Armourers and Brasiers Company Prepared by Dr Diane Aston, IOM3

Armourers and Brasiers Company Materials around us Prepared by Dr Diane Aston, IOM3

Armourers and Brasiers Company The aim of this module is to introduce you to three areas in which discoveries and developments in materials have helped to improve our technology in three key areas: Turbofan engines for civil aircraft Biomedical materials Sports equipment This builds on Module 1 in that these advances have been made by understanding the links between processing, structure and properties. Prepared by Dr Diane Aston, IOM3

Armourers and Brasiers Company Prepared by Dr Diane Aston, IOM3

Armourers and Brasiers Company The session aims to introduce the field of biomaterials and demonstrate how materials experts and clinicians are working together to repair and replace parts of the body At the end of this session you should be able to: Identify the key requirements of a material for it to be biocompatible; List a range of materials that can be used to replace body parts and give examples of where they are used. Describe the key properties of a full hip replacement, vascular graft and intraocular lens; Suggest ways in which biomaterials may help to improve our quality of life in the future. Prepared by Dr Diane Aston, IOM3

Armourers and Brasiers Company Biomaterials is a field which is continuing to expand. Scientists, engineers, surgeons and clinicians work together to develop ways of repairing and replacing broken or worn out body parts. As people live to older ages and want to retain the same quality of life worn bits need replacing. We sometimes need to repair damaged or broken body parts following disease or accident. Prepared by Dr Diane Aston, IOM3

Armourers and Brasiers Company Biomaterials are a small and special group of metals, polymers, ceramics and composites that are safe to use alongside and inside the human body. Biomaterials must fulfil a range of criteria: Similar mechanical properties to the tissue it is replacing in terms of strength, stiffness and fatigue resistance. Similar values of electrical and thermal conductivity to the tissue it is replacing. Not allow unwanted diffusion between the implant and surrounding tissue. Not absorb water from the surrounding tissue. Stable within the environment of the human body so it does not react chemically with surrounding tissues or fluids. Compatible with the surrounding tissue, that is it should not be toxic or rejected by human tissues. Prepared by Dr Diane Aston, IOM3

Armourers and Brasiers Company MaterialUses GoldDental devices (fillings, on-lays, crown bases) Surgical steel (steel containing, 12-20%Cr, 8- 12%Ni and 0.2-3%Mo Surgical tools, orthopaedic devices (including joint replacements, bone plates and fixation screws), stents, surgical sutures and staples Titanium and Ti-6Al-4V alloyOrthopaedic and dental devices, surgical staples Cobalt chromium alloy (Co / 17-30% Cr / 5-7%Mo Orthopaedic devices (particularly useful in patients with nickel sensitivity) NitinolStents, bone plates and dental devices Prepared by Dr Diane Aston, IOM3

Armourers and Brasiers Company MaterialUses SiliconeCatheters, tubing, reconstruction implants DacronVascular grafts (artificial arteries), sutures PMMAIntraocular lenses and bone cement PolyurethaneCatheters, pacemaker leads Nylon Total joint replacement bearing surfaces (artificial cartilage), sutures UHMWPE Total joint replacement bearing surfaces (artificial cartilage), HydrogelsDrug delivery, ophthalmic devices Cyanoacrylate adhesives Liquid sutures used to glue edges of a wound together SilkAbsorbable sutures Prepared by Dr Diane Aston, IOM3

Armourers and Brasiers Company MaterialUses AluminaOrthopaedic and dental devices PorcelainDental devices HydroxyapatiteCoatings for orthopaedic devices Prepared by Dr Diane Aston, IOM3

Armourers and Brasiers Company Prepared by Dr Diane Aston, IOM3 Artificial hips have changed since their introduction. Surgical steel and nylon have been replaced by UHMWPE and other alloys, including titanium. Ceramic coatings can be used instead of bone cement. Full hip replacements now have a predicted design life of over 20 years.

Armourers and Brasiers Company Prepared by Dr Diane Aston, IOM3 Vascaular grafts can be sewn in or inserted into a blood vessel to provide reinforcement or repair. Made from woven or knitted polyester fabric. Can be up to 2cm in diameter and 20cm long

Armourers and Brasiers Company Prepared by Dr Diane Aston, IOM3 Used to replace the lens at the front of the eye of cataract patients. The procedure is carried out as an outpatients and takes around an hour. The new lens is inserted into eye through a small incision after the natural lens and cataract tissue have been removed. Replacement intraocular lenses are made from PMMA.

Armourers and Brasiers Company Prepared by Dr Diane Aston, IOM3 Prosthetic limbs Carbon fibre composites, lightweight alloys and polymer foams are used to create prostheses that look and behave like the limbs they are replacing. Modern prosthetic limbs incorporate electronics and are designed with increased functionality. Eventually artificial limbs may use the impulses from severed nerve endings to function. Tissue engineering Use of man-made materials as a scaffold on which to grown natural tissues. Man-made scaffold, such as PLA, PCL PGA, dissolves over time. Possible to grow simply structure such as skin, vascular grafts and bladders. More complex organs may be possible in the future.

Armourers and Brasiers Company There is no doubt that as we continue to strive to live longer, healthier lives materials will play in increasingly important role. We will continue to improve the technology, techniques and materials used for existing body part surgery. We will continue to develop increasingly functional prosthetic limbs. We will use tissue engineering to be able to grow new body parts from natural tissues. Materials Scientists will working hand in hand with specialists from other disciplines to develop these life changing solutions. Prepared by Dr Diane Aston, IOM3

Armourers and Brasiers Company Prepared by Dr Diane Aston, IOM3 Investigating implants! Discussion on biomaterials and where they might go.

Armourers and Brasiers Company Prepared by Dr Diane Aston, IOM3

Armourers and Brasiers Company Prepared by Dr Diane Aston, IOM3 If time permits it would be great to have a go at both of these activities. However if you only have time for one we recommend you have a go at the first activity. Investigating implants Discussion on biomaterials and where they might go.

Armourers and Brasiers Company Ask the students to use the internet to investigate a particular area in which biomaterials are used. They should then write a short article (around 1000 words) on their chosen topic at a level suitable for the general public to read. Topics could include: Knee replacements The use of silicone in facial reconstruction Carbon fibre tendons Shape memory alloys for artificial muscles Stents for heart surgery Materials in dentistry Materials for drug delivery The articles should be included in the students’ portfolios and the top 6 articles will be published in the IOM3 Schools Affiliate Scheme newsletter. Prepared by Dr Diane Aston, IOM3

Armourers and Brasiers Company The idea of this activity is to get the students thinking and discussing the pros and cons, advantages and disadvantages of using materials to improve quality of life and potentially prolong life Split the group in to two teams and get them to do some research on your chosen topic. This could be any of the areas outlined in this session or mentioned for activity one. Conduct a debate between the two groups and get them to come to a group consensus on their chosen issue. Each individual should write up their research, their own argument and a summary of the debate for their portfolio. Prepared by Dr Diane Aston, IOM3

Armourers and Brasiers Company There are many excellent website around that describe various types of surgery in great detail for patients. These include: For details of how the surgery is performed: replacement/Pages/Introduction.aspxwww.nhs.uk/conditions/Hip- replacement/Pages/Introduction.aspx For the anatomy of the hip joint: pain/hip-anatomy.phphttp:// pain/hip-anatomy.php For full details of hip replacement surgery For details on vascular grafts: home.htm?tutorials/graft.htm~right, and home.htm?tutorials/graft.htm~righthttp:// For details of intraocular lenses: and For details on prosthetic limbs: and For details on tissue engineering: and Prepared by Dr Diane Aston, IOM3