Study On Drug Loading Films And Nano Drug Delivery System Of Human Hair Keratin

Human hair keratin(HHK)as a biomaterial has been used in the field of tissue engineering and regenerative medicine due to high biological activity,low immunogenicity,good compatibility,controllable biodegradation and without donor quantitative restrictions.Because the molecule structure containing hydrophobic groups and hydrophilic groups as well as reactive groups can carry positive charge or negative charge,HHK can be used as an ideal drug carrier material to decrease selectivity for drugs,to improve drug loadings and delay-release effect However,some disadvantages of HHK such as complicated extraction process,low extraction yield and low stability in aqueous extraction have restricted some application and the related research for HHK have rarely been reported at present.In the paper,a HHK solution with high reaction activity was prepared by using human hair as matrix material and a modified extraction method.Then,novel drug loading films for HHK/mupirocin and nano drug delivery system for HHK/mupirocin were fabricated respectively and their release properties and subcutaneous implant effects were also carried outThe reduction methods extracting from human hair keratin reported in literatures have not only some advantages,such as less destroy for peptide chains,higher bioactivity and molecular weight of human hair keratin solution,but also some advantages,such as necessary blocking for-SH groups to avoid-SH oxidation resulting in insoluble HHK,required crosslinking agent during application.In the study,HHK solution were prepared by using a modified reduction method.First,the human hairs were pretreated before oxidation and then swelled by using urea with high concentration.Then,the HHK solution were enriched rapidly by using high absorbing resin at room temperature.Finally,a soluble HHK was prepared after the extraction for 12 h and dialysis purification for 48 h at 45?.The component,structure,amino acid content,intrinsic viscosity,isoelectric point and stability of HHK were characterized by using SDS-PAGE,FTIR,SEM,X-ray diffraction and particle size analysis.The result showed that the molecular weight distribution of HHK were 65 kDa,50 kDa and 20-30 kDa.The improved method not only increased the extraction yield of HHK up to 51.7%,but also kept active group(-SH)of HHK successfully.In addition,the molecule of HHK could be self-crosslinked and self-assembled at room temperature.A novel drug loading film for HHK/mupirocin was fabricated by using the above HHK solution and the self-crosslinking reaction.The results showed that the breaking strength of the film was up to 30 MPa and was higher than that of HHK films prepared by using glycerol diglycidyl ether or ethylene glycol diglycidyl ether as the crosslinking agent in some literatures Furthermore,the water absorption of the film was up to 800%,and so the drug loading films have good application prospects in the field of functional dressings and biodegradable hemostatic agent.In addition,the mupirocin and HHK contents were tested through liquid chromatograph and BCA Protein Assay.The effects of some components on system performance,delivery mechanism and stability of the drug loading films were also investigated.The results showed that the films had delay-release performance and the electrostatic interaction and hydrophobic function existed between HHK and mupirocin.The drug release was related to the degradation of HHKBased on self-assembly and pH response of the above HHK solution,a novel nano drug delivery system for HHK/mupirocin was also prepared by adjusting the ratio and concentration between the drug and HHK.The effects of the drug and HHK contents on release behavior in vitro,delivery mechanism and stability of the nano drug delivery system were also discussed The results showed that the mutual hydrophobic aggregation between HHK and mupirocin was the main reason for forming nano drug delivery system.Furthermore,pH and ionic strength of the solution had effect on the stability of the systemThe antibacterial performance for golden staphylococcus of the films were tested by the optical density method and the bacteriostatic ring method.The effect of the films on NIN/3T3 fibroblasts,proliferation and adhesion for ECV304 endothelial cell were characterized and evaluated through CCK8 method,pancreatic protein etherification method and cell streaming technology.The results showed that the films had good antibacterial performance for golden staphylococcus and present sterilizing effect when mupirocin content was up to 0.942%.The films promoted cell proliferation for NIN/3T3 fibroblasts,but had no cell proliferation for ECV304 endothelial cell.Additionally,the films had no cell cytotoxicity for the two cells and improved adhesion performance for the two cells.For the subcutaneous implanted experiment of the films for SD rats,HE staining and immunohistochemical study for rats' surrounding tissues showed the films implanted for 2 days could cause body's normal inflammatory response and the inflammatory response disappeared after 7 days,suggesting the films had good biocompatibility Based on wound patches of the films by using animals' cutting model and scald model,the appearance observation and HE staining confirmed the films could accelerate tissue regeneration and promote skin wound repairMTT cell proliferation experiment and subcutaneous implant experimental results showed that the nanoparticles drug system HHK/mupirocin has no cytotoxicity,no obvious inflammation and good biocompatibilityIn conclusion,HHK originated from human tissue as a biodegradable material has potential application in the field of functional dressing and drug carrier material.