Whey Protein Concentrate Doped Elecrtospun Poly(Epsilon-caprolactone) Fibers For Antibiotic Release Improvement

Design and fabrication of scaffolds using appropriate biomaterials is a key step for the creation of functionally engineered tissues and their clinical applications. Poly(epsilon caprolactone)(PCL), a biodegradable and biocompatible material with negligible cytotoxicity, is widely used to fabricate nanofiber scaffolds by electrospinning for the applications of pharmaceutical products and wound dressings. However, the use of PCL as such in tissue engineering is limited due to its poor bioregulatory activity, high hydrophobicity, lack of functional groups and neutral charge. With the attempt to found nanofiber scaffolds with antibacterial activity for skin tissue engineering, in this study, whey protein concentrate(WPC) was used to modify the PCL nanofibers by doping it in the PCL electrospun solution. By adding proteins into PCL nanofibers, the degradability of the fibers may be increased, and this further allows an antibiotic incorporated in the fibers to be efficiently released. The morphology, wettability and degradation of the asprepared PCL/WPC nanofibers were carefully characterized. The results showed that the PCL/WPC nanofibers possessed good morphology and wettability, as well as high degradation ability to compare with the pristine PCL fibers. Afterwords, tetracycline hydrochloride as a model antibiotic drug was doped in the PCL/WPC nanofibers. In vitro drug release assays demonstrated that PCL/WPC nanofibers had higher antibiotic release capability than the PCL nanofibers. Also, antibacterial activity evaluation against various bacteria showed that the drug-doped PCL/WPC fibers possessed more efficient antibacterial activity than the PCL nanofibers.This dissertation including as follows:1- Preparation of poly(epsilon-caprolactone)(PCL), solutions for electrospinning and investigate the effects of the solvent types and polymer concentrations on the formation and the morphology of nanofibers. 2- The adding of whey protein concentrate(WPC) into(PCL) nanofibers by adequate percent, then characterization of the(PCL) electrospun nanofibers as well as PCL/WPC nanofiber scaffolds through investigation of morphology, wettability and the in vitro degradation. The results showed that the PCL/WPC nanofibers possessed good morphology and wettability, as well as high degradation ability to compare with the pristine PCL fibers.3-The antibiotic drug tetracycline hydrochloride was doped in the PCL/WPC nanofibers as well as PCL nanofibers scaffolds. Afterwards, the In vitro drug release assays was investigated and the results demonstrated that drug-doped PCL/WPC nanofibers had higher antibiotic release capability than the PCL nanofibers. 4- The antibacterial activity of the drug-doped nanofibers was evaluated against Grampositive bacteria Staphylococcus aureus ATCC 25923 and Listeria monocytogenes CMCC 54004, as well a as the Gram-negative bacteria Escherichia coli ATCC 25922, Escherichia coli HB101 and Salmonella typhimurium SL1344 and the results showed that the drug-doped PCL/WPC fibers possessed more efficient antibacterial activity than the PCL nanofibers.