WP1. Electroactive 3D porous scaffold engineering.
The first step was the establishment of the 3D matrices. Two strategies were followed to prepared conducting polymers to be used as polymer matrixes. Firstly, dispersions of poly(3,4-ethylenedioxythiophene) PEDOT:hyaluronic acid and collagen type I were prepared (in collaboration with Prof. Mecerreyes, Polymat 1.5 month secondment) and secondly, a blend composed of the conducting polymer PEDOT:polystyrene sulfonate (PEDOT:PSS) and hyaluronic acid, collagen type I and laminin. The addition of these biopolymers determine the mechanical properties of the scaffold. HA and Collagen type I were selected because they represent the biological component of the interstitium. The 3D scaffolds mimicking the interstitium were prepared by lyophilisation and characterised for their mechanical and electrical properties.
Moreover, the possibility of enhancing cell migration and proliferation was assessed by developing anisotropic scaffolds in collaboration with Prof. Ruth Cameron from Materials Science and Metallurgy Department in University of Cambridge.
Sw480 adenocarcinoma cancer cells and neuroblastoma derived SHY-5Y cells were used to assess both scaffolds cytocompatibility and their ability to influence cell proliferation and in the case of the neuronal cells, differentiation. Results are summarised in three manuscripts in preparation.
WP2. OECT fabrication, monitoring of cell migration and proliferation, and biomarker detection.
Organic electronic electrodes (instead of organic electrochemical transistors) were developed, for the capture and release of cancer cells. The capture and release process was used as a way of pre-concentrating cells and monitor the process both electrically and optically. For this PEDOT:PSS was blended with N-isopropylacrylamide polymer (pNIPAAm) to create PEDOT:PSS/pNIPAAm copolymers. Thanks to the inherent capacity of pNIPAAm to shrink above its lower critical solution temperature (>32 C), the polymer can undergo a conformational change and release cells. For the capture of cells, the copolymer was functionalized with fibronectin protein.
The results have been published in Biosensors and Bioelectronics. A PhD student at the group is currently applying this technology in clinical samples and two more publications are expected in future.
WP3. Integration of the 3D scaffold and the OECTs inside microfluidics to generate the Interstitium-on-a-Chip.
Electrodes were generated in cyclic olefin polymer (COP) as substrate and integrated into a microfluidic device to generate the interstitium-on-a-chip. The electrodes were fabricated by depositing gold onto the COP and integrating a slice of PEDOT:PSS scaffolds. The electrodes were closed by using a pressure sensitive adhesive (PSA). Sw480 cells and sw480 Tag RFP transfected cells were seeded dynamically and flow rates and time was optimised. Cell migration and proliferation both electrically and optically was assessed. Parts of this work was performed in collaboration with Dr. Fairen-Jimenez from University of Cambridge.
The results will be published in a manuscript in preparation and a conference paper has been submitted.
