Electrochemical preparation and characterization of PNIPAM-HAp scaffolds for bone tissue engineering

Ribeiro, Charlene Aparecida; Martins, Marcos Vinicius Surmani; Bressiani, Ana Helena A.; Bressiani, José Carlos; Leyva, Maria Elena; Queiroz, Álvaro Antônio Alencar de

doi:10.1016/j.msec.2017.07.048

Cited by 49 publications

(33 citation statements)

References 51 publications

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“…The progressive growth of HAp domains allowed the polymer chains to re-organize to long-range ordering. In this case, cohesive interactions appeared between the HAp particles and between the polymer chains and HAp particles [19]. The results of the semiquantitative analysis of the HAp content in the composite matrix by EDS showed that the material contains a mineral phase and organic matrix.…”

Section: Resultsmentioning

confidence: 91%

Thermal properties of polyurethane-based composites modified with chitosan for biomedical applications

Szlachta

Ordon

Nowicka

et al. 2020

J Therm Anal Calorim

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The thermal properties of chitosan and hydroxyapatite (HAp)-crosslinked polyurethanes (PU) prepared in a two-step bulk polymerization were investigated. Synthesis of PU was carried out using 1,6-hexamethylene diisocyanate, poly(ethylene glycol) 2000 and dibutyltin dilaurate as a catalyst. Various molar ratios of chitosan and 1,4-butanediol were applied, and the effects of incorporating different HAp amounts and the chitosan-to-BDO ratio were studied. It was found that the thermal properties of PU materials depend on polysaccharides and bioceramics load, which was confirmed by differential scanning calorimetry and thermogravimetry. The glass transition temperature increases with increasing chitosan fraction. Similarly, the onset temperature of degradation increased with chitosan addition. On the other hand, the presence of ceramics did not show a significant impact on the thermal properties of PU composites. Successful polymerization and chain extension of the isocyanate groups with hydroxyl moieties from chitosan and HAp were confirmed by Fourier transform infrared spectroscopy, and the morphology was examined using scanning electron microscopy.

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Section: Resultsmentioning

confidence: 91%

Thermal properties of polyurethane-based composites modified with chitosan for biomedical applications

Szlachta

Ordon

Nowicka

et al. 2020

J Therm Anal Calorim

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“…Figure 3 b shows the XRD patterns of AT-CNTs, MAX, and MAX-g-PNIPAM/AT-CNTs dried hydrogels. The gel-1, gel-5, and gel-10 exhibited two broad diffraction peaks at 2θ = 7.9° and 2θ = 19.97° which implied the amorphous structure of PNIPAM [ 38 ]. In patterns of hydrogels, there were no sharp peaks of AT-CNTs observed in formed hydrogels due to the hydrogen bonding among the functional groups of AT-CNTs and other functional groups of MAX and PNIPAM during the formation of the hydrogel [ 39 ].…”

Section: Resultsmentioning

confidence: 99%

Carbon Nanotubes Reinforced Maleic Anhydride-Modified Xylan-g-Poly(N-isopropylacrylamide) Hydrogel with Multifunctional Properties

et al. 2018

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Introducing multifunctional groups and inorganic material imparts xylan-based hydrogels with excellent properties, such as responsiveness to pH, temperature, light, and external magnetic field. In this work, a composite hydrogel was synthesized by introducing acid treated carbon nanotubes (AT-CNTs) into the maleic anhydride modified xylan grafted with poly(N-isopropylacrylamide) (MAX-g-PNIPAM) hydrogels network. It was found that the addition of AT-CNTs affected the MAX-g-PNIPAM hydrogel structure, the swelling ratio and mechanical properties, and imparted the hydrogel with new properties of electrical conductivity and near infrared region (NIR) photothermal conversion. AT-CNTs could reinforce the mechanical properties of MAX-g-PNIPAM hydrogels, being up to 83 kPa for the compressive strength when the amount was 11 wt %, which was eight times than that of PNIPAM hydrogel and four times than that of MAX-g-PNIPAM hydrogel. The electroconductibility was enhanced by the increase of AT-CNTs amounts. Meanwhile, the composite hydrogel also exhibited multiple shape memory and NIR photothermal conversion properties, and water temperature was increased from 26 °C to 56 °C within 8 min under the NIR irradiation. Thus, the AT-CNTs reinforced MAX-g-PNIPAM hydrogel possessed promising multifunctional properties, which offered many potential applications in the fields of biosensors, thermal-arrest technology, and drug-controlled release.

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“…To date, PNIPAAm hydrogels have not achieved a clinical acceptance due to the potential cytotoxic effect of NIPAAm [82]. The NIPAAm monomer has shown a concentration-dependent cytotoxicity with endothelial, epithelial, smooth muscle, and fibroblasts [83].…”

Section: Discussionmentioning

confidence: 99%

Synthesis and Evaluation of a Thermoresponsive Degradable Chitosan-Grafted PNIPAAm Hydrogel as a “Smart” Gene Delivery System

et al. 2020

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Thermoresponsive hydrogels demonstrate tremendous potential as sustained drug delivery systems. However, progress has been limited as formulation of a stable biodegradable thermosensitive hydrogel remains a significant challenge. In this study, free radical polymerization was exploited to formulate a biodegradable thermosensitive hydrogel characterized by sustained drug release. Highly deacetylated chitosan and N-isopropylacrylamide with distinctive physical properties were employed to achieve a stable, hydrogel network at body temperature. The percentage of chitosan was altered within the copolymer formulations and the subsequent physical properties were characterized using 1H-NMR, FTIR, and TGA. Viscoelastic, swelling, and degradation properties were also interrogated. The thermoresponsive hydrogels were loaded with RALA/pEGFP-N1 nanoparticles and release was examined. There was sustained release of nanoparticles over three weeks and, more importantly, the nucleic acid cargo remained functional and this was confirmed by successful transfection of the NCTC-929 fibroblast cell line. This tailored thermoresponsive hydrogel offers an option for sustained delivery of macromolecules over a prolonged considerable period.

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Electrochemical preparation and characterization of PNIPAM-HAp scaffolds for bone tissue engineering

Cited by 49 publications

References 51 publications

Thermal properties of polyurethane-based composites modified with chitosan for biomedical applications

Thermal properties of polyurethane-based composites modified with chitosan for biomedical applications

Carbon Nanotubes Reinforced Maleic Anhydride-Modified Xylan-g-Poly(N-isopropylacrylamide) Hydrogel with Multifunctional Properties

Synthesis and Evaluation of a Thermoresponsive Degradable Chitosan-Grafted PNIPAAm Hydrogel as a “Smart” Gene Delivery System

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