Summary
Chitosan/poly(ethylene oxide) (PEO) nanofibres are appealing for drug delivery and tissue engineering, but they swell and lose integrity in water unless the fibres are crosslinked. This study establishes conditions for a green crosslinking route using citric acid on electrospun chitosan/PEO mats. Applying the crosslinker thermally and in situ let it penetrate the fibre matrix, simultaneously improving antibacterial activity, thermal stability and mechanical properties. Antibacterial action against Staphylococcus aureus and Escherichia coli was strong but decreased when the crosslinking temperature rose above 80 °C. Crosslinking also gave prolonged, controlled drug release together with a marked rise in mechanical performance measured by nanoindentation. The authors conclude that citric-acid crosslinking is a key parameter for producing multifunctional chitosan/PEO material suited to drug delivery and tissue-engineering applications.