Cervical cancer has recently become one of the most prevalent cancers among women throughout the world. Traditional cancer therapies generate side effects due to off-target toxicity. Thus, novel cancer medications coupled with suitable drug delivery systems are required to improve cancer therapies. Melittin peptide has a high affinity to disrupt cancer cells. In this study, we designed targeted and redox-responsive Melittin conjugates for cervical cancer and then tested them in vitro. Folic acid and squamous cell carcinoma-specific peptide (CKQNLAEG) were used as targeting agents to design various conjugates. Our findings indicate that both anticancer conjugates were effective against different cancer cell lines, including MCF-7, C33A, and HeLa. Moreover, these conjugates were found to have antioxidant and antibacterial effects as well as reduced hemolytic activity. The CM–Target (N-terminus cysteine modified-Melittin–targeting peptide-functionalized conjugate) has become more stable and acted specifically against squamous cell carcinoma, whereas folic acid (FA)–containing conjugates acted efficiently against all cancer types studied, especially for breast cancer. According to our results, these anticancer conjugates may be possible anticancer drug candidates that have fewer adverse effects.

The need for rapidly developed diagnostic tests has gained significant attention after the recent pandemic. Production of neutralizing antibodies for vaccine development or antibodies to be used in diagnostic tests usually require the usage of recombinant proteins representing the infectious agent. However, peptides that can mimic these recombinant proteins may be rapidly utilized, especially in emergencies such as the recent outbreak. Here, we report two peptides that mimic the receptor binding domain of the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and investigate their binding behavior against the corresponding human immunoglobulin G and immunoglobulin M (IgG and IgM) antibodies in a clinical sample using a quartz crystal microbalance (QCM) sensor. These peptides were immobilized on a QCM sensor surface, and their binding behavior was studied against a clinical serum sample that was previously determined to be IgG and IgM-positive. It was determined that designed peptides bind to SARS-CoV-2 antibodies in a clinical sample. These peptides might be useful for the detection of SARS-CoV-2 antibodies using different methods such as enzyme-linked immunosorbent assay (ELISA) or lateral flow assays. A similar platform might prove to be useful for the detection and development of antibodies in other infections.

In this study, morpholinoethoxy-attached cationic tetra-substituted phthalocyanines (Pcs), including metal-free (HQH ₂ Pc), zinc (HQZnPc), and indium (HQInPc) derivatives, were synthesized following established protocols. Their structures were confirmed by using standard spectroscopic techniques. The photodynamic therapy (PDT) efficacy of these compounds was evaluated against head, neck, and colon cancer cell lines. Reactive oxygen species (ROS) levels induced by PDT with cationic Pcs were quantified by using dichlorodihydrofluorescein diacetate. To elucidate the mechanisms of action, ROS generation was assessed at two distinct time points: 30 min (immediate response) and 24 h (delayed response) post-PDT. The cellular death mechanisms induced by Pc-mediated PDT in cancer cell lines were investigated using fluorescence staining with Apopxin Green, CytoCalcein Violet 450, and 7-AAD to differentiate apoptotic and necrotic pathways and provide insights into the mode of cell death. The results indicated that the Pcs exhibited minimal cytotoxicity in the absence of light, confirming their safety as photosensitizers. Cationic Pcs, particularly HQZnPc, showed high PDT-induced cytotoxicity and ROS production, primarily inducing apoptosis in cancer cell lines, with FaDu cells exhibiting the highest sensitivity. These results highlight HQZnPc’s strong potential for cancer therapy and underscore the need for further research into its delivery and mechanisms in complex tumor models.

In this study, the in vitro photodynamic therapy (PDT) activity of two zinc phthalocyanines (ZnPc1 and ZnPc2) was systematically examined in human umbilical vein endothelial cells, focusing on PDT-induced cytotoxicity, reactive oxygen species (ROS) generation, and inhibition of angiogenic processes. Both the ZnPcs demonstrated minimal cytotoxicity in the absence of light, confirming their safety as photosensitizers. ZnPc-PDT led to significant cell death via apoptosis. ZnPc1 exhibited enhanced ROS generation, particularly at elevated concentrations. Furthermore, ZnPc1-mediated PDT showed more pronounced inhibition of endothelial cell migration, invasion, and capillary-like tube formation than ZnPc2. Wound-healing assays revealed a substantial delay in human umbilical vein endothelial cell (HUVEC) migration following ZnPc1-PDT, which also displayed a more significant inhibition of VEGF-induced directional migration and invasion. Endothelial tube formation was more effectively disrupted by ZnPc1-PDT, even at lower concentrations, compared to ZnPc2. Collectively, these findings highlight the superior cytotoxic and anti-angiogenic properties of ZnPc1 compared with ZnPc2, highlighting its potential as a highly effective photosensitizer for photodynamic therapy. The ability of ZnPc1 to simultaneously target tumor cells and disrupt angiogenesis establishes it as a potent candidate for integrated cancer therapies that combine both antitumor and antiangiogenic strategies, offering a more effective approach to combat cancer progression.

Recent reports on antibiotic resistance have highlighted the need to reduce the impact of this global health issue through urgent prevention and control. The World Health Organization currently considers antibiotic resistance as one of the most dangerous threats to global health. Therefore, Antimicrobial peptides (AMPs) are promising for the development of novel antibiotic molecules due to their high antimicrobial effects, non-inducing antimicrobial resistance (AMR) properties, and broad spectrum. Hence, in this study, we developed novel antimicrobial peptide/polymer conjugates to reduce the adverse effects of TN6 (RLLRLLLRLLR) peptide. We demonstrate how our constructs function in vitro in terms of antimicrobial activity, hemolytic activity, cytotoxicity, and protease resistance. Our findings show that our molecules are effective against different types of microorganisms such as Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, methicillin-resistant S. aureus, vancomycin-resistant Enteroccus faecium, and Candida albicans, which are known to be pathogenic and antibiotic-resistant. Our constructs generally showed low cytotoxicity relative to the peptide in HaCaT and 3T3 cells. Especially these structures are very successful in terms of hemotoxicity. In the bacteremia model with S. aureus, the naked peptide (TN6) was hemotoxic even at 1 µg/mL, while the hemotoxicity of the conjugates was considerably lower than the peptide. Remarkably in this model, the hemolytic activity of PepC-PEG-pepC conjugate decreased 15-fold from 2.36 to 31.12 µg/mL compared to the bacteria-free 60-min treatment. This is proof that in the case of bacteremia and sepsis, the conjugates specifically direct to bacterial cell membranes rather than red blood cells. In addition, the PepC-PEG-pepC conjugate is resistant to plasma proteases. Moreover, morphological and intracellular damage of the peptide/conjugates to Escherichia coli are demonstrated in SEM and TEM images. These results suggest our molecules can be considered potential next-generation broad-spectrum antibiotic molecule/drug candidates that might be used in clinical cases such as bacteremia and sepsis.

In this study, the PDT activities of 2,9(10),16(17),23(24)-tetrakis(2-dimethylammoniumethoxy) phthalocyaninatozinc(II) tetraiodide (ZnPc1) and 1,8(11),15(18),22(25)-tetrakis(2-trimethylaminoethoxy)phthalocyaninatozinc(II)tetraiodide (ZnPc2) compounds were investigated in 2D monolayer cultures and 3D spheroids of three human cancer cell lines: human submaxillary salivary gland epidermoid carcinoma (A253), human colon colorectal adenocarcinoma (HT29), and human pharynx squamous carcinoma (FaDu) cells. The results indicate that both molecules are non-toxic in the absence of light, which is a crucial feature of an effective photosensitizer. Upon exposure to light, ZnPc1 exhibited significant cytotoxicity in all three cell lines, particularly in FaDu cells, in both 2D monolayer cultures and 3D spheroids, whereas ZnPc2 showed moderate efficacy compared to ZnPc1. PDT using both phthalocyanine (Pc) molecules resulted in substantial reactive oxygen species (ROS) production. Delayed ROS production is higher than that of immediate ROS, indicating their ability to stimulate ROS production over an extended period and retain an oxidative stress response in the cells rather than immediately after PDT. Among these molecules, ZnPc1 induced both immediate and delayed ROS production more efficiently than ZnPc2. Furthermore, singlet oxygen yields of ZnPc1 were higher than ZnPc2, which is consistent with the cytotoxicity results. These findings confirmed that PDT induces an ROS-mediated cytotoxic response. The mechanisms of cellular death triggered by PDT were evaluated, and the results revealed that apoptosis was the predominant process. These findings underscore the potential of ZnPc1 as a potent photosensitizer in PDT while also highlighting the differences between 2D and 3D culture models in evaluating PDT efficacy. While the 2D system enables simplified cytotoxicity evaluation, the 3D spheroid model better replicates physiologically relevant environment and treatment resistance. This comparison underscores necessity of integrating 3D models in PDT studies for more predictive in vivo insights.