RESUMO
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
RESUMO
When hydrocolloids dressings are loaded with an antibacterial agent, they can also prevent infection during wound cicatrisation. To consider interesting properties of traditional Gum Tragacanth such as moisture absorption, hydrocolloid formation, drug holding and releasing abilities, it was aimed to introduce a scaffold wound dress based on Gum Tragacanth with drug release ability simultaneously. In this experimental study, gum tragacanth from Astragalus gossypinus species [Iranian species] is solved and loaded with an aminoglycoside antibiotic [Gentamicin]. Prepared solution transformed to a nano fibers network "scaffold" by lyophilization method. Samples were characterized by scanning electron microscopy, fourier transform infrared and X-ray diffraction methods and their antimicrobial and moisture holding properties were determined. Gum tragacanth showed a proper potential for dispersing gentamicin and the drug was loaded into polymer matrix without any aggregation. Loaded gum tragacanth with gentamicin is successfully transformed to a nanofibers scaffold by lyophilization. The diameters of fibers were in the range of 300nm to 2micro m. Transformed gum tragacanth into scaffolds showed declined regain content [up to 50%] due to the ordering and orientation of polymer chains. Ordered hydroxyl groups also observed in FTIR graphs. Regarding the zones of inhibition, scaffolds also showed acceptable antibacterial activities. Produced scaffolds are capable of absorbing wound's exocrine liquid easily due to their high specific area of nanofibers. When it is turned to gel by moisture sorption, the release of loaded Gentamicin would be enhanced