What are the Bio-Materials within the Medical Feild?

Bio-Materials are consistently being used within the medical field and researchers are developing these materials further in order to develop there uses within the  body. Bio-materials can be used in a living creatures body, taking in account of there biocompatibility. I am going to write about the different bio-materials which are used in medical industries in conjunction to my second lecture where i was briefly enlightened on some of the materials used.

“Before using biomaterials, it should in mind that, which categories they are belongs and main focuses are on biocompatibility, bioinert, bioactive/surface reactive, biodegradable, sterilizability, adequate mechanical and physical properties, manufacturability, low weight, reasonable cost etc. It is necessary to classify biomaterials for there suitable use in medical industries.” – Classification of Biomaterials used in Medicine | Parida | International Journal of Advances in Applied Sciences. 2014. Classification of Biomaterials used in Medicine | Parida | International Journal of Advances in Applied Sciences. [ONLINE] Available at:http://www.iaesjournal.com/online/index.php/IJAAS/article/view/882/751. [Accessed 16 November 2014].

The performance of bio-materials can work in the body and be classified in many ways. Bio-materials are used to replace a body part/function that is no longer working. This is done in a safe reliable way that is also economic and psychologically acceptable.

Bio-materials has been defined as a synthetic material which has been formally defined by the Clemson University Advisory Board for Biomaterials stating that “a systemically and pharmacologically inert substance designed for implantation within or incorporation with living systems” – Wong Y, J (2013). Biomaterials: Principles and Practices . Florida: CRC Press. 159.


History

‘Bone plates were introduced in the early 1900s to aid  in the fixation of long bone fractures. Many of these early plates broke as a result of unsophisticated mechanical design; they were too thin and had stress concentrating corners. Also, materials such as vanadium steel, which was chosen for its good mechanical properties, corroded rapidly in the body and caused adverse effects on the healing processes. Better designs and materials soon followed. Following the introduction of stainless steels and cobalt chromium alloys in the 1930s, greater success was achieved in fracture fixation, and the first joint replacement surgeries were performed. As for polymers, it was found that warplane pilots inWorld War II who were injured by fragments of plastic (polymethyl methacrylate) aircraft canopy did not suffer adverse chronic reactions from the presence of the fragments in the body. Polymethyl methacrylate became widely used after that time for corneal replacement and for replacements of sections of damaged skull bones. Following further advances in materials and in surgical technique, blood vessel replacements were tried in the 1950s and heart valve replacements and cemented joint replacements in the 1960s. Recent years have seen many further advances’ – Classification of Biomaterials used in Medicine | Parida | International Journal of Advances in Applied Sciences. 2014. Classification of Biomaterials used in Medicine | Parida | International Journal of Advances in Applied Sciences. [ONLINE] Available at:http://www.iaesjournal.com/online/index.php/IJAAS/article/view/882/751. [Accessed 16 November 2014].

Vanadium Steel

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Kingsley, H, (2001), Image No. 1655 [ONLINE]. Available at:http://www.bcmamedicalmuseum.org/object/993.659.1 [Accessed 16 November 14].

Due to failures in bio-compatibility vanadium steel was not suitable for a replacement of bone plates as it eroded within the body and caused further injury and medical problems.

In addition due to advances in bio-medical knowledge stainless steel implants are also rarely used in craniofacial (relating to the cranium and the face eg: craniofacial surgery) indications today.

Polymethyl Methacrylate (PMM)

dental-temporary-dentures-bridge-pmma-nano-compositeUnknown, (2011), Unknown [ONLINE]. Available at:http://www.datron.de/fileadmin/content/pictures/content/dental/indications/temporary-dentures/dental-temporary-dentures-bridge-pmma-nano-composite.jpg [Accessed 16 November 14].

‘Polymethylmethacrylate remains one of the most enduring materials in orthopaedic surgery. It has a central role in the success of total joint replacement and is also used in newer techniques such as percutaneous vertebroplasty and kyphoplasty.’ – The role of polymethylmethacrylate bone cement in modern orthopaedic surgery. J C J, Webb. The Bone and Joint Journal. [Online]. Available at:http://www.bjj.boneandjoint.org.uk/content/89-B/7/851.full. [Accessed 16 Novemember 2014]. 


Metallic Biomaterials

Medical_Alloys__Biometals__Metallic_Biomaterials_2 – Tiger International, (2005), Titanium,Nitinol,Cobalt-Chromium,and Stainless Steel for medical implant applications. [ONLINE]. Available at:http://www.bridgat.com/medical_alloys_biometals_metallic_biomaterials-o182318.html [Accessed 16 November 14].

  • Vanadium Steel (as described further above) – used to manufacture bone fracture plates (Sherman plates) and screws.
  • Iron
  • chromium
  • cobalt
  • nickel
  • titanium
  • tantalum
  • niobium
  • molybdenum
  • tungsten

These Metallic Bio-Materials were used to make alloys for manufacturing implants that can only be tolerated by the body in minute amounts. The biocompatibility of the metallic implant is of considerable concern because these implants can corrode. The consequences of corrosion are the disintegration of the implant material, which will weaken the implant, and the harmful effect of corrosion products on the surrounding tissues and organs causing further injury to the body.

Ceramic BioMaterials

Dr Larry Hench was born on 21 November 1938 in Shelby, Ohio and graduated from The Ohio State University in 1961 and 1964 with BS and PhD degrees in Ceramic Engineering. In 1969 Hench discovered BioGlass that bond to living bone.

g – Unknown, (1996), Prof. Larry Hench [ONLINE]. Available at:https://www.imperial.ac.uk/publications/reporterarchive/0029/science.htm [Accessed 16 November 14].

In 1969 Hench was seated next to a colonel who had just returned from the Vietnam War. The colonel shared that after an injury the bodies of soldiers would often reject the implant. the Vietnam war in 1969. This intrigued Hench which made him further investigate materials that are biocompatible with the human body. This led to the discovery and invention of Bioglass. This work inspired a new field called bioceramics. 

1280px-Hip_prosthesis – Nogueira, N. (2006), A titanium hip prosthesis, with a ceramic head and polyethylene acetabular cup[ONLINE]. Available at: http://commons.wikimedia.org/wiki/File:Hip_prosthesis.jpg [Accessed 16 November 14].

Ceramic Biomaterials Consist of:

  • Oxide ceramics
  • Silica ceramics
  • Carbon fiber
  • Diamond-like carbon
  • tricalcium phosphate
  • Hydroxylapatite
  • Bioglass

Ceramic Biomaterials within the medical field are commonly used for dental and bone implants. Artificial teeth, and bones are also commonly made of ceramic biomaterials. Surgical cermets are used regularly. Joint replacements are commonly coated with ceramic Biomaterials to reduce wear and inflammatory response.

Polymeric Biomaterials

fig3 (1) – Unknown, (2009), unknown [ONLINE]. Available at: http://www.tms.org/pubs/journals/jom/0909/pruitt-0909.html [Accessed 16 November 14].

‘Medical polymers are used in a broad range of applications including tissue repair and replacement, drug delivery, and wound healing.1 Polymers are capable of a wide range of structural properties that depend on backbone structure, molecular weight, entanglement density, degree of crystallinity, and degree of crosslinking. In general, polymers exhibit time-dependent mechanical behavior and are known to be viscoelastic. For example, the elastic modulus and yield strength of a polymer generally increases with increasing strain rate while the strain to failure typically decreases with increased loading rates.’ – Polymeric Biomaterials for Load-bearing Medical Devices. 2014. Polymeric Biomaterials for Load-bearing Medical Devices. [ONLINE] Available at:http://www.tms.org/pubs/journals/jom/0909/pruitt-0909.html. [Accessed 16 November 2014].

  • Polyvinylchloride – Blood and solution bag, surgical packaging, IV sets, dialysis
    devices,catheter bottles, connectors, and cannulae
  • Polyethylene – Pharmaceutical bottle, nonwoven fabric, catheter, pouch, flexible
    container, and orthopedic implants
  • Polypropylene – Disposable syringes, blood oxygenator membrane, suture,
    nonwoven fabric, and artificial vascular grafts
  • Polymethylmetacrylate – Blood pump and reservoirs, membrane for blood dialyzer,
    implantable ocular lens, and bone cement
  • Polystyrene – Tissue culture flasks, roller bottles, and filterwares
  • Polyethylenterephthalate – Implantable suture, mesh, artificial vascular grafts, and heart valve
  • Polytetrafluoroethylene – Catheter and artificial vascular grafts
  • Polyamide – Packaging film, catheters, sutures, and mold parts

Biodegradable Polymeric Biomaterial 

Why would a medical practitioner want a material to degrade?

  • Can be used as an implant and will not require a second surgical intervention for removal.
  • Using a Stainless Steel has a tendency for refracture upon removal of the implant. Because the stress is borne by the rigid stainless steel, the bone has not been able to carry sufficient load during the healing process.
  • However, an implant prepared from biodegradable polymer can be engineered to degrade at a rate that will slowly transfer load to the healing bone.
  • Can act as a basis for drug delivery into the body, either as a drug delivery system alone or in conjunction to functioning as a medical device. So when it decomposes it slowly or quickly (depending on what type of biodegradable polymer is used) gives off the medical drug into the body.

Types of Polymeric Biomaterial

  • Polylactide
  • Polycaprolactone
  • Polydioxanone
  • Polylactide-co-glycolide

Conclusion

In conclusion I feel that bio-materials are evolutionary to the human form. They are and have the potential to revive, repair and evolve our natural skeletal system and circulatory system. These Biomaterials have the potential to take the human skeletal system to the next level. Evolving our bodies to fulfil different functions that are not (normally) humanly possible as-well as medically repairing injuries to the bodies systems. It seems that the main focuses are on biocompatibility, bioinert, bioactive or surface reactive, biodegradable, sterilizability, adequate mechanical and physical properties, manufacturability, low weight, reasonable costs etc. However Bio-Materials are constantly being developed and the potentials are endless. Medical Bio-materials are already changing peoples lives and improving their standing of living. This is what i want to develop further and look into how bio-materials have changed the standard of peoples lives.

Bibliography 

Websites

Polymeric Biomaterials for Load-bearing Medical Devices. 2014. Polymeric Biomaterials for Load-bearing Medical Devices. [ONLINE] Available at:http://www.tms.org/pubs/journals/jom/0909/pruitt-0909.html. [Accessed 16 November 2014].

Online Journals

Classification of Biomaterials used in Medicine | Parida | International Journal of Advances in Applied Sciences. 2014. Classification of Biomaterials used in Medicine | Parida | International Journal of Advances in Applied Sciences. [ONLINE] Available at:http://www.iaesjournal.com/online/index.php/IJAAS/article/view/882/751. [Accessed 16 November 2014].

The role of polymethylmethacrylate bone cement in modern orthopaedic surgery. J C J, Webb. The Bone and Joint Journal. [Online]. Available at:http://www.bjj.boneandjoint.org.uk/content/89-B/7/851.full. [Accessed 16 Novemember 2014]. 

Books

Wong Y, J (2013). Biomaterials: Principles and Practices . Florida: CRC Press. 159.

Online Images

Kingsley, H, (2001), Image No. 1655 [ONLINE]. Available at:http://www.bcmamedicalmuseum.org/object/993.659.1 [Accessed 16 November 14].

Nogueira, N. (2006), A titanium hip prosthesis, with a ceramic head and polyethylene acetabular cup[ONLINE]. Available at: http://commons.wikimedia.org/wiki/File:Hip_prosthesis.jpg [Accessed 16 November 14].

Tiger International, (2005), Titanium,Nitinol,Cobalt-Chromium,and Stainless Steel for medical implant applications. [ONLINE]. Available at:http://www.bridgat.com/medical_alloys_biometals_metallic_biomaterials-o182318.html [Accessed 16 November 14].

Unknown, (2011), Unknown [ONLINE]. Available at:http://www.datron.de/fileadmin/content/pictures/content/dental/indications/temporary-dentures/dental-temporary-dentures-bridge-pmma-nano-composite.jpg [Accessed 16 November 14].

Unknown, (1996), Prof. Larry Hench [ONLINE]. Available at:https://www.imperial.ac.uk/publications/reporterarchive/0029/science.htm [Accessed 16 November 14].

Unknown, (2009), unknown [ONLINE]. Available at: http://www.tms.org/pubs/journals/jom/0909/pruitt-0909.html [Accessed 16 November 14].

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