Future topical medications in chronic rhinosinusitis

Essential considerations towards development of effective nasal antibiotic formulation: features, strategies, and future directions

INTRODUCTION

Intranasal antibiotic products are gaining popularity as a promising method of administering antibiotics, which provide numerous benefits, e.g. enhancing drug bioavailability, reducing adverse effects, and potentially minimizing resistance threats. However, some issues related to the antibiotic substances and nasal route challenges must be addressed to prepare effective formulations.

AREAS COVERED

This review focuses on the valuable points of nasal delivery as an alternative route for administering antibiotics, coupled with the challenges in the nasal cavity that might affect the formulations. Moreover, this review also highlights the application of nasal delivery to introduce antibiotics for local therapy, brain targeting, and systemic effects that have been conducted. In addition, this viewpoint provides strategies to maintain antibiotic stability and several crucial aspects to be considered for enabling effective nasal formulation.

EXPERT OPINION

In-depth knowledge and understanding regarding various key considerations with respect to the antibiotic substances and nasal route delivery requirement in preparing effective nasal antibiotic formulation would greatly improve the development of nasally administered antibiotic products, enabling better therapeutic outcomes of antibiotic treatment and establishing appropriate use of antibiotics, which in turn might reduce the chance of antibiotic resistance and enhance patient comfort.

A Decade of Pathogenesis Advances in Non-Type 2 Inflammatory Endotypes in Chronic Rhinosinusitis: 2012-2022

Chronic rhinosinusitis (CRS) is a heterogeneous disease characterized by localized inflammation of the upper airways. CRS includes two main phenotypes, namely, CRS with nasal polyps and CRS without nasal polyps. The phenotype-based classification method cannot reflect the pathological mechanism. The endotype-based classification method has been paid more and more attention by researchers. It is mainly divided into type 2 and non-type 2 endotypes. The mechanism driving the pathogenesis of non-type 2 inflammation is currently unknown. In this review, the PubMed and Web of Science databases were searched to conduct a critical analysis of representative literature works on the pathogenesis of non-type 2 inflammation in CRS published in the past decade. This review summarizes the latest evidence that may lead to the pathogenesis of non-type 2 inflammation. It is the main method that analyzing the pathogenesis from the perspective of immunology. Genomics and proteomics technique provide new approaches to the study of the pathogenesis. Due to differences in race, environment, geography, and living habits, there are differences in the occurrence of non-type 2 inflammation, which increase the difficulty of understanding the pathogenesis of non-type 2 inflammation in CRS. Studies have confirmed that non-type 2 endotype is more common in Asian patients. The emergence of overlap and unclassified endotypes has promoted the study of heterogeneity in CRS. In addition, as the source of inflammatory cells and the initiation site of the inflammatory response, microvessels and microlymphatic vessels in the nasal mucosal subepithelial tissue participate in the inflammatory response and tissue remodeling. It is uncertain whether CRS patients affect the risk of infection with SARS-CoV-2. In addition, the pathophysiological mechanism of non-type 2 CRS combined with COVID-19 remains to be further studied, and it is worth considering how to select the befitting biologics for CRS patients with non-type 2 inflammation.

Sinonasal Outcomes Using Oral Corticosteroids in Patients with Chronic Rhinosinusitis with Nasal Polyps and Positive Sinonasal Cultures

Introduction Patients with chronic rhinosinusitis with nasal polyps (CRSwNP) and positive sinonasal bacterial cultures may be recalcitrant to topical therapy alone due to the additional local inflammatory burden associated with bacterial infection/colonization.

Objective To evaluate sinonasal outcomes in CRSwNP patients with a positive perioperative bacterial culture, who were treated with postoperative intranasal corticosteroids (INCS) alone versus INCS in combination with a short-term course of oral corticosteroids (OCS).

Methods This is a retrospective chart review of CRSwNP patients. A total of 59 patients met inclusion criteria, including positive perioperative bacterial culture and treatment with INCS with or without concomitant use of OCS. Two cohorts were formed based on the chosen postoperative medical treatment; 32 patients underwent postoperative INCS alone, while 27 underwent INCS plus a ≤ 2-week course of OCS. The 22-item sinonasal outcome test (SNOT-22) scores and Lund-Kennedy scores (LKS) were assessed preoperatively, and at 2-week, 4-week, and 4 to 6 months after endoscopic sinus surgery (ESS).

Results There were no statistically significant differences in postoperative sinonasal symptoms or endoscopic scores between the cohorts treated with INCS plus OCS versus those prescribed INCS alone (p > 0.05). Our regression model failed to demonstrate a relationship between the use of OCS and better sinonasal outcomes at 2-week, 4-week, and 4 to 6 months after ESS (p > 0.05).

Conclusion Our study suggests that in a cohort of CRSwNP patients with recent bacterial infections, the postoperative use of combined OCS and INCS did not result in a statistical improvement of endoscopic and symptomatic outcomes over INCS irrigation alone. However, both treatment groups had a clinically significant improvement based on the Minimal Clinically Important Difference.

Role and Function of Regulatory T Cell in Chronic Rhinosinusitis with Nasal Polyposis

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a subtype of chronic rhinosinusitis characterized by high edema in the stroma, albumin deposition, and formation of pseudocysts. The pathogenesis of CRSwNP is not yet fully understood. Regulatory T (Treg) cells are a subset of CD4+ T cells that play a suppressive immunoregulatory role in the process of CRSwNP. Recent studies have found that there was a significant reduction in Treg cells in polyp tissues, which leads to the onset of CRSwNP. An imbalance between Th17 and Treg cells can also aggravate inflammation toward the Th2 type. This review focuses on our understanding of the function and role of Treg cells and their regulatory factors and clinical significance in CRSwNP. We also summarize the current drug treatments for CRSwNP with Tregs as the potential therapeutic target, which will provide new ideas for the treatment of CRSwNP in the future.

A randomized, double-blind, placebo- -controlled study to investigate the use of bacteriophages in patients with chronic rhinosinusitis with nasal polyps

Background A randomized, double-blind placebo-controlled study investigated the use of bacteriophages in the treatment of chronic rhinosinusitis with nasal polyps. Materials and Methods 40 adult patients with сhronic rhinosinusitis with nasal polyps were examined. All patients underwent functional endoscopic sinus surgery. After the surgery, 20 patients got the intranasal gel with a bacteriophages mixture (Otofag, Micromir, Russia) twice a day for ten weeks, and 20 patients got a placebo. Results On the 10th day, IL-1β secretion diminished (63 mg/ml versus 440 mg/ml in control). There was a decrease in the total number of microorganisms and Enterobacteriaceae (5.7 x 106 CFU/ml versus 1.2 x 109 CFU/ml in control), and the absence of Streptococci (versus 2.1 x 109 CFU/ml in control) on the 30th day of the treatment in the group with the bacteriophages. On the 10th day, a decrease in the activity of secretory IL-1β and IL-8 strongly and very strongly correlated with a total number of microorganisms (r = 0.7; r = 0.9 respectively), as well as secretory IL-8 with Enterobacteriaceae (r = 0.72) and Staphylococci (r = 0.65) in the active group treated with the bacteriophages. On the 30th day, the decrease in serum IL-1β significantly correlated with the total number of microorganisms (r = 0.80) and enterobacteria (r = 0.90) in the active group. Conclusions The administration of bacteriophages restored the balance of microorganisms in the nasal cavity and decreased the inflammatory response in chronic rhinosinusitis with nasal polyps. These changes, such as an inflammation dampening, could theoretically reduce the recurrent growth of polyp tissue in the future.

The Potential Role of Bacteriophages in the Treatment of Recalcitrant Chronic Rhinosinusitis

Chronic rhinosinusitis is a common condition affecting 5-12% of the general population worldwide. In a limited number of cases, the disease is recalcitrant to medical and surgical interventions, causing a major impact on physical, social and emotional well-being and increasing pressure on healthcare systems. Biofilm formation and dysbiosis caused by Staphylococcus aureus and Pseudomonas aeruginosa play a role in the pathogenesis of recalcitrant chronic rhinosinusitis. In these cases, a promising treatment alternative is the application of bacteriophages, which are viruses that infect and lyse bacteria. In this review, we appraise the evidence for the use of bacteriophages in the treatment of recalcitrant chronic rhinosinusitis. Additionally, (dis)advantages of bacteriophages and considerations for implementation of phage therapy in otorhinolaryngology practice will be discussed.

Current Perspective on Nasal Delivery Systems for Chronic Rhinosinusitis

Chronic rhinosinusitis is an upper respiratory disease during which topical drug treatment via the nasal cavity is the most actively utilized therapeutic strategy. In addition to steroids, antibiotics, and antifungal agents, which are widely used in clinical practice, research on novel topical agents to improve the bacterial biofilm or mucociliary clearance remains ongoing. Moreover, owing to the complex structure of the nasal cavity, the effects of nasal drug delivery vary depending on factors related to delivery fluid dynamics, including device, volume, and compounds. In this article, we review methods and compounds that have been applied to chronic rhinosinusitis management and introduce recent advances and future perspectives in nasal drug delivery for upper respiratory diseases.

Current Understanding of the Acute Exacerbation of Chronic Rhinosinusitis

Background: Acute exacerbations of chronic rhinosinusitis (CRS) have been increasingly recognized as an important disease entity with a significant impact on the quality of life. There is a growing amount of research on the etiopathogenesis and management of acute exacerbations of CRS. This review aims to summarize the current literature and provide an overall understanding of acute CRS exacerbations.

Methods: A related literature review with the key terms of “chronic rhinosinusitis” and “exacerbation” was performed using PubMed.

Results: There is no consensus definition of the acute exacerbation of CRS. Impaired mucociliary clearance, atrophic rhinitis, and immunologic changes are important predisposing factors for acute CRS exacerbations. Current evidence supports the role of the transient viral infection as the initial inflammatory stimulus in the pathogenesis of acute CRS exacerbations. Secondary bacterial infection or microbial community dysbiosis within the sinonasal cavity is the main event during the acute exacerbation of CRS. Distinct changes in local and systemic immune responses during exacerbation provide new insights into the pathophysiology of CRS exacerbation. Although current guidelines suggest the use of short-term antibiotics in patients with acute CRS exacerbation for symptomatic relief, evidence-based treatment recommendations for acute CRS exacerbation are still lacking, and large-high-quality RCTs are required.

Conclusion: There have been significant advances in understanding the etiology and immunological feathers of acute CRS exacerbation. Nevertheless, consensus definition, diagnostic criterion, biomarkers to differentiate acute CRS exacerbation from CRS, assessment of disease severity, and evidence-based treatment options for acute CRS exacerbation are still lacking.