Dods, SR;
(2016)
Characterising electrospun nanofibre adsorbents for bioprocessing.
Doctoral thesis (PhD), UCL (University College London).
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Abstract
Biopharmaceutical manufacturing is one of largest sectors in the world and purification steps are expensive. Packed-bed resins are widely used, but are limited by diffusion mass transfer. Convective mass transfer media offer improved productivities using high flowrates. Electrospun nanofibres are a non-woven with an open structure and high surface area. Cellulose acetate was electrospun into reproducible adsorbents and activation methodologies were evaluated. Aldehyde activation caused degradation. Epoxy, carboxyl and cyanuric chloride activations were successful and recommended for cellulose nanofibres. Compressing cellulose acetate nanofibres improved mechanical strength. Functionalisation to diethylaminoethyl and carboxyl adsorbents showed the highest DBC10% values at the lowest compression load of 1 MPa at 20 and 27 mg /mL, respectively. However, at this load the DBC decreased for increasing flowrate, whereas, the DBCs of higher loads were consistent. Glucose isomerase is an important industrial enzyme used as a sweetener in the drinks industry. Immobilised glucose isomerase by epoxy activation showed similar initial activities in static and dynamic assays, which represented batch and flowthrough process, respectively. The activity of free enzyme was notably higher in the static assay than the immobilised, but the poorer mixing in the dynamic assay reduced its activity. The retained activity of nanofibre-immobilised glucose isomerase in the dynamic assay supports its application to flowthrough reactors. Protein A chromatography is an expensive stage in antibody manufacture and was immobilised by cyanuric chloride and spacer arms. For comparison, an aldehyde activation was developed with glycidol modification, which was preferred to that of cyanuric chloride, recording equilibrium and DBC10% capacities of 4.37 and 2.99 mg/mL, respectively. The versatility of electrospun cellulose adsorbents are characterised in protein binding and biocatalysis applications, showing static and dynamic operations. The continued development of nanofibres into largescale systems and a whole process context will reveal their full benefits to bioprocessing.
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | PhD |
| Title: | Characterising electrospun nanofibre adsorbents for bioprocessing |
| Event: | UCL (University College London) |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1474544 |
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