abstract
Antimicrobial photodynamic therapy (aPDT) is a potent tool to surpass the global rise of antimicrobial resistance; still, the effective topical administration of photosensitizers remains a challenge. Biopolymer-based adhesive films can safely extend the residence time of photosensitizers. However, their wide application is narrowed by their limited water absorption capacity and gel strength. In this study, pullulan-based films with a switchable character (from a solid film to an adhesive hydrogel) were developed. This was accomplished by the incorporation of a betaine-based deep eutectic solvent (DES) containing curcumin (4.4 mu g.cm(-2)) into the pullulan films, which tuned the films' skin moisture absorption ability, and therefore they switch into an adhesive hydrogel capable of delivering the photosensitizer. The obtained transparent films presented higher extensibility (elongation at break up to 338.2%) than the pullulan counterparts (6.08%), when stored at 54% of relative humidity, and the corresponding hydrogels a 4-fold higher adhesiveness than commercial hydrogels. These non-cytotoxic adhesives allowed the inactivation (similar to 5 log reduction), down to the detection limit of the method, of multi-resistant strains of Staphylococcus aureus in ex vivo skin samples. Overall, these materials are promising for aPDT in the treatment of resistant skin infections, while being easily removed from the skin.
keywords
STAPHYLOCOCCUS-AUREUS; EPIDEMIOLOGY; INACTIVATION; THERAPY; PHOTOSENSITIZERS; PROLIFERATION; MECHANISMS; STABILITY; CELLULOSE; HYDROGEL
subject category
Engineering; Materials Science
authors
Pedro, SN; Valente, BFA; Vilela, C; Oliveira, H; Almeida, A; Freire, MG; Silvestre, AJD; Freire, CSR
our authors
Armando Jorge Domingues Silvestre
Full professor
Bruno Filipe Afonso Valente
PhD Student
Carla Vilela
Assistant Professor
Carmen Sofia da Rocha Freire Barros
Coordinating Researcher
Helena Oliveira
Post-Doc Fellowship
Mara Guadalupe Freire Martins
Coordinating Researcher
Sónia Isabel Neto Pedro
PhD StudentGroups
G4 - Renewable Materials and Circular Economy
G5 - Biomimetic, Biological and Living Materials
Projects
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
acknowledgements
This work was developed within the scope of the project CICECO- Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC) and CESAM, UIDP/50017/2020, UIDB/50017/2020 & amp; LA/P/0094/2020, financed by national funds through the FCT/MEC and when appropriate co -financed by FEDER under the PT2020 Partnership Agreement. FCT is also acknowledged for the doctoral grant (SFR H/BD/132584/2017) to S.N.P. and the research contracts under Scientific Employment Stimulus to H.O. (CEECIND/04050/2017) , C.V. (CEE- CIND/00263/2018 and 2021.01571.CEECIND) and C.S.R.F. (CEECIND/00464/2017) .