Intro And History 1 Flashcards
What is a biomaterial?
A nonviable material used in a device intended to interact with biological systems
What is biocompatibility?
Ability of material to perform appropriate host response in a specific application
What is a host response?
Response of host organism to implanted material
Uses of biomaterials
RRICCH Replace diseased parts Replace rotten or dead material Improve function Correct function Cosmetic Healing
What properties should biomaterials have
BMSMS Biocompatibility Mechanical properties Stability/degradable Malleability Sterilisable
Innate properties of biomaterials
Non toxic
Non immunogenic
Non irritating
Degrees of biocompatibility
Biologically inert - no integration
Fully integrated - invades tissue
Features of 1st generation biomaterials and examples
Ad hoc implants Most successes were accidental Mainly metals initially Plastics then introduced Mixture if materials Eg. Tooth fillings, breast implants, bone cements
Features of 2nd generation biomaterials and examples
Bioengineered implants Some are modified New polymeric devices Tend to be more bioactive Eg. Implantable drug delivery devices
Features of 3rd generation biomaterials and examples
Uses techniques such as cell and tissue engineering
Regenerative medical techniques
Mainly in development
Eg. Growing artificial limbs, tissues
3 examples of tissue engineering
Stem cell use
Eg. Taken from tooth root
Grown in scaffold and used to repair damage
Artificial tissues and structures designed based on host
Decellularisation of donor tissue to avoid rejection
Eg. A kidney
How does Hayflick limit cause senescence
Every time DNA replicates it gets shorter End of chromosomes have telomeres When they get too short Chromosomes become disorganised Division disrupted Cell senescence
Why dont stem cells senesce
Express telomerase - extends telomeres
What is an explant culture
Intermediate between cell and tissue culture
2 main types of cells used in culture
Primary cells - derived directly from tissues
Cell lines
2 main formats of cell culture
Growth in suspension
Growth on surface - require to be adherent
What is the behaviour of cells in suspension
Spherical in suspension
Settle and start to spread
Will eventually form confluent monolayer and stop proliferating
How is serial culture carried out?
Cells in suspension Formed layer and stop dividing Broken down by enzymes with EDTA cells detach from culture plate Seeded in new culture vessel Grow and form layer Cycle is repeated
How does an explant culture work
Tissue is fragmented and seeded
Monolayer formed of a mixture of cells
