WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Citation - WoS: 1The Impact of Oxygen and Antimicrobial Tea Tree Oil Carrying Biomaterial on Cell Viability Under Hypoxic Conditions(Wiley, 2025) Demir, Yagmur Damla; Tepeli, Dilek; Guvensen, Mahmut Deniz; Soyer, Ferda; Akin, Ozlem; Kehr, Nermin SedaTraditional wound treatment involves protecting the wound with dressing and administering antibiotics to prevent tissue infection due to bacteria. However, these methods are inadequate due to the side effects of antibiotics on healthy cells and microbial resistance to antibiotics. Therefore, new strategies involving the application of natural resources such as essential oils as antimicrobial agents in combination with biomaterials as wound dressings have been tested in the treatment of wounds. Furthermore, oxygen (O2)-releasing biomaterials have attracted great interest due to the important role of O2 in wound healing processes. However, the co-application of O2 and essential oil as antimicrobial and cell-promoting agents has not been studied. In this context, we report a novel biomaterial capable of co-delivering O2 and natural antimicrobial tea tree oil (TTO) for 15 and 5 days, respectively. The biomaterial consists of an alginate scaffold (Alg-PMOF-O) containing O2-carrying nanomaterial, laponite and TTO. In vitro bacterial experiments have shown that O2 release from Alg-PMOF-O is an additional parameter acting as an antibacterial agent to inhibit bacterial growth but is not sufficient alone to inhibit bacteria. 5 mu L of TTO in Alg-PMOF-O is necessary to suppress both E. coli and S. aureus over a 1-day incubation period. The effect of TTO and O2 alone or in combination on cell viability is examined using WST-1 and PrestoBlue assays. According to the WST-1 and PrestoBlue tests, the combined application of TTO and O2 does not show any toxic effect on fibroblast cells under normoxic conditions during the 5-day incubation period. Under hypoxic conditions, the WST-1 test shows no toxic effect after only 1 day of incubation, while the PrestoBlue test shows no toxicity under hypoxia during both 1 and 5 days of incubation. On the other hand, the combined application of TTO and O2 indicates toxic effects on cancer Malme-3M cells during both normoxic and hypoxic conditions over 1 and 5 days of incubation. This effect is confirmed by both the WST-1 and PrestoBlue tests. The overall results demonstrate that Alg-PMOF-O exhibits antibacterial activity while having a lower toxic effect on fibroblasts under hypoxic conditions, and therefore has potential for use as wound dressing.Article Citation - WoS: 2Citation - Scopus: 4Injectable Nanocomposite Hydrogels With Co-Delivery of Oxygen and Anticancer Drugs for Higher Cell Viability of Healthy Cells Than Cancer Cells Under Normoxic and Hypoxic Conditions(Iop Publishing Ltd, 2025) Kehr, Nermin SedaInjectable nanocomposite hydrogels (NC hydrogels) have the potential to be used for minimally invasive local drug delivery. In particular, pH-sensitive injectable NC hydrogels can be used in cancer treatment to deliver high doses of anticancer drugs to the target site in cancer tissue without damaging healthy tissue. Recent studies have shown that in addition to stimuli-responsive delivery of anticancer drugs to cancer cells, oxygen delivery to the hypoxic environment of cancer tissue can lead to advanced effects, as hypoxia and an acidic pH are common characteristics of cancer tissue. However, few studies have investigated the effects of simultaneous administration of oxygen (O2) and pH-dependent anticancer drugs via injectable NC hydrogels on the viability of healthy and cancer cells under normoxic and hypoxic conditions. In this context, we describe the synthesis of injectable NC hydrogels composed of pH-responsive nanomaterials carrying oxygen and anticancer drugs. Our system provides sustained O2 release and pH-responsive sustained release of anticancer drugs for 15 and 30 d, respectively. Moreover, O2 delivery and/or simultaneous delivery of O2 and anticancer drug resulted in higher cell survival of healthy fibroblast cells than malignant Colo-818 cells under hypoxic conditions (1% O2) after 7 d of incubation.Article Citation - WoS: 31Citation - Scopus: 34Curcumin: Novel Treatment in Neonatal Hypoxic-Ischemic Brain Injury(Frontiers Media S.A., 2019) Rocha-Ferreira, Eridan; Sisa, Claudia; Bright, Sarah; Fautz, Tessa; Harris, Michael; Riquelme, Ingrid Contreras; Kurulday, Tuğçe; Hristova, MariyaHypoxic-ischemic encephalopathy (HIE) is a major cause of mortality and morbidity in neonates, with an estimated global incidence of 3/1,000 live births. HIE brain damage is associated with an inflammatory response and oxidative stress, resulting in the activation of cell death pathways. At present, therapeutic hypothermia is the only clinically approved treatment available for HIE. This approach, however, is only partially effective. Therefore, there is an unmet clinical need for the development of novel therapeutic interventions for the treatment of HIE. Curcumin is an antioxidant reactive oxygen species scavenger, with reported anti-tumor and anti-inflammatory activity. Curcumin has been shown to attenuate mitochondrial dysfunction, stabilize the cell membrane, stimulate proliferation, and reduce injury severity in adult models of spinal cord injury, cancer, and cardiovascular disease. The role of curcumin in neonatal HIE has not been widely studied due to its low bioavailability and limited aqueous solubility. The aim of this study was to investigate the effect of curcumin treatment in neonatal HIE, including time of administration and dose-dependent effects. Our results indicate that curcumin administration prior to HIE in neonatal mice elevated cell and tissue loss, as well as glial activation compared to HI alone. However, immediate post-treatment with curcumin was significantly neuroprotective, reducing grey and white matter tissue loss, TUNEL+ cell death, microglia activation, reactive astrogliosis, and iNOS oxidative stress when compared to vehicle-treated littermates. This effect was dose-dependent, with 200 mu g/g body weight as the optimal dose-regimen, and was maintained when curcumin treatment was delayed by 60 or 120 min post-HI. Cell proliferation measurements showed no changes between curcumin and HI alone, suggesting that the protective effects of curcumin on the neonatal brain following HI are most likely due to curcumin's anti-inflammatory and antioxidant properties, as seen in the reduced glial and iNOS activity. In conclusion, this study suggests curcumin as a potent neuroprotective agent with potential for the treatment of HIE. The delayed application of curcumin further increases its clinical relevance.