Fluorescence labelled XT5 modified nano-capsules enable highly sensitive myeloma cells detection.

Accurate diagnosis of cancer cells in early stages plays an important role in reliable therapeutic strategies. In this study, we aimed to develop fluorescence-conjugated polymer carrying nanocapsules (NCs) which is highly selective for myeloma cancer cells. To gain specific targeting properties, NCs, XT5 molecules (a benzamide derivative) which shows high affinity properties against protease-activated receptor-1 (PAR1), that overexpressed in myeloma cancer cells, was used. For this purpose, 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[carboxy(polyethylene glycol)-2000]-carboxylic acid (DSPE-PEG2000-COOH) molecules, as a main encapsulation material, was conjugated to XT5 molecules due to esterification reaction using N,N'-dicyclohexylcarbodiimide as a coupling agent. The synthesized DSPE-PEG2000-COO-XT5 was characterized by using FT-IR and1H NMR spectroscopies and results indicated that XT5 molecules were successfully conjugated to DSPE-PEG2000-COOH. Poly(fluorene-alt-benzothiadiazole) (PFBT) conjugated polymer (CP) was encapsulated with DSPE-PEG2000-COO-XT5 due to dissolving in tetrahydrofuran and ultra-sonication in an aqueous solution, respectively. The morphological properties, UV-vis absorbance, and emission properties of obtainedCPencapsulatedDSPE-PEG2000-COO-XT5(CPDP-XT5) NCs was determined by utilizing scanning electron microscopy, UV-vis spectroscopy, and fluorescent spectroscopy, respectively. Cytotoxicity properties of CPDP-XT5 was evaluated by performing MTT assay on RPMI 8226 myeloma cell lines. Cell viability results confirmed that XT5 molecules were successfully conjugated to DSPE-PEG2000-COOH. Specific targeting properties of CPDP-XT5 NCs and XT5-free NCs (CPDP NCs) were investigated on RPMI 8226 myeloma cell lines by utilizing fluorescent microscopy and results indicated that CPDP-XT5 NCs shows significantly high affinity in comparison to CPDP NCs against the cells. Homology modeling and molecular docking properties of XT5 molecules were evaluated and simulation results confirmed our results.

Rapid fabrication of teflon apertures by controlled high voltage pulses for formation of free standing planar lipid bilayer membrane.

Free standing artificial lipid bilayers are widely used in the study of biological pores. In these types of studies, the free standing planar lipid bilayer is formed over a micron-sized aperture consisting of either polymer such as Polytetrafluoroethylene (PTFE, Teflon) or glass. Teflon is chemically inert, has a low dielectric constant, and has a high electrical resistance which combined allow for obtaining low noise recordings. This study investigates the reproducible generation of micropores in the range of 50-100 microns in diameter in a Teflon film using a high energy discharge set-up. The discharger set-up consists of a microprocessor, a transformer, a voltage regulator, and is controlled by a computer. We compared two approaches for pore creation: single and multi-pulse methods. The results showed that the multi-pulse method produced narrower aperture size distributions and is more convenient for lipid bilayer formation, and thus would have a higher success rate than the single-pulse method. The bilayer stability experiments showed that the lipid bilayer lasts for more than 33 h. Finally, as a proof-of-concept, we show that the single and multi-channel electrophysiology experiments were successfully performed with the apertures created by using the mentioned discharger. In conclusion, the described discharger provides reproducible Teflon-pores in a cheap and easy-to-operate manner.

In vivo imaging/detection of MRSA bacterial infections in mice using fluorescence labelled polymeric nanoparticles carrying vancomycin as the targeting agent.

This study aims to develop fluorescence labelled polymeric nanoparticle (NP) carrying vancomycin as the targeting agent for in vivo imaging of Methicillin-resistant Staphylococcus aureus bacterial infections in animal models. Maleimide functionalized 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[maleimide (polyethylene glycol)-2000] as the main was carrier matrix to prepare the NPs. A fluorescence probe, namely, poly[9,9'-bis (6″-N,N,N-trimethylammonium) hexyl) fluorene-co-alt-4,7-(2,1,3-benzothiadiazole) dibromide] was encapsulated within these NPs by ultrasonication successfully. UV-Vis spectro- photometry of the NPs showed the characteristic shifting on the peak of conjugated polymers indicating successful packaging of this compound with lipid bilayers in nanoscales. Zeta-sizer and TEM analysis showed that the prepared NPs have a diameter of 80-100 nm in a narrow size distribution. Thiolated vancomycin was synthesized and attached to the NPs as the targeting agent. FTIR and MALDI-TOF spectroscopy analysis confirmed the immobilization. The specific targeting properties of the vancomycin conjugated NPs to the target bacteria were first confirmed in in vitro bacterial cultures in which Escherichia coli was the non-target bacteria - using confocal microscopy and TEM. Imaging of bacterial infections in vivo was investigated in mice model using a non-invasive live animal fluorescence imaging technique. The results confirmed that bacterial infections can be detected using these novel polymeric NPs carrying fluorescence probes for imaging and vancomycin as the targeting agent - in vivo successfully.