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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: 15Citation - Scopus: 15Targeted mesoporous silica nanoparticles for improved inhibition of disinfectant resistant Listeria monocytogenes and lower environmental pollution(Elsevier, 2021) Sudagidan, Mert; Yildiz, Gulsah; Onen, Selin; Al, Rabia; Temiz, S. Sevval Nur; Yurt, Mediha Nur Zafer; Ozalp, Veli C.Benzalkonium chloride (BAC) is a common ingredient of disinfectants used for industrial, medical, food safety and domestic applications. It is a common pollutant detected in surface and wastewaters to induce adverse effects on Human health as well as aquatic and terrestrial life forms. Since disinfectant use is essential in combatting against microorganisms, the best approach to reduce ecotoxicity level is to restrict BAC use. We report here that encapsulation of BAC in mesoporous silica nanoparticles can provide an efficient strategy for inhibition of mi-crobial activity with lower than usual concentrations of disinfectants. As a proof-of-concept, Listeria mono-cytogenes was evaluated for minimum inhibitory concentration (MIC) of nanomaterial encapsulated BAC. Aptamer molecular gate structures provided a specific targeting of the disinfectant to Listeria cells, leading to high BAC concentrations around bacterial cells, but significantly reduced amounts in total. This strategy allowed to inhibition of BAC resistant Listeria strains with 8 times less the usual disinfectant dose. BAC encapsulated and aptamer functionalized silica nanoparticles (AptBACNP) effectively killed only target bacteria L. monocytogenes, but not the non-target cells, Staphylococcus aureus or Escherichia coli. AptBACNP was not cytotoxic to Human cells as determined by in vitro viability assays.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.
