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Article Enhanced Doxorubicin Cytotoxicity on Breast Cancer Spheroids by Aptamer Targeted Co-Delivery With Hyaluronidase(Wiley, 2025) Kavruk, Murat; Demirel, Dide Su; Bonyadi, Farzaneh; Guner, Buket Cakmak; Dursun, Ali Dogan; Vakifahmetoglu, Cekdar; Ozalp, Veli CengizBreast cancer is one of the most prevalent solid tumors in women and can be classified into subtypes based on molecular characteristics, such as hormone receptor status and HER2 expression. Aptamers, highly specific affinity molecules, are extensively studied for targeted drug delivery using nanocarriers to enhance anti-cancer efficacy. This study focused on HER2-responsive co-delivery of doxorubicin and hyaluronidase via aptamer-gated mesoporous silica nanoparticles to improve therapeutic outcomes in solid tumors. SK-BR-3 spheroids are employed as a model for resistant tumor environments in solid tumors. Previous research is shown that conjugating cytotoxic drugs with nanoparticles or cells enhances drug penetration into tumor spheroids. In this work, doxorubicin is loaded into mesoporous silica nanoparticles and capped with HER2-specific aptamers, while the particle surface is functionalized with hyaluronidase. This dual-functionalized nanocarrier system achieves an approximate to 8.5-fold increase in cytotoxicity compared to aptamer-targeted delivery lacking hyaluronidase. The enhanced effect is attributed to hyaluronidase-mediated loosening of the spheroid structure, facilitating nanoparticle penetration and localized release of doxorubicin at high concentrations on HER2-positive cells.Article Citation - WoS: 39Citation - Scopus: 46Inhibitory Effects of Aptamer Targeted Teicoplanin Encapsulated Plga Nanoparticles for staphylococcus Aureus Strains(Springer, 2020) Ucak, Samet; Özalp, Veli Cengiz; Sudagidan, Mert; Borsa, Baris A.; Mansuroglu, Banu; Ozalp, Veli C.; Özalp, Veli Cengiz; Basic Sciences; Basic SciencesEmergence of resistance to traditional antibiotic treatments necessitates alternative delivery systems. Teicoplanin is a glycopeptide antibiotic used in the treatments of serious infections caused by Gram-positive bacteria, including Methicillin Resistant Staphylococcus aureus (MRSA). One strategy to keep up with antibiotic resistance development is to limit dose and amount during treatments. Targeted delivery systems of antibiotics have been suggested as a mechanism to slow-down the evolution of resistance and to increase efficiency of the antimicrobials on already resistant pathogens. In this study, we report teicoplanin delivery nanoparticles of Poly Lactic-co-Glycolic Acid (PLGA), which are functionalized with S. aureus specific aptamers. A 32-fold decrease in minimum inhibitory concentration (MIC) values of teicoplanin for S. aureus was demonstrated for susceptible strains and about 64-fold decline in MIC value was achieved for moderately resistant clinical isolates of MRSA upon teicoplanin treatment with aptamer-PLGA nanoparticles. Although teicoplanin delivery in PLGA nanoparticles without targeting demonstrated eightfold decrease in MIC of susceptible strains of S. aureus and S. epidermidis and twofold in MIC of resistant strains, the aptamer targeting specifically decreased MIC for S. aureus, but not for S. epidermidis. Therefore, aptamer-targeted PLGA delivery of antibiotic can be an attractive alternative to combat with some of the multi-drug resistant bacterial pathogens.Article Citation - WoS: 6Citation - Scopus: 8Aptamer-Based Magnetic Isolation and Specific Detection System for listeria Monocytogenes from Food Samples(Elsevier, 2024) Bayramoglu, Gulay; Ozalp, Veli Cengiz; Arica, Mehmet YakupIn this work, an aptamer-based magnetic system was designed for specific and rapid detection of Listeria monocytogenes in food samples. To prepare the selective magnetic system against the target bacterium, firstly, magnetic particles (Fe3O4) were coated with two hydrophilic polymer layers. The specific aptamer immobilized magnetic system efficiently captured L. monocytogenes cells in a competitive response time of approximately 10 min. The magnetic aptamer detection system was very specific to L. monocytogenes and had high selective, up to 97.6 % compared to the Listeria species (Listeria ivanovii, Listeria innocua, and Listeria seeligeri) and other bacteria species Escherichia coli, Staphylococcus aureus, and Basillus subtilus. The isolation and detection of L. monocytogenes from food samples using the presented method are fast and reliable. Moreover, another significant factor to be contemplated is the use of a few chemicals for detection, reducing the cost of analysis, and the results can be obtained within 18 h.
