Dual effective core-shell electrospun scaffolds: Promoting osteoblast maturation and reducing bacteria activity

Herein, we electrospun ultrathin core-shell fibers based on polycaprolactone (PCL), polyethylene glycol (PEG), gelatin and osteogenic growth peptide (OGP), and evaluated their potential to upregulate human osteoblast cells (hFOB) and to reduce Gram-positive and Gram-negative bacteria. We also evaluated the fiber morphology, chemical structure and peptide delivery efficacy. The employment of core-shell fibers compared to fibers without a core-shell showed improved mechanical strength, comparable to the strength of pure PCL, as well as improved hydrophilicity and wettability. The careful selection of polymer combination and core-shell strategy promoted a controlled and sustained release of OGP. Moreover, increased calcium deposition (CD) (1.3-fold) and alkaline phosphate (ALP) activity was observed when hFOBs were cultivated onto core-shell fibers loaded with OGP after 21 days of culture. Our developed scaffolds were also able to reduce the amount of Pseudomonas aeruginosa (ATCC 25668) bacteria by a factor of two compared to raw PCL without the use of any antibiotics. All of these results demonstrate a promising potential of the developed core-shell electrospun scaffolds based on PCL:PEG:Gelatin:OGP for numerous bone tissue applications.