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Article Citation - WoS: 33Citation - Scopus: 37Surface Plasmon Resonance Aptasensor for Brucella Detection in Milk(Elsevier, 2022) Dursun, Ali D.; Borsa, Baris A.; Bayramoglu, Gulay; Arica, M. Yakup; Ozalp, Veli C.A Surface Plasmon Resonance (SPR) aptasensor was developed for the detection of Brucella melitensis (B. melitensis) in milk samples. Brucellosis is a bacterial zoonotic disease with global distribution caused mostly by contaminated milk or their products. Aptamers recognizing B. melitensis were selected following a whole bacteria-SELEX procedure. Two aptamers were chosen for high affinity and high specificity. The high affinity aptamer (B70 aptamer) was immobilized on the surface of magnetic silica core-shell nanoparticles for initial purification of the target bacteria cells from milk matrix. Another aptamer, highly specific for B. melitensis cells (B46 aptamer), was used to prepare SPR sensor chips for sensitive determination of Brucella in eluted samples from magnetic purification since direct injection of milk samples to SPR sensor chips is known for a high background unspecific signal. Thus, we integrated a quick and efficient magnetic isolation step for subsequent instant detection of B. melitensis contamination in one ml of milk sample by SPR with a LOD value as low as 27 +/- 11 cells.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.

