Abstract
Biocompatible hydrogels with antibacterial properties derived from γ-polyglutamic acid (γ-PGA) were prepared from bulk and electrospun nanofibers. The antibacterial drugs loaded in these hydrogels were triclosan (TCS), chlorhexidine (CHX) and polyhexamethylene biguanide (PHMB); furthermore, bacteriophages were loaded as an alternative antibacterial agent. Continuous and regular γ-PGA nanofibers were successfully obtained by the electrospinning of trifluoroacetic acid solutions in a narrow polymer concentration range and restricted parameter values of flow rate, voltage and needle-collector distance. Hydrogels were successfully obtained by using cystamine as a crosslinking agent following previous published procedures. A closed pore structure was characteristic of bulk hydrogels, whereas an open but structurally consistent structure was found in the electrospun hydrogels. In this case, the morphology of the electrospun nanofibers was drastically modified after the crosslinking reaction, increasing their diameter and surface roughness according to the amount of the added crosslinker. The release of TCS, CHX, PHMB and bacteriophages was evaluated for the different samples, being results dependent on the hydrophobicity of the selected medium and the percentage of the added cystamine. A high efficiency of hydrogels to load bacteriophages and preserve their bactericide activity was demonstrated too.
Highlights
Development of new materials with bactericidal activity involves continuous research that is fundamental for sectors such as healthcare, reparative medicine and even food packaging [1,2,3,4]
Important limitation to use this electrospinning was the high viscosity of the ymer solution, which limited the system polymerfor concentration to a value of 16 wt‐%
Carboxylic side groups of the main polyamide chain can be effectively crosslinked by using the disulphide agent cystamine in the presence of a carbodiimide to favour the condensation reaction. γ-polyglutamic acid (γ-PGA) can be electrospun, conditions are highly limited due to its high insolubility in most organic solvents and to its relatively high molecular weight. 1,1,1,3,3,3-trifluoroacetic acid was the most appropriate solvent for electrospinning, being necessary to control the dissolution process which had to be extended for a minimum of 72 h to ensure complete dissolution
Summary
Development of new materials with bactericidal activity involves continuous research that is fundamental for sectors such as healthcare, reparative medicine and even food packaging [1,2,3,4]. The adhesion and proliferation of microorganisms on material surfaces leads to biofilms with organized bacterial microcolonies, which can cause severe health problems, especially in hospital environments [5,6]. Efforts have mainly been focused to incorporate the appropriate biologically active agent into a polymeric matrix. In this sense, a good compatibility between selected polymers and agents, and a high surface-to-mass ratio of the polymeric matrix are desirable in order to avoid unfavourable agent aggregation [7] and to enhance the contact between the agent and the target bacteria [8].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
