Peptide-modified polymer for endothelialization

Jamie Lyn Ostroha

doi:10.17918/etd-73

A functionalized polycarbonate material derived from tyrosine containing varying levels of free acid functionality along the backbone, poly(DTE-co-X%DT carbonate), has been functionalized with a peptide to promote endothelial cell attachment and evaluated as a potential synthetic vascular graft material. Lysine derivatives have been produced to promote the attachment of engineered peptides for promoting endothelialization. NMR has been used to analyze the initial structure of the poly(DTEC-co-X%DTC) and changes in the structure with the attachment of L-lysine ethyl ester and polylysine, polyalanine, and the (ARKKAAKA)4 peptide. The polymer peak at 4.8 ppm has been labeled the [alpha]-peak. This peak is the primary peak used to evaluate changes in the spectra related to changing polymer functionality and the attachment of molecules to the pendant acid group. Changes in the [beta]-peak (3.05 ppm), the R2 peak (4.1 ppm) and the R3 peak (1.3 ppm) are compared to the [alpha]-peak for quantification purposes. Key NMR peaks have been identified and lysine attachment and quantification is discussed. A lysine peak has been identified at 4.38 ppm. This peak is also compared to the polymer [alpha]-peak, indicating 85-90% attachment efficiency. The use of polylysine, polyalanine, and peptides establish that peptide binding is successful; qualitative and semi-quantitative results are presented. Semi-quantitative results with polyalanine indicate a large degree of attachment, although some interference with the spectral peaks has been noted. The effect of poly(DTEC-co-X%DTC) on human endothelial cell attachment and growth is also studied and compared to current synthetic materials. Cell attachment has been shown to increase significantly as the polymer becomes more hydrophilic. Nonfunctionalized polymers show that less than five percent of cells remained attach at a force of 300 g, while 50% functionalized polymers show 40% attachment at the same force. Cell growth studies show an increase in cell affinity with increasing hydophilicity. 35% functionalized polymer shows over double the number of cells as the nonfunctionalized material after seven days. The results for the p(DTEC) at increasing levels of functionality bracket Dacron and PLA depending. Cell spreading, confluence, and division have been confirmed by visual analysis.

Peptide-modified polymer for endothelialization

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Peptide-modified polymer for endothelialization

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