Tuning the mechanical and physicochemical properties of cross‐linked protein films

Abstract

Films derived from natural sources such as proteins provide an advantage over synthetic films due to their noncytotoxicity, biodegradability, and vast functionality. A new protein source gained from the cataractous eye protein isolate (CEPI) obtained after surgery has been investigated for this purpose. Glycerol has been employed as the plasticizer and glutaraldehyde (GD) as a cross‐linker. Fourier transform infrared spectroscopy was employed to characterize the films. Nanoindentation and thermogravimetric analyses reveal improved mechanical and thermal properties of the cross‐linked films. The films with 20% (w/w) GD exhibited properties such as the highest modulus and low water solubility. It is possible to tune the properties based on the extent of cross‐linking. All the films were completely degraded by the enzyme trypsin. The similarity of these films was checked by using the prepared films as a delivery vehicle for a model compound, ampicillin sodium. The encapsulation efficiency was found to be 74%, and in vitro release studies showed significant amounts of drug release at physiological pH. This study will help us understand how the properties of protein films can be tuned to obtain the desired physicochemical properties. These biodegradable protein films could find use in pharmaceutical industries as delivery carriers.

Biodegradable Solid Polymer Electrolytes from the Discarded Cataractous Eye Protein Isolate

“…The images of the PS film and cross-linked PSN4 film are shown in Figure (other images have been shown in Figure S2, Supporting Information). All the films were found to have a rough surface with a porous morphology, which are consistent with previously reported CEPI films from this laboratory. − It was observed that the rough surface of the films had small pores (indicated with yellow arrows in Figure ). The roughness of the films reduces upon cross-linking following a reduction in the pore size with a concomitant increase in the number of pores.…”

“…Earlier it was observed that the proteins extracted from the processing of lens emulsions discarded postsurgery, i.e. cataractous eye protein isolate (CEPI), are capable of film formation with tunable properties. − However, the possibility of employing this protein for the construction of SPEs has not been explored. The human eye lens is abundant with lens Crystallin proteins that comprise ∼90% of the total lens proteins that retain lens transparency with their high refractive index .…”

Cell Penetrability of a γ-Crystallin Peptide Fragment from the Discarded Cataractous Eye Emulsion

“…Water-soluble γ-crystallin is found to be present in the supernatant post centrifugation . Following a previous procedure from our lab, we have obtained γ-crystallin from the CEPI. ,, In addition, theoretical trypsin digestion was performed on the sequence of human γ-crystallin. The result of the cleavage of γD crystallin (PDB ID: 1HK0) is shown in Table (γB and γC crystallin are shown in Tables S1 and S2 of the Supporting Information, respectively).…”

“…31 Following a previous procedure from our lab, we have obtained γ-crystallin from the CEPI. 25,31,32 In S1 and S2 of the Supporting Information, respectively).…”

“…The emulsion produced following cataract surgery was obtained in an autoclaved vessel and stored at 4 °C until further use. An earlier approach from this laboratory was used to isolate and purify the protein. − In brief, the emulsion was centrifuged at 4 °C and 7900 rpm for 40 min. The supernatant was collected and lyophilized.…”