Assessing Differential Binding of Aggregation-Induced Emission-Based Luminogens to Host Interacting Surface Proteins of SARS-CoV-2 and Influenza Virus-An in silico Approach

Review of advancement in aggregation-induced emission-based fluorescent biosensors for enzyme detection: Mechanisms and biomedical applications

BACKGROUND

Enzymes, primarily proteins produced by living organisms, exhibit high substrate selectivity and catalytic efficiency. Many are crucial for normal biological processes and are closely associated with the onset of various diseases. As such, developing methods for detecting disease-related enzymes is essential. Biosensors based on aggregation-induced emission (AIE) have gained significant attention due to their outstanding properties, including excellent photostability, high luminescence efficiency in the aggregated state, large Stokes shift, and favorable biocompatibility. This has led researchers to design a variety of fluorogens with AIE characteristics (AIEgens).

RESULTS

This review provides an overview of the luminescence mechanism behind AIE and the key properties of AIEgens. It focuses on the physiological roles of disease-related enzymes and outlines various AIE-based fluorescent biosensors developed for enzyme recognition and detection. These biosensors are categorized according to their mechanisms, including hydrolysis, electrostatic adsorption, biological redox reactions, and pH-response. Additionally, this review explores the application of enzymes in disease progression, highlighting their value in inhibitor screening, traditional Chinese medicine research, sensing, bioimaging, and disease diagnosis and therapy. It also discusses the current limitations of AIEgens and explores emerging opportunities for their application.

SIGNIFICANCE AND NOVELTY

Enzyme activity and levels are closely linked to the development of specific diseases, underscoring the importance of advancing methods for enzyme detection in disease diagnosis and treatment. This review provides valuable insights for the development of innovative AIEgens for enzyme detection, expands the options for detection mechanisms, and offers a theoretical foundation for clinical diagnostics and therapeutic applications.

Cardioprotective effects of cinnamoyl imidazole on apoptosis and oxidative stress in hypoxia/reoxygenation-induced H9C2 cell lines

BACKGROUND

This study explored the effects of cinnamoyl imidazole on alleviating oxidative stress and apoptosis in hypoxia/reoxygenation (H/R)-induced H9C2 cells, using computational analysis with in-vitro validation.

METHODS

Computational techniques, including SwissADME and Swiss Target Prediction, were employed to predict the ADME properties and to identify targets of cinnamoyl imidazole. Differential gene expression (DEG) analysis was conducted on myocardial infarction (MI) datasets obtained from the Gene Expression Omnibus. Gene enrichment and molecular simulation studies were done to focus on apoptotic pathways. The computational findings were validated through In vitro experiments on H9C2 cardiomyocytes subjected to 8 h of hypoxia followed by 24 h of reoxygenation. Antioxidant enzyme levels (catalase, GST, GSH-Px, and SOD), mitochondrial membrane potential (ΔΨm), caspase-3 activity, and the expression of CASP3, MAPK8, JAK2, and BCL2L1 were assessed.

RESULTS

Cinnamoyl imidazole has demonstrated favourable pharmacokinetic properties, characterized by high gastrointestinal absorption and low toxicity with negative toxicity for organ endpoints. Molecular docking studies revealed the strong binding affinities for CASP3, MAPK8, and JAK2. In vitro results showed a significant increase in cell viability (94.7 % at 10 μM, p < 0.001) and antioxidant enzyme activity, along with a 64.3 % reduction in caspase-3 activity at 1000 μM (p < 0.01). Cinnamoyl imidazole treatment preserved mitochondrial membrane potential, downregulated pro-apoptotic genes CASP3 and MAPK8, and upregulated the anti-apoptotic gene BCL2L1.

CONCLUSION

Cinnamoyl imidazole effectively mitigates oxidative stress and apoptosis in H/R-induced H9C2 cells, enhancing cell viability and antioxidant defenses while maintaining mitochondrial integrity.

Noncancerous disease-targeting AIEgens

Noncancerous diseases include a wide plethora of medical conditions beyond cancer and are a major cause of mortality around the world. Despite progresses in clinical research, many puzzles about these diseases remain unanswered, and new therapies are continuously being sought. The evolution of bio-nanomedicine has enabled huge advancements in biosensing, diagnosis, bioimaging, and therapeutics. The recent development of aggregation-induced emission luminogens (AIEgens) has provided an impetus to the field of molecular bionanomaterials. Following aggregation, AIEgens show strong emission, overcoming the problems associated with the aggregation-caused quenching (ACQ) effect. They also have other unique properties, including low background interferences, high signal-to-noise ratios, photostability, and excellent biocompatibility, along with activatable aggregation-enhanced theranostic effects, which help them achieve excellent therapeutic effects as an one-for-all multimodal theranostic platform. This review provides a comprehensive overview of the overall progresses in AIEgen-based nanoplatforms for the detection, diagnosis, bioimaging, and bioimaging-guided treatment of noncancerous diseases. In addition, it details future perspectives and the potential clinical applications of these AIEgens in noncancerous diseases are also proposed. This review hopes to motivate further interest in this topic and promote ideation for the further exploration of more advanced AIEgens in a broad range of biomedical and clinical applications in patients with noncancerous diseases.

Bis(thio)carbohydrazone Luminogens with AIEE and ACQ Features and Their In Silico Investigations with SARS-CoV-2

Herein, we report two novel multidentate luminogen proligands bis(3,5-diiodosalicylidene) carbohydrazone (H4L1) and bis(3,5-diiodosalicylidene) thiocarbohydrazone (H4L2), which are suitable candidates for biomedical applications. Though the thiocarbohydrazone H4L2 shows aggregation caused quenching (ACQ), the carbohydrazone H4L1 exhibits stronger fluorescence due to aggregation induced emission enhancement (AIEE). Molecular docking studies of H4L1 and H4L2 along with four similar (thio)carbohydrazones with the active sites of SARS-CoV-2 main protease 3CLpro reveals that the thiocarbohydrazones, in general, are showing better propensity compared to their oxygen analogues. Both the thiocarbohydrazones and the carbohydrazones, however, exhibit better binding potential at the active sites than that of some of the repurposed drugs such as chloroquine, hydroxychloroquine, lopinavir, ritonavir, darunavir and remdesivir. Also, the carbohydrazone H4L1 can be a better bioprobe compared to H4L2 as the former is found to have better binding potential with SARS-CoV-2 spike glycoprotein along with AIEE feature.