Development of a braided electrospun suture to augment tendon repairs
Tendon tears are common and often require surgical repair. However, many surgical repairs fail, despite continued advances in surgical materials and techniques. Rotator cuff surgery, the clinical focus of this thesis, has particularly poor outcomes. Repair failure can be partially attributed to the...
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| Other Authors: | |
| Format: | Thesis |
| Language: | English |
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2019
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| _version_ | 1826316401156030464 |
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| author | Abhari, RE |
| author2 | Snelling, S |
| author_facet | Snelling, S Abhari, RE |
| author_sort | Abhari, RE |
| collection | OXFORD |
| description | Tendon tears are common and often require surgical repair. However, many surgical repairs fail, despite continued advances in surgical materials and techniques. Rotator cuff surgery, the clinical focus of this thesis, has particularly poor outcomes. Repair failure can be partially attributed to the inappropriate repurposing of sutures from use in other tissues, which fail to integrate with the specialised tendon tissue.
The overall aim of this study was to develop a novel polydioxanone suture that has the potential to provide both biological and mechanical support to torn tendons. It is hypothesized that electrospun submicron fibres, which mimic native tendon extra-cellular matrix (ECM), can provide biological support to tendon. Meanwhile, larger and more robust melt-extruded microscale fibres can mechanically support surgical tendon repair. It is further hypothesized that a suture containing both electrospun and extruded fibres will overcome structural limitations associated with electrospun-only sutures, while still providing biological improvements over current sutures.
This thesis describes a process to fabricate and evaluate translatable suture biomaterials deliberately designed for tendon, by engineering materials on the fibre, filament, and multifilament level. On the fibre level, annealing enables tailoring of the degradation rate of electrospun fibres, which could allow for biomaterial degradation kinetics to match new tissue deposition. On the filament level, melt-extruded materials had superior strength and stiffness to support surgical repair. Electrospun filaments had a higher surface area, porosity, and faster degradation rate, making them more suitable as biological support. On the multifilament level, industrial braiding enabled further control over suture size, porosity, and mechanical properties by altering braiding design and component ratios.
A hybrid braided suture with an electrospun sheath and melt-extruded cores was designed to meet the demands of tendon: electrospun fibres on the outside approximate ECM and will be in contact with the biological milieu, while the melt-extruded fibres in the core provide prolonged mechanical support. The hybrid suture had a similar size and tensile strength to currently used sutures, but was less stiff and more porous. It induced differential serum protein binding and promoted more favourable tendon fibroblast attachment and proliferation, when compared to currently used sutures.
This novel hybrid suture has potential to improve current treatment options for tendon repair. Future work should investigate its local surface properties, followed by a dynamic culture and in vivo study, to bring the device to the standard needed for pre-clinical and clinical trials. The design process and pipeline of characterisation methods developed in this thesis could be applicable and adaptable to biomaterials for other soft tissues in need of improved treatments. |
| first_indexed | 2024-03-07T08:18:25Z |
| format | Thesis |
| id | oxford-uuid:3df9a2c6-84a2-4658-b052-b30c3932e6af |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-12-09T03:44:29Z |
| publishDate | 2019 |
| record_format | dspace |
| spelling | oxford-uuid:3df9a2c6-84a2-4658-b052-b30c3932e6af2024-12-07T15:57:23ZDevelopment of a braided electrospun suture to augment tendon repairsThesishttp://purl.org/coar/resource_type/c_db06uuid:3df9a2c6-84a2-4658-b052-b30c3932e6afEnglishHyrax Deposit2019Abhari, RESnelling, SMouthuy, PCarr, AStride, ETendon tears are common and often require surgical repair. However, many surgical repairs fail, despite continued advances in surgical materials and techniques. Rotator cuff surgery, the clinical focus of this thesis, has particularly poor outcomes. Repair failure can be partially attributed to the inappropriate repurposing of sutures from use in other tissues, which fail to integrate with the specialised tendon tissue. The overall aim of this study was to develop a novel polydioxanone suture that has the potential to provide both biological and mechanical support to torn tendons. It is hypothesized that electrospun submicron fibres, which mimic native tendon extra-cellular matrix (ECM), can provide biological support to tendon. Meanwhile, larger and more robust melt-extruded microscale fibres can mechanically support surgical tendon repair. It is further hypothesized that a suture containing both electrospun and extruded fibres will overcome structural limitations associated with electrospun-only sutures, while still providing biological improvements over current sutures. This thesis describes a process to fabricate and evaluate translatable suture biomaterials deliberately designed for tendon, by engineering materials on the fibre, filament, and multifilament level. On the fibre level, annealing enables tailoring of the degradation rate of electrospun fibres, which could allow for biomaterial degradation kinetics to match new tissue deposition. On the filament level, melt-extruded materials had superior strength and stiffness to support surgical repair. Electrospun filaments had a higher surface area, porosity, and faster degradation rate, making them more suitable as biological support. On the multifilament level, industrial braiding enabled further control over suture size, porosity, and mechanical properties by altering braiding design and component ratios. A hybrid braided suture with an electrospun sheath and melt-extruded cores was designed to meet the demands of tendon: electrospun fibres on the outside approximate ECM and will be in contact with the biological milieu, while the melt-extruded fibres in the core provide prolonged mechanical support. The hybrid suture had a similar size and tensile strength to currently used sutures, but was less stiff and more porous. It induced differential serum protein binding and promoted more favourable tendon fibroblast attachment and proliferation, when compared to currently used sutures. This novel hybrid suture has potential to improve current treatment options for tendon repair. Future work should investigate its local surface properties, followed by a dynamic culture and in vivo study, to bring the device to the standard needed for pre-clinical and clinical trials. The design process and pipeline of characterisation methods developed in this thesis could be applicable and adaptable to biomaterials for other soft tissues in need of improved treatments. |
| spellingShingle | Abhari, RE Development of a braided electrospun suture to augment tendon repairs |
| title | Development of a braided electrospun suture to augment tendon repairs |
| title_full | Development of a braided electrospun suture to augment tendon repairs |
| title_fullStr | Development of a braided electrospun suture to augment tendon repairs |
| title_full_unstemmed | Development of a braided electrospun suture to augment tendon repairs |
| title_short | Development of a braided electrospun suture to augment tendon repairs |
| title_sort | development of a braided electrospun suture to augment tendon repairs |
| work_keys_str_mv | AT abharire developmentofabraidedelectrospunsuturetoaugmenttendonrepairs |