PurposeStaphylococcus aureus is the most common persistent pathogen in humans, so development of new formulations to combat pathogen invasion is quite necessary.MethodsIn the current study, for the first time, the synergistic activity of recombinant lysostaphin and LL-37 peptide was studied against S. aureus. Moreover, different niosomal formulations of the peptide and protein were prepared and analyzed in terms of size, shape, zeta potential, and entrapment efficiency. Also, a long-term antibacterial activity of the best niosomal formulation and free forms was measured against S. aureus in vitro.ResultsThe optimal niosomal formulation was obtained by mixing the surfactants (span60 and tween60; 2:1 w/w), cholesterol, and dicetylphosphate at a ratio of 47:47:6, respectively. They showed uniform spherical shapes with the size of 565 and 325 nm for lysostaphin and LL-37, respectively. This formulation showed high entrapment efficiency for the peptide, protein, and a slow-release profile over time. Release kinetic was best fitted by Higuchi model indicating a diffusion-based release of the drugs. The lysostaphin/LL-37 niosomal formulation synergistically inhibited growth of S. aureus for up to 72 hours. However, the same amounts of free forms of both anti-microbial agents could not hold the anti-microbial effect and growth was seen in the following 72 hours. Cytotoxicity assay specified that lysostaphin/LL-37 niosomal combination had no deleterious effect on normal fibroblast cells at effective antimicrobial concentrations.ConclusionThis study indicated that the use of lysostaphin in combination with LL-37, either in niosomal or free forms, synergistically inhibited growth of S. aureus in vitro. In addition, niosomal preparation of antimicrobial agents could provide a long-term protection against bacterial infections.
Molecular theranostics is of the utmost interest for diagnosis as well as treatment of different malignancies. In the present study, anionic linear globular dendrimer G2 is employed as a suitable carrier for delivery and AS1411 aptamer is exploited as the targeting agent to carry Iohexol specifically to the human breast cancer cells (MCF-7). Dendrimer G2 was prepared and conjugation of dendrimer and aptamer was carried out thereafter. Based on the data yielded by AFM, morphology of smooth and spherical non-targeted dendrimer changed to the rough aspherical shape when it conjugated. Then, conjugation was confirmed using DLS, ELS and SLS methods. Toxicity on nucleolin positive MCF-7 cells and nucleolin negative HEK-293 cells was assessed by XTT and apoptosis/necrosis assays. In vitro uptake was determined using DAPI-FITC staining and ICP-MS methods. In vivo studies including in vivo CT imaging, pathology and blood tests were done to confirm the imaging ability, bio-safety and targeted nature of the Nano-Theranostics in vivo. In a nutshell, the prepared construction showed promising effects upon decreasing the toxicity of Iohexol on normal cells and accumulation of it in the cancer tumors as well as reducing the number of cancer cells.
In the current study, in vitro biological feature of imatinib-loaded silver nanoparticles (IMAB-AgNPs) on human breast cancer cell line was investigated. The formation of synthesized silver nanoparticles (AgNPs) was characterized by UV-Visible spectroscopy, EDS, TEM imaging, SEM, FTIR, DLS and Zeta potentiometer. The developed IMAB-AgNPs with maximum percentage of loading efficiency was demonstrated in the average of 130 nm and mostly spherical. Additionally, in vitro drug release study showed a slow and continuous release of imatinib over a period of 80 h. We demonstrated that the synthesized IMAB-AgNPs exhibited a dose-dependent cytotoxicity against MCF-7 cell line. Then, real-time PCR method was also applied for the investigation of Bax and Bcl-2 gene expression in the cells. Comparing IMAB-AgNPs to AgNPs and Imatinib revealed the ability of IMAB-AgNPs to up-regulating Bax/Bcl-2 ratio. An induction of apoptosis was evidenced by Annexin-V/PI detection assay. Based on the current obtained data, the IMAB-AgNPs can exhibit inhibitory effect on viability through up regulation of apoptosis in MCF-7 cancer cells, which provides influencing evidence for the green synthesized AgNPs as a promising sustained drug delivery system.
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