Engineering of poly(glycerol sebacate) scaffolds

Official URL: https://risc01.sabanciuniv.edu/record=b2767349_(Table of contents)

40% of blindness in humankind is because of a problem in the human cornea. The only effective cure for most human cornea diseases is transplantation which is costly, and 1 out of 3 is unsuccessful due to rejection. Tissue engineering is an emerging field that can be a promising solution for human cornea disease. Fabricating a suitable scaffold for cell proliferation and attachment is where engineering can step in to carry a burden in this field. For human cornea, the scaffold should be transparent to provide proper eyesight, and transparent polymer can be a good option as a scaffold for human cornea tissue engineering. Transparent polymers are widely used in various applications, such as tissue engineering, optoelectronics, automotive, biosensors, etc. Most well-known transparent polymers are not biodegradable, among which poly (glycerol sebacate) PGS has shown promising properties in bio applications. However, there is minimal knowledge about PGS’s optical properties and crosslinking mechanism. In this study, three PGS pre-polymer with different molecular weight is synthesized, shaped into 300-micron films, and each pre-polymer is crosslinked at different durations. The sample with the highest molecular 4 weight, PGS3, exhibits a decrease in transmittance from 86 % to 78% in UV-vis data. XPS, FTIR, UV-vis spectroscopy, and Refractometer were utilized to shed light on the correlations between crosslinking and optical properties. This research suggests that the pre-PGS chains with acid endings react with secondary OH in other PGS chains to establish a link between the chains during crosslinking. By doing so, the binding energy of carbon electrons energy decreases, and they get excited by electromagnetic waves with lower energies. Carbon 1 s electrons in ester function in PGS3 decrease from 289.16 eV to 288.6 eV, causing PGS color formation in samples with a higher degree of crosslinking. The Refractive index of crosslinked PGS does not indicate a significant change. The refractive index of PGS3 increased by 1.488 and 1.491 when the crosslinking time escalated from 1 hour to 48 hours. PGS1-PGS3 films, crosslinked for 48 hours, seeded with human corneal epithelium and retinal pigment epithelial (ARPE-19) cells to investigate the effect of cell culture on the PGS films’ optical properties.