Engineering of Fibrous Scaffolds for use in Regenerative Medicine
Author(s)
George, Julian H.S.
Type
Thesis
Abstract
Tissue engineering with fibrous scaffolds is emerging as a major research area in the field of
regenerative medicine. The major themes pursued in this thesis are the study of the cellular
response to nanofibrous constructs, the role of nanofibres in the engineering of synthetic scaffolds,
and the development of technology to facilitate the fabrication of nanofibrous scaffolds with
controlled architectures. Cells cultured on multi‐walled carbon nanotubes displayed reduced
proliferation and altered cytoskeletal development, thought to be due to the undermining of the
maturation of focal adhesions. Development of an electrospinning chamber enabled the creation of
poly(methyl methacrylate), poly(lactic acid) and poly(caprolactone) fibres for the study of cellular
response to nano‐ and macro‐fibrous scaffolds. Cell attachment and organisation on the electrospun
fibres was visualised using scanning electron microscopy, oblique microscopy and live cell
microscopy. It was found that the incorporation of nanofibres into scaffolds restricts the maturation
of focal adhesions which modulates cytoskeletal formation. This can be used to restrict the
migration and the proliferation of attachment dependant cells such as osteoblasts or maintain the
differentiation of cells such as chodrocytes. To scale up electrospun fibre production, use of rotating
collectors, multi‐jet spinning and secondary electrodes to focus the spinning were investigated.
Further to this, development of an array of focusing electrodes to control, stabilise and deflect the
jet was also investigated towards the creation of a rapid‐prototype electrospinning system. The
secondary electrode array was found to reduce the spreading of the jet to a spot diameter of 10mm
and charged deflection plates successfully redirecting the position of the jet as it arrived at the
collector.
regenerative medicine. The major themes pursued in this thesis are the study of the cellular
response to nanofibrous constructs, the role of nanofibres in the engineering of synthetic scaffolds,
and the development of technology to facilitate the fabrication of nanofibrous scaffolds with
controlled architectures. Cells cultured on multi‐walled carbon nanotubes displayed reduced
proliferation and altered cytoskeletal development, thought to be due to the undermining of the
maturation of focal adhesions. Development of an electrospinning chamber enabled the creation of
poly(methyl methacrylate), poly(lactic acid) and poly(caprolactone) fibres for the study of cellular
response to nano‐ and macro‐fibrous scaffolds. Cell attachment and organisation on the electrospun
fibres was visualised using scanning electron microscopy, oblique microscopy and live cell
microscopy. It was found that the incorporation of nanofibres into scaffolds restricts the maturation
of focal adhesions which modulates cytoskeletal formation. This can be used to restrict the
migration and the proliferation of attachment dependant cells such as osteoblasts or maintain the
differentiation of cells such as chodrocytes. To scale up electrospun fibre production, use of rotating
collectors, multi‐jet spinning and secondary electrodes to focus the spinning were investigated.
Further to this, development of an array of focusing electrodes to control, stabilise and deflect the
jet was also investigated towards the creation of a rapid‐prototype electrospinning system. The
secondary electrode array was found to reduce the spreading of the jet to a spot diameter of 10mm
and charged deflection plates successfully redirecting the position of the jet as it arrived at the
collector.
Date Issued
2009
Date Awarded
2009-10
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
Advisor
Stevens, Molly
Creator
George, Julian H.S.
Publisher Department
Materials
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)