Novel multi-stimuli responsive sodium alginate-grafted-poly(N-isopropylacrylamide) copolymers: II. Dilute solution properties

Vasile, Cornelia; Niţă, Loredana E.

doi:10.1016/j.carbpol.2011.04.012

Cited by 32 publications

(20 citation statements)

References 43 publications

(48 reference statements)

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“…Concerning the first effect, SA is a hydrophilic polymer, which was previously reported as having no influence upon T ph of a crosslinked PNIPAM hydrogel [33] or increasing T ph in the case of alginate-graft-PNIPAM copolymers [37]. However, for our system, which is a different one, T ph decreased with alginate concentration, as indicated by the evolution of both T vi and T peak,DSC (Figure 3, Table 1).…”

Section: Resultssupporting

confidence: 34%

“…All these properties have led to frequently use of SA in various medical applications, including hydrogel formulations based on SA alone or in association with various other polymers [29][30][31]. From this point of view, three types of structurally different hydrogels containing both SA and PNIPAM blocks have been reported in literature up to now: (a) hydrogels based on linear PNIPAM and Ca 2þ -crosslinked sodium alginate [32]; (b) hydrogels based on covalently crosslinked PNIPAM and linear SA [33][34][35][36]; and (c) hydrogels from SA-graft-PNIPAM copolymers [37][38][39][40].…”

Section: Introductionmentioning

confidence: 99%

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Novel Thermoreversible Injectable Hydrogel Formulations Based on Sodium Alginate and Poly(N-Isopropylacrylamide)

Teodorescu

Mihai

Turturicǎ

et al. 2015

International Journal of Polymeric Materials and Polymeric Biom

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Novel injectable thermoreversible hydrogel compositions with semi-interpenetrating network structure were prepared through the addition of sodium alginate (SA) to poly(N-isopropylacrylamide) (PNIPAM) aqueous solutions. The addition of the hydrophilic alginate strongly improved the stability against syneresis of the 15 wt% PNIPAM hydrogels formed at 37 C from less than 15 min in the absence of alginate to more than 7 days in the presence of 4 wt% SA. Besides the SA concentration, the hydrogel stability depended on the molecular weight and polydispersity of PNIPAM, being lower when a high molecular weight fraction was present. The phase transition temperature (T ph ) of the PNIPAM aqueous solutions decreased with alginate concentration, while the dynamic viscosity and elastic modulus of the hydrogels increased. By decreasing the PNIPAM molecular weight and polydispersity, the dynamic viscosity and elastic modulus of the PNIPAM-alginate hydrogels formed above T ph diminished, while their viscoelastic behavior changed from predominantly elastic to predominantly viscous.

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Section: Resultssupporting

confidence: 34%

Section: Introductionmentioning

confidence: 99%

Novel Thermoreversible Injectable Hydrogel Formulations Based on Sodium Alginate and Poly(N-Isopropylacrylamide)

Teodorescu

Mihai

Turturicǎ

et al. 2015

International Journal of Polymeric Materials and Polymeric Biom

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“…70 Likewise, thermo-responsive alginate hydrogels presented in the literature do not exhibit shear-thinning and self-healing behavior. 71-73 …”

Section: Resultsmentioning

confidence: 99%

Self-Healing and Thermoresponsive Dual-Cross-Linked Alginate Hydrogels Based on Supramolecular Inclusion Complexes

et al. 2015

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β-cyclodextrin (β-CD), with a lipophilic inner cavity and hydrophilic outer surface, interacts with a large variety of non-polar guest molecules to form non-covalent inclusion complexes. Conjugation of β-CD onto biomacromolecules can form physically-crosslinked hydrogel networks upon mixing with a guest molecule. Herein describes the development and characterization of self-healing, thermo-responsive hydrogels, based on host-guest inclusion complexes between alginate-graft-β-CD and Pluronic® F108 (poly(ethylene glycol)-b-poly(propylene glycol)-b-poly(ethylene glycol)). The mechanics, flow characteristics, and thermal response were contingent on the polymer concentrations, and the host-guest molar ratio. Transient and reversible physical crosslinking between host and guest polymers governed self-assembly, allowing flow under shear stress, and facilitating complete recovery of the material properties within a few seconds of unloading. The mechanical properties of the dual-crosslinked, multi-stimuli responsive hydrogels were tuned as high as 30 kPa at body temperature, and are advantageous for biomedical applications such as drug delivery and cell transplantation.

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“…The peak at 1650 cm −1 in the graft copolymer is the overlap resulting from the carboxyl group of CMC and amide group of PNIPAM. This indicates that grafting reaction of CMC with PNIPAM took place . The characterization of two graft copolymers was summarized in Table .…”

Section: Resultsmentioning

confidence: 93%

Formation of thermo‐sensitive polyelectrolyte complex micelles from two biocompatible graft copolymers for drug delivery

Meng

Guo

et al. 2013

J Biomedical Materials Res

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Thermo-sensitive polyelectrolyte complex (PEC) micelles assembled from two biocompatible graft copolymers chitosan-g-poly(N-isopropylacrylamide) (CS-g-PNIPAM) and carboxymethyl cellulose-g-poly(N-isopropylacrylamide) (CMC-g-PNIPAM) were prepared for delivery of 5-fluorouracil (5-FU). The PEC micelles showed a narrow size distribution with core-shell structure, in which the core formed from positively charged CS and negatively charged CMC by electrostatic interactions and the shell formed from thermo-sensitive PNIPAM. The synthesized PEC micelles have lower critical solution temperatures (LCST) in the region of 37°C, which is favorable for smart drug delivery applications. The hydrogen bondings between PEC micelles and 5-FU increased the drug loading. Changing temperature, pH or ionic strength, a sustained and controlled release was observed due to the deformation of PEC micelles. Adding glutaraldehyde, a chemical crosslinking reagent, was an efficient way to reinforce the micelles structure and decrease the initial burst release. Cytotoxicity assays showed that drug-loaded PEC micelles retained higher cell inhibition efficiency in HeLa cells.

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Novel multi-stimuli responsive sodium alginate-grafted-poly(N-isopropylacrylamide) copolymers: II. Dilute solution properties

Cited by 32 publications

References 43 publications

Novel Thermoreversible Injectable Hydrogel Formulations Based on Sodium Alginate and Poly(N-Isopropylacrylamide)

Novel Thermoreversible Injectable Hydrogel Formulations Based on Sodium Alginate and Poly(N-Isopropylacrylamide)

Self-Healing and Thermoresponsive Dual-Cross-Linked Alginate Hydrogels Based on Supramolecular Inclusion Complexes

Formation of thermo‐sensitive polyelectrolyte complex micelles from two biocompatible graft copolymers for drug delivery

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