Novel strategies for inhibition of bacterial biofilm in chronic rhinosinusitis

Mesenchymal Stem Cell Exosome-Integrated Antibacterial Hydrogels for Nasal Mucosal Injury Treatment

Hydrogels have emerged as appealing prospects for wound healing due to their superior biocompatible qualities. However, the integration of antibacterial active substances into hydrogels for effective wound repair remains challenging. Here, we present a novel double-network hydrogel for nasal mucosal injury repair with antibacterial and self-healing capabilities. This hydrogel is the result of mixing aldehyde polyethylene glycol (PEG) and a carboxymethyl chitosan (CMCS)-based hydrogel with a photocured methylacrylate gelatin (GelMA) hydrogel to envelop mesenchymal stem cell exosomes (MSC-Exos). CMCS is rich in amino groups and facilitates antibacterial repair. Given the dynamically reversible Schiff base connections between the amino group of chitosan and the aldehyde group of modified PEG, the hydrogel can be easily injected into the lesion site because of its excellent injection and shear thinning properties. GelMA introduces an additional network layer for the hydrogel, which enhances its strength and extends the duration of stem cell exosomes on the wound surface. On the basis of these characteristics, we provide evidence that this compound hydrogel can substantially increase cell proliferation and regeneration, inhibit scar hyperplasia, and stimulate angiogenesis in rabbit nasal septum mucosa trauma models. These results suggest that MSC exosome-loaded hydrogels (ME-Gel) have substantial clinical potential for the repair and regeneration of nasal mucosa after surgery or trauma.

Relationship between biofilm formation and antibiotic resistance of Klebsiella pneumoniae and updates on antibiofilm therapeutic strategies

Klebsiella pneumoniae is a Gram-negative bacterium within the Enterobacteriaceae family that can cause multiple systemic infections, such as respiratory, blood, liver abscesses and urinary systems. Antibiotic resistance is a global health threat and K. pneumoniae warrants special attention due to its resistance to most modern day antibiotics. Biofilm formation is a critical obstruction that enhances the antibiotic resistance of K. pneumoniae. However, knowledge on the molecular mechanisms of biofilm formation and its relation with antibiotic resistance in K. pneumoniae is limited. Understanding the molecular mechanisms of biofilm formation and its correlation with antibiotic resistance is crucial for providing insight for the design of new drugs to control and treat biofilm-related infections. In this review, we summarize recent advances in genes contributing to the biofilm formation of K. pneumoniae, new progress on the relationship between biofilm formation and antibiotic resistance, and new therapeutic strategies targeting biofilms. Finally, we discuss future research directions that target biofilm formation and antibiotic resistance of this priority pathogen.

Biofilm in sino-nasal infectious diseases: the role nasal cytology in the diagnostic work up and therapeutic implications

BACKGROUD

Biofilm formation has been recently recognised as one of the most important etiopathological mechanisms underlying chronic rhinosinusitis (CRS) and its recalcitrance. In this context, nasal cytology (NC) has become an integral part of diagnostic work up of patients suffering from sino-nasal diseases, since it is an easy-to-apply, reproducible and non-invasive diagnostic tool that allows to assess both the nasal inflammatory infiltrate and the presence of biofilms on nasal mucosal surface, further orienting the therapeutic choices in case of infectious diseases for eradicating infections and biofilms. Nevertheless, biofilms are typically resistant to common antibiotic treatments and may trigger or maintain chronic inflammation. Hence, the importance of correctly detecting the presence of biofilm and identifying new effective treatments.

PURPOSE

The aim of this brief review is to better clarify the role of biofilm in the pathogenesis and recurrence of sino-nasal disorders and to highlight the role of nasal cytology (NC) in the rhino-allergologic diagnostic path and in the evaluation of the effectiveness of new treatments.

Immunological mechanisms and treatable traits of chronic rhinosinusitis in Asia: A narrative review

OBJECTIVES

To review the current literature on immunological mechanisms and treatable traits of chronic rhinosinusitis (CRS) in Asia.

DESIGN

This is a narrative review of published data on the immunological mechanisms and treatable traits of CRS in Asia. Published English literature on CRS in Asian and Western countries was reviewed. Where available, the data extracted included epidemiology, immunology, bacterium, phenotype, endotype and treatment.

RESULTS AND CONCLUSION

CRS is a heterogeneous disease characterised by persistent locoregional mucosal inflammation of the paranasal sinuses. The inflammatory signatures of CRS vary across patients with distinct racial and ethnic backgrounds and geographic areas. Compared to CRS patients in Western countries, Asian CRS patients display less eosinophilic and Type 2 inflammation, which is associated with lower asthma and allergic rhinitis comorbidities. In contrast, Asian patients with CRS have more prominent non-eosinophilic inflammation than those in Western countries. In addition, Asian CRS patients may have different bacterial colonisation than patients in Western countries. Our review suggests that the distinct immunological mechanisms between Asian and Western CRS patients may influence the clinical phenotype, responses to treatment and outcomes. The treatable trait is a new strategy and therapeutic target identified by phenotype or endotype and has been proposed as a new paradigm for the management of diseases. Improved understanding of CRS phenotypic and endotypic heterogeneity and incorporation of treatable traits into clinical care pathways may facilitate more effective selections of therapeutic interventions, including surgery and biologics.