Download Biocompatibility

Biocompatibility
Biological response
Biocompatibility tests
Sterilization Issues
Biocompatibility
• Arises from differences between living and
non-living materials
• Bioimplants trigger inflammation or foreign
body response
• New biomaterials must be tested prior to
implantation according to FDA regulation
• WWII: Validated biocompatibility of several
materials including PMMA
Biomaterial-Tissue Interactions
Definitions
• Neutrophil- common leucocyte of the blood- short-lived phagocytic
cell
• Lymphocyte- small cell in blood- recirculates through tissues and
back through lymph --polices body for non-self material-- recognizes
antigens through surface receptors
• Antigen- produces antibody- stimulate adaptive immune response
• Antibody- Serum globulins with wide range of specificity for
different antigens-- bind to surface
• Monocyte- largest nucleated cell of blood-develops into
macrophage when it migrates to tissues
• Macrophage- phagocyte--scavenger cell-- of tissues
• Lysozyme- enzyme secreted by macrophages- attack cell wall of
bacteria “natural antibiotic”
• Mast Cell- large tissue cell which releases inflammatory mediators-increases vascular permeability-- allows complement to enter
tissues from blood
• Complement- a series of enzymes in blood- when activated
produce inflammatory effects
Wear-Mediated Osteolysis
wear
particles
Wear particles from
the replacement head
and liner cause
inflammation that can
lead to pain, bone
loss, and ultimately
revision surgery
bone loss
Archibeck, MJ; Jacobs, JJ; Roebuck, KA; Glant, TT. Journal of Bone & Joint Surgery, 2000