A research group has experimented with a polyethylene glycol (PEG)-based tissue-engineering scaffold. This scaffold was then modified with an RGD peptide sequence. In this experiment, the RGD sequence was synthesized in one of two forms:
a) RGD coupled to a large PEG spacer (MW = 3400 Da) and attachment site moiety (***),
or
b) RGD coupled to the attachment site moiety (***) with very small PEG spacer as shown below. (MW = 800 Da).
1) Now that you know the role of the RGD terminal sequence in cell adhesion, what is the role of the PEG chain? Why did the researchers try different PEG molecular weight?
2) Based on the different designs we have seen in class for hemocompatible surfaces (e.g., Carmeda and Trillium), which form of the RGD sequence peptide will yield the highest cell attachment per given number of peptides when attached to the polymer scaffold? Justify your answer
A research group has experimented with a polyethylene glycol (PEG)-based tissue-engineering scaffold. This scaffold was then modified with an RGD peptide sequence. In this experiment, the RGD sequence was synthesized in one of two forms:
a) RGD coupled to a large PEG spacer (MW = 3400 Da) and attachment site moiety (***),
or
b) RGD coupled to the attachment site moiety (***) with very small PEG spacer as shown below. (MW = 800 Da).
1) Now that you know the role of the RGD terminal sequence in cell adhesion, what is the role of the PEG chain? Why did the researchers try different PEG molecular weight?
2) Based on the different designs we have seen in class for hemocompatible surfaces (e.g., Carmeda and Trillium), which form of the RGD sequence peptide will yield the highest cell attachment per given number of peptides when attached to the polymer scaffold? Justify your answer
