Preparation and characterization of non-linear poly(ethylene glycol) analogs from oligo(ethylene glycol) functionalized polyisocyanopeptides

Koepf, Matthieu; Kitto, Heather J.; Schwartz, Eduard; Kouwer, Paul H. J.; Nolte, Roeland J. M.; Rowan, Alan E.

doi:10.1016/j.eurpolymj.2013.01.009

Cited by 40 publications

(54 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…G 0 scales with polymer length L as G 0 ∝ L 2.3 (Figure a, Table 2 ). This is in perfect agreement with theoretical predictions for hydrogels derived from semi‐flexible biopolymers and compares to values reported for nonfunctionalized PIC hydrogels . These results suggest that the DNA cross‐linked hydrogel at 30 °C possesses similar mechanical properties as the original hydrophobically bundled PIC hydrogel formed above 50 °C.…”

Section: Resultssupporting

confidence: 89%

“…The PIC polymer exhibits a temperature‐dependent sol‐to‐gel transition as a result of polymer bundling induced by the hydrophobic aggregation of the tetra(ethylene glycol) tails . To obtain first proof that DNA cross‐links can promote gel formation below the PIC transition temperature, we investigated the rheological properties of samples prepared from polymers of different lengths over a range of different temperatures.…”

Section: Resultsmentioning

confidence: 99%

“…Previously, we developed a synthetic thermoresponsive hydrogel based on helical oligo(ethylene glycol)‐functionalized polyisocyanopeptides (PIC) . These PIC hydrogels form a biomimetic network that stress‐stiffens in a stress regime similar to natural scaffolds assembled from extracellular (collagen, fibrin) or intracellular (F‐actin, microtubules) biopolymers .…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

DNA‐Responsive Polyisocyanopeptide Hydrogels with Stress‐Stiffening Capacity

Deshpande¹,

Hammink²,

Das

et al. 2016

Adv Funct Materials

Self Cite

View full text Add to dashboard Cite

Biological materials have evolved to combine a number of functionally relevant properties. They are sensitive to chemical and mechanical signals and respond to these signals in a highly specific manner. Many biological hydrogels possess the ability to stress-stiffen, a property that is difficult to mimic in synthetic systems. A novel synthetic hydrogel is described that possesses stress-stiffening behavior in the biologically relevant stress regime and, at the same time, contains DNA cross-links as stimuli-responsive elements. The hydrogel scaffold is composed of oligo(ethylene glycol)-functionalized polyisocyanopeptides (PIC), which show a sol-to-gel transition upon increasing the temperature. It is shown that the mechanical properties of the hybrid hydrogel depend on DNA cross-linker concentration and temperature. At high temperature, a hydrophobically bundled stress-stiffening PIC network forms. By contrast, gel formation is controlled by DNA cross-linking at temperatures below the PIC sol-to-gel transition. The DNA cross-linked hydrogel also exhibits stress-stiffening behavior and its properties are controlled by the DNA cross-linker concentration. The hydrogel properties can further be tuned when using DNA cross-linkers with different melting temperature or when breaking cross-links by strand displacement. This clearly shows the potential of DNA cross-links as stimuli-responsive elements, highlighting the possible applications of this hybrid hydrogel as a new sensor

show abstract

Section: Resultssupporting

confidence: 89%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

DNA‐Responsive Polyisocyanopeptide Hydrogels with Stress‐Stiffening Capacity

Deshpande¹,

Hammink²,

Das

et al. 2016

Adv Funct Materials

Self Cite

View full text Add to dashboard Cite

show abstract

“…Polymer Synthesis and Characterization : The isocyanide monomer was polymerized following a previously described protocol . The molecular weight of the polymer was characterized by viscometry.…”

Section: Methodsmentioning

confidence: 99%

Tuning Hydrogel Mechanics Using the Hofmeister Effect

Jaspers

Rowan

Kouwer

2015

Adv Funct Materials

Self Cite

121

View full text Add to dashboard Cite

6503wileyonlinelibrary.com mechanical properties. The large morphological and volume change at the LCST of PNIPAM-based gels [ 10 ] make mechanical studies meaningless. A series of studies on the Hofmeister effect on supramolecular hydrogels showed a dependence of the mechanical properties, but this was merely induced by the hugely different morphologies found for the different assembly conditions of the gels. [11][12][13] Here, we describe for the fi rst time that we can use the Hofmeister effect to controllably manipulate the mechanical properties of polymer hydrogels. As expected, the addition of salts directly affects the gelation temperature and, for our thermoresponsive hydrogel, this changes the stiffness of the gel over two orders of magnitude at a constant temperature, for instance 37 °C. We construct hydrogels that range from very soft to stiff, but all at identical concentration. To achieve such change in mechanical response, one commonly needs to vary parameters such as concentration, morphology and bundle (or fi ber) diameter and stiffness. [ 14 ] Some of these are diffi cult to control, while others simultaneously change many important network characteristics; for instance, the concentration changes the biomedically relevant pore size and stiffness of the gel (as well as nonlinear gel properties). The salts, however, are able to shift the mechanics, without changing porosity and network morphology.The polymers we use are ethylene glycol-functionalized polyisocyanides (PICs, Figure 1 b), which form a thermoreversible gel upon heating when dissolved in water. [ 15 ] At the LCST, the polymers become hydrophobic and form a network of entangled semi-fl exible bundles of polymer chains. The mechanical properties of the PIC hydrogels mimic those of biological gels, [ 15 ] including the nonlinear mechanics at large stress (or strain), which is markedly different than that of other synthetic hydrogels. The mechanics of PIC hydrogels is readily tuned by changing concentration, temperature, and polymer length. [ 16 ] Here, we add two additional parameters to this list: the nature of the salt (more precisely the anion) and its concentration.For a long time, the molecular basis of the Hofmeister series was related to the effect of ions on the bulk structure of water. [ 17 ] More recently, however, it was shown that salts generally do not affect the bulk water structure. [ 18,19 ] Instead, more recent theories hypothesize that direct interactions between ions and macromolecules and their fi rst hydration shell can explain the effects fi rst described by Hofmeister. [ 7,[20][21][22][23] The Hofmeister effect is usually more pronounced for anions than for cations and some ions have a stronger effect than others. The general order of the anions, termed the Hofmeister series is shown in Figure 1 a. [ 7,24 ] The ions on the The mechanical properties of hydrogels are commonly modifi ed by changing the concentration of the molecular components. This approach, however, does not only change hydrogel mechanics, but also th...

show abstract

“…One of the best-characterized thermoresponsive polymers is poly(N-isopropyl acrylamide) (PNIPAAm), which displays a lower critical solution temperature (LCST) of 32˝C, just below body temperature [2][3][4][5]. Other classes of thermoresponsive polymers that have emerged in recent years are for example poly(oligo ethylene glycol acrylate)s [2,6], polyisocyanopeptides grafted with oligo(ethylene glycol) side chains [7][8][9], poly(2-oxazine)s [10] and poly(2-oxazoline)s [3,5,[11][12][13][14][15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Thermal Properties of Methyl Ester-Containing Poly(2-oxazoline)s

et al. 2015

View full text Add to dashboard Cite

This paper describes the synthesis and thermal properties in solution and bulk of poly(2-alkyl-oxazoline)s (PAOx) containing a methyl ester side chain.Homopolymers of 2-methoxycarbonylethyl-2-oxazoline (MestOx) and 2-methoxycarbonylpropyl-2-oxazoline (C3MestOx), as well as copolymers with 2-ethyl-2-oxazoline (EtOx) and 2-n-propyl-2-oxazoline (nPropOx), with systematic variations in composition were prepared. The investigation of the solution properties of these polymers revealed that the cloud point temperatures (T CP s) could be tuned in between 24˝C and 108˝C by variation of the PAOx composition. To the best of our knowledge, the T CP s of PMestOx and PC3MestOx are reported for the first time and they closely resemble the T CP s of PEtOx and PnPropOx, respectively, indicating similar hydrophilicity of the methyl ester and alkyl side chains. Furthermore, the thermal transitions and thermal stability of these polymers were investigated by DSC and TGA measurements, respectively, revealing amorphous polymers with glass transition temperatures between´1˝C and 54˝C that are thermally stable up to >300˝C.

show abstract

Preparation and characterization of non-linear poly(ethylene glycol) analogs from oligo(ethylene glycol) functionalized polyisocyanopeptides

Cited by 40 publications

References 52 publications

DNA‐Responsive Polyisocyanopeptide Hydrogels with Stress‐Stiffening Capacity

DNA‐Responsive Polyisocyanopeptide Hydrogels with Stress‐Stiffening Capacity

Tuning Hydrogel Mechanics Using the Hofmeister Effect

Thermal Properties of Methyl Ester-Containing Poly(2-oxazoline)s

Contact Info

Product

Resources

About