The protective effects of Zingiber zerumbet rhizome against fevers in rats.

The Zingiber zerumbet rhizomes are traditionally used to treat fever, and the in vitro inhibitory effect of ethyl acetate extract from Zingiber zerumbet rhizomes (EAEZZR) against DENV2 NS2B/NS3 (two non-structural proteins, NS2 and NS3 of dengue virus type 2) has been reported earlier. This study was carried out to establish an acute toxicity profile and evaluate the anti-fever (anti-pyretic) activities of EAEZZR in yeast-induced fever in rats. The major compound of EAEZZR, zerumbone, was isolated using chromatographic methods including column chromatography (CC) and preparative thin-layer chromatography (PTLC). Additionally, the structure of zerumbone was elucidated using nuclear magnetic resonance (NMR), liquid chromatography mass spectrometer-ion trap-time of flight (LCMS-IT-TOF), infrared (IR), and ultraviolet (UV) spectroscopy. The toxicity of EAEZZR was evaluated using Organization for Economic Cooperation and Development Test Guideline 425 (OECD tg-425) with minor modifications at concentrations EAEZZR of 2000 mg/kg, 3000 mg/kg, and 5000 mg/kg. Anti-fever effect was determined by yeast-induced fever (pyrexia) in rats. The acute toxicity study showed that EAEZZR is safe at the highest 5000 mg/kg body weight dose in Sprague Dawley rats. Rats treated with EAEZZR at doses of 125, 250, and 500 mg/kg exhibited a significant reduction in rectal temperature (TR) in the first 1 h. EAEZZR at the lower dose of 125 mg/kg showed substantial potency against yeast-induced fever for up to 2 h compared to 0 h in controls. A significant reduction of TR was observed in rats treated with standard drug aspirin in the third through fourth hours. Based on the present findings, ethyl acetate extract of Zingiber zerumbet rhizomes could be considered safe up to the dose of 5000 mg/kg, and the identification of active ingredients of Zingiber zerumbet rhizomes may allow their use in the treatment of fever with dengue virus infection.

Development, optimization and characterization of cisplatin loaded cubosomes for human lung carcinoma.

OBJECTIVES: This study aimed to develop, optimize and evaluate glyceryl monooleate (GMO) based cubosomes as a drug delivery system containing cisplatin for treatment of human lung carcinoma. SIGNIFICANCE: The significance of this research was to successfully incorporate slightly water soluble and potent anticancer drug (cisplatin) into cubosomes, which provide slow and sustained release of drug for longer period of time. METHODS: The delivery system was developed through top-down approach by melting GMO and poloxamer 407 (P407) at 70 °C and then drop-wise addition of warm deionized water (70 °C) containing cisplatin. The formulation then exposed to probe sonicator for about 2 min. A randomized regular two level full factorial design with help of Design Expert was used for optimization of blank cubosomal formulations. Cisplatin loaded cubosomes were then subjected to physico-chemical characterization. RESULTS: The characterization of the formulation revealed that it had a sufficient surface charge of -9.56 ± 1.33 mV, 168.25 ± 5.73 nm particle size, and 60.64 ± 0.11% encapsulation efficiency. The in vitro release of cisplatin from the cubosomes at pH 7.4 was observed to be sustained, with 94.5% of the drug being released in 30 h. In contrast, 99% of cisplatin was released from the drug solution in just 1.5 h. In vitro cytotoxicity assay was conducted on the human lung carcinoma NCI-H226 cell line, the cytotoxicity of cisplatin-loaded cubosomes was relative to that of pure cisplatin solution, while blank (without cisplatin) cubosomes were nontoxic. CONCLUSIONS: The obtained results demonstrated the successful development of cubosomes for sustained delivery of cisplatin.

Cubosomes were prepared, optimized, and evaluated for cisplatin delivery.A randomized regular two level full factorial design was constructed to optimize blank cubosomes.Blank cubosomes consisted of GMO as the lipid and P407 as an emulsifying agent.In vitro release studies demonstrated sustained release of cisplatin from cubosomes at pH 7.4.Cytotoxicity assay on human lung carcinoma cell line NCI-H226 showed similar cytotoxicity between cisplatin-loaded cubosomes and pure cisplatin solution while blank cubosomes exhibited no toxicity.

Platinum-based targeted chemotherapies and reversal of cisplatin resistance in non-small cell lung cancer (NSCLC).

Lung cancer is the one of the most prevalent cancer in the world. It kills more people from cancer than any other cause and is especially common in underdeveloped nations. With 1.2 million instances, it is also the most prevalent cancer in men worldwide, making about 16.7% of the total cancer burden. Surgery is the main form of curative treatment for early-stage lung cancer. However, the majority of patients had incurable advanced non-small cell lung cancer (NSCLC) recurrence after curative purpose surgery, which is indicative of the aggressiveness of the illness and the dismal outlook. The gold standard of treatment for NSCLC patients includes drug targeting of specific mutated genes drive in development of lung cancer. Furthermore, patients with advanced NSCLC and those with early-stage illness needing adjuvant therapy should use cisplatin as it is the more active platinum drug. So, this review encompasses the non-small cell lung cancer microenvironment, treatment approaches, and use of cisplatin as a first-line regimen for NSCLC, its mechanism of action, cisplatin resistance in NSCLC and also the prevention strategies to revert the drug resistance.

Synthesis, biological activities, and evaluation molecular docking-dynamics studies of new phenylisoxazole quinoxalin-2-amine hybrids as potential α-amylase and α-glucosidase inhibitors.

New phenylisoxazole quinoxalin-2-amine hybrids 5a-i were successfully synthesised with yields of 53-85% and characterised with various spectroscopy methods. The synthesised hybrids underwent in vitro α-amylase and α-glucosidase inhibitory assays, with acarbose as the positive control. Through the biological study, compound 5h exhibits the highest α-amylase inhibitory activity with IC50 = 16.4 ± 0.1 µM while compounds 5a-c, 5e and 5h exhibit great potential as α-glucosidase inhibitors, with 5c being the most potent (IC50 = 15.2 ± 0.3 µM). Among the compounds, 5h exhibits potential as a dual inhibitor for both α-amylase (IC50 = 16.4 ± 0.1 µM) and α-glucosidase (IC50 = 31.6 ± 0.4 µM) enzymes. Through the molecular docking studies, the inhibition potential of the selected compounds is supported. Compound 5h showed important interactions with α-amylase enzyme active sites and exhibited the highest binding energy of -8.9 ± 0.10 kcal mol-1, while compound 5c exhibited the highest binding energy of -9.0 ± 0.20 kcal mol-1 by forming important interactions with the α-glucosidase enzyme active sites. The molecular dynamics study showed that the selected compounds exhibited relative stability when binding with α-amylase and α-glucosidase enzymes. Additionally, compound 5h demonstrated a similar pattern of motion and mechanism of action as the commercially available miglitol.

Quassinoids from Eurycoma longifolia as Potential Dihydrofolate Reductase Inhibitors: A Computational Study.

BACKGROUND: Quassinoids are degraded triterpene compounds that can be obtained from various species of the Simaroubaceae plant family, including Eurycoma longifolia. Quassinoids are the major compounds in E. longifolia, and they are known to have various medicinal potentials, such as anticancer and antimalarial properties. Dihydrofolate reductase (DHFR) was reported to be one of the important targets for certain anticancer and antimalarial drugs. Twelve quassinoids from E. longifolia were identified to have anticancer effects based on their IC50 values. This study aimed to evaluate the interactions of these twelve quassinoids with DHFR via Autodock 4.2 software and Biovia Discovery Studio Visualiser. METHODS: Twelve quassinoids from E. longifolia and their interactions with DHFR were evaluated via Autodock 4.2 software and Biovia Discovery Studio Visualiser. Their drug-likeness and pharmacokinetic properties were also assessed using the ADMETlab 2.0 program. RESULTS: The molecular docking results showed that eleven quassinoids showed better docking scores than methotrexate, in which the binding energy (BE) of these quassinoids ranged from - 7.87 to -9.58 kcal/mol. Their inhibition constant (Ki) ranged from 0.095 to 1.71 µM. At the same time, the BE and Ki values for methotrexate were -7.80 kcal/mol and 1.64 µM, respectively. CONCLUSION: From the analysis, 6-dehydrolongilactone and eurycomalide B are among the twelve compounds that showed great potential as hit-to-lead compounds based on the docking score on DHFR, drug-likeness, and ADMET properties. These results suggest a great potential to pursue validation studies via in vitro and in vivo models.

Synthesis and biological activity of imidazole phenazine derivatives as potential inhibitors for NS2B-NS3 dengue protease.

A series of new imidazole-phenazine derivatives were synthesized via a two-step process. The condensation of 2,3-diaminophenazine and benzaldehyde derivatives proceeds with intermediate formation of an aniline Schiff base, which undergoes subsequent cyclodehydrogenation in situ. The structures of the synthesized compounds were characterized by 1D and 2D NMR, FTIR and HRMS. A total of thirteen imidazole phenazine derivatives were synthesized and validated for their inhibitory activity as anti-dengue agents by an in vitro DENV2 NS2B-NS3 protease assay using a fluorogenic Boc-Gly-Arg-Arg-AMC substrate. Two para-substituted imidazole phenazines, 3e and 3k, were found to be promising lead molecules for novel NS2B-NS3 protease inhibitors with IC50 of 54.8 µM and 71.9 µM, respectively, compared to quercetin as a control (IC50 104.8 µM). The in silico study was performed using AutoDock Vina to identify the binding energy and conformation of 3e and 3k with the active site of the DENV2 NS2B-NS3 protease Wichapong model. The results indicate better binding properties of 3e and 3k with calculated binding energies of -8.5 and -8.4 kcal mol-1, respectively, compared to the binding energy of quercetin of -7.2 kcal mol-1, which corroborates well with the experimental observations.

Breaking barriers: bilosomes gel potentials to pave the way for transdermal breast cancer treatment with Tamoxifen.

OBJECTIVE: Breast cancer affects women globally, regardless of age or location. On the other hand, Tamoxifen (TXN), a class II biopharmaceutical drug is acting as a prophylactic/treating agent for women at risk of and/or with hormone receptor-positive breast cancer. However, its oral administration has life-threatening side effects, which have led researchers to investigate alternative delivery methods. One such method is transdermal drug delivery utilizing bile salts as penetration enhancers, aka Bilosomes. METHODS: Bilosomes formulations were optimized statistically for the outcome of vesicle shape, size, and entrapment efficiency using two types of bile, i.e. sodium taurocholate and sodium cholate. These bilosomes were then loaded into HPMC base gel and further characterized for their morphology, drug content, pH, viscosity, spreadability and eventually ex-vivo skin penetration and deposition studies. RESULTS: Findings showed that sodium cholate has superiority as a penetration enhancer over sodium taurocholate in terms of morphological characterizes, zeta potential, and cumulative amounts of tamoxifen permeated per unit area (15.13 ± 0.71 µg/cm2 and 6.51 ± 0.6 µg/cm2 respectively). In fact, bilosomes designed with sodium cholate provided around 9 folds of skin deposition compared to TXN non-bilosomal gel. CONCLUSION: Bilosomes gels could be a promising option for locally delivering tamoxifen to the breast through the skin, offering an encouraging transdermal solution.

Comparative Study of In Situ Gel Formulation Based on the Physico-Chemical Aspect: Systematic Review.

In recent years, in situ gel delivery systems have received a great deal of attention among pharmacists. The in situ gelation mechanism has several advantages over ointments, the most notable being the ability to provide regular and continuous drug delivery with no impact on visual clarity. Bioavailability, penetration, duration, and maximum medication efficacy are all improved by this mechanism. Our review systematically synthesizes and discusses comparisons between three types of in situ gelling system according to their phase change performance based on the physicochemical aspect from publications indexed in the Pubmed, ResearchGate, Scopus, Elsevier, and Google Scholar databases. An optimal temperature-sensitive in situ gelling solution must have a phase change temperature greater than ambient temperature (25 °C) to be able to be readily delivered to the eye; hence, it was fabricated at 35 °C, which is the precorneal temperature. In a pH-sensitive gelling system, a gel develops immediately when the bio-stimuli come into contact with it. An in situ gelling system with ionic strength-triggered medication can also perhaps be used in optical drug-delivery mechanisms. In studies about the release behavior of drugs from in situ gels, different models have been used such as zero-order kinetics, first-order kinetics, the Higuchi model, and the Korsmeyer-Peppas, Peppas-Sahlin and Weibull models. In conclusion, the optimum triggering approach for forming gels in situ is determined by a certain therapeutic delivery application combined with the physico-chemical qualities sought.

Synthesis, biological evaluation, and molecular modelling of novel quinoxaline-isoxazole hybrid as anti-hyperglycemic.

In our effort to develop potent anti-hyperglycemic compounds with inhibitory activity against α-amylase and α-glucosidase, a series of novel quinoxaline-isoxazole moieties were synthesized. The novel quinoxaline-isoxazole derivatives were assessed in vitro for their anti-hyperglycemic activities on α-amylase and α-glucosidase inhibitions. The results revealed promising IC50 values compared to acarbose as a positive control for α-amylase and α-glucosidase. Among them, N-Ethyl-7-chloro-3-((3-phenylisoxazol-5-yl)methoxy)quinoxalin-2-amine 5b showed dual inhibitory with IC50 of 24.0 µM for α-amylase and 41.7 µM for α-glucosidase. In addition, N-Ethyl-7-methoxy-3-((3-(2-chlorophenyl)isoxazol-5-yl)methoxy)quinoxalin-2-amine 5j also had dual bioactivities against α-amylase and α-glucosidase with IC50 of 17.0 and 40.1 µM, respectively. Nevertheless, two more compounds N-Ethyl-7-cyano-3-((3-phenylisoxazol-5-yl)methoxy)quinoxaline-2-amine 5e showed strong mono-inhibition for α-glucosidase with IC50 of 16.6 µM followed by N-Ethyl-7-methoxy-3-((3-phenylisoxazol-5-yl)methoxy)quinoxalin-2-amine 5 f with IC50 of 18.6 µM. The molecular docking study for α-glucosidase inhibitor provided the binding energy ranging from 8.3 to 9.1 kcal/mol and α-amylase inhibitor showed the binding energy score at 8.4 and 8.5 kcal/mol. The dual inhibitions nature of 5b and 5j were further analyzed and confirmed via molecular dynamics including the stability of the compound, interaction energy, binding free energy, and the interaction residue analysis using the MM-GBSA approach. The results showed that compound 5j was the most potent compound. Lastly, the drug-likeness properties were also evaluated with all synthesized compounds 5a-5j and the results reveal that all potent compounds meet Lipinski's rules of five.

In Vitro and In Silico Analysis of the Anticancer Effects of Eurycomanone and Eurycomalactone from Eurycoma longifolia.

Eurycomanone and eurycomalactone are known quassinoids present in the roots and stems of Eurycoma longifolia. These compounds had been reported to have cytotoxic effects, however, their mechanism of action in a few cancer cell lines have yet to be elucidated. This study was aimed at investigating the anticancer effects and mechanisms of action of eurycomanone and eurycomalactone in cervical (HeLa), colorectal (HT29) and ovarian (A2780) cancer cell lines via Sulforhodamine B assay. Their mechanism of cell death was evaluated based on Hoechst 33342 assay and in silico molecular docking toward DHFR and TNF-α as putative protein targets. Eurycomanone and eurycomalactone exhibited in vitro anticancer effects manifesting IC50 values of 4.58 ± 0.090 µM and 1.60 ± 0.12 µM (HeLa), 1.22 ± 0.11 µM and 2.21 ± 0.049 µM (HT-29), and 1.37 ± 0.13 µM and 2.46 ± 0.081 µM (A2780), respectively. They induced apoptotic cancer cell death in dose- and time-dependent manners. Both eurycomanone and eurycomalactone were also predicted to have good inhibitory potential as demonstrated by the docking into TNF-α with binding affinity of -8.83 and -7.51 kcal/mol, respectively, as well as into DHFR with binding affinity results of -8.05 and -8.87 kcal/mol, respectively. These results support the evidence of eurycomanone and eurycomalactone as anticancer agents via apoptotic cell death mechanism that could be associated with TNF-α and DHFR inhibition as among possible protein targets.

Phaleria macrocarpa (Scheff.) Boerl.: An updated review of pharmacological effects, toxicity studies, and separation techniques.

Phaleria macrocarpa (Scheff.) Boerl. is geographically distributed around Papua Island, Indonesia. Traditionally, P. macrocarpa is exercised to reduce pain, stomachache, diarrhea, tumor problems, blood glucose, cholesterol, and blood pressure. A growing interest in the medicinal values of P. macrocarpa especially in Asia reflects the usage of diverse extraction techniques, particularly modern approaches. In this review article, the extraction methods and solvents relevant to P. macrocarpa were discussed, with the extent of its pharmacological activities. Recent bibliographic databases such as Google Scholar, PubMed, and Elsevier between 2010 and 2022 were assessed. Based on the findings, the pharmacological studies of P. macrocarpa are still pertinent to its traditional uses but primarily emphasise anti-proliferative activity especially colon and breast cancer cells with low toxicity and fruit as the most studied plant part. The utilization of modern separation techniques has predominantly been aimed at extracting mangiferin and phenolic-rich compounds and evaluating their antioxidant capacity. However, the isolation of bioactive compounds remains a challenge, leading to the extensive utilization of the extracts in in vivo studies. This review endeavors to highlight modern extraction methods that could potentially be used as a point of reference in the future for exploring novel bioactive compounds and drug discovery on a multi-scale extraction level.

Assessing the potential of NS2B/NS3 protease inhibitors biomarker in curbing dengue virus infections: In silico vs. In vitro approach.

An increase in the occurrence of viral infectious diseases is a global concern for human health. According to a WHO report, dengue virus (DENV) is one of the most common viral diseases affecting approximately 400 million people annually, with worsening symptoms in nearly 1% of cases. Both academic and industrial researchers have conducted numerous studies on viral epidemiology, virus structure and function, source and route of infection, treatment targets, vaccines, and drugs. The development of CYD-TDV or Dengvaxia® vaccine has been a major milestone in dengue treatment. However, evidence has shown that vaccines have some drawbacks and limitations. Therefore, researchers are developing dengue antivirals to curb infections. DENV NS2B/NS3 protease is a DENV enzyme essential for replication and virus assembly, making it an interesting antiviral target. For faster hit and lead recognition of DENV targets, methods to screen large number of molecules at lower costs are essential. Similarly, an integrated and multidisciplinary approach involving in silico screening and confirmation of biological activity is required. In this review, we discuss recent strategies for searching for novel DENV NS2B/NS3 protease inhibitors from the in silico and in vitro perspectives, either by applying one of the approaches or by integrating both. Therefore, we hope that our review will encourage researchers to integrate the best strategies and encourage further developments in this area.

Potential Anti-Cholinesterase Activity of Bioactive Compounds Extracted from Cassia grandis L.f. and Cassia timoriensis DC.

Acetylcholinesterase (AChE) inhibitors remain the primary therapeutic drug that can alleviate Alzheimer's disease's (AD) symptoms. Several Cassia species have been shown to exert significant anti-AChE activity, which can be an alternative remedy for AD. Cassia timoriensis and Cassia grandis are potential plants with anti-AChE activity, but their phytochemical investigation is yet to be further conducted. The aims of this study were to identify the phytoconstituents of C. timoriensis and C. grandis and evaluate their inhibitory activity against AChE and butyrylcholinesterase (BChE). Two compounds were isolated for the first time from C. timoriensis: arachidyl arachidate (1) and luteolin (2). Five compounds were identified from C. grandis: ß-sitosterol (3), stigmasterol (4), cinnamic acid (5), 4-hydroxycinnamic acid (6), and hydroxymethylfurfural (7). Compound 2 showed significant inhibition towards AChE (IC50: 20.47 ± 1.10 µM) and BChE (IC50: 46.15 ± 2.20 µM), followed by 5 (IC50: 40.5 ± 1.28 and 373.1 ± 16.4 µM) and 6 (IC50: 43.4 ± 0.61 and 409.17 ± 14.80 µM) against AChE and BChE, respectively. The other compounds exhibited poor to slightly moderate AChE inhibitory activity. Molecular docking revealed that 2 showed good binding affinity towards TcAChE (PDB ID: 1W6R) and HsBChE (PDB ID: 4BDS). It formed a hydrogen bond with TYR121 at the peripheral anionic site (PAS, 2.04 Å), along with hydrophobic interactions with the anionic site and PAS (TRP84 and TYR121, respectively). Additionally, 2 formed three H-bonds with the binding site residues: one bond with catalytic triad, HIS438 at distance 2.05 Å, and the other two H-bonds with GLY115 and GLU197 at distances of 2.74 Å and 2.19 Å, respectively. The evidence of molecular interactions of 2 may justify the relevance of C. timoriensis as a cholinesterase inhibitor, having more promising activity than C. grandis.

Insights into the Pathophysiology of Alzheimer's Disease and Potential Therapeutic Targets: A Current Perspective.

The aging population increases steadily because of a healthy lifestyle and medical advancements in healthcare. However, Alzheimer's disease (AD) is becoming more common and problematic among older adults. AD-related cases show an increasing trend annually, and the younger age population may also be at risk of developing this disorder. AD constitutes a primary form of dementia, an irreversible and progressive brain disorder that steadily damages cognitive functions and the ability to perform daily tasks. Later in life, AD leads to death as a result of the degeneration of specific brain areas. Currently, the cause of AD is poorly understood, and there is no safe and effective therapeutic agent to cure or slow down its progression. The condition is entirely preventable, and no study has yet demonstrated encouraging findings in terms of treatment. Identifying this disease's pathophysiology can help researchers develop safe and efficient therapeutic strategies to treat this ailment. This review outlines and discusses the pathophysiology that resulted in the development of AD including amyloid-ß plaques, tau neurofibrillary tangles, neuroinflammation, oxidative stress, cholinergic dysfunction, glutamate excitotoxicity, and changes in neurotrophins level may sound better based on the literature search from Scopus, PubMed, ScienceDirect, and Google Scholar. Potential therapeutic strategies are discussed to provide more insights into AD mechanisms by developing some possible pharmacological agents for its treatment.

tLyp-1: A peptide suitable to target NRP-1 receptor.

Targeting vascular endothelial growth factor receptor (VEFGR) and its co-receptor neuropilin-1 (NRP-1) is an interesting vascular strategy. tLyp-1 is a tumor-homing and penetrating peptide of 7 amino acids (CGNKRTR). It is a truncated form of Lyp-1 (CGNKRTRGC), which is known to target NRP-1 receptor, with high affinity and specificity. It is mediated by endocytosis via C-end rule (CendR) internalization pathway. The aim of this study is to evaluate the importance of each amino acid in the tLyp-1 sequence through alanine-scanning (Ala-scan) technique, during which each of the amino acid in the sequence was systematically replaced by alanine to produce 7 different analogues. In silico approach through molecular docking and molecular dynamics are employed to understand the interaction between the peptide and its analogues with the NRP-1 receptor, followed by in vitro ligand binding assay study. The C-terminal Arg is crucial in the interaction of tLyp-1 with NRP-1 receptor. Substituting this residue dramatically reduces the affinity of this peptide which is clearly seen in this study. Lys-4 is also important in the interaction, which is confirmed via the in vitro study and the MM-PBSA analysis. The finding in this study supports the CendR, in which the presence of R/K-XX-R/K motif is essential in the binding of a ligand with NRP-1 receptor. This presented work will serve as a guide in the future work pertaining the development of active targeting agent towards NRP-1 receptor.

Computational study of nitro-benzylidene phenazine as dengue virus-2 NS2B-NS3 protease inhibitor.

According to the World Health Organisation (WHO), as of week 23 of 2022, there were more than 1,311 cases of dengue in Malaysia, with 13 deaths reported. Furthermore, there was an increase of 65.7% during the same period in 2021. Despite the increase in cumulative dengue incidence, there is no effective antiviral drug available for dengue treatment. This work aimed to evaluate several nitro-benzylidene phenazine compounds, especially those that contain 4-hydroxy-3,5-bis((2-(4-nitrophenyl)hydrazinylidene)-methyl)benzoate through pharmacophore queries selection method as potential dengue virus 2 (DENV2) NS2B-NS3 protease inhibitors. Herein, molecular docking was employed to correlate the energies of selected hits' free binding and their binding affinities. Pan assay interference compounds (PAINS) filter was also adopted to identify and assess the drug-likeness, toxicity, mutagenicity potentials, and pharmacokinetic profiles to select hit compounds that can be considered as lead DENV2 NS2B-NS3 protease inhibitors. Molecular dynamics assessment of two nitro-benzylidene phenazine derivatives bearing dinitro and hydroxy groups at the benzylidene ring showed their stability at the main binding pocket of DENV2 protease, where their MM-PBSA binding energies were between -22.53 and -17.01 kcal/mol. This work reports those two nitro-benzylidene phenazine derivatives as hits with 52-55% efficiency as antiviral candidates. Therefore, further optimisation is required to minimise the lead compounds' toxicity and mutagenicity.

Fluorescent Multifunctional Organic Nanoparticles for Drug Delivery and Bioimaging: A Tutorial Review.

Fluorescent organic nanoparticles (FONs) are a large family of nanostructures constituted by organic components that emit light in different spectral regions upon excitation, due to the presence of organic fluorophores. FONs are of great interest for numerous biological and medical applications, due to their high tunability in terms of composition, morphology, surface functionalization, and optical properties. Multifunctional FONs combine several functionalities in a single nanostructure (emission of light, carriers for drug-delivery, functionalization with targeting ligands, etc.), opening the possibility of using the same nanoparticle for diagnosis and therapy. The preparation, characterization, and application of these multifunctional FONs require a multidisciplinary approach. In this review, we present FONs following a tutorial approach, with the aim of providing a general overview of the different aspects of the design, preparation, and characterization of FONs. The review encompasses the most common FONs developed to date, the description of the most important features of fluorophores that determine the optical properties of FONs, an overview of the preparation methods and of the optical characterization techniques, and the description of the theoretical approaches that are currently adopted for modeling FONs. The last part of the review is devoted to a non-exhaustive selection of some recent biomedical applications of FONs.