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McCune, M. P.

Publications and source records attributed to McCune, M. P..

2 recordsLinked to original sources
bioRxiv2025

The Effects of DMSO Cryopreservation on the Biomechanics and Histology of Human Cerebrovascular Tissue

IntroductionTissue preservation techniques, chiefly cryopreservation, have been demonstrated to alter vascular histology and tissue biomechanics via rapid osmotic change--resulting in collagen fiber rearrangement and internal elastic laminae (IEL) microfractures; however, this has not yet been evaluated in cerebrovascular tissue. As such, we sought to measure the effectiveness of a canonical cryopreservation strategy on the thickness and continuity of human cerebrovascular tissue. With the recent rise in biomechanical analyses of cerebrovascular tissue for the design of novel treatments and optimization of surgical strategies, the importance of designing models with accurate tissue proxies is paramount. MethodsFresh, human cerebrovascular tissue was obtained through the Cleveland Clinic institutional cadaver donation program. Donors with prior craniotomy, intracranial malignancy, or history of cerebrovascular disease were excluded. Cadaveric tissue dissections were completed within fourteen days of patient expiration and sectioned into four specimens. The 164 tissue samples obtained from three donors were then randomized into one of the following experimental conditions: 10% formalin (control), distilled water (dH2O), dimethyl sulfoxide (DMSO), or -80 {degrees}C DMSO cryopreservation. Specimens were then processed into paraffin-embedded sections and treated with Movat pentachrome staining. Vessel layers were measured by two blinded evaluators and discontinuities in internal elastin lamina were tallied. ResultsWe found that DMSO cryopreservation failed to consistently provide a protective effect to cerebrovascular specimens. Tissue stored via this method was reported to occasionally swell in specific vessel tunics of select vessel territories compared to formalin controls. We also observed an increase in the number of transverse elastin breaks with DMSO cryopreservation. ConclusionsThis data demonstrates that conventional tissue preservation methods may fail to preserve layer thicknesses between some vessels and alter biomechanical properties for future testing. Further, with more frequent elastin fractures in the cryopreservation group, recoilability of preserved vessels may vary from in vivo counterparts. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=130 SRC="FIGDIR/small/679363v1_ufig1.gif" ALT="Figure 1"> View larger version (45K): org.highwire.dtl.DTLVardef@1d8cc51org.highwire.dtl.DTLVardef@4ddcd6org.highwire.dtl.DTLVardef@1dd94f1org.highwire.dtl.DTLVardef@5d99bf_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗
bioRxiv2025

Fluid-structure Interaction Simulation of the Cerebrovascular Circulation: Immersed Boundary versus Arbitrary Lagrangian Eulerian Mesh Formulations

PurposePatient-specific fluid-structure interaction (FSI) simulations allow for the in silico modeling of vascular pathology. Though existing attempts to model the cerebrovasculature confirm the potential of FSI as a future diagnostic tool, standard simulation methods and modeling parameters remain undefined. The purpose of this investigation was to compare immersed boundary (IB) and arbitrary Lagrangian Eulerian (ALE) formulations to discern whether the increased modeling complexity offered by ALE is necessary for the modeling of smaller-caliber vessels, given increased computational load. MethodsDirect comparisons of Fluent and Mechanical behavior were conducted between IB and ALE methods of FSI simulation. Simulations utilized an internal carotid artery geometry conduit with optimized mesh. Boundary constraints were derived from previous investigation of vascular tissue and fit to a Prony series. Both qualitative profile comparisons and quantitative parametric analyses of variance were conducted to assess differences in simulation output. ResultsIn this study, we report deviations in Fluent and Mechanical output between IB and ALE cases of FSI simulation. More specifically, ALE-method simulations boast higher stress, lower wall shear stress, and lower strain. These differences persist across the vessel geometry and increase with high strain. Additionally, inconsistencies between solving methods are exacerbated in areas of more complex mesh geometry (i.e. vessel bifurcation). ConclusionSubstantial alterations in intraluminal stress, shear stress, and strain suggest that ALE formulation is necessary for modeling blood vessels of the cerebrovasculature. Our findings highlight the importance of accurately modeling the dynamic interactions that occur between the fluid and material domains of simulation.

bioengineering↗