biomaterials exam 3

Thermoplastics

Have weak, secondary bonds like van der Waals forces, soften when heated, and can be reshaped.

Thermosetting plastics

Possess strong covalent bonds between polymer chains, are cross-linked, and become rigid and non-meltable once set.

Elastomers

Combine weak secondary bonds and covalent bonds, allowing them to stretch and return to their original shape.

Copolymers

Polymers composed of two or more different monomers, can be random, alternating, block, or graft copolymers.

Biodegradable/Resorbable thermoplastic polymers

Include polylactic acid (PLA), polyglycolic acid (PGA), PLGA, PDO, and PCL.

Hydrogels

Can be physically or chemically cross-linked, and can be natural (e.g., collagen, alginate) or synthetic (e.g., polyethylene glycol, polyacrylamide).

Bioceramics

Include bioinert ceramics (e.g., alumina, zirconia) and bioactive ceramics (e.g., hydroxyapatite, tricalcium phosphate).

Bioglass

Contains silicon dioxide (SiO2), calcium oxide (CaO), sodium oxide (Na2O), and phosphorus pentoxide (P2O5) to promote bioactivity and bone bonding.

Ionic bonding

Can lead to ion release and influence biocompatibility.

Covalent bonding

Provides stability and strength to materials.

Surface erosion

Involves degradation starting from the outer surface of materials.

Bulk erosion

Involves uniform degradation throughout the material.

Physical hydrogels

Reversible, rely on physical interactions for cross-linking.

Chemical hydrogels

Have covalent bonds for cross-linking, more stable but less reversible.

FDA approval of medical devices

Involves biocompatibility testing, mechanical testing, sterilization validation, material characterization, and clinical trials.