Geometry optimization of a fibrous scaffold based on mathematical modelling and CFD simulation of a dynamic cell culture

In recent years, there has been a move away from the use of static in vitro two-dimensional cell culture models for testing the chemical safety and efficacy of drugs. Such models are increasingly being replaced by more physiologically relevant cell culture systems featuring dynamic flow and/or three-dimensional structures of cells. While it is acknowledged that such systems provide a more realistic environment within which to test drugs, progress is being hindered by a lack of understanding of the physical and chemical environment that the cells are exposed to. Mathematical and computational modelling may be exploited in this regard to unravel the dependency of the cell response on spatio-temporal differences in chemical and mechanical cues, thereby assisting with the understanding and design of these systems. In this paper, we present a mathematical modelling framework that characterizes the fluid flow and solute transport in perfusion bioreactors featuring an inlet and an outlet. To demonstrate the utility of our model, we simulated the fluid dynamics and solute concentration profiles for a variety of different flow rates, inlet solute concentrations and cell types within a specific commercial bioreactor chamber. Our subsequent analysis has elucidated the basic relationship between inlet flow rate and cell surface flow speed, shear stress and solute concentrations, allowing us to derive simple but useful relationships that enable prediction of the behaviour of the system under a variety of experimental conditions, prior to experimentation. We describe how the model may used by experimentalists to define operating parameters for their particular perfusion cell culture systems and highlight some operating conditions that should be avoided. Finally, we critically comment on the limitations of mathematical and computational modelling in this field, and the challenges associated with the adoption of such methods.

Download Full-text

Development of an Arbitrary Waveform Membrane Stretcher for Dynamic Cell Culture

Annals of Biomedical Engineering ◽

10.1007/s10439-014-0976-x ◽

2014 ◽

Vol 42 (5) ◽

pp. 1062-1073 ◽

Cited By ~ 9

Author(s):

Jason J. Lau ◽

Raymond M. Wang ◽

Lauren D. Black

Keyword(s):

Cell Culture ◽

Dynamic Cell ◽

Arbitrary Waveform

Download Full-text

4D hydrogel for dynamic cell culture with orthogonal, wavelength-dependent mechanical and biochemical cues

Materials Horizons ◽

10.1039/c9mh00665f ◽

2020 ◽

Vol 7 (1) ◽

pp. 111-116 ◽

Cited By ~ 8

Author(s):

Yijun Zheng ◽

Mitchell Kim Liong Han ◽

Qiyang Jiang ◽

Bin Li ◽

Jun Feng ◽

...

Keyword(s):

Cell Culture ◽

Cellular Environment ◽

Dynamic Cell

A 4D hydrogel allows user-defined stiffening of the cellular environment and presentation of bioadhesive cues in an orthogonal manner using light of different wavelengths.

Download Full-text

A Continuous, Semi-Automated Workflow: From 3D City Models with Geometric Optimization and CFD Simulations to Visualization of Wind in an Urban Environment

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi9110657 ◽

2020 ◽

Vol 9 (11) ◽

pp. 657

Author(s):

Martina E. Deininger ◽

Maximilian von der Grün ◽

Raul Piepereit ◽

Sven Schneider ◽

Thunyathep Santhanavanich ◽

...

Keyword(s):

Cfd Simulation ◽

Smart Cities ◽

Geometry Optimization ◽

Simulation Models ◽

Geometric Optimization ◽

Strong Impact ◽

Time Saving ◽

Web Based ◽

Important Approach ◽

Model Preparation

The concept and implementation of Smart Cities is an important approach to improve decision making as well as quality of life of the growing urban population. An essential part of this is the presentation of data from different sources within a digital city model. Wind flow at building scale has a strong impact on many health and energy issues in a city. For the analysis of urban wind, Computational Fluid Dynamics (CFD) has become an established tool, but requires specialist knowledge to prepare the geometric input during a time-consuming process. Results are available only as predefined selections of pictures or videos. In this article, a continuous, semi-automated workflow is presented, which ❶ speeds-up the preparation of CFD simulation models using a largely automated geometry optimization; and ❷ enables web-based interactive exploration of urban wind simulations to a large and diverse audience, including experts and layman. Results are evaluated based on a case study using a part of a district in Stuttgart in terms of: ➀ time saving of the CFD model preparation workflow (85% faster than the manual method), ➁ response time measurements of different data formats within the Smart City platform (3D Tiles loaded 30% faster than geoJSON using the same data representations) and ➂ protocols (3DPS provided much higher flexibility than static and 3D container API), as well as ➃ subjective user experience analysis of various visualization schemes of urban wind. Time saving for the model optimization may, however, vary depending on the data quality and the extent of the study area.

Download Full-text

Enhancement of Virus Infection Using Dynamic Cell Culture in a Microchannel

Micromachines ◽

10.3390/mi9100482 ◽

2018 ◽

Vol 9 (10) ◽

pp. 482

Author(s):

Jeong Kim ◽

Hye Choi ◽

Chul Kim ◽

Hee Jin ◽

Jae-sung Bae ◽

...

Keyword(s):

Cell Culture ◽

Virus Infection ◽

Soft Lithography ◽

Fluorescent Protein ◽

Microfluidic Devices ◽

Petri Dish ◽

Culture Method ◽

Dynamic Culture ◽

Conventional Culture ◽

Dynamic Cell

With increasing interest in induced pluripotent stem cells (iPSCs) in the field of stem cell research, highly efficient infection of somatic cells with virus factors is gaining importance. This paper presents a method of employing microfluidic devices for dynamic cell culture and virus infection in a microchannel. The closed space in the microchannel provided a better environment for viruses to diffuse and contact cell surfaces to infect cells. The microfluidic devices were fabricated by photolithography and soft lithography. NIH/3T3 fibroblast cells were cultured in the microfluidic device in static and dynamic conditions and compared with the conventional culture method of using Petri dishes. Virus infection was evaluated using an enhanced green fluorescent protein virus as a model. Dynamic culture in the microchannel showed similar growth of cells to that in Petri dish culture, but the virus infection efficiency was four-times higher. The proposed dynamic culture system could be useful in iPSC research by providing efficient virus infection tools.

Download Full-text

Laser microstructured scaffolds for tissue engineering under dynamic cell culture conditions

10.12681/eadd/48433 ◽

2020 ◽

Author(s):

Ελευθερία Μπαμπαλιάρη

Keyword(s):

Tissue Engineering ◽

Cell Culture ◽

Culture Conditions ◽

Dynamic Cell ◽

Cell Culture Conditions

Παρόλο που το περιφερικό νευρικό σύστημα εμφανίζει υψηλότερο ρυθμό αναγέννησης από εκείνο του κεντρικού νευρικού συστήματος μέσω αυθόρμητης αναγέννησης μετά από έναν τραυματισμό, η καθοδηγούμενη αξονική νευρική αναγέννηση και η λειτουργική αποκατάσταση είναι αρκετά σπάνια. Συνεπώς, η ανάπτυξη επιτυχημένων μεθόδων για την καθοδήγηση της νευρικής ανάπτυξης, «in vitro», είναι υψίστης σημασίας. Έχει αναφερθεί λεπτομερώς ότι η τοπογραφία του υποστρώματος επηρεάζει την ανάπτυξη, τον προσανατολισμό και τη διαφοροποίηση των νευρικών κυττάρων. Ωστόσο, η συνδυασμένη δράση της διατμητικής τάσης και της τοπογραφίας του υποστρώματος στην νευρική ανάπτυξη έχει ελάχιστα μελετηθεί, παρόλο που οι διατμητικές τάσεις είναι ευρέως γνωστό ότι διαδραματίζουν καθοριστικό ρόλο στην οργάνωση, ανάπτυξη και λειτουργία των ιστών. Σε αυτή τη μελέτη, ένα σύστημα μικροροών ακριβούς ελεγχόμενης ροής με συγκεκριμένους ειδικά σχεδιασμένους θαλάμους, που ενσωματώνουν μικροδομημένα υποστρώματα λέιζερ, αναπτύχθηκε για να μελετηθεί η συνδυασμένη δράση της διατμητικής τάσης και της τοπογραφίας υποστρώματος στην ανάπτυξη, στον προσανατολισμό, στην επιμήκυνση και στη διαφοροποίηση νευρικών κυττάρων. Πολυμερικά μικροδομημένα υποστρώματα, με ελεγχόμενη γεωμετρία και κανονικότητα μοτίβου, κατασκευάστηκαν με χρήση υπερβραχέων παλμών λέιζερ. Πραγματοποιήθηκε συγκριτική μελέτη μεταξύ στατικών και δυναμικών κυτταρικών καλλιεργειών για να αξιολογηθεί η συνεργατική ή ανταγωνιστική επίδραση της διατμητικής τάσης και της τοπογραφίας στη συμπεριφορά των νευρικών κυττάρων. Τα αποτελέσματα της κυτταρικής καλλιέργειας συμπληρώθηκαν με υπολογιστικές προσομοιώσεις ροής με σκοπό τον ακριβή υπολογισμό των αντίστοιχων τιμών διατμητικής τάσης.

Download Full-text