Microfluidic construction and operation of artificial cell chassis encapsulating living cells and pharmaceutical compounds towards their controlled interaction

Dimitriou, Pantelitsa 2023. Microfluidic construction and operation of artificial cell chassis encapsulating living cells and pharmaceutical compounds towards their controlled interaction. PhD Thesis, Cardiff University. Item availability restricted.

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Abstract

Droplet-based microfluidic devices can generate complex, soft-matter emulsion systems towards drug screening applications and artificial cell membrane studies. This thesis investigates a methodology for the eventual ‘programmed’ release of pharmaceuticals to treat breast cancer cells that are encapsulated and cultured within small diameter (<2 mm), artificial cell chassis hydrogel capsules. A pharmaceutical analogue was compartmentalised within smaller, membrane-bound, inner cores, that are arranged inside the overall hydrogel capsule. The membrane was based upon droplet interface bilayers (DIBs), which are widely employed for the study of artificial cell membrane transport properties. The whole capsule and contents were produced using enclosed 3D-printed multi-material, microfluidic devices. Methods to control the (programmed) release of compounds from the inner cores to the hydrogel shell, were investigated. The application-specific study was used as an exemplar for a more generally applicable model system. Monolithic microfluidic devices were fabricated using 3D printing and filaments of cyclic olefin copolymer (COC) and nylon for the production of single, double and triple emulsions. With these devices, monodispersed single-emulsion microgels suitable for cell encapsulation were produced, whilst dual-junction devices generated double-emulsion capsules with a controlled number of oil cores. Multi-junction devices also produced triple emulsion, encapsulated droplet interface bilayers (eDIBs), which were subsequently monitored and characterised. Additionally, to demonstrate the ability of eDIBs to act as programmed pharmaceutical delivery systems, assays were performed to induce core release, using membrane modulation by lysolipids (LPC). Computational simulations and DIB electrophysiology experiments were performed to investigate the effect of LPC on the system. MCF-7 model breast cancer cells were encapsulated in alginate-collagen emulsion capsules and their viability was assessed. Moreover, multicellular tumour spheroids (MCTSs) in oil core microgels showed no response to tested doxorubicin concentrations, while proliferated at certain LPC concentrations. Encapsulated cells in eDIBs formed tumour spheroids, however, the DIB survival was low. The integration of living cells and artificial cell membranes within a single entity presents a hybrid model for studying their interaction, towards applications in synthetic biology and drug delivery/screening.

Item Type:	Thesis (PhD)
Date Type:	Completion
Status:	Unpublished
Schools:	Engineering
Uncontrolled Keywords:	1) 3D printing 2) Droplet Microfluidics 3) artificial cells 4) droplet interface bilayers 5) Phospholipid membranes 6) Cancer cells
Date of First Compliant Deposit:	25 July 2023
Last Modified:	26 Jul 2023 09:41
URI:	https://orca.cardiff.ac.uk/id/eprint/161260

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