ALSO BIOMATERIALS

1. Nature of Chemical Bonding:

   • Thermoplastics: Weak intermolecular forces (van der Waals, hydrogen bonds).

   • Thermosetting Plastics: Strong covalent bonds, cross-linked structure.

   • Elastomers: Combination of covalent bonds and weak intermolecular forces.

2. Structures of Repeat Units:

   • Polyethylene (PE): Repeating ethylene monomer units.

   • Polylactic Acid (PLA): Derived from lactic acid, linear structure.

   • Polyvinyl Alcohol (PVA): Composed of vinyl alcohol monomer units.

   • Polyurethane (PU): Contains urethane linkages.

3. Thermal Behavior:

   • Thermoplastics: Soften on heating, can be reshaped.

   • Thermosetting Plastics: Irreversible changes, rigid when set.

4. Influence of Molecular Weight and Morphology:

   • Higher molecular weight: Increased strength, toughness, and chemical resistance.

   • Morphology (amorphous/crystalline): Affects stiffness, impact resistance, and thermal stability.

5. Molecular Weight Determination:

   • Techniques: Gel permeation chromatography (GPC), calculations based on degree of polymerization.

6. Surface Alterations on Polyethylene/UHMWPE:

   • Plasma treatment, chemical functionalization, coatings.

   • Effects: Altered surface properties like roughness, hydrophilicity, and biocompatibility.

7. Types of Copolymers:

   • Random, alternating, block, graft copolymers.

8. Attributes and Limitations of Silicone Elastomers/Rubber:

   • Attributes: Biocompatibility, flexibility, durability.

   • Limitations: Adhesion issues, potential degradation.

9. Use of Polymerics in Biomedical Applications:

   • Vascular: Biocompatibility, mechanical properties, thrombogenicity.

   • Orthopedic: Strength, wear resistance, osseointegration.

   • Dental: Biocompatibility, durability, esthetics.

Biodegradable/Resorbable Polymers:

10. Types of Biodegradable/Resorbable Polymers:

    • Polylactic Acid (PLA), Polyglycolic Acid (PGA), Polycaprolactone (PCL).

11. Factors Affecting Degradation Rates:

    • Chemical groups, morphology, environmental factors (pH, temperature, enzymes).

Hydrogels:

12. Types of Hydrogels:

    • Natural (e.g., collagen, alginate), synthetic (e.g., polyethylene glycol, polyacrylamide).

13. Surface Erosion vs Bulk Erosion:

    • Surface erosion: Outer layer degradation.

    • Bulk erosion: Uniform degradation throughout.

14. Physical vs Chemical Hydrogels:

    • Physical: Reversible, based on physical interactions.

    • Chemical: Covalent bonds, more stable but less reversible.

Bioceramics and Bioglass:

15. Types of Bioceramics:

    • Bioinert (e.g., alumina, zirconia), bioactive (e.g., hydroxyapatite, tricalcium phosphate).

16. Significance of Ionic and Covalent Bonding:

    • Ionic: Ion release, biocompatibility.

    • Covalent: Stability, strength.

17. Mechanical Properties:

    • Hardness, stiffness, wear resistance, biocompatibility.

18. Influence of Pore Size:

    • Cell/tissue ingrowth, mechanical properties.

19. Use in Tissue Regeneration, Orthopedic, Dental Applications:

    • Biocompatibility, mechanical compatibility, osseointegration.

General:

20. Chemical Composition of Bioglass:

    • Includes silicon dioxide (SiO2), calcium oxide (CaO), sodium oxide (Na2O), phosphorus pentoxide (P2O5).

21. FDA Approval Process for Medical Devices:

    • Biocompatibility testing, mechanical testing, sterilization validation, material characterization, clinical trials.