocks In Triblocks Copolymersmentioning

confidence: 97%

“…Only our group and Park et al 70 have studied triblock terpolymers with all three blocks being based on different monomers; usually ABA triblock terpolymers have been reported where one block was a statistical polymeric segment of two monomers.…”

Section: Effect Of the Sequence Of The Blocks In Triblocks Copolymersmentioning

confidence: 99%

“…70 The thermoresponsive behaviour was investigated by rheological and visual tests. According to visual tests, the ABC polymer gelled upon increasing the temperature.…”

Section: Effect Of the Sequence Of The Blocks In Triblocks Copolymersmentioning

confidence: 99%

See 2 more Smart Citations

Tuning the gelation of thermoresponsive gels

Constantinou

Georgiou

2016

European Polymer Journal

View full text Add to dashboard Cite

Thermoresponsive gels are exciting polymeric materials with many biomedical applications in medical devices, drug delivery, tissue engineering and bio-printing. Also, they have great potential to be used in 3-D printing and thus in the fabrication of many different devices and materials. As it is crucial for the application of these gels to be able to control and tailor the gelation temperature and concentration this was the main focus and point of discussion of this feature article. Thus, it is discussed in detail how by varying the molar mass, composition, stereochemistry and architecture the thermoresponsive properties of these gels are altered.

show abstract

Section: Effect Of the Sequence Of The Blocks In Triblocks Copolymersmentioning

confidence: 97%

Section: Effect Of the Sequence Of The Blocks In Triblocks Copolymersmentioning

confidence: 99%

See 1 more Smart Citation

Tuning the gelation of thermoresponsive gels

Constantinou

Georgiou

2016

European Polymer Journal

View full text Add to dashboard Cite

show abstract

“…In particular, temperature-responsive reverse thermal gels (RTG) have gained much attention 10–20 . At room temperature, RTG systems exist in a solution state (sol) with low viscosity that allows injection through a small gauge needle 11,12 .…”

Section: Introductionmentioning

confidence: 99%

A heparin‐mimicking reverse thermal gel for controlled delivery of positively charged proteins

Peña

Shandas

2014

J Biomedical Materials Res

View full text Add to dashboard Cite

Positively charged therapeutic proteins have been used extensively for biomedical applications. However, the safety and efficacy of proteins are mostly limited by their physical and chemical instability and short half-lives in physiological conditions. To this end, we created a heparin-mimicking sulfonated reverse thermal gel as a novel protein delivery system by sulfonation of a graft copolymer, poly(serinol hexamethylene urea)-co-poly(N-isopropylacylamide), or PSHU-NIPAAm. The net charge of the sulfonated PSHU-NIPAAm was negative due to the presence of sulfonate groups. The sulfonated PSHU-NIPAAm showed a typical temperature-dependent sol-gel phase transition, where polymer solutions turned to a physical gel at around 32°C and maintained gel status at body temperature. Both in vitro cytotoxicity tests using C2C12 myoblast cells and in vivo cytotoxicity tests by subcutaneous injections demonstrated excellent biocompatibility. In vitro release tests using bovine serum albumin (BSA) revealed that the release from the sulfonated PSHU-NIPAAm was more sustained than that from the plain PSHU-NIPAAm. Furthermore, this sulfonated PSHU-NIPAAm system did not affect protein structure after 70-day observation periods.

show abstract

“…11 In addition, the molecular architecture of the block copolymer affects the secondary structure of polypeptide. [12][13][14] Therefore, the sol-gel transition behavior can be different for the polymers with different architectures even though total molecular weight is similar. In this article, we designed AB-type diblock copolymers with the same number of repeating units to focus on the effect of ester versus amide bonds on the sol-gel transition behavior.…”

mentioning

confidence: 99%

Thermal gelation or gel melting: (ethylene glycol)₁₁₃‐(l‐alanine)₁₂ and (ethylene glycol)₁₁₃‐(l‐lactic acid)₁₂

Jung

Park

Moon

et al. 2014

J. Polym. Sci. Part A: Polym. Chem.

Self Cite

View full text Add to dashboard Cite

When PEG (M.W.5000 Daltons) is conjugated to poly(L-alanine), the polymer aqueous solutions (<10.0 wt.%) undergo sol-to-gel (thermal gelation), whereas it is conjugated to poly(L-lactic acid), the polymer aqueous solutions (>30.0 wt.%) undergo gel-to-sol (gel melting) as the temperature increases. In the search for molecular origins of such a quite different phase behavior, poly(ethylene glycol)-poly(L-alanine) (PEG-PA; EG 113 -A 12 ) and poly(ethylene glycol)-poly(L-lactic acid) (PEG-PLA; EG 113 -LA 12 ) are synthesized and their aqueous solution behavior is investigated. PEG-PAs with an a-helical core assemble into micelles with a broad size distribution, and the dehydration of PEG drives the aggregation of the micelles, leading to thermal gelation, whereas increased molecular motion of the PLA core overwhelms the partial dehydration of PEG, thus gel melting of the PEG-PLA aqueous solutions occurs. The core-rigidity of micelles must be one of the key factors in determining whether a polymer aqueous solution undergoes sol-to-gel or gel-to-sol transition, as the temperature increases. V C 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 2434-2441 KEYWORDS: sol-gel transition; block copolymers; stimuli-sensitive polymers; self-assembly; micelles INTRODUCTION Polymer aqueous solutions that undergo temperature-sensitive sol-gel transition have been extensively investigated during the last decade, not only for their biomedical applications, but also for their unique transition mechanism.1-10 Basically, the sol-gel transition is observed for aqueous solutions of polymers with a delicate balance of hydrophilicity and hydrophobicity. The sol-gel transition behavior is affected by the architecture and chemical structure of a polymer. AB-type diblock copolymers and ABA-type triblock copolymers, where A is hydrophilic and B is hydrophobic, tend to form spherical micelles, whereas BAB-type triblock copolymers tend to form flower-like micelles or intermicellar bridges.11 In addition, the molecular architecture of the block copolymer affects the secondary structure of polypeptide.12-14 Therefore, the sol-gel transition behavior can be different for the polymers with different architectures even though total molecular weight is similar. In this article, we designed AB-type diblock copolymers with the same number of repeating units to focus on the effect of ester versus amide bonds on the sol-gel transition behavior. Even though, there have been extensive reports on the poly(ethylene glycol)/poly(L-lactic acid-co-glycolic acid) (PEG/PLGA) and poly(ethylene glycol)/poly(L-lactic acid) (PEG/PLA) block

show abstract

Block sequence affects thermosensitivity and nano-assembly: PEG-l-PA-dl-PA and PEG-dl-PA-l-PA block copolymers

Cited by 39 publications

References 39 publications

Tuning the gelation of thermoresponsive gels

Tuning the gelation of thermoresponsive gels

A heparin‐mimicking reverse thermal gel for controlled delivery of positively charged proteins

Thermal gelation or gel melting: (ethylene glycol)₁₁₃‐(l‐alanine)₁₂ and (ethylene glycol)₁₁₃‐(l‐lactic acid)₁₂

Contact Info

Product

Resources

About

Block sequence affects thermosensitivity and nano-assembly: PEG-l-PA-dl-PA and PEG-dl-PA-l-PA block copolymers

Cited by 39 publications

References 39 publications

Tuning the gelation of thermoresponsive gels

Tuning the gelation of thermoresponsive gels

A heparin‐mimicking reverse thermal gel for controlled delivery of positively charged proteins

Thermal gelation or gel melting: (ethylene glycol)113‐(l‐alanine)12 and (ethylene glycol)113‐(l‐lactic acid)12

Contact Info

Product

Resources

About

Thermal gelation or gel melting: (ethylene glycol)₁₁₃‐(l‐alanine)₁₂ and (ethylene glycol)₁₁₃‐(l‐lactic acid)₁₂