Effect of microwave irradiation on the hydroxypropyl methylcellulose powder and its hydrogel studied by Magnetic Resonance Imaging

Kowalczuk, Joanna; Tritt‐Goc, Jadwiga

doi:10.1016/j.carbpol.2010.07.037

Cited by 8 publications

(2 citation statements)

References 22 publications

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“…The fact that the mixture of various proton-containing molecules with dramatically different mobility demonstrates single-exponential relaxation decay can be simply explained by prevalence of the water in the system (> 80 Wt.%) and by fast proton exchange between free (bulk water in micropores, defects, and larger spaces of the polymer network) and bound (protons in hydroxyl groups majorly presented in allyl chitosan chains) states. Examples of the polymers exhibiting such proton exchange are widely present in the literature (Baumgartner et al , 2005; Mikac et al , 2010; Kowalczuk and Tritt-Goc, 2011; Pregent et al , 2012). The component with relatively short relaxation time attributed to PEG-DA is not probably seen in decays due to long “dead” time (time between the excitation radiofrequency pulse and the first measured point) which is ∼ 3 ms for the apparatus used.…”

Section: Resultsmentioning

confidence: 99%

NMR imaging of 3D printed biocompatible polymer scaffolds interacting with water

Morozov

Novikov

Bouznik

et al. 2019

RPJ

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Purpose Active employment of additive manufacturing for scaffolds preparation requires the development of advanced methods which can accurately characterize the morphologic structure and its changes during an interaction of the scaffolds with substrate and aqueous medium. This paper aims to use the method of nuclear magnetic resonance (NMR) imaging for preclinical characterization of 3D-printed scaffolds based on novel allyl chitosan biocompatible polymer matrices. Design/methodology/approach Biocompatible polymer scaffolds were fabricated via stereolithography method. Using NMR imaging the output quality control of the scaffolds was performed. Scaffolds stability, polymer matrix homogeneity, kinetic of swelling processes, water migration pathways within the 3D-printed parts, effect of post-print UV curing on overall scaffolds performance were studied in details. Findings NMR imaging visualization of water uptake and polymer swelling processes during the interaction of scaffolds with aqueous medium revealed the formation of the fronts within the polymer matrices those dynamics is governed by case I transport (Fickian diffusion) of the water into polymer network. No significant difference was observed in front propagation rates along the polymer layers and across the layers stack. After completing the swelling process, the polymer scaffolds retain their integrity and no internal defects were detected. Research limitations/implications NMR imaging revealed that post-print UV curing aimed to improve the overall performance of 3D-printed scaffolds might not provide a better quality of the finish product, as this procedure apparently yield strongly inhomogeneous distribution of polymer crosslink density which results in subsequent inhomogeneity of water ingress and swelling processes, accompanied by stress-related cracks formation inside the scaffolds. Practical implications This study introduces a method which can successfully complement the standard tests which now are widely used in either additive manufacturing or scaffolds engineering. Social implications This work can help to improve the overall performance of the polymer scaffolds used in tissue engineering. Originality/value The results of this study demonstrate feasibility of NMR imaging for preclinical characterization of 3D printed biocompatible polymer scaffolds. The results are believed to contribute to better understanding of the processes vital for improving the design of 3D-printed polymer scaffolds.

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Section: Resultsmentioning

confidence: 99%

NMR imaging of 3D printed biocompatible polymer scaffolds interacting with water

Morozov

Novikov

Bouznik

et al. 2019

RPJ

View full text Add to dashboard Cite

show abstract

“…). Accordingly, several articles indicate that the D of water in hydrogels is substantially affected by the water content and MW of polymers. Water diffusivity in the hydrogel is mostly obstructed by the water‐compartmentalization and hydration effects.…”

Section: Discussionmentioning

confidence: 99%