Reproduction method for dried biomodels composed of poly (vinyl alcohol) hydrogels

Shimizu, Yasutomo; Putra, Narendra Kurnia; Ohta, Makoto

doi:10.1038/s41598-018-24235-z

Cited by 6 publications

(6 citation statements)

References 20 publications

(30 reference statements)

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“…Drying linearity is expected for sample drying, 34 , 41 though the investigated gels are non-spherical. We assume that the cylinder samples’ drying behaves similar to spherical hydrogels.…”

Section: Resultsmentioning

confidence: 82%

Swelling of kappa carrageenan hydrogels in simulated body fluid for hypothetical vessel occlusion applications

et al. 2022

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The swelling ability of kappa-carrageenan (KC) hydrogels was investigated in simulated body fluid (SBF). The SBF mimics the ionic concentrations in the vasa deferentia of human males. The study clarifies if these hydrogels can be adjusted to occlude the vasa deferentia by swelling. For this purpose, swelling to twice the initial volume is desirable. In this study, hydrogels of different primary potassium concentrations, biopolymer concentrations and ethanol-exchanged gels, were immersed in SBF either directly or after drying (pre-dried). We measured the absolute and relative swelling degree, and the swelling rates of the gels. Extensive pre-drying leads to irreversible gel densification and absolute swelling magnitudes decrease. We found that immersion into the SBF also leads to potassium ion accumulation, and network restructuring in the hydrogels. This markedly increases the storage moduli of the gel networks. The ion content in the gel structures also directly affects the swelling speed, the fastest swelling occurred in ethanol-exchanged and pre-dried gels. We found that by pre-drying and potassium content adjustment, swelling of the hydrogels is sufficient to render KC hydrogels as a possible candidate for the occlusion of the vasa deferentia.

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Section: Resultsmentioning

confidence: 82%

Swelling of kappa carrageenan hydrogels in simulated body fluid for hypothetical vessel occlusion applications

et al. 2022

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“…XRD measurement can reveal the crystal structure of the PVA-H specimens. From our previous study, the profiles indicate the first 2θ peak around 7.12° comes from PVA-H and the others come from the PP sheet 12 . The XRD profiles of all the specimens were not dramatically changed after containing XG, indicating that the change in crystal structure is slightly affected by both XG inclusion and PVA concentration.…”

Section: Discussionmentioning

confidence: 81%

Viscosity measurement of Xanthan–Poly(vinyl alcohol) mixture and its effect on the mechanical properties of the hydrogel for 3D modeling

Shimizu

Tanabe

Yoshida

et al. 2018

Sci Rep

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Biomodels made of poly(vinyl alcohol) (PVA) are demanded because they can represent the geometries and mechanical properties of human tissues realistically. Injecting and molding, commonly used in three-dimensional (3D) modeling, help to represent the blood vessels accurately. However, these techniques sometimes require higher pressures than the upper pressure limit of the dispensers for pouring in high viscosity materials; the material viscosity should therefore be lower. Moreover, the mechanical properties of the biomodels should be reproduced. This study proposes a PVA solution through the addition of xanthan gum (XG) for 3D modeling, which lowers liquid viscosity while maintaining the mechanical properties of biomodels. XG is known to facilitate the achievement of non-Newtonian fluidity; however, the effects of XG on a PVA solution and PVA hydrogel (PVA-H) are not confirmed. The viscosity measurement using 15 wt% PVA with XG solution (PVA/XG) shows that it will provide easier pouring than 17 wt% PVA solution. The tensile test using the PVA-H of PVA(15 wt%)/XG(0.2 wt%) reveals that the gel is comparable in Young’s modulus to 17 wt% PVA-H. X-ray diffraction shows the crystalline structures of the PVA/XG gel and PVA-H are identical. Thus, this PVA/XG would be useful for fabricating biomodels using injection molding techniques.

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“…In the current work, the models were printed using a rigid material that is best suited for high‐resolution prints, according to the manufacturer (Formlabs). Flexible materials are recommended for a more realistic model that resembles the elasticity of the vasculature, and some are already available or currently under investigation 36,37 . New generations of SLA printers can already print using flexible and elastic materials.…”

Section: Discussionmentioning

confidence: 99%

“…Flexible materials are recommended for a more realistic model that resembles the elasticity of the vasculature, and some are already available or currently under investigation. 36,37 New generations of SLA printers can already print using flexible and elastic materials. However, the allowed minimum printing layer has increased to 50 and 100 µm, respectively.…”

Section: B 3d Printingmentioning

confidence: 99%

3D‐printed, patient‐specific intracranial aneurysm models: From clinical data to flow experiments with endovascular devices

et al. 2021

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Flow models of intracranial aneurysms (IAs) can be used to test new and existing endovascular treatments with flow modulation devices (FMDs). Additionally, 4D flow magnetic resonance imaging (MRI) offers the ability to measure hemodynamics. This way, the effect of FMDs can be determined noninvasively and compared to patient data. Here, we describe a cost-effective method for producing flow models to test the efficiency of FMDs with 4D flow MRI. Methods: The models were based on human radiological data (internal carotid and basilar arteries) and printed in 3D with stereolithography. The models were printed with three different printing layers (25, 50, and 100 µm thickness). To evaluate the models in vitro, 3D rotational angiography, time-offlight MRI, and 4D flow MRI were employed. The flow and geometry of one model were compared with in vivo data. Two FMDs (FMD1 and FMD2) were deployed into two different IA models, and the effect on the flow was estimated by 4D flow MRI. Results: Models printed with different layer thicknesses exhibited similar flow and little geometric variation. The mean spatial difference between the vessel geometry measured in vivo and in vitro was 0.7 AE 1.1 mm. The main flow features, such as vortices in the IAs, were reproduced. The velocities in the aneurysms were similar in vivo and in vitro (mean velocity magnitude: 5.4 AE 7.6 and 7.7 AE 8.6 cm/s, maximum velocity magnitude: 72.5 and 55.1 cm/s). By deploying FMDs, the mean velocity was reduced in the IAs (from 8.3 AE 10 to 4.3 AE 9.32 cm/s for FMD1 and 9.9 AE 12.1 to 2.1 AE 5.6 cm/s for FMD2). Conclusions: The presented method allows to produce neurovascular models in approx. 15 to 30 h. The resulting models were found to be geometrically accurate, reproducing the main flow patterns, and suitable for implanting FMDs as well as 4D flow MRI.

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Reproduction method for dried biomodels composed of poly (vinyl alcohol) hydrogels

Cited by 6 publications

References 20 publications

Swelling of kappa carrageenan hydrogels in simulated body fluid for hypothetical vessel occlusion applications

Swelling of kappa carrageenan hydrogels in simulated body fluid for hypothetical vessel occlusion applications

Viscosity measurement of Xanthan–Poly(vinyl alcohol) mixture and its effect on the mechanical properties of the hydrogel for 3D modeling

3D‐printed, patient‐specific intracranial aneurysm models: From clinical data to flow experiments with endovascular devices

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