Thermosensitive phase behavior and drug release of in situ N-isopropylacrylamide copolymer

Chen, Saibo; Zhong, Hui; Gu, Bin; Wang, Yinzhu; Li, Xiao-mo; Cheng, Zhipeng; Zhang, Lili; Yao, Cheng

doi:10.1016/j.msec.2012.05.052

Cited by 27 publications

(15 citation statements)

References 37 publications

(36 reference statements)

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“…The thermogelling capabilities of PNVCL were found to be affected by the electron beam process. This is a result that is auspicious for biomedical applications, as having the ability to control the M w of the PNVCL postpolymerization is desirable . Similar trends were established using the sol–gel method in comparison to the results obtained for LCST (Table ).…”

Section: Resultssupporting

confidence: 67%

Enhancing and controlling the critical attributes of poly (N‐vinylcaprolactam) through electron beam irradiation for biomedical applications

Halligan

Murray²,

Hopkins

et al. 2019

J of Applied Polymer Sci

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The primary aim of this body of work is to investigate the effect of an industrial scale electron beam sterilization process on novel PNVCL-based smart polymers. There is limited literature available that examines the effects of modifying PNVCL by electron beam irradiation, and as a means of potentially enhancing properties such as the lower critical solution temperature and mechanical behavior. Physically crosslinked poly(N-vinylcaprolactam)-vinyl acetate (PNVCL-VAc) copolymers were prepared by photopolymerization and were subsequently exposed to ionizing radiation via electron beam technology. The mechanical characteristics and phase transitions of the physically crosslinked PNVCL samples were tailored by controlling the electron beam irradiation dose. Importantly, PNVCL and PNVCL-VAc samples (5 wt % in solution) underwent a phase transition between 33.5 and 26.5 C, following electron beam irradiation. Furthermore, all samples displayed a Young's modulus between 1024.3 and 1516.4 MPa depending on the addition of copolymer and electron beam irradiation dose. The industrial scale electron beam sterilization process proved successful in enhancing/modifying many key smart polymer properties, and this ability to formulate and sterilize in one step could prove a very attractive approach for many biomedical applications.

show abstract

Section: Resultssupporting

confidence: 67%

Enhancing and controlling the critical attributes of poly (N‐vinylcaprolactam) through electron beam irradiation for biomedical applications

Halligan

Murray²,

Hopkins

et al. 2019

J of Applied Polymer Sci

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“…The LCST values are almost the same, around 34 ± 0.1 °C, regardless of differences in the synthetic parameters. These LCSTs agree with those of other compounds containing PNIPAm …”

Section: Resultssupporting

confidence: 88%

Thermoresponsive behavior and rheology of SiO₂–hyaluronic acid/poly(N‐isopropylacrylamide) (NaHA/PNIPAm) core–shell structured microparticles

Chen

et al. 2014

J of Chemical Tech & Biotech

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BACKGROUND: Injectable polymer gels for tissue engineering offer specific advantages over preformed scaffolds. They can transform from a sol to a block gel as a response to an external stimulus. One effective strategy for improving the mechanical strength of a gel is to introduce an inorganic material. RESULTS: Microparticles composed of a hard SiO 2 core covered with a thermoresponsive hybrid gel (sodium hyaluronate/poly(Nisopropylacrylamide); NaHA/PNIPAm) were synthesized. The microparticles were characterized by dynamic light-scattering and transmission electron microscopy; rheological measurements were also performed. The microparticles were perfectly spherical and had a core-shell structure. They can perform a sol-gel transformation, that is, they shrank and assembled to form a macroscopic hydrogel through physical cross-linking at the gelation temperature (T gel ), which was determined by rheological measurements. The T gel was adjusted by changing the concentration of microparticles or Ca 2+ ions. CONCLUSION: The introduction of NaHA and SiO 2 improved the mechanical properties of the macroscopic gels. The rigidity and stability of the macroscopic gel were controlled by the molecular weight of NaHA and the amount of PNIPAm. Such injectable hydrogels might have potential as scaffold biomaterials, and are expected to be the 'ink' for three-dimensional bioprinters.

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“…For example, poly( N ‐isopropylacrylamide) (PNIPAAm) polymer is an amphiphilic polymer with a sol–gel transition or LCST at 32 °C. At this temperature, polymerization occurs forming a dehydrated shrunken configuration due to the disruption of hydrogen bonding of water molecules around the amide group of the side polymer chains . Given that the LCST of PNIPAAm occurs at near normal body temperature, this polymer has potential applications in controlled drug delivery and bone tissue engineering.…”

Section: Introductionmentioning

confidence: 99%

“…The P(Alg‐g‐NIPAAm) hydrogel can be synthesized using chemical linkers or through the creation of free radicals to graft the pendant group NIPAAm onto the hydrophilic alginate chain. Current literature promotes grafting using intermediary reactions, including the formation of amino functionalized PNIPAAm . Moreover, grafted PNIPAAm to alginate molecules without previous modifications where the polymerization is mediated by microwave radiation creates a very complex system .…”

Section: Introductionmentioning

confidence: 99%

Simple Radical Polymerization of Poly(Alginate‐Graft‐N‐Isopropylacrylamide) Injectable Thermoresponsive Hydrogel with the Potential for Localized and Sustained Delivery of Stem Cells and Bioactive Molecules

Pentlavalli

Chambers

Sathy

et al. 2017

Macromolecular Bioscience

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In this study, thermoresponsive copolymers that are fully injectable, biocompatible, and biodegradable and are synthesized via graft copolymerization of poly(N-isopropylacrylamide) onto alginate using a free-radical reaction are presented. This new synthesis method does not involve multisteps or associated toxicity issues, and has the potential to reduce scale-up difficulties. Chemical and physical analyses verify the resultant graft copolymer structure. The lower critical solution temperature, which is a characteristic of sol-gel transition, is observed at 32 °C. The degradation properties indicate suitable degradation kinetics for drug delivery and bone tissue engineering applications. The synthesized P(Alg-g-NIPAAm) hydrogel is noncytotoxic with both human osteosarcoma (MG63) cells and porcine bone marrow derived mesenchymal stem cells (pBMSCs). pBMSCs encapsulated in the P(Alg-g-NIPAAm) hydrogel remain viable, show uniform distribution within the injected hydrogel, and undergo osteogenic and chondrogenic differentiation under appropriate culture conditions. Furthermore, for the first time, this work will explore the influence of alginate viscosity on the viscoelastic properties of the resulting copolymer hydrogels, which influences the rate of medical device formation and subsequent drug release. Together the results of this study indicate that the newly synthesized P(Alg-g-NIPAAm) hydrogel has potential to serve as a versatile and improved injectable platform for drug delivery and bone tissue engineering applications.

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Thermosensitive phase behavior and drug release of in situ N-isopropylacrylamide copolymer

Cited by 27 publications

References 37 publications

Enhancing and controlling the critical attributes of poly (N‐vinylcaprolactam) through electron beam irradiation for biomedical applications

Enhancing and controlling the critical attributes of poly (N‐vinylcaprolactam) through electron beam irradiation for biomedical applications

Thermoresponsive behavior and rheology of SiO₂–hyaluronic acid/poly(N‐isopropylacrylamide) (NaHA/PNIPAm) core–shell structured microparticles

Simple Radical Polymerization of Poly(Alginate‐Graft‐N‐Isopropylacrylamide) Injectable Thermoresponsive Hydrogel with the Potential for Localized and Sustained Delivery of Stem Cells and Bioactive Molecules

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Thermosensitive phase behavior and drug release of in situ N-isopropylacrylamide copolymer

Cited by 27 publications

References 37 publications

Enhancing and controlling the critical attributes of poly (N‐vinylcaprolactam) through electron beam irradiation for biomedical applications

Enhancing and controlling the critical attributes of poly (N‐vinylcaprolactam) through electron beam irradiation for biomedical applications

Thermoresponsive behavior and rheology of SiO2–hyaluronic acid/poly(N‐isopropylacrylamide) (NaHA/PNIPAm) core–shell structured microparticles

Simple Radical Polymerization of Poly(Alginate‐Graft‐N‐Isopropylacrylamide) Injectable Thermoresponsive Hydrogel with the Potential for Localized and Sustained Delivery of Stem Cells and Bioactive Molecules

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Thermoresponsive behavior and rheology of SiO₂–hyaluronic acid/poly(N‐isopropylacrylamide) (NaHA/PNIPAm) core–shell structured microparticles