The Influence of Gamma Radiation on Different Gelatin Nanofibers and Gelatins

Abstract

Gelatin nanofibers are known as wound-healing biomaterials due to their high biocompatible, biodegradable, and non-antigenic properties compared to synthetic-polymer-fabricated nanofibers. The influence of gamma radiation doses on the structure of gelatin nanofiber dressings compared to gelatin of their origin is little known, although it is very important for the production of stable bioactive products. Different-origin gelatins were extracted from bovine and donkey hides, rabbit skins, and fish scales and used for fabrication of nanofibers through electrospinning of gelatin solutions in acetic acid. Nanofibers with sizes ranging from 73.50 nm to 230.46 nm were successfully prepared, thus showing the potential of different-origin gelatin by-products valorization as a lower-cost alternative to native collagen. The gelatin nanofibers together with their origin gelatins were treated with 10, 20, and 25 kGy gamma radiation doses and investigated for their structural stability through chemiluminescence and FTIR spectroscopy. Chemiluminescence analysis showed a stable behavior of gelatin nanofibers and gelatins up to 200 °C and increased chemiluminescent emission intensities for nanofibers treated with gamma radiation, at temperatures above 200 °C, compared to irradiated gelatins and non-irradiated nanofibers and gelatins. The electron paramagnetic (EPR) signals of DMPO adduct allowed for the identification of long-life HO● radicals only for bovine and donkey gelatin nanofibers treated with a 20 kGy gamma radiation dose. Microbial contamination with aerobic microorganisms, yeasts, filamentous fungi, Staphylococcus aureus, Escherichia coli, and Candida albicans of gelatin nanofibers treated with 10 kGy gamma radiation was under the limits required for pharmaceutical and topic formulations. Minor shifts of FTIR bands were observed at irradiation, indicating the preservation of secondary structure and stable properties of different-origin gelatin nanofibers.

Donkey Gelatin and Keratin Nanofibers Loaded with Antioxidant Agents for Wound Healing Dressings

“…However, the fabricated bioactive nanofibers showed an average diameter very similar to the diameter of ECM collagen fibers found in the skin, typically ranging from 50 nm to 500 nm. In an extensive study examining the average diameter of gelatin nanofibers prepared by electrospinning gelatins derived from different sources—bovine, donkey, rabbit, and fish scale—it was observed that the donkey gelatin exhibited the smallest nanofiber diameter (73.15 nm ± 3.37 nm) [ 34 ]. The authors concluded that the origin of gelatin and optimized electrospinning conditions are essential for achieving nanofibers with dimensions closely resembling those of the extracellular matrix (ECM).…”

“…Nonetheless, there is evidence that the use of inflammable liquids with high shear strength and voltage can potentially generate permanent denaturation of the collagen fibrous structure [ 28 ]. Our previous publications reported the fabrication of nanofibrous wound dressings by the electrospinning process of different protein extracts, such as collagen derived from cattle hides [ 29 , 30 ], rabbit skins [ 31 , 32 ], fish scales [ 33 , 34 ], donkey hides [ 34 ], or keratin extracted from sheep wool [ 35 ], loaded with various non-active antimicrobial agents and having advanced regenerative properties for acute and chronic wound healing.…”