Herbal dry extract BNO 1011 improves clinical and mucociliary parameters in a rabbit model of chronic rhinosinusitis

Hypoxia-induced cystic fibrosis transmembrane conductance regulator dysfunction is a universal mechanism underlying reduced mucociliary transport in sinusitis

INTRODUCTION

Hypoxia due to sinus obstruction is a major pathogenic mechanism leading to sinusitis. The objective of the current study is to define the electrophysiologic characteristics of hypoxia in vitro and in vivo.

METHODS

Cystic fibrosis bronchoepithelial cells expressing wild-type cystic fibrosis transmembrane conductance regulator (CFTR) and human sinonasal epithelial cells were exposed to 1% or atmospheric O2 for 24 h. Time-dependent production of cytoplasmic free radicals was measured. Cells were subjected to Ussing chamber and patch clamp technique where CFTR currents were recorded in whole-cell and cell-attached mode for single channel studies. Indices of mucociliary transport (MCT) were measured using micro-optical coherence tomography. In a rabbit hypoxic maxillary sinus model, tissue oxygenation, relative mRNA expression of HIF-1α, pH, sinus potential difference (SPD), and MCT were determined.

RESULTS

Ussing chamber (p < 0.05), whole-cell (p < 0.001), and single channel patch-clamp (p < 0.0001) showed significant inhibition of Cl- currents in hypoxic cells. Cytoplasmic free radicals showed time-dependent elevation peaking at 4 h (p < 0.0001). Airway surface liquid (p < 0.0001), periciliary liquid (p < 0.001), and MCT (p < 0.01) were diminished. Co-incubation with the free radical scavenger glutathione negated the impact of hypoxia on single channel currents and MCT markers. In sinusitis rabbits, mucosa exhibited low tissue oxygenation (p < 0.0001), increased HIF1α mRNA (p < 0.05), reduced pH (p < 0.01), and decreased MCT (p < 0.001). SPD measurements demonstrated markedly diminished transepithelial Cl- transport (p < 0.0001).

CONCLUSION

Hypoxia induces severe CFTR dysfunction via free radical production causing reduced MCT in vitro and in vivo. Improved oxygenation is critical to reducing the impact of persistent mucociliary dysfunction.

Glutathione and bicarbonate nanoparticles improve mucociliary transport in cystic fibrosis epithelia

INTRODUCTION

Cystic fibrosis (CF) airway disease is characterized by thick mucus and impaired mucociliary transport (MCT). Loss of functional cystic fibrosis transmembrane receptor (CFTR) leads to acidification and oxidation of airway surface mucus. Replacing bicarbonate (HCO3 -) topically fails due to rapid reabsorption and neutralization, while the scavenging antioxidant, glutathione sulfhydryl (GSH), is also rapidly degraded. The objective of this study is to investigate GSH/NaHCO3 nanoparticles as novel strategy for CF airway disease.

METHODS

GSH/NaHCO3 poly (lactic-co-glycolic acid) nanoparticles were tested on primary CF (F508del/F508del) epithelial cultures to evaluate dose-release curves, surface pH, toxicity, and MCT indices using micro-optical coherence tomography. In vivo tests were performed in three rabbits to assess safety and toxicity. After 1 week of daily injections, histopathology, computed tomography (CT), and blood chemistries were performed and compared to three controls. Fluorescent nanoparticles were injected into a rabbit with maxillary sinusitis and explants visualized with confocal microscopy.

RESULTS

Sustained release of GSH and HCO3 - with no cellular toxicity was observed over 2 weeks. Apical surface pH gradually increased from 6.54 ± 0.13 (baseline) to 7.07 ± 0.10 (24 h) (p < 0.001) and 6.87 ± 0.05 at 14 days (p < 0.001). MCT, ciliary beat frequency, and periciliary liquid were significantly increased. When injected into the maxillary sinuses of rabbits, there were no changes to histology, CT, or blood chemistries. Nanoparticles penetrated rabbit sinusitis mucus on confocal microscopy.

CONCLUSION

Findings suggest that GSH/NaHCO3 - nanoparticles are a promising treatment option for viscous mucus in CF and other respiratory diseases of mucus obstruction such as chronic rhinosinusitis.

Guaifenesin: The Ubiquitous Orphan

Guaifenesin, a widely used ingredient in over-the-counter cough and cold medications, has been a subject of debate regarding its efficacy in treating respiratory conditions. Despite its historical use and US Food and Drug Administration approval, recent studies have questioned its claimed expectorant effect and its effectiveness in managing symptoms. This article examines the available evidence, highlighting the lack of significant benefits over placebo for upper respiratory disease. The rationale for clinical use is examined alongside the potential downside and alternatives to recommending guaifenesin as a treatment option.

Safety and Pharmacokinetics of a Ciprofloxacin and Azithromycin Stent for Chronic Rhinosinusitis

OBJECTIVES

Previously, we developed a novel double-coated sinus stent containing ciprofloxacin (inner layer) and azithromycin (outer layer) (CASS), but released drug concentrations were found to be insufficient for clinical usage. Our objectives are to improve drug release of CASS and assess safety and pharmacokinetics in rabbits.

METHODS

Dip coating was used to create the CASS with 2 mg ciprofloxacin and 5 mg azithromycin. A uniformed double coating was assessed with scanning electron microscopy (SEM), and the release patterns of both drugs and lactate dehydrogenase (LDH) assay were evaluated over 14 days in vitro. Safety, tolerability, and pharmacokinetics of the CASS were tested in rabbits through insertion into the maxillary sinus and evaluated with nasal endoscopy, CT scans, histology, blood counts and chemistries, and in vivo drug release.

RESULTS

SEM confirmed the uniformity of the dual coating of ciprofloxacin and azithromycin, and thickness (μm) was found to be 14.7 ± 2.4 and 28.1 ± 4.6, respectively. The inner coated ciprofloxacin showed a sustained release over 14 days (release %) when soaked in saline solution (day 7, 86.2 ± 3.4 vs. day 14,99.2 ± 5.1). In vivo analysis showed that after 12 days, 78.92 ± 7.67% of CP and 84.12 ± 0.45% of AZ were released into the sinus. There were no significant differences in body weight, white blood cell counts, and radiographic changes before and after CASS placement. No significant histological changes were observed compared to the contralateral control side.

CONCLUSION

Findings suggest that the CASS is an effective method for delivering therapeutic levels of antibiotics. Further studies are needed to validate efficacy in a preclinical sinusitis model.

LEVEL OF EVIDENCE

N/A Laryngoscope, 2024.

Optical Coherence Tomography as a Tool for Imaging the Sinonasal Mucosa in Patients: A Systematic Review

Objectives: To summarize the current applications and potential uses of optical coherence tomography (OCT), a noninvasive imaging modality that uses near-infrared light to produce cross-sectional, high-resolution images of biologic tissues, for evaluating the sinonasal mucosa in patients. Methods: Original articles utilizing OCT to image the sinonasal mucosa in patients were identified from the PubMed, Embase, Cochrane Library, Web of Science, and Scopus databases using the search phrase: "Optical Coherence Tomography" AND (sinonasal OR intranasal OR sinus OR nose OR sinusitis OR rhinitis OR olfactory). Strength of evidence, quality of evidence, and risk of bias were measured using validated scales. Study results were qualitatively assessed. Results: Out of 1662 original records identified through database searching, 9 studies were included in the systematic review. Levels of evidence ranged from III to IV and quality of evidence ranged from moderate to very low. Endoscopic OCT systems as well as OCT systems integrated with surgical microscopes were described in the literature. Applications of OCT for imaging the sinonasal mucosa included identifying morphological patterns unique to individual diseases, detecting mucosal structural changes after medical therapies and procedures, and evaluating mucociliary clearance. Conclusions: Most studies investigating OCT imaging of the sinonasal mucosa featured small sample sizes and lacked control groups. While OCT imaging could be a useful adjunct for diagnosing sinonasal disorders and monitoring response to treatment in the future, additional high-quality studies are necessary to determine if the use of OCT imaging can lead to improved diagnostic accuracy and health outcomes for patients with sinonasal pathologies.

Red ginseng aqueous extract improves mucociliary transport dysfunction and histopathology in CF rat airways

BACKGROUND

We previously discovered that Korean red ginseng aqueous extract (RGAE) potentiates the TMEM16A channel, improved mucociliary transport (MCT) parameters in CF nasal epithelia in vitro, and thus could serve as a therapeutic strategy to rescue the MCT defect in cystic fibrosis (CF) airways. The hypothesis of this study is that RGAE can improve epithelial Cl- secretion, MCT, and histopathology in an in-vivo CF rat model.

METHODS

Seventeen 4-month old CFTR-/- rats were randomly assigned to receive daily oral control (saline, n = 9) or RGAE (Ginsenosides 0.4mg/kg/daily, n = 8) for 4 weeks. Outcomes included nasal Cl- secretion measured with the nasal potential difference (NPD), functional microanatomy of the trachea using micro-optical coherence tomography, histopathology, and immunohistochemical staining for TMEM16a.

RESULTS

RGAE-treated CF rats had greater mean NPD polarization with UTP (control = -5.48 +/- 2.87 mV, RGAE = -9.49 +/- 2.99 mV, p < 0.05), indicating, at least in part, potentiation of UTP-mediated Cl- secretion through TMEM16A. All measured tracheal MCT parameters (airway surface liquid, periciliary liquid, ciliary beat frequency, MCT) were significantly increased in RGAE-treated CF rats with MCT exhibiting a 3-fold increase (control, 0.45+/-0.31 vs. RGAE, 1.45+/-0.66 mm/min, p < 0.01). Maxillary mucosa histopathology was markedly improved in RGAE-treated cohort (reduced intracellular mucus, goblet cells with no distention, and shorter epithelial height). TMEM16A expression was similar between groups.

CONCLUSION

RGAE improves TMEM16A-mediated transepithelial Cl- secretion, functional microanatomy, and histopathology in CF rats. Therapeutic strategies utilizing TMEM16A potentiators to treat CF airway disease are appropriate and provide a new avenue for mutation-independent therapies.

Efficacy and effectiveness of the herbal medicinal product BNO 1016 in the management of acute rhinosinusitis in the context of antibiotic stewardship

OBJECTIVES

To substantiate the clinical efficacy and investigate the real-world effectiveness of the herbal medicinal product BNO 1016 in acute rhinosinusitis (ARS) in the context of antibiotic stewardship.

METHODS

We performed a meta-analysis of the clinical trials ARhiSi-1 (EudraCT No. 2008-002794-13) and ARhiSi-2 (EudraCT No. 2009-016682-28) comprising 676 patients, analyzing the reduction of the Major Symptom Score (MSS) and improvement of the Sino-Nasal Outcome Test 20 (SNOT-20) by the herbal medicinal product BNO 1016. In addition, we performed a retrospective cohort study including 203,382 patients, comparing the real-life effectiveness of BNO 1016 in reducing ARS-related adverse outcomes in comparison to antibiotics and several other established therapies.

RESULTS

Treatment with BNO 1016 ameliorated symptoms of ARS by reducing MSS by 1.9 points (p < 0.0001) and improved quality of life (QoL) for patients by improving SNOT-20 by 3.5 points (p = 0.001) in comparison to placebo. In patients with moderate/severe symptoms, the positive effects of BNO 1016 were even more pronounced (MSS: -2.3 points (p < 0.0001); SNOT-20: -4.9 points (p = 0.0158)). In addition, treatment with BNO 1016 was as effective or significantly more effective in reducing the risk for adverse ARS-related outcomes such as follow-up antibiotic prescriptions, sick leave ≥7 days or medical appointments due to ARS, especially when compared to antibiotics.

CONCLUSION

BNO 1016 is a safe and effective treatment for ARS that can help reduce the overuse of antibiotics.

Comparative study of optical coherence tomograph and histological images of eustachian tube nasopharyngeal region and adjacent structures in vivo and ex-vivo miniature pigs

OBJECTIVES

Optical Coherence Tomograph (OCT) imaging technology can be used to examine, in vivo, the human ET. At present, it is impossible to achieve the OCT scanning vivo and ex vivo in the same individual human body, or study the consistency between OCT images and histological images of the eustachian tube nasopharyngeal region and adjacent structures. The aim of this study was to determine the consistency between OCT images and histological sections in vivo and ex vivo in miniature pigs.

METHODS

OCT imaging was performed on five adult miniature pigs in vivo and ex vivo. The images of the eustachian tube OCT (ET-OCT), nasopharynx OCT (NP-OCT) and histological cross sections were further studied.

RESULTS

All five miniature pigs achieved the OCT scan successfully, acquiring ET-OCT and NP-OCT images in vivo and ex vivo on both sides. The acquired ET OCT images closely matched the histological images, revealing details of the cartilage, submucosa, glands, and mucosa. The lower segment of the ET wall mucosa had an abundance of glands and submucosal tissues, with more low-signal areas appearing in the ex vivo images. The NP-OCT images of the nasopharynx matched the details of the mucosa and submucosal tissues. The ex-vivo OCT images showed thicker mucosa and more scattered slightly lower signal areas compared to the vivo OCT images.

CONCLUSIONS

ET-OCT images and NP-OCT images matched the histological structure of eustachian tube nasopharyngeal region structures in miniature pigs both in vivo and ex vivo. OCT images may be sensitive to changes in edema and ischemia status. There is a great potential for morphological assessment of inflammation, edema, injure, mucus gland status.

Efficacy of Low-Level Laser Therapy in a Rabbit Model of Rhinosinusitis

Little is known about alternative treatment options for rhinosinusitis (RS). We aimed to evaluate the efficacy of low-level laser therapy (LLLT) for RS in experimentally induced rabbit models of RS. A total of 18 rabbits were divided into four groups: a negative control group (n = 3), an RS group without treatment (n = 5, positive control group), an RS group with natural recovery (n = 5, natural recovery group), and an RS group with laser irradiation (n = 5, laser-treated group). Computed tomography and histopathological staining were performed for each group. mRNA and protein expression levels of local cytokines (IFN-γ, IL-17, and IL-5) were also measured. Tissue inflammation revealed a significant improvement in the laser-treated group compared with the RS and natural recovery groups (p < 0.01). In addition, sinus opacification in the CT scans and cytokine expression was reduced in the laser-treated group, though without statistical significance. LLLT could be an effective option for the management of RS concerning radiological, histological, and molecular parameters.

Contribution of Symptomatic, Herbal Treatment Options to Antibiotic Stewardship and Microbiotic Health

Epithelial surfaces in humans are home to symbiotic microbes (i.e., microbiota) that influence the defensive function against pathogens, depending on the health of the microbiota. Healthy microbiota contribute to the well-being of their host, in general (e.g., via the gut-brain axis), and their respective anatomical site, in particular (e.g., oral, urogenital, skin, or respiratory microbiota). Despite efforts towards a more responsible use of antibiotics, they are often prescribed for uncomplicated, self-limiting infections and can have a substantial negative impact on the gut microbiota. Treatment alternatives, such as non-steroidal anti-inflammatory drugs, may also influence the microbiota; thus, they can have lasting adverse effects. Herbal drugs offer a generally safe treatment option for uncomplicated infections of the urinary or respiratory tract. Additionally, their microbiota preserving properties allow for a more appropriate therapy of uncomplicated infections, without contributing to an increase in antibiotic resistance or disturbing the gut microbiota. Here, herbal treatments may be a more appropriate therapy, with a generally favorable safety profile.

Ivacaftor restores delayed mucociliary transport caused by Pseudomonas aeruginosa-induced acquired cystic fibrosis transmembrane conductance regulator dysfunction in rabbit nasal epithelia

BACKGROUND

Abnormal chloride (Cl^- ) transport dehydrates airway surface liquid (ASL) in sinonasal epithelium leading to mucus stasis and chronic rhinosinusitis. As an experimental epithelium, rabbit tissue provides an excellent representation of human sinus disease, and the rabbit sinusitis model is both established and well suited for therapeutic interventions in vivo. Our objective in this study was to evaluate whether ivacaftor reverses the consequences of Pseudomonas aeruginosa-induced acquired cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction.

METHODS

Rabbit nasal cavities were assessed for responsiveness to ivacaftor in vivo (by nasal potential difference [NPD] assay). Rabbit nasal epithelial (RNE) cultures were incubated with an ultrafiltrate of P aeruginosa (PAO1 strain) for 4 hours and tested for acquired CFTR dysfunction. Markers of mucociliary function, including airway surface liquid depth (ASL), periciliary liquid depth (PCL), ciliary beat frequency (CBF), and mucociliary transport (MCT), were measured by micro-optical coherence tomography (μOCT) after PAO1 and/or ivacaftor incubation.

RESULTS

Ivacaftor resulted in a significant mean NPD polarization of 21.8 ± 2.1 mV, which was significantly greater than that seen in the low Cl^- control (12.9 ± 1.3; p = 0.01). PAO1 exposure induced a state of acquired CFTR dysfunction in rabbit nasal epithelium as measured by forskolin-stimulated short-circuit current (I_SC ) (control, 37.0 ± 1.1 μA/cm² ; PAO1, 24.4 ± 1.1 μA/cm² ; p < 0.001). RNE cultures exposed to PAO1 had inhibited mucociliary function, whereas coincubation with ivacaftor restored mucociliary clearance, as measured by μOCT.

CONCLUSION

In rabbit nasal epithelium, ivacaftor robustly stimulates CFTR-mediated Cl^- secretion and normalizes ASL and CBF in PAO1-induced acquired CFTR dysfunction. Preclinical testing of CFTR potentiators as therapy for P aeruginosa rabbit sinusitis is planned.

LPS decreases CFTR open probability and mucociliary transport through generation of reactive oxygen species

Lipopolysaccharide (LPS) serves as the interface between gram-negative bacteria (GNB) and the innate immune response in respiratory epithelial cells (REC). Herein, we describe a novel biological role of LPS that permits GNB to persist in the respiratory tract through inducing CFTR and mucociliary dysfunction. LPS reduced cystic fibrosis transmembrane conductance regulater (CFTR)-mediated short-circuit current in mammalian REC in Ussing chambers and nearly abrogated CFTR single channel activity (defined as forskolin-activated Cl^- currents) in patch clamp studies, effects of which were blocked with toll-like receptor (TLR)-4 inhibitor. Unitary conductance and single-channel amplitude of CFTR were unaffected, but open probability and number of active channels were markedly decreased. LPS increased cytoplasmic and mitochondrial reactive oxygen species resulting in CFTR carbonylation. All effects of exposure were eliminated when reduced glutathione was added in the medium along with LPS. Functional microanatomy parameters, including mucociliary transport, in human sinonasal epithelial cells in vitro were also decreased, but restored with co-incubation with glutathione or TLR-4 inhibitor. In vivo measurements, following application of LPS in the nasal cavities showed significant decreases in transepithelial Cl^- secretion as measured by nasal potential difference (NPD) – an effect that was nullified with glutathione and TLR-4 inhibitor. These data provide definitive evidence that LPS-generated reactive intermediates downregulate CFTR function in vitro and in vivo which results in cystic fibrosis-type disease. Findings have implications for therapeutic approaches intent on stimulating Cl^- secretion and/or reducing oxidative stress to decrease the sequelae of GNB airway colonization and infection.

International consensus statement on allergy and rhinology: rhinosinusitis 2021

I.

EXECUTIVE SUMMARY

BACKGROUND: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR-RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR-RS-2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence-based findings of the document.

METHODS

ICAR-RS presents over 180 topics in the forms of evidence-based reviews with recommendations (EBRRs), evidence-based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary.

RESULTS

ICAR-RS-2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence-based management algorithm is provided.

CONCLUSION

This ICAR-RS-2021 executive summary provides a compilation of the evidence-based recommendations for medical and surgical treatment of the most common forms of RS.

The potential of herbal extracts to inhibit SARS-CoV-2: a pilot study

Background

Herbal medicinal products have a long-standing history of use in the therapy of common respiratory infections. We sought to assess the potential of five validated herbal extracts regarding their ability to restrict SARS-CoV-2 replication in vitro: Bronchipret thyme-ivy (BRO TI), Bronchipret thyme-primrose (BRO TP), Imupret (IMU), Sinupret extract (SINx) and Tonsipret (TOP).

Methods

Vero cells were incubated with different concentrations of herbal extracts and infected with SARS-CoV-2 for 48 hours. The inhibition of viral replication was assessed by determination of the viral RNA load in the cell culture supernatant using quantitative polymerase chain reaction (qPCR).

Results

SARS-CoV-2 RNA load was reduced by non-cytotoxic concentrations of BRO-TP (up to approximately 1,000-fold) and, to a lesser extent, IMU and TOP (approximately 10-fold).

Conclusions

Some herbal extracts showed a promising in vitro effectiveness against SARS-CoV-2, suggesting an antiviral potential of herbal medicinal products. The potential of herbal medicines to restrict SARS-CoV-2 and to treat COVID-19 should be investigated further in a clinical setting.

Expression of silent information regulator 1 in chronic rhinosinusitis and regulatory effects of inflammatory factors

We aimed to investigate the expression of silent information regulator 1 (Sirt1) in chronic rhinosinusitis (CRS) and the regulatory effects of inflammatory factors. The mucosal epithelial tissues of the nasal ethmoid sinus were collected from 30 patients with CRS from March 2017 to March 2019, and tissues from patients undergoing functional rhinoplasty were included as a control group. H&E staining and immunohistochemistry were performed to detect the histopathologic changes in the nasal mucosa and the expression of Sirt1. Epithelial cells in the control group were extracted from the ethmoid sinus mucosa and cultured in vitro. After the cells were treated with 0, 1, 10, and 100 ng/mL interleukin-5 (IL-5) and interferon-gamma (IFN-γ) for 24 h, qRT-PCR and western blotting were carried out to detect the mRNA and protein expressions of Sirt1. Nasal mucosal tissues of the control group were complete in structure, whereas large quantities of inflammatory cells infiltrated in nasal mucosa of the CRS group. Compared with the control group, the CRS group had significantly decreased protein and mRNA expression levels of Sirt1 (P<0.05), which significantly declined with increasing concentrations of IL-5 and IFN-γ (P<0.05). Thus, expression of Sirt1 in the nasal mucosa tissues of CRS patients is decreased, and inflammatory factors can reduce such expression in a dose-dependent manner. Sirt1 may participate in the inflammatory stress process of CRS.

Antibiotic eluting sinus stents

OBJECTIVES

Chronic rhinosinusitis (CRS) is a multifactorial disease affecting up to 16% of the United States population and disproportionately affecting the cystic fibrosis (CF) patient population. Despite treating the underlying infection, the use of systemic antibiotics has shown little efficacy in alleviation of symptom burden. This review seeks to discuss recent research on novel antibiotic eluting stent therapy in vitro and within animal models as well as the factors that contribute to its efficacy.

DATA SOURCES

PubMed literature review.

REVIEW METHODS

A review of all published literature related to antibiotic eluting sinus stents was conducted to integrate and summarize this innovative approach to chronic sinus infections.

RESULTS

Placement of the ciprofloxacin sinus stent (CSS) and ciprofloxacin-ivacaftor sinus stent (CISS) exhibited improvement in endoscopic and radiographic findings in rabbit CRS models. While the CSS showed an overall trend toward improvement in microscopic findings and a reduction in biofilm mass, there remained a significant quantity of planktonic bacteria due to antibiotic depletion from an initial burst release in the first 48 hours of stent placement. The CISS and ciprofloxacin-azithromycin sinus stents (CASSs) exhibited controlled antibiotic release over the study period leading to greatly reduced planktonic bacterial load and biofilm mass. In vitro studies indicate that CASS may be just as efficacious at reducing biofilm mass.

CONCLUSION

Antibiotic eluting sinus stents show significant promise as a novel therapeutic strategy for CRS. The CISS may have particular promise for the CF patient population by addressing both the infectious and genetic components of disease. Animal studies demonstrate significant promise for translation into human studies. Human clinical trials are warranted to determine the efficacy of antibiotic sinus stents in human patients.

LEVEL OF EVIDENCE

NA.

The impact of Lactococcus lactis (probiotic nasal rinse) co-culture on growth of patient-derived strains of Pseudomonas aeruginosa

BACKGROUND

The Lactococcus strain of bacteria has been introduced as a probiotic nasal rinse for alleged salubrious effects on the sinonasal bacterial microbiome. However, data regarding interactions with pathogenic bacteria within the sinuses are lacking. The purpose of this study is to assess the interaction between L. lactis and patient-derived Pseudomonas aeruginosa, an opportunistic pathogen in recalcitrant chronic rhinosinusitis (CRS).

METHODS

Commercially available probiotic suspension containing L. lactis W136 was grown in an anaerobic chamber and colonies were isolated. Colonies were co-cultured with patient-derived P. aeruginosa strains in the presence of porcine gastric mucin (mimicking human mucus) for 72 hours. P. aeruginosa cultures without L. lactis served as controls. Colony forming units (CFUs) were compared.

RESULTS

Six P. aeruginosa isolates collected from 5 CRS patients (3 isolates from cystic fibrosis [CF], 1 mucoid strain) and laboratory strain PAO1 were co-cultured with L. lactis. There was no statistical difference in CFUs of 5 P. aeruginosa isolates grown with L. lactis compared to CFUs without presence of L. lactis. CFU counts were much higher when the mucoid strain was co-cultured with L. lactis (CFU+L.lactis = 1.9 × 108 ± 1.44 × 107, CFU-L.lactis = 1.3 × 108 ± 8.9 × 106, p = 0.01, n = 7). L. lactis suppressed the growth of 1 P. aeruginosa strain (CFU+L.lactis = 2.15 × 108 ± 2.9 × 107, CFU-L.lactis = 3.95 × 108 ± 4.8 × 106, p = 0.03, n = 7).

CONCLUSION

L. lactis suppressed the growth of 1 patient P. aeruginosa isolate and induced growth of another (a mucoid strain) in in vitro co-culture setting in the presence of mucin. Further experiments are required to assess the underlying interactions between L. lactis and P. aeruginosa.

Controlled delivery of ciprofloxacin and ivacaftor via sinus stent in a preclinical model of Pseudomonas sinusitis

BACKGROUND

Pseudomonas aeruginosa is common in chronic rhinosinusitus (CRS) and frequently resistant to antibiotic treatment. We recently described the ciprofloxacin and ivacaftor-releasing biodegradable sinus stent (CISS)-a drug-delivery system that administers ciprofloxacin and the mucociliary activator (ivacaftor) at high local concentrations with prolonged mucosal contact time and sustained delivery. The objective of this study is to evaluate the efficacy of the CISS in a rabbit model of P aeruginosa (PAO1 strain) sinusitis.

METHODS

Ciprofloxacin/ivacaftor (double layer) was coated on biodegradable poly-D/L-lactic acid (PLLA). A total of 10 sinus stents (5 bare PLLA stent controls, 5 CISSs) were placed unilaterally in rabbit maxillary sinuses via dorsal sinusotomy after inducing infection for 1 week with PAO1. Animals were assessed 3 weeks after stent insertion with sinus culture, nasal endoscopy, computed tomography scan, histopathology, and in-vivo sinus potential difference (SPD) assay.

RESULTS

Rabbits treated with CISS had significant reductions in computed tomography (∆ Kerschner scale: control, 0.55 ± 0.92; CISS, -5.92 ± 1.69; p = 0.024) and endoscopy (control, 4.0 ± 0.0; CISS, 1.875 ± 0.74; p = 0.003) scores. A 2-log reduction of PAO1 was observed (control, -2.14 ± 0.77; CISS, 1.84 ± 1.52; p = 0.047). SPD revealed significantly increased Cl^- transport in the CISS group compared with the control group (Cl^- -free + forskolin ΔPD: control, -4.23 ± 1.04 mV; CISS, -18.36 ± 6.31 mV; p = 0.026). Finally, marked improvements were noted in the histology of the mucosa and submucosa in treated animals.

CONCLUSION

The CISS had robust clinical efficacy in treating P aeruginosa rabbit sinusitis. The innovative design of double-layered drug coating on the surface of the biodegradable stent may provide therapeutic advantages over current treatment strategies for P aeruginosa sinusitis.

In-vitro evaluation of a ciprofloxacin and azithromycin sinus stent for Pseudomonas aeruginosa biofilms

BACKGROUND

Chronic rhinosinusitis (CRS) is a chronic inflammatory disease characterized by persistent inflammation and bacterial infection. Ciprofloxacin and azithromycin are commonly prescribed antibiotics for CRS, but the ability to provide targeted release in the sinuses could mitigate side effects and improve drug concentrations at the infected site. This study was aimed to evaluate the efficacy of the novel ciprofloxacin-azithromycin sinus stent (CASS) in vitro.

METHODS

The CASS was created by coating ciprofloxacin (hydrophilic, inner layer) and azithromycin (hydrophobic, outer layer) onto a biodegradable poly-l-lactic acid (PLLA) stent. In-vitro evaluation included: (1) assessment of drug-coating stability within the stent using scanning electron microscopy (SEM); (2) determination of ciprofloxacin and azithromycin release kinetics; and (3) assessment of anti-biofilm activities against Pseudomonas aeruginosa.

RESULTS

The ciprofloxacin nanoparticle suspension in the inner layer was confirmed by zeta potential. Both ciprofloxacin (60 µg) and azithromycin (3 mg) were uniformly coated on the surface of the PLLA stents. The CASS showed ciprofloxacin/azithromycin sustained release patterns, with 80.55 ± 11.61% of ciprofloxacin and 93.85 ± 6.9% of azithromycin released by 28 days. The CASS also significantly reduced P aeruginosa biofilm mass compared with bare stents and controls (relative optical density units at 590-nm optical density: CASS, 0.037 ± 0.006; bare stent, 0.911 ± 0.015; control, 1.000 ± 0.000; p < 0.001; n = 3).

CONCLUSION

The CASS maintains a uniform coating and sustained delivery of ciprofloxacin and azithromycin, providing anti-biofilm activities against P aeruginosa. Further studies evaluating the efficacy of CASS in a preclinical model are planned.