Pegylated metal-free and zinc(II) phthalocyanines: synthesis, photophysicochemical properties and in vitro photodynamic activities against head, neck and colon cancer cell lines.

In this study, a series of peripherally and non-peripherally tetra-substituted metal-free and zinc(II) phthalocyanines were successfully prepared in good yields by cyclotetramerization of the phthalonitrile derivative bearing a tetraethylene glycol methyl ether group at 3- and 4- positions. All newly synthesized compounds were characterized using spectroscopic methods, such as FT-IR, NMR, mass and UV-Vis spectroscopy. To determine the therapeutic potential of the synthesized phthalocyanines, the effects of the substitution pattern (peripheral and non-peripheral) and central metal atom on the photophysicochemical properties were investigated. When comparing their singlet oxygen generation capabilities (ΦΔ), metallo-phthalocyanine derivatives with zinc (0.73 for 1b and 0.70 for 2b) showed higher singlet oxygen yield than metal-free derivatives (0.21 for 1a and 0.12 for 2a) in DMSO. The photodynamic therapy activities of the water-soluble phthalocyanines were tested via in vitro studies using the A253, FaDu (head and neck cancer cell lines), and HT29 (colon cancer) cell lines. The strongest photodynamic activity was found in 1b and 2b molecules with a metal core among the four molecules studied. The results suggested that the non-peripherally tetra-substituted 1b molecule was regarded as a suitable photodynamic therapy agent due to its light cytotoxicity and secondary impact induced by ROS production.

Structure-based engineering of an antiangiogenic scFv antibody for soluble production in E. coli without loss of activity.

Development of monoclonal antibody therapeutics against vascular endothelial growth factor receptor 2 (VEGFR-2) protein, which is the main regulator in angiogenesis, has been a major challenge for years. In the current study, we engineer an inclusion body forming single-chain variable fragment (scFv) against VEGFR-2 by using complementarity determining regions (CDR) grafting technique to improve its solubility and investigate the activity of the engineered molecule. CDR sequences of the target scFv were grafted into the framework of another intrinsically soluble scFv molecule. Based on the computational results, CDR grafting has increased the solubility of the grafted scFv molecule. Results confirmed that the grafting approach increased in vivo folding properties of the target scFv molecule compared with the original scFv molecule. Similar binding affinities to the VEGFR-2 were observed for the original and the grafted scFv by surface plasmon resonance assays. Biological activity assays, including human umbilical vein endothelial cells proliferation and wound healing assays, showed that grafted scFv molecule has an antiangiogenic property. This study suggests that an antiangiogenic scFv fully expressed as an inclusion body can be rescued by grafting its CDR regions to a scFv expressed in a soluble form without any loss in its binding property and its activity.

The neutralization effect of montelukast on SARS-CoV-2 is shown by multiscale in silico simulations and combined in vitro studies.

Small molecule inhibitors have previously been investigated in different studies as possible therapeutics in the treatment of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). In the current drug repurposing study, we identified the leukotriene (D4) receptor antagonist montelukast as a novel agent that simultaneously targets two important drug targets of SARS-CoV-2. We initially demonstrated the dual inhibition profile of montelukast through multiscale molecular modeling studies. Next, we characterized its effect on both targets by different in vitro experiments including the enzyme (main protease) inhibition-based assay, surface plasmon resonance (SPR) spectroscopy, pseudovirus neutralization on HEK293T/hACE2+TMPRSS2, and virus neutralization assay using xCELLigence MP real-time cell analyzer. Our integrated in silico and in vitro results confirmed the dual potential effect of montelukast both on the main protease enzyme inhibition and virus entry into the host cell (spike/ACE2). The virus neutralization assay results showed that SARS-CoV-2 virus activity was delayed with montelukast for 20 h on the infected cells. The rapid use of new small molecules in the pandemic is very important today. Montelukast, whose pharmacokinetic and pharmacodynamic properties are very well characterized and has been widely used in the treatment of asthma since 1998, should urgently be completed in clinical phase studies and, if its effect is proved in clinical phase studies, it should be used against coronavirus disease 2019 (COVID-19).

Identifying specific matrix metalloproteinase-2-inhibiting peptides through phage display-based subtractive screening.

Gelatinases A and B, which are members of the matrix metalloproteinase (MMP) family, play essential roles in cancer development and metastasis, as they can break down basal membranes. Therefore, the determination and inhibition of gelatinases is essential for cancer treatment. Peptides that can specifically block each gelatinase may, therefore, be useful for cancer treatment. In this study, subtractive panning was carried out using a 12-mer peptide library to identify peptides that block gelatinase A activity (MMP-2), which is a key pharmacological target. Using this method, 17 unique peptide sequences were determined. MMP-2 inhibition by these peptides was evaluated through zymogram analyses, which revealed that four peptides inhibited MMP-2 activity by at least 65%. These four peptides were synthesized and used for in vitro wound healing using human umbilical vein endothelial cells, and two peptides, AOMP12 and AOMP29, were found to inhibit wound healing by 40%. These peptides are, thus, potential candidates for MMP-2 inhibition for cancer treatment. Furthermore, our findings suggest that our substractive biopanning screening method is a suitable strategy for identifying peptides that selectively inhibit MMP-2.