جستجوی مقالات مرتبط با کلیدواژه "keratin" در نشریات گروه "پزشکی"

Billions of chickens are consumed annually in the world and about billions of tons of chicken feathers are produced. About 5 to 7 percent of the chickenchr('39')s weight is feather and about 90 percent of the feathers are keratin. Feather is a pure keratin protein that is highly insoluble and difficult to break down. Some bacteria have the ability to produce the keratinase enzyme to break down keratin. The aim of this study was to determine the factors affecting the growth of SKH14-isolated bacilli megatrium strain SKH14 and to measure the enzymatic activity of keratinase.

Soil samples were collected in sterile plastic containers. Seven bacterial isolates were grown on a specific environment, of which 5 showed clear decomposition and were selected for biochemical tests, 16S rRNA sequencing and keratin measurement activity. These five bacteria were then sequenced and GeneBank accession number was assigned for each of them as a new strain. Five bacteria were tested for keratinase production and the strongest strain was optimized for keratinase production.

Five isolates were belonged to different strains of bacilli, and all five isolates were feather decomposer at different times. The highest enzymatic activity was reported in Bacillus megaterium SKH14 with 18.01 units per ml and the lowest in Bacillus felexus SKH4 with 10.81 units per ml.

The complete decomposition of Bacillus megaterium SKH14 isolate showed that this bacterium has high protease activity and is able to decompose complete keratin.

As cytotoxicity and antibacterial properties are considered as two essential factors for advanced wound care dressings, many attempts have been made to introduce and apply potent substances to provide these requirements. In this study, keratin as a valuable substance extracted of human hair waste and fabricated to a nanofibrous scaffold for achieving to least cytotoxic and improved antibacterial properties. Keratin was extracted of human hair waste by an alkaline method and it was characterized by SDS-PAGE electrophoresis method. Extracted keratin was accompanied in different concentrations with PVA and silver nanoparticles and then fabricated into nano-fibrous scaffold through electrospinning method. Fabricated scaffolds were investigated and compared by scanning electron microscopy, measuring antibacterial activity (AATCC Test method 100-2004) and MTT assay (directly and by ISO 10993-5 standard method). Keratin with molecular masses of 56—65 kDa observed in the extracted substance. 3D scaffolds of nanofibers with diameter between 90-180 nm fabricated with different concentrations of kertain successfully. With the increase in keratin concentrations in fabricated scaffolds, their antibacterial activity against both Escherichia coli (ATCC8793) and Staphylococcus aureus (ATCC6538) bacteria were improved significantly. Furthermore, incorporating of keratin caused improved cell viability about 21% more in compare with the control sample. Valuable keratin was obtained from an economical source with an alkaline method. Beside the intrinsic and proven properties of keratin such as compatibility with human skin, introducing this substance to nanofibrous scaffolds caused improved antibacterial properties and cell viability making it as a potent candidate for advanced wound caring purposes.