Silk as a biomaterial Flashcards
What are silks?
Structural proteins spun into fibres for use outside the body
Fibrous proteins
Biopolymers
What is the primary protein structure of silk?
Polyamide (protein hydration and hydrogen bonding is key0
Multiscale hierachrical nano-structured (bio)polymers
100s KDa long
• Contain high proportions of Glycine and Alanine
Why is silk different to all other biological materials?
Silks are spun
Rapid manufaturing
How is silk collected?
Silk worms
Spiders
What can processing silk achieve?
1) control of hard/soft phases
2) hierarchical structuring
How is silk processed?
• Apply energy
– By pulling the dope through the spinning duct
– Causing it to flow
– Proteins absorb energy as they are stretched
– Water is stripped from the protein (water-amide H-bond)
– Proteins changes conformation
– Aggregates (amide-amide H-bond)
– Falls out of solution (dry fibre)
(evolved to be denatured)
(flow induced crystallisation)
What is rheology?
The study of flow and deformation of matter
mechanical testing for liquids and gel
What are applications of silk?
Silk fibres
- Textiles (thread for fabric is made by spinning together several fibres)
- Medical suture and implant (blood vessels composed of hardened fibre can replace diseased sections of clogged arteries)
Liquid Silk Solution
Sponges and mat (can serve as implanted scaffolds on which to rebuild tissue or bone)
Films (can contain silicon circuits and holograms or diffraction gratings that could liee just below the skin and shift color as blood oxygen changes
Fibres (can be drawn from liquid silk into optical waveguides - U-shaped strand) that could deliver light into or out of the body)
Coating and gels (flexible electrodes printed on a silk substrat can conform to the complexx furrows of a cat’s cortex and respond to electrical signals)
Why is it difficult to get full length sequence of silk?
high degree of repetition of internal structural units
Why is silk sample environment and sampling conditions important?
influence silk fibre mechanical properties
How is silk structure and function linked?
order : disorder ratio
= determines mechanical properties
What is neurotex?
peripheral nerve repair
- resorbable, biocompatible nerve conduit
What are oxford biomaterials: vascular repair?
- vascular graft from haemodialysis access
- Improved integration, resistance to puncture and patency for reduced postoperative interventions
What is Orthox?
orthopaedic implants
Treatment of meniscus and cartilage damage in the knee
Patented FibroFix™ Technology
Matches performance of natural material
