Browsing by Author "Fidan, O."

Now showing 1 - 2 of 2

Citation - WoS: 2
Citation - Scopus: 2
Antifungal Efficacy of 3D-Cultured Palatal Mesenchymal Stem Cells and Their Secreted Factors Against Candida albicans
(American Chemical Society, 2025) Bicer, M.; Öztürk, E.; Sener, F.; Hakki, S.S.; Fidan, O.
Candida albicans is among the life-threatening fungal species and the primary contributor to hospital-acquired systemic infections, accounting for nearly 70% of all fungal infections worldwide. The current treatment primarily relies on azoles, pyrimidine analogs, polyenes, and echinocandins. However, growing antifungal resistance highlights the urgent need for the development of alternative treatments against C. albicans. Mesenchymal stem cells (MSCs) offer huge therapeutic potential for the treatment of C. albicans-associated diseases. In this study, palatal adipose tissue-derived MSCs (PAT-MSCs) and PAT-MSCs cultured in 3D biomaterial using nanofibrillar cellulose were tested against C. albicans strains ATCC 10231 and ATCC MYA 2876 using an in vitro antifungal activity assay. In addition, the conditioned medium from both PAT-MSCs and PAT-MSCs cultured in 3D hydrogel biomaterial (CM-PAT-MSCs-3D) were evaluated for their antifungal activities. The combined effect of PAT-MSCs and their secreted factors was also investigated. The expression of five antimicrobial peptide (AMP)-encoding genes was analyzed by quantitative real-time PCR. The expression of antimicrobial peptides was further confirmed via immunocytochemical staining. PAT-MSCs significantly inhibited the growth of C. albicans strains at varying inoculum concentrations (500 and 2000 CFU). Similarly, a comparable antifungal effect was observed when Candida strains were treated with PAT-MSC secreted factors alone. Statistical analysis revealed significant differences between the antifungal activities of PAT-MSCs and CM-PAT-MSCs. Lastly, the combination of PAT-MSCs and CM-PAT-MSC-3D led to a marked reduction in fungal growth, with inhibition rates of 99.75% and 99.91% for C. albicans ATCC 10231 and ATCC MYA-2876, respectively, at 500 CFU inocula. At 2000 CFU inocula, inhibition rates were 99.54% and 99.91%, respectively (****P ≤ 0.0001). These antifungal activities were further confirmed by using RT-PCR and immunocytochemical analysis. Our findings underscore a perspective on the potent antifungal activity of secreted factors from PAT-MSCs cultured within a 3D hydrogel matrix, specifically against various strains of C. albicans. Particularly, the combination of PAT-MSCs with their secreted factors represents a promising therapeutic platform, potentially offering a safer and more effective alternative to conventional antifungal treatments. © 2025 Elsevier B.V., All rights reserved.
CRISPR/Cas9-mediated Metabolic Engineering of Endophytic Pseudomonas Loganensis Sp. Nov. for the Production of Nutritionally Valuable Carotenoids
(American Chemical Society, 2026) Arslansoy, N.; Karaman, M.Z.; Fidan, O.
Carotenoids with significant nutritional and antioxidant properties have been widely utilized in the food, feed, pharmaceutical, and cosmetic industries. They improve the nutritional value of foodstuffs and have been used as natural food colorants. However, their current supply chain is mainly dependent on extraction from plants and chemical synthesis, both of which have bottlenecks, including environmental concerns, toxicity, and allergenicity. To address global demand for sustainable and environmentally friendly production of nutrients, we engineered the endophytic Pseudomonas loganensis sp. nov. as a niche microbial chassis for nutritionally valuable carotenoid production. Using CRISPR-Cas9, we knocked out key carotenogenic genes to construct strains capable of producing zeaxanthin, lycopene, and β-carotene. Additionally, an overexpression plasmid was introduced to produce astaxanthin. HPLC analysis confirmed the successful production of four target carotenoids. The culture conditions and media compositions were optimized using response surface methodology, resulting in a ∼5-fold increase in the titers of zeaxanthin (13.4 mg/L), lycopene (9.67 mg/L), and β-carotene (23.53 mg/L), and a ∼12-fold increase in astaxanthin titer (1 mg/L) compared to LB medium without optimization. Our results indicate the potential of endophytic bacteria as a microbial chassis for carotenoid bioproduction, underscoring the potential of synthetic biology to contribute to global efforts toward nutritional security and sustainable food systems. © 2026 The Authors. Published by American Chemical Society