ACS Omega

Biophysics is a rapidly advancing field with an incredible breadth of topics. Thus, undergraduate biophysics instructors have to strategize and decide what topics they will cover in their courses. Educational institutions utilize a variety of biophysics textbooks. A common deficiency of each of the existing texts is that it serves well a given set of topics (theory, illustrations, practice problems) and leaves out other areas. A typical example includes good theory and problems for thermodynamics and kinetics while presenting molecular dynamics and various spectroscopic methods in a lacking or outdated way. The authors of this manuscript teach a capstone Biophysical Chemistry three-quarter series (Western Washington University/WWU, Bellingham, WA) which ideally should resonate with the general and major-specific courses the students take within their major at WWU. To achieve this goal and to enrich the traditional lecture-based delivery, the instructors have developed and brought together key pedagogical elements: purpose-built online textbook with a uniform structure of the academic content and practice problems, a study sample (oligopeptide) of biophysical significance with a growing set of experimental and computational data and student-centric in-class activities including computer labs. Our Biophysical series emphasizes concepts and methods of computational structural biology (Molecular Dynamics) and spectroscopic approaches (IR, UV and NMR). Here we describe the details of our integrative approach, summarize key outcomes and chart ways to advance the biophysical chemistry series further. Our textbook can be found through LibreText.

Marine macroalgae host endophytic microbial communities that serve as valuable reservoirs for drug discovery. In this study, the endophytic actinomycete Streptomyces sp. UL09 was isolated from the internal thallus tissues of the green macroalga Ulva rigida C. Agardh. Fermentation of strain UL09 yielded the nitrobenzoyl sesquiterpenoids insulicolide B (1.63 mg/L) and insulicolide C (1.79 mg/L). The planar structures of compounds 1 and 2 were assigned as insulicolides B and C, respectively, via spectroscopic analysis and comparison with literature data. In vitro bioassays revealed moderate activity against Gram-positive bacteria (MIC 128-512 g/mL), including MRSA Sp3 (MIC 128-256 g/mL). These compounds exhibited cytotoxic activity against human cancer cell lines (HeLa, HepG2, and MDA-MB-231) with IC50 values ranging from 34.35 to 142.64 g/mL. Both compounds demonstrated lower cytotoxicity toward non-malignant Vero cells. Molecular docking simulations predicted that both metabolites target the catalytic ATP-binding cleft of human Polo-like kinase 1 (Plk1), with insulicolide B displaying a favorable docking score ({Delta}G = -9.273 kcal/mol). Furthermore, pkCSM predicted high intestinal absorption and no alerts for the assessed toxicity endpoints. These findings establish Streptomyces sp. UL09 as a viable alternative biological source of insulicolides B and C, highlighting their potential as leads for oncology applications.

IL-4Ra is a key regulatory receptor for type 2 inflammatory responses, signal transduce from IL-4 and IL-13 through binding with IL-13Ra or the gamma c chain to activate the downstream JAK1-STAT6 pathway. IL-4Ra is currently the most successful "golden target" in the field of allergic disease therapeutics. Its representative monoclonal antibody drug, dupilumab, through the dual blockade mechanism of IL-4/IL-13 has pioneered a new era of precision therapy for type 2 inflammation. In our manuscript, we employed large-scale deep learning-based computational design methods to de novo design mini-protein antagonists specific for both human and mouse IL-4Ra. The binding affinity was improved from 22.1 nM to 569 pM through partial diffusion. The design accuracy and binding specificity were verified through X-ray crystallography and biochemical studies. In vitro IL4/IL13 signal blockade assays revealed that de novo designed monomeric mini-protein antagonist exhibited comparable blockade ability to bivalent dupilumab. In vivo pharmacokinetic half-life studies demonstrated that fusion to an HSA-binding domain extended the half-life of the mini-protein antagonist from 2.7 hours to 60.6 hours. The IL-4Ra mini-protein antagonist had excellent expression levels, solubility and thermal stability. The IL4/IL13 signal blockade ability remained unchanged even after being heating to 95 degrees. In conclusion, through large-scale cluster computing and deep learning-based de novo design, we developed well-performed IL-4Ra mini-protein antagonist, and demonstrates certain potential for drug development.

Kinema is a traditional fermented soybean food indigenous to the eastern Himalayan regions of Nepal and India. The fermentation process is primarily mediated by the bacterium Bacillus subtilis, which produces several bioactive compounds and enzymes with potential therapeutic applications. Considering the growing burden of cardiovascular diseases and the need for effective fibrinolytic agents for thrombolytic therapy, this study aimed to extract, partially purify, and evaluate the thrombolytic potential of kinemakinase derived from kinema prepared from white soybeans. Partial purification of the enzyme was achieved using ammonium sulfate precipitation. Thrombolytic activity was assessed in vitro using human blood clots, where three enzyme dilutions demonstrated clot lysis ranging from 66% to 68%, indicating considerable fibrinolytic potential. In silico analyses were also performed to investigate the structural and functional characteristics of the enzyme. The tertiary structure obtained from UniProt was modeled using the Robetta server and refined with GalaxyRefine. Docking with fibrin using ClusPro 2.0 and molecular dynamics simulations using iMODS confirmed favorable interaction and structural stability, while disulfide engineering enhanced protein stability. The findings suggest that kinema-derived kinemakinase may serve as a promising alternative thrombolytic agent, warranting further biochemical characterization and dosage optimization.

Histone deacetylases (HDACs) are pivotal epigenetic regulators that modulate diverse cellular pathways by removing acetyl groups from lysine residues on both histone and non-histone proteins. Histone deacetylase 11 (HDAC11), the sole member of class IV HDACs, exhibits both deacetylation and fatty acid deacylation activities. Accumulating evidence implicates HDAC11 as a key epigenetic regulator of fundamental cellular processes, including metabolism, immune responses, and tissue development. Dysregulation of HDAC11 activity has been associated with inflammatory diseases, metabolic disorders, neurodegenerative conditions, and cancer, highlighting its potential as a therapeutic target. Although several HDAC11-specific inhibitors have been identified, none have progressed to clinical development. In this study, we aimed to discover HDAC11-selective inhibitors by integrating in silico and in vitro validation approaches. Homology modelling of the HDAC11 structure was conducted, followed by model validation, structure-based virtual screening, molecular dynamics (MD) simulations, and binding free energy calculations. We identified and validated three lead compounds and their intermediates using biochemical and cell-based assays. Fluorescence-based and HPLC-based enzymatic assays demonstrated potent inhibition of both the deacetylase and deacylase activities of HDAC11, with Inhibitor 6 and Inhibitor 3 exhibiting the strongest effects among the six compounds tested. Further, a decrease in lipid accumulation, reduced stability of the HDAC11 substrate SHMT2, as determined by immunoblot analysis and decreased cell viability, as assessed by MTT assay, confirmed HDAC11 inhibition in cellular models. The study shows that new HDAC11 inhibitors significantly reduce the viability of breast cancer cells and induce apoptosis; inhibitor 6, in particular, showed high potency, similar to the reference compound SIS-17. Flow cytometry showed that treated MDA-MB-231 cells exhibited cell-cycle arrest and increased apoptosis, a finding further confirmed by Annexin V/PI staining. Molecular analysis showed that BAX increased while BCL2 decreased, indicating that apoptotic pathways were activated in novel compound-treated MDA-MB-231 cells. The results suggest that inhibiting HDAC11 is an effective way to induce cancer cell death and provide a basis for further assessment of these compounds as potential treatments for breast cancer. Collectively, this study identifies novel zinc-chelating HDAC11 inhibitors containing a nitro-sp2 group, providing promising candidates for further therapeutic development.

Small RNAs (sRNAs) regulate the expression of many genes including those involved in antibiotic resistance and bacterial virulence, making them potential therapeutic targets. A molecule that binds an sRNA could interfere with its ability to bind its target mRNA and disrupt the regulation mechanism. Randomization and screening of natural arginine rich motif (ARM) peptides led to peptides capable of interfering with the sRNA MicF's ability to regulate ompF in Escherichia coli. Molecular dynamics simulations suggested that this effect was not a result of a direct disruption of the MicF-ompF interaction. Instead, the peptides interfere with binding of the chaperone Hfq, which is required for MicF-mediated regulation. Subsequent testing demonstrated peptide specificity for MicF over two other Hfq scaffolds and the ability to disrupt regulation of two additional MicF targets. Together, these findings support the use of synthetic ARMs as a potential tool for modulating sRNA function in bacteria.

Engulfment and Cell Motility protein 1 (ELMO1) regulates cell migration, phagocytosis, and cytoskeletal remodeling, positioning it as a compelling therapeutic target across kidney diseases, oncology, enteric infections and inflammation. Despite this potential, no approved therapeutics or clinically validated small-molecule modulators of ELMO1 currently exist. ELMO1 functions by forming a complex with DOCK180 (or DOCK2) to activate the small GTPase Rac1, and the recent structural resolution of the ELMO1/DOCK2 complex now provides an opportunity to target this protein-protein interface directly. Here, we present the first investigation into the druggability of the ELMO1/DOCK2 complex and report the initial virtual screening to identify small-molecule inhibitors of this interaction. Molecular dynamics (MD) and free energy level (FEL) studies were carried out to validate the potential of the predicted hits. This work establishes a computational framework for the development of the first generation of ELMO1-targeted therapeutics. In addition to demonstrating the drugability of ELMO1, this work introduces two open-source Python tools for the rapid analysis and visualization of protein-protein interaction and ligand-protein MD trajectories from DESMOND output files. These tools are designed to be broadly accessible, offering practical utility to the wider DESMOND user community.

Background: Chronic obstructive pulmonary disease (COPD) is a complex, heterogeneous disease influenced by genetic and environmental factors. However, the interactions between COPD risk genes and their collective role in COPD susceptibility remain largely elusive. We hypothesize that the protein-protein interaction (PPI) network of genes associated with COPD risk can provide molecular insight into the mechanisms of COPD pathogenesis. Methods: We used affinity purification mass spectrometry (AP-MS) to detect protein-protein interactions of six well-established COPD GWAS gene products (AGER, FAM13A, FBXO38, HHIP, IREB2, MFAP2) in two relevant lung cell lines (IMR90, 16HBE). These genes are located in significant COPD GWAS regions, and their physiological role in COPD has been previously confirmed by functional studies. We analyzed the impact of the newly identified interactions in contextual, cell type-specific PPI networks built from the combination of publicly available PPI data (HUBRIS) and cell type-specific gene expression data. Results: Using AP-MS, we identified 482 unique interactors across 701 newly identified protein interactions with the six GWAS gene products in at least one of the cell lines (AGER: 122, FAM13A: 83, FBXO38: 71, HHIP: 108, IREB2: 8, MFAP2: 309). Subsequent network analysis incorporating these new PPIs with public PPI databases revealed: (1) the new interactions significantly reduce the network distance between known COPD GWAS gene products; (2) 5.2% of the newly identified interactors are differentially abundant between COPD cases and controls in lung proteomic data from the Lung Tissue Research Consortium (LTRC); and (3) 41 (14.3%) of the newly identified interactors were directly connected to more than one of the six COPD GWAS genes. We identified a tightly connected core network of COPD GWAS gene products and protein biomarkers with intersecting signals; this network consists of 8 proteins, including 5 of the 6 GWAS gene products (AGER, FAM13A, HHIP, FBXO38, and MFAP2) as well as CAVIN1, TGM2, and HSPA1A. Conclusions: By combining AP-MS experimental data, multiple types of "omics" data, and network analysis, we have constructed a disease network module for COPD. This module can be a foundation for understanding the collective influence of COPD GWAS gene products in disease pathogenesis.

FluPep is a 16 amino-acid peptide with potent anti-viral activity against influenza A virus, including the H1N1 subtype. To understand how FluPep exerts its effects, gold nanoparticles were functionalised with FluPep, since gold nanoparticles provide a very sensitive probe that can be detected optically. Our results demonstrate that nanoparticle-FluPep conjugates did not bind to influenza virus particles in vitro. However, the nanoparticle-FluPep conjugates bound to polyanions on the cell surface, and after washing cells they remained cell-associated and were able to inhibit flu virus infectivity. Nanoparticle-FluPep conjugates bound to heparin affinity columns and their binding to cells could be reduced by pre-treatment of the cells with heparinase and neuraminidase, but not with chondroitinase ABC. These data indicated that FluPep bound to heparan sulfate and sialic acid-containing glycans in the pericellular matrix and in doing so prevented viral infectivity. The importance of the interaction of FluPep with heparan sulfate (HS) was examined by extending FluPep at its C-terminus with amino acid sequences responsible for the interactions of growth factors with heparin. The resultant two new engineered peptides, termed superFluPep1 and superFluPep2, were more potent than parental FluPep. The results demonstrate that FluPep likely exerts its antiviral activity by interfering with virus-cell interactions and that enhancing the binding of such peptides to heparan sulfate is an effective strategy to increase their anti viral potency.

Melittin, the principal bioactive peptide of bee venom, exhibits promising antitumor activity, whereas its molecular mechanisms in cervical cancer remain incompletely understood. In this study, the biological effects and molecular responses of melittin in U14 cervical cancer cells were investigated using Astral data-independent acquisition (Astral-DIA)-based quantitative proteomics combined with molecular validation. The effects of melittin on cell migration, invasion, and cell death were evaluated by Transwell assays and PI/Hoechst staining. Differentially expressed proteins (DEPs) were screened and subjected to Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and protein-protein interaction (PPI) analyses. Representative oxidative stress-related genes and proteins were further validated by RT-qPCR and Western blotting. Melittin significantly inhibited the migration and invasion of U14 cervical cancer cells and increased cell death. Quantitative proteomics identified 9,782 protein groups and 187 DEPs, including 71 up- and 116 down-regulated proteins. KEGG pathway enrichment analysis revealed oxidative phosphorylation (OXPHOS) as the most significantly enriched pathway, together with glutathione metabolism, ferroptosis-related pathways, reactive oxygen species signaling, and mitophagy. GO term enrichment analysis indicated that DEGs were mainly engaged in mitochondrial function, electron transport, oxidoreductase activity, and energy metabolism. RT-qPCR assay demonstrated altered expression of Duox1, Gpx4, Gsx2, Nfe2l2, and Gstp2. Additionally, PPI analysis identified Gstp2 and ODC1 as representative hub proteins involved in redox regulation and metabolic adaptation. Furthermore, Western blotting confirmed increased GSTP2 expression following melittin treatment. Overall, these findings provide a comprehensive proteomic landscape of melittin-treated U14 cervical cancer cells and suggest that mitochondrial OXPHOS remodeling and redox-associated pathways may contribute to the antitumor activity of melittin.

Breast cancer remains one of the leading causes of cancer-related deaths among women worldwide. Drug resistance, toxicity, and limited target specificity are the major challenges in the development of effective therapeutics. Anti-breast cancer peptides (ABCPs) have emerged as effective drug candidate due to its low toxicity, high selectivity, and ability to target cancer. However, it is very time consuming and expensive to identify novel ABCPs only through experiment methods. To address this challenge, we developed ABCP_finder, the first dedicated computational framework specifically designed for the prediction of ABCPs using transformer-based protein language model embeddings. Positive and negative datasets were carefully constructed to ensure a biologically meaningful classification task. To prevent the data leakage and realistic evaluation, homology aware train-test split strategy was utilized by using CD-HIT at 30% sequence identity with 80% coverage. Peptide representations were generated using pretrained transformer models, ProtBERT and ESM2, followed by classification using a multilayer perceptron (MLP). Among the tested models, ProtBERT showed superior performance, achieving 93.82% accuracy, 86.88% recall, 90.59% F1-score, 0.8618 MCC, 96.67% AUC, and a Brier Score of 0.0633, demonstrating strong predictive capability under imbalanced conditions. Calibration analysis supported the selection of a 0.7 probability threshold for identifying high confidence ABCPs. Further external validation using xDeep-AcPEP demonstrated that unknown peptide sequences that has been predicted as ABCPs by ABCP_finder are exhibiting favourable IC values. This supports the biological relevance of these unknown peptides. Overall, ABCP_finder provides a reliable and practical platform for large-scale ABCP screening and can significantly accelerate the discovery of novel peptide therapeutics for breast cancer treatment.

Identifying short peptides that bind therapeutically relevant proteins is a practical step toward developing peptide-based inhibitors. Here we screened 64 tetrapeptides for binding to the IL-17A homodimer using classical all-atom molecular dynamics simulations (GROMACS 2022.2, FF19SB force field, TIP3P water, 200 ns production per complex). Binding was ranked by a composite score that combines short-range interaction energies (Coul-SR + LJ-SR), close-contact frequency, mean intermolecular distance, and hydrogen bond occupancy. The tetrapeptide LYS-THR-CYS-ASP achieved the highest score in the set (composite score 2.85, total interaction energy -556 kJ/mol, average 8.0 H-bonds). Across all 64 simulations, electrostatic interactions accounted for approximately 72% of the total interaction energy. Stronger binders tended to contain charged and polar residues (Asp, Glu, Cys, Arg, Thr), while weaker binders were enriched in hydrophobic residues. Contact analysis identified a recurring interaction surface on IL-17A centered on cysteine and aromatic residues (Chain A: CYS87, Chain B:CYS196, A:HIS86, B:TYR175, B:HIS195), which we describe as a cysteine-aromatic cradle. These results nominate LYS-THR-CYS-ASP as a candidate for experimental binding validation and suggest simple sequence guidelines for designing IL-17A-targeting peptides.

Breast cancer (BC) is the second most common noncutaneous cancer and the second leading cause of cancer-related death in women. BC is classified into three primary subtypes, with triple-negative breast cancer (TNBC) having the poorest prognosis because it lacks specific targetable markers. Preclinical studies on TNBC indicated a common occurrence of diminished tumor-suppressor activity of PTEN, activating the PI3K/AKT/mTOR signaling pathway. Notably, published studies reveal that the WWP1 enzyme plays a pivotal role in driving PTEN degradation via ubiquitination, unveiling a promising therapeutic target for treating TNBC. In the search of new WWP1 inhibitors, we used artificial intelligence (AI)-driven computational strategies for de novo design of peptide-based WWP1 inhibitors and identified a hexapeptide, termed WI23-B, which demonstrated high nanomolar binding affinity to WWP1. In TR-FRET enzymatic assays, WI23-B inhibited WWP1 activity with an IC of approximately 11 {micro}M. In MCF7 and MDA-MB-231 breast cancer cell lines, WI23-B showed promising cytotoxic efficacy, particularly in combination with the PI3K inhibitor BYL719, also when it was loaded into nanocapsules. Collectively, these findings highlight WI23-B as a promising lead peptide with potent WWP1 inhibitory activity and synergistic antiproliferative effects when combined with PI3K inhibitors. While further structural optimization is required to enhance its potency and pharmacological properties, our results provide a strong foundation for the development of next-generation WWP1 inhibitors. Such agents have the potential to reshape therapeutic strategies for BC and TNBC by enabling more effective and less toxic treatment regimens, ultimately reducing the reliance on high-dose chemotherapy and minimizing adverse effects.

Although therapeutic advancements have dramatically improved outcomes for cancer patients in recent decades, advanced cancer remains a significant challenge. There is still an urgent need for new and more effective strategies that minimize toxicity and improve survival outcomes in cancer patients. Natural products from microorganisms are a rich and promising source of bioactive compounds with substantial therapeutic potential in cancer treatment. Recently, B. proteolyticus strain OSUB18, isolated from switchgrass, has been demonstrated to promote plant growth and regulate reactive oxygen species (ROS) production. Here, we investigated the anticancer potential of this plant-associated microbe and demonstrated that its crude extracts exhibited broad-spectrum cytostatic activity across diverse solid tumor cell lines. Importantly, OSUB18 extracts displayed limited cytotoxicity toward normal human mammary epithelial cells and mouse fibroblasts. This potentially selective cytostatic activity was retained within a water soluble, heat-labile, and protease-resistant fraction. The extracts primarily suppressed cell proliferation, accompanied by increased lipid peroxidation, with preliminary evidence suggesting the potential involvement of ferroptosis. These findings suggest that the bioactive component may be a selective cytostatic agent with multifaceted mechanisms of action.

Three copper(II) complexes containing 1,10-phenanthroline derivatives, [CuCl2(phen)].0.5H2O (1), [CuCl2(neo)].0.75H2O (2), and [CuCl2(tmp)].H2O (3), were evaluated for their antitumor activity in MDA-MB-231 breast cancer cells. All complexes markedly reduced cell viability, exhibiting significantly lower IC values and higher selectivity indices than the corresponding free ligands, CuCl2, and cisplatin, highlighting the therapeutic advantage of metal complexation. Among them, only 1 induced DNA damage at sub-IC concentrations. Cytotoxicity in all complexes was associated with intracellular ROS generation and apoptosis, although 2 and 3 produced a stronger oxidative response. Complex 3 additionally promoted necrosis. Cell proliferation was inhibited in a concentration-dependent manner, accompanied by increased intracellular copper accumulation. Moreover, 2 and 3 significantly inhibited Na/H exchanger 1 (NHE1) activity, reducing cell migration and MMP-9 activity. Western blot analysis further demonstrated that all three complexes modulated the expression of NHE1, G protein-coupled estrogen receptor (GPER), and apoptosis-related proteins. Overall, our findings show that ligand methylation enhances the antitumor activity of copper(II) complexes and shifts their mechanism of action from DNA damage-driven cytotoxicity toward ROS-mediated apoptosis, while also improving inhibition of NHE1-dependent migratory pathways. These results identify NHE1 as a key molecular target underlying the enhanced antitumor activity of methylated phenanthroline copper(II) complexes.

This study aims to identify potential inhibitors of the Ag85C enzyme from Mycobacterium tuberculosis through primary docking, pharmacophore modelling, and ADME/pharmacokinetics analysis. Delamanid and Pretomanid emerged as the top hits in primary docking, demonstrating strong binding affinities and interactions with key active site residues. A robust pharmacophore model was developed, identifying essential features for binding and used to screen 4254 antituberculotic compounds, yielding three promising candidates: F0314-0040, F0398-0505, and F0349-2716. These compounds exhibited high binding affinities in major docking studies. ADME and pharmacokinetics analysis revealed favorable Drug likeness and absorption profiles, supporting their potential as effective antituberculotic agents. The integration of computational methods provided a comprehensive approach for rational drug design.

Long noncoding RNAs encode for microproteins that regulate cellular functions. Small regulatory peptide of amino acid response (SPAR) is a microprotein in the lysosome that responds to amino acid availability of the cell. In this study, we investigated the interactions between SPAR and SLC38A9, a lysosomal amino acid transporter and receptor involved in the mechanistic target of rapamycin 1 (mTORC1) pathway. We found that SPAR binds SLC38A9 and inhibits arginine transport in SLC38A9. Moreover, the downstream recruitment of Rag GTPases is also inhibited when SPAR is present in SLC38A9 liposomes. Docking model shows potential interactions between SPAR and SLC38A9. Together, these findings reveal the mechanism of mTORC1 inhibition through microprotein SPAR and illustrates the power of non long coding RNAs in altering cellular functions. Statement of SignificanceMicroproteins encoded from long noncoding RNAs are emerging as critical regulators of many pathways. This study investigates a novel mechanism of SPAR microprotein that directly regulates the mechanistic target of rapamycin complex1 (mTORC1) signaling pathway through the lysosomal amino acid transporter SLC38A9. SPAR blocks both arginine transport and the downstream recruitment of Rag GTPases. These findings provide critical results in how SPAR controls cellular amino acid availability, while broadly highlighting the powerful regulatory mechanism of microproteins in cellular processes.

Translation initiation is a critical stage of protein synthesis in prokaryotes, where ribosomes assemble on mRNA to begin decoding genetic information. The interactions between ribosomal RNA (rRNA) and mRNA significantly influence this process, with features like ribosomal binding site (RBS) affecting ribosomal dynamics. However, direct experimental validation of these types of interaction is yet to be provided. In this study, we developed an optimized small sub-unit sequencing (SSU-seq) protocol for Escherichia coli, enabling the detailed examination of ribosomal complexes and subunits dynamics. Unlike Ribo-seq, which primarily maps fully assembled ribosomes, SSU-seq captures both ribosomal subunits and intact ribosomes, offering a comprehensive view of translation initiation and elongation events. By integrating experimental data with predictive models, our study advances the understanding of translation regulation in prokaryotes and underscores the utility of SSU-seq in decoding the complexities of ribosome-mRNA interactions. Our analysis reveals distinct patterns of small subunit distribution across the entire mRNAs with higher density near positions with stronger rRNA-mRNA hybridization. The results may suggest that rRNA-mRNA hybridization positions along the entire transcript facilitate efficient start codon recognition by maintaining proximity between the small subunit and the mRNA.

The development of NIR fluorescent dyes with favorable optical properties is of great importance especially for applications within the field of optical imaging. In this study, we report the design, synthesis and photophysical characterization of novel BODIPY-Xanthene hybrid dyes obtained via Knoevenagel condensation between an asymmetrical BODIPY core and the functionalized xanthene aldehydes intermediates. The synthesized dyes ex-hibit absorption (667 nm) and emission bands (720-722 nm) within the NIR region. Detailed UV-Vis and fluo-rescence studies were performed and molar extinction coefficients and stokes shifts also calculated. Moreover, findings highlighting the influence of structural modifications on the optical behavior of the hybrid dyes and their potential utility in optical imaging applications are reported.

The cornea is the outermost layer of the eye, most vulnerable to injury including from chemical exposure, either environmental, industrial or chemical weapons. For example, exposure of the eye to sulfur mustard (SM) can cause mustard gas keratopathy, resulting in devastating consequences for vision. Available treatments for corneal mustard keratopathy are either ineffective, or if used for a prolonged time, have deleterious side effects. Here, we aimed to harness the anti-inflammatory and anti-angiogenic peptide angiotensin-(1-7), known as Ang-(1-7), that is derived from the renin-angiotensin system (RAS). We designed and developed a protein-like polymer (PLP) displaying a brush of norleucine modified Ang (1-7) peptides (NLE Ang (1-7) PLP), which is a more potent derivative of Ang-(1-7), for administration as an eye drop. In a mouse model of nitrogen mustard (NM)-induced corneal injury, topical treatment and intraperitoneal (i.p.) injection of NLE Ang (1-7) PLP persistently minimized: (i) corneal haze; (ii) edema; (iii), expression of pro-inflammatory and pro-angiogenic genes; and (iv) neovascularization and conjunctivalization as evidenced after a prolonged treatment and recovery period. Collectively, our observations have demonstrated the efficacy of this novel polymer proteomimetic based eye drop treatment in reducing chemical agent-induced corneal injury as well as indicating its potential application in other ocular surface diseases associated with inflammation and angiogenesis.