Scaffold Materials: ceramics, ECM and Mg

Question 1

State and elaborate on the three causes of degradation for calcium phosphate based biodegradable ceramics

Answer 1

–physiologic dissolution (depends on environment pH, type of calcium phosphate)
–biological factors (phagocytosis etc.)
–Mechanical degradation (grain boundary attack

Question 2

Describe the various factors that could affect the physiochemical degradation of calcium phospate`

Answer 2

• ionic transfer from solid phase to aqueous phases, depends on environmental pH
• type of calcium phospate

crystalline features

presence of additives

Question 3

State and elaborate on the three causes of degradation for bioactive glasses based biodegradable ceramics

Answer 3

–Physicochemical degradation (depends on environment pH,) –Cellular degradation (phagocytosis etc.) –Mechanical degradation (grain boundary attack

Question 4

Describe what happens during ionic transfer to aqueous phase in physiochemical degradation of bioactive glasses?

Answer 4

1. Formation of silanols through loss of soluble silica. It hydrated to form a hydrated silica gel. A these leads to formation of a calcium phosphate layer, crystallization of carbonated hydroxyapataite

Question 5

State advantages and disadvantages of using magnesium as biodegradable metallic scaffold?

Answer 5

advantages- attacked by most acids, so it may easily degrade, magnesium is found in bone, and it is already found in the body

disadvantages- may partake in stress shielding, may weaken new bone,

Question 6

State the criterion that the ECM scaffold must meet to be considered as effectively decellularized

Answer 6

–Lack of nuclei present following histologic nuclear staining

–Total scaffold DNA content must be less than 50ng/mg

–Any remaining DNA remnants must be less than 200 base pairs in nucleotide length.