The Promise of Aggregation-Induced Emission Luminogens for Detecting COVID-19

Aminoguanidine-based bioactive proligand as AIEE probe for anticancer and anticovid studies

The emission features of a novel bioactive compound, 1,3-bis(2-hydroxy-3,5-diiodophenyl-methylideneamino)guanidine is found impressive with aggregation induced emission enhancement. The nitrogen and iodine rich multidentate proligand was characterized physicochemically. SCXRD and Hirshfeld surface investigation have revealed the presence of significant triangular iodine bonding apart from hydrogen bonding, weak C-H⋯π and π⋯π intermolecular interactions. These interactions collectively contribute to the solid-state packing arrangement of the molecules within the crystal lattice. The band gap of the compound was estimated experimentally and is supported with theoretical calculations. The solid-state fluorescence quantum yield of Φ = 0.36 emphasizes the utility of the proligand and the AIEE characteristics is attributed to restricted intramolecular motions as indicated by fluorescence lifetime decay studies. Strong interaction of the compound with calf thymus DNA was explored experimentally and found to align with in silico docking results. Notably, in vitro anticancer assessment on MCF-7 breast cancer cells show an IC50 value of 181.05 μg mL-1 and signifying its potent cytotoxic properties. Also, the compound is found to have lesser cytotoxicity against L929 normal cell line with an IC50 value of 356.54 μg mL-1. Computational studies further underscore the exceptional binding affinity with active sites in the SARS-CoV-2 main protease 3CLpro, surpassing established repurposed drugs. Furthermore, the proligand demonstrates excellent putative affinity towards the SARS-CoV-2 spike glycoprotein, accompanied by its distinctive AIEE attributes, drug likeness and DNA binding capability rendering it a valuable tool for prospective research investigations.

Recent Advances in Organic Molecular-to-Supramolecular Self-Assembled Room-Temperature Phosphorescent Materials for Biomedical Applications

This minireview focuses on recent advancements in organic molecular-to-supramolecular self-assembled room-temperature phosphorescent (RTP) materials and their prospective biomedical applications. RTP materials, having their unique capacity to emit long-lasting phosphorescence at ambient temperature, have piqued researchers' interest in various biological applications, including biosensing, bioimaging, drug delivery, and photodynamic therapy (PDT). These materials have several benefits, including high sensitivity, remarkable photostability, and low cytotoxicity. RTP materials' self-assembly into supramolecular structures improves their performance and broadens their uses. Researchers have built organic RTP systems with long-lasting phosphorescence by leveraging weak noncovalent interactions in aquatic conditions. These materials have demonstrated incredible promise as biosensors that enable sensitive analyte detection and as photosensitizers in PDT that target and sensitize specific cell types. The review also outlines future directions and challenges in developing and utilizing pure organic RTP materials for biological imaging purposes, providing valuable guidelines for their future design and application.

Review of HIV Self Testing Technologies and Promising Approaches for the Next Generation

The ability to self-test for HIV is vital to preventing transmission, particularly when used in concert with HIV biomedical prevention modalities, such as pre-exposure prophylaxis (PrEP). In this paper, we review recent developments in HIV self-testing and self-sampling methods, and the potential future impact of novel materials and methods that emerged through efforts to develop more effective point-of-care (POC) SARS-CoV-2 diagnostics. We address the gaps in existing HIV self-testing technologies, where improvements in test sensitivity, sample-to-answer time, simplicity, and cost are needed to enhance diagnostic accuracy and widespread accessibility. We discuss potential paths toward the next generation of HIV self-testing through sample collection materials, biosensing assay techniques, and miniaturized instrumentation. We discuss the implications for other applications, such as self-monitoring of HIV viral load and other infectious diseases.

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.

Highly Efficient Photodynamic Therapy with Mitochondria-Targeting Aggregation-Induced Emission Photosensitizer for Retinoblastoma

Retinoblastoma (RB) is an aggressive eye cancer in infancy and childhood, lethal by metastasis if left untreated. Currently, the survival rate and the chance of saving vision depend on the severity of the disease. In this work, a highly efficient photodynamic ophthalmic therapy for RB is reported by employing an isoquinolinium-based aggregation-induced-emission (AIE) photosensitizer (PS) TPE-IQ-2O for photodynamic inactivation (PDI). TPE-IQ-2O is an efficient mitochondria-targeting photosensitizer as an efficient guided photodynamic therapy (PDT) agent against cancer cells. Maximizing cancer-selectively damage to tumors with minimized side effects on normal tissue is essential for effective anticancer PDT and provides long-lasting protection against metastasis. In addition, TPE-IQ-2O can effectively reduce the degree of tissue inflammation by inhibiting the expression of related inflammatory factors. TPE-IQ-2O also exhibits excellent biocompatibility with a neglectable hemolysis effect on mouse red blood cells and almost no killing effect on mammalian cells, which enables its potential applications in the treatment of RB.

An AIEgen/graphene oxide nanocomposite (AIEgen@GO)-based two-stage "turn-on" nucleic acid biosensor for rapid detection of SARS-CoV-2 viral sequence

The ongoing outbreak of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic has posed significant challenges in early viral diagnosis. Hence, it is urgently desirable to develop a rapid, inexpensive, and sensitive method to aid point-of-care SARS-CoV-2 detection. In this work, we report a highly sequence-specific biosensor based on nanocomposites with aggregation-induced emission luminogens (AIEgen)-labeled oligonucleotide probes on graphene oxide nanosheets (AIEgen@GO) for one step-detection of SARS-CoV-2-specific nucleic acid sequences (Orf1ab or N genes). A dual "turn-on" mechanism based on AIEgen@GO was established for viral nucleic acids detection. Here, the first-stage fluorescence recovery was due to dissociation of the AIEgen from GO surface in the presence of target viral nucleic acid, and the second-stage enhancement of AIE-based fluorescent signal was due to the formation of a nucleic acid duplex to restrict the intramolecular rotation of the AIEgen. Furthermore, the feasibility of our platform for diagnostic application was demonstrated by detecting SARS-CoV-2 virus plasmids containing both Orf1ab and N genes with rapid detection around 1 h and good sensitivity at pM level without amplification. Our platform shows great promise in assisting the initial rapid detection of the SARS-CoV-2 nucleic acid sequence before utilizing quantitative reverse transcription-polymerase chain reaction for second confirmation.

PEG-Polymer Encapsulated Aggregation-Induced Emission Nanoparticles for Tumor Theranostics

In the field of tumor imaging and therapy, the aggregation-caused quenching (ACQ) effect of fluorescent dyes at high concentration is a great challenge. In this regard, the aggregation-induced emission luminogens (AIEgens) show great potential, since AIEgens effectively overcome the ACQ effect and have better fluorescence quantum yield, photobleaching resistance, and photosensitivity. Polyethylene glycol (PEG)-polymer is the most commonly used carrier to prepare nanoparticles (NPs). The advantage of PEGylation is that it can greatly prolong the metabolic half-life and reduce immunogenicity and toxicity. Considering that the hydrophobicity of most AIEgens hinders their application in organisms, the use of PEG-polymer encapsulation is an effective strategy to overcome this obstacle. Importantly, bioactive functional groups can be modified on PEG-polymers to enhance the biological effect of NPs. The combination of powerful AIEgens and PEG-polymers provides a new strategy for tumor imaging and therapy, which is promising for clinical application.