A Novel Bioreactor System for the Assessment of Endothelialization on Deformable Surfaces

Bachmann, Björn J.; Bernardi, Laura; Loosli, Christian; Marschewski, Julian; Perrini, Michela; Ehrbar, Martin; Ermanni, Paolo; Poulikakos, Dimos; Ferrari, Aldo; Mazza, Edoardo

doi:10.1038/srep38861

Cited by 22 publications

(24 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A single rotating inlet design eliminates the static-rotating interfacing walls that share a common edge, by having rotation in all interfacing walls. Considering the sensitive nature of mammalian cell growth and stimulation to shear stress via mechano-transduction 15 , 24 – 33 , non-homogenous wall shear stress profiles is greatly undesirable for the culturing of a fully functional tissue-engineered tracheal scaffold. Hence, the rotating single inlet design exhibited a more consistent flow field environment for tracheal scaffolds than the double static inlet design.…”

Section: Discussionmentioning

confidence: 99%

Computational fluid dynamics for enhanced tracheal bioreactor design and long-segment graft recellularization

Lee

Marin-Araujo

Aoki

et al. 2021

Sci Rep

View full text Add to dashboard Cite

Successful re-epithelialization of de-epithelialized tracheal scaffolds remains a challenge for tracheal graft success. Currently, the lack of understanding of the bioreactor hydrodynamic environment, and its relation to cell seeding outcomes, serve as major obstacles to obtaining viable tracheal grafts. In this work, we used computational fluid dynamics to (a) re-design the fluid delivery system of a trachea bioreactor to promote a spatially uniform hydrodynamic environment, and (b) improve the perfusion cell seeding protocol to promote homogeneous cell deposition. Lagrangian particle-tracking simulations showed that low rates of rotation provide more uniform circumferential and longitudinal patterns of cell deposition, while higher rates of rotation only improve circumferential uniformity but bias cell deposition proximally. Validation experiments with human bronchial epithelial cells confirm that the model accurately predicts cell deposition in low shear stress environments. We used the acquired knowledge from our particle tracking model, as a guide for long-term tracheal repopulation studies. Cell repopulation using conditions resulting in low wall shear stress enabled enhanced re-epithelialization of long segment tracheal grafts. While our work focuses on tracheal regeneration, lessons learned in this study, can be applied to culturing of any tissue engineered tubular scaffold.

show abstract

Section: Discussionmentioning

confidence: 99%

Computational fluid dynamics for enhanced tracheal bioreactor design and long-segment graft recellularization

Lee

Marin-Araujo

Aoki

et al. 2021

Sci Rep

View full text Add to dashboard Cite

show abstract

“…25 Low WSS on the other hand help to minimize blood trauma and are necessary for the endothelial cell layer not to be washed off by the blood flow. We assume that the survival is achievable at a physiological WSS lower than 7 Pa. 26,27 Acceptable thresholds of RT for blood propulsion devices are challenging to define. They depend on the specific application and fail to account for the complex phenomena of blood damage and thrombosis.…”

Section: Methodsmentioning

confidence: 99%

High-frequency operation of pulsatile ventricular assist devices: A computational study on circular and elliptically shaped pumps

et al. 2019

Self Cite

View full text Add to dashboard Cite

Pulsatile positive displacement pumps as ventricular assist devices were gradually replaced by rotary devices due to their large volume and high adverse event rates. Nevertheless, pulsatile ventricular assist devices might be beneficial with regard to gastrointestinal bleeding and cardiac recovery. Therefore, aim of this study was to investigate the flow field in new pulsatile ventricular assist devices concepts with an increased pump frequency, which would allow lower stroke volumes to reduce the pump size. We developed a novel elliptically shaped pulsatile ventricular assist devices, which we compared to a design based on a circular shape. The pump size was adjusted to deliver similar flow rates at pump frequencies of 80, 160, and 240 bpm. Through a computational fluid dynamics study, we investigated flow patterns, residence times, and wall shear stresses for different frequencies and pump sizes. A pump size reduction by almost 50% is possible when using a threefold pump frequency. We show that flow patterns inside the circular pump are frequency dependent, while they remain similar for the elliptic pump. With slightly increased wall shear stresses for higher frequencies, maximum wall shear stresses on the pump housing are higher for the circular design (42.2 Pa vs 18.4 Pa). The calculated blood residence times within the pump decrease significantly with increasing pump rates. A smaller pump size leads to a slight increase of wall shear stresses and a significant improvement of residence times. Hence, high-frequency operation of pulsatile ventricular assist devices, especially in combination with an elliptical shape, might be a feasible mean to reduce the size, without any expectable disadvantages in terms of hemocompatibility.

show abstract

“…We described the most relevant aspects of the in vitro pump development. 3,11,24,29,36 Specifically, the pump structure comprises two superimposed chambers horizontally separated by the hybrid membrane (Figs. 1a, 1d).…”

Section: Pump Designmentioning

confidence: 99%

A Novel Hybrid Membrane VAD as First Step Toward Hemocompatible Blood Propulsion

et al. 2020

Self Cite

View full text Add to dashboard Cite

Heart failure is a raising cause of mortality. Heart transplantation and ventricular assist device (VAD) support represent the only available lifelines for end stage disease. In the context of donor organ shortage, the future role of VAD as destination therapy is emerging. Yet, major drawbacks are connected to the long-term implantation of current devices. Poor VAD hemocompatibility exposes the patient to life-threatening events, including haemorrhagic syndromes and thrombosis. Here, we introduce a new concept of artificial support, the Hybrid Membrane VAD, as a first-of-its-kind pump prototype enabling physiological blood propulsion through the cyclic actuation of a hyperelastic membrane, enabling the protection from the thrombogenic interaction between blood and the implant materials. The centre of the luminal membrane surface displays a rationally-developed surface topography interfering with flow to support a living endothelium. The precast cell layer survives to a range of dynamically changing pump actuating conditions i.e., actuation frequency from 1 to 4 Hz, stroke volume from 12 to 30 mL, and support duration up to 313 min, which are tested both in vitro and in vivo, ensuring the full retention of tissue integrity and connectivity under challenging conditions. In summary, the presented results constitute a proof of principle for the Hybrid Membrane VAD concept and represent the basis for its future development towards clinical validation.

show abstract

A Novel Bioreactor System for the Assessment of Endothelialization on Deformable Surfaces

Cited by 22 publications

References 59 publications

Computational fluid dynamics for enhanced tracheal bioreactor design and long-segment graft recellularization

Computational fluid dynamics for enhanced tracheal bioreactor design and long-segment graft recellularization

High-frequency operation of pulsatile ventricular assist devices: A computational study on circular and elliptically shaped pumps

A Novel Hybrid Membrane VAD as First Step Toward Hemocompatible Blood Propulsion

Contact Info

Product

Resources

About