Biocompatability Flashcards
Define biomaterial.
any substance or combination of substances synthetic/natural in origin which can be used for any period of time as a whole/part of a system which treats, augments or replaces tissue, lorgan or function
What is biocompatibility?
Capacity of a biomaterial to perform, with an appropriate host response in a specific context over the product life
What is tissue engineering?
Application of cells, drugs, biomaterial scaffolds to repair/regenerate tissue & thereby restore health
What will a biocompatible material reach?
Healthy equilibrium with biological environment over time
What 4 cases are biomaterials being used for?
Drug delivery
drug-device combinations (drug eluting stents)
tissue engineering
nanotech products
What are 4 adverse reactions to implant devices?
Direct damage
functionality may be impaired due to abberant cellular response/accumulation
Thrombus formation
non-thrombo device - local or systemic effects
What are 3 responses to implanted devices?
Wound healing response
inflammatory reactions
remodeling around implant
What are 3 interactions in in vivo systems?
Interaction with regulatory, parenchymal * stromal cells
paracrine & endocrine factors
interaction with blood
What 5 things dictate the foreign body response?
Extent of injury & surgical technique
implantation site
implant shape/size
material chemical & physical properties
systemic health of recipient
What is the ideal implantation reaction?
High neutrophil response which dissipates after 12 hrs
increasing macrophages & foreign body giant cells
some fibrosis
Why is biofilm so important?
outer contacting layer - can influence how immune system responds
What are 2 coatings?
Collagen IV
Collagen VII
What are 4 non-biological factors?
Hydrophobicity
Charge
Functional groups
Roughness
Why is hydrophobicity important?
Protects against bio-fouling
What does toxicology risk assessment identify?
Context-specific threshold safety limits for human health effects of chemicals using epidemiological & experimental toxicology data
What does toxicology risk assessment estimate?
Association between exposure to a chemical or physical agent & incidence of adverse outcome
What is ISO 10993?
Primary guidance for biological evaluation of medical devices
What does ISO 10993 allow for?
Manufactures to appropriately mitigate biological risks to an acceptable benefit/risk level & determines level of biological testing required
Detailed test protocols
What are 3Rs of animal testing?
Reduce
Refine
Replace
What are 3 sections to the biological risk assessment?
- Identification of intended use/purpose
- hazard identification
- Risk estimation
