Background and methods Nanoparticles engineered to carry both a chemotherapeutic drug and a sensitive imaging probe are valid tools for early detection of cancer cells and to monitor the cytotoxic effects of anticancer treatment simultaneously. Here we report on the effect of size (10–30 nm versus 50 nm), type of material (mesoporous silica versus polystyrene), and surface charge functionalization (none, amine groups, or carboxyl groups) on biocompatibility, uptake, compartmentalization, and intracellular retention of fluorescently labeled nanoparticles in cultured human ovarian cancer cells. We also investigated the involvement of caveolae in the mechanism of uptake of nanoparticles. Results We found that mesoporous silica nanoparticles entered via caveolae-mediated endocytosis and reached the lysosomes; however, while the 50 nm nanoparticles permanently resided within these organelles, the 10 nm nanoparticles soon relocated in the cytoplasm. Naked 10 nm mesoporous silica nanoparticles showed the highest and 50 nm carboxyl-modified mesoporous silica nanoparticles the lowest uptake rates, respectively. Polystyrene nanoparticle uptake also occurred via a caveolae-independent pathway, and was negatively affected by serum. The 30 nm carboxyl-modified polystyrene nanoparticles did not localize in lysosomes and were not toxic, while the 50 nm amine-modified polystyrene nanoparticles accumulated within lysosomes and eventually caused cell death. Ovarian cancer cells expressing caveolin-1 were more likely to endocytose these nanoparticles. Conclusion These data highlight the importance of considering both the physicochemical characteristics (ie, material, size and surface charge on chemical groups) of nanoparticles and the biochemical composition of the cell membrane when choosing the most suitable nanotheranostics for targeting cancer cells.

Background: There is no generally accepted methodology for in vivo assessment of antiviral activity in SARS-CoV-2 infections. Ivermectin has been recommended widely as a treatment of COVID-19, but whether it has clinically significant antiviral activity in vivo is uncertain.Methods: In a multicentre open label, randomized, controlled adaptive platform trial, adult patients with early symptomatic COVID-19 were randomized to one of six treatment arms including high dose oral ivermectin (600µg/kg daily for seven days), the monoclonal antibodies casirivimab and imdevimab (600mg/600mg), and no study drug. The primary outcome was the comparison of viral clearance rates in the modified intention-to-treat population (mITT). This was derived from daily log10 viral densities in standardized duplicate oropharyngeal swab eluates. This ongoing trial is registered at ClinicalTrials.gov (NCT05041907).Results: Randomization to the ivermectin arm was stopped after enrolling 205 patients into all arms, as the prespecified futility threshold was reached. Following ivermectin the mean estimated rate of SARS-CoV-2 viral clearance was 9.1% slower [95%CI -27.2% to +11.8%; n=45] than in the no drug arm [n=41], whereas in a preliminary analysis of the casirivimab/imdevimab arm it was 52.3% faster [95%CI +7.0% to +115.1%; n=10 (Delta variant) versus n=41].Conclusions: High dose ivermectin did not have measurable antiviral activity in early symptomatic COVID-19. Pharmacometric evaluation of viral clearance rate from frequent serial oropharyngeal qPCR viral density estimates is a highly efficient and well tolerated method of assessing SARS CoV-2 antiviral therapeutics in vivo.Funding: 'Finding treatments for COVID-19: A phase 2 multi-centre adaptive platform trial to assess antiviral pharmacodynamics in early symptomatic COVID-19 (PLAT-COV)' is supported by the Wellcome Trust Grant ref: 223195/Z/21/Z through the COVID-19 Therapeutics Accelerator.Clinical trial number: ClinicalTrials.gov (NCT05041907).

In infectious diseases, the disease pathogenesis is the outcome of the interaction between the genome of the host and the genome of the pathogen. Despite the wide distribution of dengue infections in the world, and the large number of annual infections, few studies have investigated how the dengue genome alters the global transcriptional profile of the host cell. To investigate alterations in the liver cell transcriptome in response to dengue virus infection, liver cells (HepG2) were infected with dengue serotype 2 at MOI 5 and at 3 days post-infection RNA extracted and analyzed by cDNA-AFLP in parallel with mock-infected cells. From 73 primer combinations over 5,000 transcription-derived fragments (TDFs) were observed, of which approximately 10% were regulated differentially in response to infection. Sixty-five TDFs were subsequently cloned and sequenced and 27 unique gene transcripts identified. Semi-quantitative reverse transcription (RT)-PCR was used to validate the expression of 12 of these genes and 10 transcripts (CK2, KIAA509, HSP70, AK3L, NIPA, PHIP, RiboS4, JEM-1, MALT1, and HSI12044) were confirmed to be differentially regulated, with four transcripts (HSP70, NIPA, RiboS4, and JEM-1) showing a greater than twofold regulation. These results suggest that the expression of a large number of genes is altered in response to dengue virus infection of liver cells, and that cDNA-AFLP is a useful tool for obtaining information on both characterized and as yet uncharacterized transcripts whose expression is altered during the infection process.

Background: Uncertainty over the therapeutic benefit provided by parenteral remdesivir in COVID-19 has resulted in varying treatment guidelines. Early in the pandemic the monoclonal antibody cocktail, casirivimab/imdevimab, proved highly effective in clinical trials but because of weak or absent in vitro activity against the SARS-CoV-2 Omicron BA.1 subvariant, it is no longer recommended. Methods: In a multicenter open label, randomized, controlled adaptive platform trial, low-risk adult patients with early symptomatic COVID-19 were randomized to one of eight treatment arms including intravenous remdesivir (200mg followed by 100mg daily for five days), casirivimab/imdevimab (600mg/600mg), and no study drug. The primary outcome was the viral clearance rate in the modified intention-to-treat population derived from daily log10 viral densities (days 0-7) in standardized duplicate oropharyngeal swab eluates. This ongoing adaptive trial is registered at ClinicalTrials.gov (NCT05041907). Results: Acceleration in mean estimated SARS-CoV-2 viral clearance, compared with the contemporaneous no study drug arm (n=64), was 42% (95%CI 18 to 73%) for remdesivir (n=67). Acceleration with casirivimab/imdevimab was 58% (95%CI: 10 to 120) in Delta (n=13), and 20% (95%CI: 3 to 43) in Omicron variant (n=61) infections compared with contemporaneous no study drug arm (n=84). In a post hoc subgroup analysis viral clearance was accelerated by 8% in BA.1 (95%CI: -21 to 59) and 23% (95%CI: 3 to 49) in BA.2 and BA.5 Omicron subvariants. Conclusions: Parenteral remdesivir accelerates viral clearance in early symptomatic COVID-19. Despite substantially reduced in vitro activities, casirivimab/imdevimab retains in vivo antiviral activity against COVID-19 infections caused by currently prevalent Omicron subvariants.

Background Uncertainty over the therapeutic benefit provided by parenteral remdesivir in COVID-19 has resulted in varying treatment guidelines. Methods In a multicenter open label, controlled, adaptive, pharmacometric platform trial, low-risk adult patients with early symptomatic COVID-19 were randomized to one of eight treatment arms including intravenous remdesivir (200 mg followed by 100 mg daily for five days) or no study drug. The primary outcome was the rate of viral clearance (estimated under a linear model fit to the daily log10 viral densities, days 0-7) in standardized duplicate oropharyngeal swab eluates, in a modified intention-to-treat population (mITT). This ongoing adaptive trial is registered at ClinicalTrials.gov (NCT05041907). Results The two study arms enrolled 131 patients (remdesivir n = 67, no study drug n = 64) and estimated viral clearance rates from a median of 18 swab samples per patient (a total of 2356 qPCRs). Under the linear model, compared with the contemporaneous control arm (no study drug), remdesivir accelerated mean estimated SARS-CoV-2 viral clearance by 42% (95% credible interval [CI] 18 to 73). Interpretation Parenteral remdesivir accelerates viral clearance in early symptomatic COVID-19. Pharmacometric assessment of therapeutics using the described method can rapidly and efficiently determine in vivo clinical efficacy.

Thai traditional medicine employs a wide range of indigenous herbs in the forms of tincture or tea for the cure of skin and systemic inflammatory diseases. The protection by Thai plants extracts against UVB DNA damage and cytotoxicity was investigated in human keratinocytes. Petroleum ether, dichloromethane and ethanol extracts were prepared from 15 Thai herb species, and the total phenolic and flavonoid contents, the antioxidant and UV-absorbing properties were assessed by standard procedures. Cytoprotective effects were evaluated on the basis of cell survival, caspase-3 activity and pyrimidine dimers determination. High total phenolic and flavonoid contents were found in the ethanol and dichloromethane fractions. Dichloromethane extract of turmeric was shown to possess the highest antioxidant activity. The maximum UV absorptions were found in the ethanol extract of turmeric and in the dichloromethane extract of ginger. These extracts stimulated the synthesis of Thioredoxin 1, an antioxidant protein, and could protect human HaCaT keratinocytes from UV-induced DNA damage and cytotoxicity. The present data support the utilization of turmeric and ginger extracts in anti-UV cosmetic pharmaceuticals.

Background: Favipiravir, an anti-influenza drug, has in vitro antiviral activity against SARS-CoV-2. Clinical trial evidence to date is inconclusive. Favipiravir has been recommended for the treatment of COVID-19 in some countries. Methods: In a multicentre open-label, randomised, controlled, adaptive platform trial, low-risk adult patients with early symptomatic COVID-19 were randomised to one of ten treatment arms including high dose oral favipiravir (3.6g on day 0 followed by 1.6g daily to complete 7 days treatment) or no study drug. The primary outcome assessed in a modified intention-to-treat population (mITT) was the rate of viral clearance (derived under a linear mixed-effects model from the daily log10 viral densities in standardised duplicate oropharyngeal swab eluates taken daily over 8 days [18 swabs per patient]). The safety population included all patients who received at least one dose of the allocated intervention. This ongoing adaptive platform trial is registered at ClinicalTrials.gov (NCT05041907). Results: In the final analysis, the mITT population contained data from 114 patients randomised to favipiravir and 126 patients randomised concurrently to no study drug. Under the linear mixed-effects model fitted to all oropharyngeal viral density estimates in the first 8 days from randomisation (4,318 swabs), there was no difference in the rate of viral clearance between patients administered favipiravir and patients receiving no study drug -1% (95% CI: -14 to 14% change). High dose favipiravir was well tolerated. Interpretation: Favipiravir does not accelerate viral clearance in early symptomatic COVID-19.

BackgroundThere is no generally accepted methodology for in vivo assessment of antiviral activity in SARS-CoV-2 infection. Ivermectin has been recommended widely as a treatment of COVID-19, but whether it has significant antiviral activity in vivo is uncertain.MethodsIn a multicentre open label, randomized, controlled adaptive platform trial, adult patients with early symptomatic COVID-19 were randomized to one of six treatment arms including high dose ivermectin (600µg/kg daily for seven days), the monoclonal antibodies casirivimab and imdevimab (600mg/600mg), and no study drug. Viral clearance rates were derived from daily duplicate oropharyngeal quantitative PCR measurements. This ongoing trial is registered at ClinicalTrials.gov (NCT05041907).ResultsRandomization to the ivermectin arm was stopped after enrolling 205 patients into all arms, as the prespecified futility threshold was reached. Compared with the no study drug arm, the mean estimated SARS-CoV-2 viral clearance following ivermectin was 9.1% slower [95%CI -27.2% to +11.8%; n=45 versus n=41], whereas in a preliminary analysis of the casirivimab/imdevimab arm it was 52.3% faster [95%CI +7.0% to +115.1%; n=10 (Delta variant) versus n=41].ConclusionsHigh dose ivermectin did not have measurable antiviral activity in early symptomatic COVID-19. Measured in this way viral clearance rate is a valuable pharmacodynamic measure in assessing antiviral COVID-19 therapeutics in vivo.Funding“Finding treatments for COVID-19: A phase 2 multi-centre adaptive platform trial to assess antiviral pharmacodynamics in early symptomatic COVID-19 (PLAT-COV)” is funded by the Wellcome Therapeutics Accelerator (223195/Z/21/Z).ImpactRate of viral clearance determined from daily duplicate oropharyngeal swabs over one week is an efficient measure of antiviral efficacy in early COVID-19 infection.High dose ivermectin did not demonstrate measurable antiviral activity in early symptomatic COVID-19 infection.