Research Information System
22nd EADO Congress, Praha, Czech Republic, 23 - 25 April 2026, no.254, pp.318-319, (Full Text)
Background
Cutaneous toxicities induced by cancer therapies such as radiotherapy, chemotherapy, and targeted treatments commonly result in skin
barrier disruption, pH imbalance, and increased susceptibility to microbial colonization, particularly in immunocompromised patients.
Chitosan, a naturally derived biopolymer with film-forming, adhesive, antimicrobial, and barrier-supportive properties, and carbopol, a
polymer providing formulation stability and sprayability, are suitable for oncology-related dermal applications. In parallel, postbiotic
solutions derived from Lacticaseibacillus casei offer antimicrobial activity without the safety concerns associated with live
microorganisms; however, data on postbiotic dose selection and incorporation into topical spray systems for therapy-compromised skin
remain limited.
Methods
A cell-free postbiotic solution was produced by controlled fermentation of L. casei, followed by filtration and sterilization. Antimicrobial
and antibiofilm activities of the postbiotic solution was evaluated in vitro against selected skin-associated microorganisms. Based on
these findings, an appropriate dose was determined and incorporated into two topical spray formulations: a chitosan-based and a
carbopol-based system. Physicochemical characterization included pH determination to assess skin compatibility.
Results
The L. casei–derived postbiotic solution showed clear antimicrobial activity, supporting its role in microbial load control and guiding dose
selection. The postbiotics exhibited low to moderate inhibition zones against B. subtilis, E. faecalis, P.s aeruginosa, and Candida spp. in
the agar diffusion assay, indicating a broad-spectrum antimicrobial activity. MIC results demonstrated that the postbiotics exerted
inhibitory effects particularly against Gram-positive bacteria and yeast species, with MIC values ranging between 2500 and 5000 µg/mL.
At a concentration of 10 mg/mL, L. casei–derived postbiotics inhibited biofilm formation by 51.94% in Staphylococcus aureus and
42.35% in Pseudomonas aeruginosa. Both spray formulations showed skin-compatible pH values for oncology-related compromised
skin, and incorporation of the postbiotic solution did not affect formulation homogeneity or spray performance; antimicrobial testing of
the final formulations is ongoing.
Conclusions
This study reports the development of postbiotic-based topical sprays for supportive skin care in oncology-associated cutaneous
complications. Antimicrobial and antibiofilm activities of the L. casei–derived postbiotic solution supported dose selection, while chitosan
and carbopol provided suitable functions for compromised skin. The cell-free nature of the formulation may offer a safety advantage for
immunocompromised patients and supports further in vitro microbial and pharmaceutical evaluation for oncology-related dermal care.
This study was supported by Anadolu University Scientific Research Projects Commission under the grant no: YTT-2024-2606.