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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: 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.Article Citation - WoS: 3Citation - Scopus: 2Targeted Multidrug Delivery Systems To Kill Antibiotic-Resistant Staphylococcus Aureus(Elsevier, 2023) Ozalp, Veli Cengiz; Ucak, Samet; Dursun, Ali D.; Sudagidan, Mert; Icin, Oyku; Vakifahmetoglu, Cekdar; Gurlo, AleksanderDifferent ordered mesoporous silica (OMS) nanoparticles, ranging from regular COK-12 to COK-12 modified in terms of pore shape and size, have been employed as standard drug carriers for the controlled adsorption and release of drug molecules in comparison to well-known OMS SBA-15 and MCM-41. The cytotoxicity analysis demonstrated that regular COK-12 particles were less harmful to mammalian cultured cells, causing lower apoptosis induction than modified COK-12, MCM-41, and SBA-15 particles.Thus, regular COK-12 was further used to prepare a dual antibiotic-loaded drug delivery material, followed by surface functionalization with Staphylococcus aureus-specific aptamers for targeting. The results demonstrated that the joint loading of lysozyme and vancomycin in regular COK-12 improved the ability of the antibiotic treatments to kill methicillin-resistant Staphylococcus strains via aptamer targeting. The minimum inhibitory concentration (MIC) values decreased 4.1-fold and 12-fold compared to the non-targeted use of the antimicrobial agents in homogeneous solutions for vancomycin and lysozyme, respectively, clearly demonstrating the high potential of COK-12 to be used as a carrier in multidrug therapy.
