Probing the internal environment of PVP networks generated by irradiation with different sources

Ricca, Mariaelena; Foderà, Vito; Giacomazza, Daniela; Leone, Maurizio; Spadaro, Giuseppe; Dispenza, Clelia

doi:10.1007/s00396-010-2217-7

Cited by 22 publications

(25 citation statements)

References 53 publications

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“…G' being larger than G'' reflects a dominant elastic character specific to elastic solids 58 and suggests that the hydrogels obtained by e-beam processing in these conditions form a permanent network due to cross-links. [59][60][61] The magnitude of the storage and viscous moduli (G') and (G'') was depended on the hydrogel composition, namely of collagen and PVP concentration, as well as of CA (Figure 4). For those hydrogels prepared in the absence of CA, the G' values do not exceed 66.5 Pa, in contrast with the hydrogels prepared with various concentrations of CA, were the G' values ranged between 1800 -14100 Pa.…”

Section: Dynamic Mechanical Propertiesmentioning

confidence: 99%

E-Beam Processing of Collagen-Poly(N-vinyl-2-pyrrolidone) Double-Network Superabsorbent Hydrogels: Structural and Rheological Investigations

et al. 2019

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Collagen (C)-poly(N-vinyl-2-pyrrolidone) (PVP) double-network superabsorbent hydrogels were synthesized by e-beam (electron beam) radiation processing, both with the addition of water-soluble cross-linking agents (CA), as well as without CA. The aim of the study was to develop a hydrogel for future application as wound dressings via e-beam radiation cross-linking of two biocompatible polymers. The formation of C-PVP hydrogels was confirmed by Fourier transform infrared (FTIR) spectroscopy and their performance was determined from morphological and rheological experiments, such as sol-gel analysis, swelling capacity, storage (G') and viscous (G'') moduli, cross-linking density, and pore size. Sol-gel analysis was performed in order to determine the gel properties as function of absorbed dose and it was found that the degradation density (p 0)/cross-linking density (q 0) ratio indicates a negligible contribution of chain scission processes. The rheological data confirmed that the elastic properties were predominant: G' moduli were larger than G'' moduli, as is specific to elastic solids and indicate the formation of a permanent hydrogel network were cross-links are present. Moreover, the swelling studies indicated that the hydrogels have good stability both in deionized water and phosphate-buffered saline (PBS) solution at 37 o C, and superabsorbent properties. The hydrogels network parameters obtained with lower content of CA, could be controlled by changing the absorbed dose.

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Section: Dynamic Mechanical Propertiesmentioning

confidence: 99%

E-Beam Processing of Collagen-Poly(N-vinyl-2-pyrrolidone) Double-Network Superabsorbent Hydrogels: Structural and Rheological Investigations

et al. 2019

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“…Measurements were carried out placing samples in a quartz cell within the thermostated cell compartment of the instrument at 25 ± 0.1 °C and at 90° scattering angle after filtration (pore size 0.45 μm). In consideration of their monomodal size distribution, DLS data were analyzed according to the method of cumulants [17,23,24,25]. Ζ-potential measurements were acquired at 25 °C using a Malvern Zetasizer Nano-ZS (Malvern instrument Ltd., Malvern, UK) equipped with a He–Ne laser at a power of 4.0 mW.…”

Section: Methodsmentioning

confidence: 99%

Multi-Functional Nanogels for Tumor Targeting and Redox-Sensitive Drug and siRNA Delivery

et al. 2016

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(1) Background: A new family of nanosystems able to discern between normal and tumor cells and to release a therapeutic agent in controlled way were synthetized by e-beam irradiation. This technique permits to obtain biocompatible, sterile, carboxyl-functionalized polyvinylpyrrolidone (PVP-co-acrylic acid) nanogels (NGs); (2) Methods: Here, we performed a targeting strategy based on the recognition of over-expressed proteins on tumor cells, like the folate receptor. The selective targeting was demonstrated by co-culture studies and flow cytometry analysis, using folate conjugated NGs. Moreover, nanoparticles were conjugated to a chemotherapeutic drug or to a pro-apoptotic siRNA through a glutathione sensitive spacer, in order to obtain a controlled release mechanism, specific for cancer cells. The drug efficiency was tested on tumor and healthy cells by flow cytometric analysis, confocal and epifluorescence microscopy and cytotoxicity assay; the siRNA effect was investigated by RNAi experiment; (3) Results: The data obtained showed that the use of NGs permits a faster cargo release in cancer cells, in response to high cytosolic glutathione level, also improving their efficacy; (4) Conclusion: The possibility of releasing biological molecules in a controlled way and to recognize a specific tumor target allows overcoming the typical limits of the classic cancer therapy.

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“…These methodologies lead to average values of network mesh size that are a convincing description of the network organization only for homogeneous network structures. This is not often the case of radiation crosslinked networks (D'Errico et al, 2008;Ricca et al, 2010). Furthermore, these conventional characterization methodologies are not suitable for nanogels.…”

Section: Introductionmentioning

confidence: 95%

Studies of network organization and dynamics of e-beam crosslinked PVPs: From macro to nano

Dispenza

Grimaldi

Sabatino

et al. 2012

Radiation Physics and Chemistry

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a b s t r a c tIn this work the influence of poly(N-vinyl pyrrolidone) (PVP) concentration in water on the organization and dynamics of the corresponding macro-/nanogel networks has been systematically investigated. Irradiation has been performed at the same irradiation dose (within the sterilization dose range) and dose rate. In the selected irradiation conditions, the transition between macroscopic gelation and micro-/nanogels formation is observed just below the critical overlap concentration ( $ 1 wt%), whereas the net prevalence of intra-molecular over inter-molecular crosslinking occurs at a lower polymer concentration (below 0.25 wt%). Dynamic-mechanical spectroscopy has been applied as a classical methodology to estimate the network mesh size for macrogels in their swollen state, while 13 C NMR spin-lattice relaxation spectroscopy has been applied on both the macrogel and nanogel freeze dried residues to withdraw interesting information of the network spatial organization in the passage of scale from macro to nano.

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Probing the internal environment of PVP networks generated by irradiation with different sources

Cited by 22 publications

References 53 publications

E-Beam Processing of Collagen-Poly(N-vinyl-2-pyrrolidone) Double-Network Superabsorbent Hydrogels: Structural and Rheological Investigations

E-Beam Processing of Collagen-Poly(N-vinyl-2-pyrrolidone) Double-Network Superabsorbent Hydrogels: Structural and Rheological Investigations

Multi-Functional Nanogels for Tumor Targeting and Redox-Sensitive Drug and siRNA Delivery

Studies of network organization and dynamics of e-beam crosslinked PVPs: From macro to nano

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