Review of the use of nasal and oral antiseptics during a global pandemic

Novel anionic surfactant-modified chlorhexidine and its potent antimicrobial properties

Chlorhexidine dodecyl sulfate (CHX-DS) was synthesized and characterized via single-crystal X-ray diffraction (SC-XRD), 1H nuclear magnetic resonance (NMR) spectroscopy, 1H nuclear Overhauser effect spectroscopy (NOESY), and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR). The solid-state structure, comprising a 1 : 2 stoichiometric ratio of chlorhexidine cations [C22H30Cl2N10]2+ to dodecyl sulfate anions [C12H25SO4]-, is the first report of chlorhexidine isolated with a surfactant. CHX-DS exhibits broad-spectrum antibacterial activity and demonstrates superior efficacy for reducing bacteria-generated volatile sulfur compounds (VSCs) as compared to chlorhexidine gluconate (CHG). The minimum inhibitory concentrations (MICs) of CHX-DS were 7.5, 2.5, 2.5, and 10 μM for S. enterica, E. coli, S. aureus, and S. mutans, respectively. Furthermore, MIC assays for E. coli and S. mutans demonstrate that CHX-DS and CHX exhibit a statistically significant efficacy enhancement in 2.5 μM treatment as compared to CHG. CHX-DS was incorporated into SBA-15, a mesoporous silica nanoparticle (MSN) framework, and its release was qualitatively measured via UV-vis in aqueous media, which suggests its potential as an advanced functional material for drug delivery applications.

Effectiveness of mouth rinses against COVID-19: a systematic review and network meta-analysis

OBJECTIVE

This systematic review and network meta-analysis (NMA) comprehensively compared the effectiveness of different mouth rinses in reducing the viral load/infectivity of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) (Part I), alleviating clinical symptoms or severity of disease (Part II), and decreasing the incidence of SARS-CoV-2 infection (Part III).

METHODS

Randomized controlled trials (RCTs) and non-randomized controlled trials (NRCTs) with restrictions were searched up to 3rd March 2023. Twenty-three studies (22 RCTs and one NRCT) met the inclusion criteria for this systematic review.

RESULTS

Five RCTs (454 patients and nine interventions) in Part I were eligible for NMA. The NMA results showed that, in comparison with no rinse, sodium chloride (NaCl) was the most effective mouth rinse for reducing the viral load, followed by povidone-iodine (PVP-I), ß-cyclodextrin + citrox (CDCM), hydrogen peroxide (HP), chlorhexidine gluconate (CHX), cetylpyridinium chloride (CPC), placebo and hypochlorous acid (HClO). However, these results were not significant. Based on surface under the cumulative ranking curve scores, PVP-I was likely to be the most efficacious mouth rinse for reducing SARS-CoV-2 viral load, followed by CDCM, HP, NaCl, CHX, CPC, placebo, no rinse and HClO.

CONCLUSION

Due to heterogeneity of the primary studies, the effectiveness of different mouth rinses to reduce viral infectivity, improve clinical symptoms or prevent SARS-CoV-2 infection remains inconclusive.

Do Disinfectant Solutions during Gargling Reach the Pharynx?

INTRODUCTION

In times of COVID-19, gargling disinfectant is commonly used. Disinfectant solutions seem to decrease the infection's symptoms. For disinfection, several techniques are reported. So far, there are no data about the regions in the upper airways achieved by gargled fluid.

METHODS

Ten healthy volunteers without any dysphagia were investigated with a high-sensitivity flexible endoscopic evaluation of swallowing (hsFEES®) during and after gargling colored water. One volunteer repeated the gargling process in fast and real-time MRI.

RESULTS

In all cases, no color accumulation was detected on the posterior pharyngeal wall, epi- or hypopharynx during gargling. The MRI scans confirmed the results.

CONCLUSIONS

hsFEES® and fast MRI provide an insight into the gargling pattern. Data show that during gargling, the fluid covers the soft tissue in the oral cavity and the anterior part of the soft palate, but not the posterior pharyngeal wall nor the epi- and hypopharynx.

Effect of phthalocyanine oral and nasal antiseptic solutions on the infectivity of SARS-CoV-2 in patients with COVID-19: a randomized controlled trial

Background

In individuals with coronavirus disease (COVID-19), the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral load (VL) plays an important role in infectivity.

Objectives

This study aimed to evaluate the reduction in the VL and infectivity induced by phthalocyanine mouthwash and nasal spray in patients with COVID-19.

Methods

Patients with mild COVID-19 were recruited to participate in a triple-blinded randomized controlled trial. Participants were assigned to one of three groups: Group 1, non-active mouthwash and saline nasal spray (SNS); Group 2, phthalocyanine mouthwash and SNS; and Group 3 phthalocyanine mouthwash and phthalocyanine nasal spray. VL was assessed in nasopharyngeal and oropharyngeal swabs collected at the time of clinical diagnosis at baseline as well as 24 and 72 hours after starting the rinsing protocols.

Findings

Forty-six participants were included in the analysis: 15, 16, and 15 in Groups 1, 2, and 3, respectively. After 72 hours, the reduction in VL was significantly higher in Group 3 (mean cycle threshold (Ct) decrease: 11.21) than in Group 1 (mean Ct decrease: 5.53). Additionally, only the mean VL in Group 3 was reduced to a non-contagious level after 72 hours.

Main conclusions

Use of phthalocyanine mouthwash and nasal spray is effective at reducing SARS-CoV-2 infectivity.

Supporting the Aspecific Physiological Defenses of Upper Airways against Emerging SARS-CoV-2 Variants

The rapid rollout of COVID-19 vaccines in 2021 sparked general optimism toward controlling the severe form of the disease, preventing hospitalizations and COVID-19-associated mortality, and the transmissibility of SARS-CoV-2 infection [...].

Antimicrobial efficacy, mode of action and in vivo use of hypochlorous acid (HOCl) for prevention or therapeutic support of infections

The objective is to provide a comprehensive overview of the rapidly developing field of the current state of research on in vivo use of hypochlorous acid (HOCl) to aid infection prevention and control, including naso-pharyngeal, alveolar, topical, and systemic HOCl applications. Also, examples are provided of dedicated applications in COVID-19. A brief background of HOCl's biological and chemical specifics and its physiological role in the innate immune system is provided to understand the effect of in vivo applications in the context of the body's own physiological defense mechanisms.

Mega-scale desalination Efficacy (Reverse Osmosis, Electrodialysis, Membrane Distillation, MED, MSF) during COVID-19: Evidence from salinity, pretreatment methods, temperature of operation

The unprecedented situation of the COVID-19 pandemic heavily polluted water bodies whereas the presence of SARS-CoV-2, even in treated wastewater in every corner of the world is reported. The main aim of the present study is to show the effectiveness and feasibility of some well-known desalination technologies which are reverse osmosis (RO), Electrodialysis (ED), Membrane Distillation (MD), multi effect distillation (MED), and multi stage flashing (MSF) during the COVID-19 pandemic. Systems’ effectiveness against the novel coronavirus based on three parameters of nasopharynx/nasal saline-irrigation, temperature of operation and pretreatment methods are evaluated. First, based on previous clinical studies, it showed that using saline solution (hypertonic saline >0.9% concentration) for gargling/irrigating of nasal/nasopharynx/throat results in reducing and replication of the viral in patients, subsequently the feed water of desalination plants which has concentration higher than 3.5% (35000ppm) is preventive against the SARS-CoV-2 virus. Second, the temperature operation of thermally-driven desalination; MSF and MED (70-120°C) and MD (55-85°C) is high enough to inhibit the contamination of plant structure and viral survival in feed water. The third factor is utilizing various pretreatment process such as chlorination, filtration, thermal/precipitation softening, ultrafiltration (mostly for RO, but also for MD, MED and MSF), which are powerful treatment methods against biologically-contaminated feed water particularly the SARS-CoV-2. Eventually, it can be concluded that large-scale desalination plants during COVID-19 and similar situation are completely reliable for providing safe drinking water.

The effect of q-RT-PCR analysis method on saline gargle samples in SARS-CoV-2 clinical diagnostic methods

COVID‑19 is a devastating disease, and its control is difficult due to its high transmissibility rate and a long incubation average period (6.4 days). Additionally, more than half of the infected patients were asymptomatic young people or children. The asymptomatic virus transmission is the actual challenge to controlling the disease. Because of limited treatment options, diagnosis techniques have been the first focus all over the world, involving q-RT-PCR as a gold standard, serological tests, point of care studies, or RT-LAMP. Generally, nasopharyngeal, and oropharyngeal samples are preferred clinically as sources. However, alternative sources are being researched, particularly for healthcare professionals who have difficulty taking samples, patients who are afraid of giving samples, and pediatric patients. Herein, physiological saline has been utilized to offer an alternative source besides the swab samples for use in q-RT-PCR. In this study, 212 randomly chosen patients’ samples were studied, and we evaluated the concordance and accurate q-RT-PCR results in two different sources, obtained from swab and gargle samples of patients. Herein, physiological saline is utilized, which is widely used medically as a recommended irrigating and wound dressing solution. We obtained in our experiments with this method, the confidence interval determines 74.50% positivity when compared to the routine q-RT-PCR procedure as summarized. In addition, when only the gargle sampling method is studied in low-income countries, the cost of testing for COVID-19 will decrease significantly. Because this method does not require vNAT or VTM transport solution sterile swab sticks as shown. The plastic container with a lid in which the patient can gargle with SF and spit it out is an ideal method for this. Additionally, it provides a great cost-benefit in low-income countries.

Self-Assembling Imageable Silk Hydrogels for the Focal Treatment of Osteosarcoma

Background: The standard treatment for osteosarcoma comprises complete surgical resection and neoadjuvant chemotherapy, which may cause serious side effects and partial or total limb loss. Therefore, to avoid the disadvantages of traditional treatment, we developed self-assembling imageable silk hydrogels for osteosarcoma.

Methods: We analysed whether iodine induced apoptosis in MG-63 and Saos-2 cells by using CCK-8 and flow cytometry assays and transmission electron microscopy. Western blotting was used to analyse the pathway of iodine-induced apoptosis in osteosarcoma cells. PEG400, silk fibroin solution, polyvinylpyrrolidone iodine (PVP-I), and meglumine diatrizoate (MD) were mixed to produce an imageable hydrogel. A nude mouse model of osteosarcoma was established, and the hydrogel was injected locally into the interior of the osteosarcoma with X-ray guidance. The therapeutic effect and biosafety of the hydrogel were evaluated.

Results: Iodine treatment at 18 and 20 µM for 12 h resulted in cell survival rate reduced to 50 ± 2.1% and 50.5 ± 2.7% for MG-63 and Sao-2 cells, respectively (p < 0.01). The proportion of apoptotic cells was significantly higher in the iodine-treatment group than in the control group (p < 0.05), and apoptotic bodies were observed by transmission electron microscopy. Iodine could regulate the death receptor pathway and induce MG-63 and Saos-2 cell apoptosis. The hydrogels were simple to assemble, and gels could be formed within 38 min. A force of less than 50 N was required to inject the gels with a syringe. The hydrogels were readily loaded and led to sustained iodine release over 1 week. The osteosarcoma volume in the PEG-iodine-silk/MD hydrogel group was significantly smaller than that in the other three groups (p < 0.001). Caspase-3 and poly (ADP-ribose) polymerase (PARP) expression levels were significantly higher in the PEG-iodine-silk/MD hydrogel group than in the other three groups (p < 0.001). Haematoxylin and eosin (H&E) staining showed no abnormalities in the heart, liver, spleen, lung, kidney, pancreas or thyroid in any group.

Conclusions: Self-assembling imageable silk hydrogels could be injected locally into osteosarcoma tissues with X-ray assistance. With the advantages of good biosafety, low systemic toxicity and minimal invasiveness, self-assembling imageable silk hydrogels provide a promising approach for improving the locoregional control of osteosarcoma.

Further observations on hydrogen peroxide antisepsis and COVID-19 cases among healthcare workers and inpatients

Background

The use of prophylactic antisepsis to protect against coronavirus disease 2019 (COVID-19) has been suggested. This study investigated hydrogen peroxide antisepsis (HPA) at two hospitals in Ghana.

Methods

Cases of COVID-19 among healthcare workers (HCWs) using hydrogen peroxide (HP-HCWs) or not using hydrogen peroxide (NHP-HCWs), vaccinated or unvaccinated, were recorded at Shai-Osudoku Hospital (SODH), Dodowa, and Mount Olives Hospital (MOH), Techiman, between May 2020 and December 2021. The effect of HPA in all inpatients at MOH was also observed. Permutation tests were used to determine P values.

Findings

At SODH, there were 62 (13.5%) cases of COVID-19 among 458 NHP-HCWs but no cases among eight HP-HCWs (P=0.622) from May to December 2020. Between January and March 2021, 10 (2.7%) of 372 NHP-HCWs had COVID-19, but there were no cases among 94 HP-HCWs (P=0.206). At MOH, prior to HPA, 17 (20.2%) of 84 HCWs and five (1.4%) of 370 inpatients had COVID-19 in July 2020. From August 2020 to March 2021, two of 54 (3.7%) HCWs who stopped HPA had COVID-19; none of 32 NHP-HCWs contracted COVID-19. At SODH, none of 23 unvaccinated HP-HCWs and 35 (64%) of 55 unvaccinated NHP-HCWs had COVID-19 from April to December 2021 (P<0.0001). None of 34 vaccinated HP-HCWs and 53 (13.6%) of 390 vaccinated NHP-HCWs had COVID-19 (P=0.015). No inpatients on prophylactic HPA (total 7736) contracted COVID-19.

Conclusion

Regular, daily HPA protects HCWs from COVID-19, and curtails nosocomial spread of SARS-CoV-2.

Virucidal Effect of Povidone Iodine on SARS-CoV-2 in Nasopharynx: An Open-label Randomized Clinical Trial

To assess the virucidal effect of povidone iodine (PVP-I) on severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) located in the nasopharynx and suitable dose-formulation for nasal application were the purpose of this clinical trial. This single-center, open-label randomized clinical trial with a 7-arm parallel-group design was conducted in Dhaka Medical College (DMC) Hospital. A total of 189 reverse transcription-polymerase chain reaction (RT-PCR)-confirmed SARS CoV-2 positive cases aged 12–90 years with symptoms was sequentially enrolled following randomization. Nasopharyngeal clearance of SARS-CoV-2 was tested against PVP-I nasal irrigation (NI) at diluted concentrations of 0.4%, 0.5% and 0.6%, and PVP-I nasal spray (NS) at diluted concentrations of 0.5% and 0.6%. All groups were compared to the corresponding controls (distilled water). Written informed consent was ensured before participation. All procedures were conducted in after ethical clearance from the Ethical Review Board and in accordance with the Declaration of Helsinki. Viral clearance in a repeat RT-PCR (qualitative) was the primary outcome, and occurrence of any adverse event following administration of testing drug was considered as the secondary outcome. Analysis was performed using SPSS (Version 26). All cases were randomized into seven groups and each group consists of 27-patient. Mean age of the cases 43.98 ± 12.67 years (SD). All strength of NI were effective in nasopharyngeal clearance compared to the control (0.4%, p = 0.006; 0.5%, p < 0.001; and 0.6%, p = 0.018). Similarly, all strength of the NS is also effective than control (0.5%, p =  < 0.001; and 0.6%, p ≤ 0.001). Highest nasopharyngeal clearance was observed in patients using 0.5% NI (n = 25, 92.6%, p = 0.018). Nasal irritation was the single most adverse event recorded in this trial and found in two patients using 0.4%, and 0.6% PVP-I NI, respectively. Both PVP-I NS and NI are effective for nasopharyngeal clearance in-vivo. However, further community trials are needed to repurpose these solutions as preventive agents against SARS-CoV2.

Ethical clearance memo no ERC-DMC/ECC/2020/93.

Trial registration NCT Identifier number NCT04549376.

Mouthrinses against SARS-CoV-2 – high antiviral effectivity by membrane disruption in vitro translates to mild effects in a randomized placebo-controlled clinical trial

The emergence of the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) represents an unprecedented threat for the human population, necessitating rapid and effective intervention measures. Given the main infection route by airborne transmission, significant attention has been bestowed upon the use of antiseptic mouthrinses as a way to possibly reduce infectious viral titers. However, clinical evaluations are still sparse. Thus, we evaluated a wide variety of antiseptic agents that can be used as mouthrinses for their antiviral effects in vitro and their respective mode of action. One of the most promising antiseptic agents (benzalkoniumchloride, BAC) was used in a randomized placebo-controlled clinical trial with subsequent analysis of viral loads by RT-qPCR and virus rescue in cell culture. Mechanistic analysis revealed that treatment with BAC and other antiseptic agents efficiently inactivated SARS-CoV-2 in vitro by primarily disrupting the viral envelope, without affecting viral RNA integrity. However, the clinical application only resulted in a mild reduction of viral loads in the oral cavity. These results indicate that gargling with mouthrinses comprising single antiseptic agents may play a minor role towards a potential reduction of transmission rates and thus, these findings are of utmost importance when considering alternative COVID-19 prevention strategies.

Polysaccharides and Тheir Derivatives as Potential Antiviral Molecules

In the current context of the COVID-19 pandemic, it appears that our scientific resources and the medical community are not sufficiently developed to combat rapid viral spread all over the world. A number of viruses causing epidemics have already disseminated across the world in the last few years, such as the dengue or chinkungunya virus, the Ebola virus, and other coronavirus families such as Middle East respiratory syndrome (MERS-CoV) and severe acute respiratory syndrome (SARS-CoV). The outbreaks of these infectious diseases have demonstrated the difficulty of treating an epidemic before the creation of vaccine. Different antiviral drugs already exist. However, several of them cause side effects or have lost their efficiency because of virus mutations. It is essential to develop new antiviral strategies, but ones that rely on more natural compounds to decrease the secondary effects. Polysaccharides, which have come to be known in recent years for their medicinal properties, including antiviral activities, are an excellent alternative. They are essential for the metabolism of plants, microorganisms, and animals, and are directly extractible. Polysaccharides have attracted more and more attention due to their therapeutic properties, low toxicity, and availability, and seem to be attractive candidates as antiviral drugs of tomorrow.

Molecular iodine is not responsible for cytotoxicity in iodophors

Background

Ten percent povidone-iodine (PVP-I) was initially promoted as ‘tamed iodine’ as the chemical activity of the active biocide, uncomplexed or free molecular iodine (I₂), is reduced 30- to 50-fold compared with Lugol's solution. The idea that I₂ is responsible for topical iodine staining and irritation remains widely held. However, there are no controlled studies that characterize the cytotoxicity and staining of the hydrophobic I₂ species compared with the other hydrophilic iodine species that comprise over 99.9% of the total iodine in topical iodine disinfectants.

Aims

To compare the staining properties of the I₂ species with other topical iodine disinfectants; to evaluate if the concentrations of I₂ in diluted PVP-I used to reduce severe acute respiratory syndrome coronavirus-2 in the nasal cavity are potentially cytotoxic; and to determine if high concentrations of I₂ can be delivered beyond the stratum corneum into the hypodermis, which could provide a mechanistic rationale for I₂ out-gassing.

Methods

Five liquid compositions that contained complexed and uncomplexed (free) I₂ in aqueous and non-aqueous carriers were used to evaluate the interaction of I₂ with mammalian cells in culture as well as human and pig skin.

Findings

Concentrations of I₂ (7800 ppm) that are 1500 times higher than that found in PVP-I can be applied to skin without irritation and staining. I₂ is not cytotoxic at concentrations >100 times higher than that found in PVP-I, and does not contribute materially to staining of skin at concentrations found in Lugol's solution (approximately 170 ppm). I₂ can partition into hypodermis tissue, remain there for hours and out-gas from skin. PVP-I and Lugol's solution are highly effective topical disinfectants, but do not facilitate diffusion of I₂ through the stratum corneum.

Conclusion

The maximum concentration of I₂ found in diluted PVP, approximately 25 ppm, is not cytotoxic or irritating. The potential clinical utility of I₂ has been limited by incorporating this broad-spectrum biocide into acidic aqueous formulations that contain numerous chemical species that contribute toxicity but not biocidal activity. I₂ can be delivered topically into hypodermis tissue without irritation.

ANTIVIRAL EFFECT OF MOUTHWASHES AGAINST SARS-COV-2: A SYSTEMATIC REVIEW

Objective

This systematic review aimed to evaluate the antiviral effect of mouthwashes against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Material and methods

An electronic search was performed on PubMed, Scopus, Web of Science, Cochrane Library, LILACS, ProQuest, and Google Scholar, and was complemented by a manual search. Both clinical and in vitro studies that focused on the antiviral effect of mouthwashes against SARS-CoV-2 were included. Risk of bias assessment was performed only on the clinical studies using the RoB-2 and ROBINS-I tools.

Results

A total of 907 records were found; after initial selection by title and abstract, 33 full-text articles were selected to be evaluated for eligibility. Finally, a total of 27 studies were included for the qualitative synthesis, including 16 in vitro studies and 11 clinical trials. Antiviral effects were evaluated separately for the in vitro and clinical studies. In vitro studies included mouthwashes containing hydrogen peroxide, chlorhexidine digluconate, povidone-iodine, essential oils, cetylpyridinium chloride, and other compounds; in vivo studies included mouthwashes containing hydrogen peroxide, chlorhexidine digluconate, povidone-iodine, cetylpyridinium chloride, essential oils, chlorine dioxide, β-cyclodextrin-citrox, and sorbitol with xylitol. Povidone-iodine, cetylpyridinium chloride, and essential oils were effective in vitro, while hydrogen peroxide, chlorhexidine digluconate, povidone-iodine, cetylpyridinium chloride, β-cyclodextrin-citrox, and sorbitol with xylitol were effective in vivo. Unclear or high risk of bias was found for almost all clinical studies, and only one study presented with a low risk of bias. No further quantitative analysis was performed.

Conclusion

Although povidone-iodine, cetylpyridinium chloride, and essential oils may be an alternative to reduce the viral load in vitro and in vivo, more studies are needed to determine the real antiviral effect of these different mouthwashes against SARS-CoV-2.

This work was not funded. The protocol was registered in PROSPERO (identification number: CRD42021236134).

Cluster randomised, controlled, triple-blind trial assessing the efficacy of intranasally administered virus-neutralising bovine colostrum supplement in preventing SARS-CoV-2 infection in household contacts of SARS-CoV-2-positive individuals: a study protocol

The SARS-CoV-2 enters into the human body mainly through the nasal epithelial cells. Prevention of SARS-CoV-2 infection at the point of nasal entry is a novel strategy that has the potential to help contain the ongoing pandemic. BioBlock is a nasal spray of anti-SARS-CoV-2 preparation based on virus-neutralising antibodies prepared from colostrum from cows immunised with SARS-CoV-2 spike protein. This triple-blind placebo-controlled cluster randomised parallel trial seeks to evaluate the efficacy of a BioBlock spray in the prevention and treatment of SARS-CoV-2 infection. Laboratory-confirmed COVID-19 cases and their household members will be randomly allocated to each of either the intervention (BioBlock nasal spray) or the placebo (nasal spray) arms. The intervention is a 14-day course of nasal spray used by index case and household contacts. In most countries, those with confirmed or suspected infections are requisitioned to isolate at home, putting other members of their household at risk of infection. Therefore, in parallel to the need of household transmission prevention measures, households also present as a good model for infection transmission studies, allowing for the testing of several close contact transmission prevention study hypotheses. Our hope is that if the trial results are encouraging, this will provide new and additional COVID-19 prevention strategies. TRIAL REGISTRATION: ISRCTN48554326 Registered on June 14, 2021.

Pandemic Ethics and Status Quo Risk

Conservative assumptions in medical ethics risk immense harms during a pandemic. Public health institutions and public discourse alike have repeatedly privileged inaction over aggressive medical interventions to address the pandemic, perversely increasing population-wide risks while claiming to be guided by ‘caution’. This puzzling disconnect between rhetoric and reality is suggestive of an underlying philosophical confusion. In this paper, I argue that we have been misled by status quo bias—exaggerating the moral significance of the risks inherent in medical interventions, while systematically neglecting the (objectively greater) risks inherent in the status quo prospect of an out-of-control pandemic. By coming to appreciate the possibility and significance of status quo risk, we will be better prepared to respond appropriately when the next pandemic strikes.

Iota-carrageenan extracted from red algae is a potent inhibitor of SARS-CoV-2 infection in reconstituted human airway epithelia

Iota-carrageenan (IC) nasal spray, a medical device approved for treating respiratory viral infections, has previously been shown to inhibit the ability of a variety of respiratory viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), to enter and replicate in the cell by interfering with the virus binding to the cell surface. The aim of this study was to further investigate the efficacy and safety of IC in SARS-CoV-2 infection in advanced in vitro models of the human respiratory epithelium, the primary target and entry port for SARS-CoV-2. We extended the in vitro safety assessment of nebulized IC in a 3-dimensional model of reconstituted human bronchial epithelium, and we demonstrated the efficacy of IC in protecting reconstituted nasal epithelium against viral infection and replication of a patient-derived SARS-CoV-2 strain. The results obtained from these two advanced models of human respiratory tract epithelia confirm previous findings from in vitro SARS-CoV-2 infection assays and demonstrate that topically applied IC can effectively prevent SARS-CoV-2 infection and replication. Moreover, the absence of toxicity and functional and structural impairment of the mucociliary epithelium demonstrates that the nebulized IC is well tolerated.

•

IC had a potent antiviral effect in SARS-CoV-2 infected organotypic nasal epithelial cultures.

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Topical application (nasal drops) was non-toxic at anti-virally efficient doses.

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Aerosolized IC had no adverse effects on reconstituted human bronchial epithelium.

The effectiveness of mouthwash against SARS-CoV-2 infection: A review of scientific and clinical evidence

BACKGROUND/PURPOSE

The COVID-19 pandemic, caused by the spread of SARS-CoV-2 infection that is mainly through the airborne transmission, is a worldwide health concern. This review seeks to assess the potential effectiveness of mouthwash in reducing the oropharyngeal load of SARS-CoV-2 based on the available evidence.

METHODS

Articles related to mouthwash and COVID-19 in PubMed were electronically searched in July, 2021. After manually excluding articles lacking sufficient scientific evidence or validation processes, those with inaccessible online full text, those that did not test the effectiveness of mouthwash against SARS-CoV-2, and those not written in English, 17 original and 13 review articles were chosen for this review.

RESULTS

The eligible articles revealed that the main virucidal mechanism of mouthwash was via interactions with the viral envelope. Povidone-iodine (PVP-I), cetylpyridinium chloride (CPC), and essential oils with ethanol showed virucidal effects on SARS-CoV-2 in vitro, potentially by interfering with the viral envelope. A few clinical studies demonstrated that PVP-I, CPC, hydrogen peroxide, and chlorhexidine reduced the oropharyngeal load of SARS-CoV-2.

CONCLUSION

Although the available evidence is limited, mouthwash containing PVP-I or CPC shows potential for reducing the oropharyngeal load of SARS-CoV-2 and thus may present a risk-mitigation strategy for COVID-19 patients.

Inhibitory Effect of Ophthalmic Solutions against SARS-CoV-2: A Preventive Action to Block the Viral Transmission?

In 2020, a global pandemic was declared following the spread of SARS-CoV-2, the pathogen responsible for COVID-19. The risk of infection is high due to the ease of transmission, which can occur orally, through droplets, or via contact with contaminated surfaces and objects. It has also been demonstrated that the ocular surface can constitute a transmission route, especially in hospital settings, where health care workers can become a dangerous source of infection. In order to increase prevention and reduce the spread of the virus on the ocular surface, the antiviral activity of already-marketed eye drops against SARS-CoV-2 was evaluated. Iodim, Ozodrop, Septavis, and Dropsept were tested against SARS-CoV-2 in plaque-assay experiments at different stimulation times. Furthermore, the expression levels of early and late genes were evaluated through molecular assays. Results indicated that three of the four ophthalmic solutions showed a considerable dose-dependent inhibition of viral replication, highlighting their use as potential antiviral drugs against SARS-CoV-2 and preventing other ocular infections.