Search Results (315)

Despite the widespread accessibility of vaccines and antivirals, seasonal influenza virus epidemics continue to pose a threat to public health. In this study, we constructed a recombinant replication-deficient simian adenovirus type 25 vector carrying the full-length hemagglutinin (HA) of the H1N1 influenza virus, named rSAd25-H1. Both systemic and mucosal humoral immune responses, as well as the protective efficacy, were assessed in mice immunized via the intramuscular (IM) or intranasal (IN) route. A single-dose IM or IN administration of rSAd25-H1 elicited a robust systemic IgG antibody response, including hemagglutination inhibition antibodies. As expected, only IN immunization was able to induce IgA production in serum and respiratory mucosa. Notably, a single dose of rSAd25-H1 at the highest dose (10¹⁰ viral particles) conferred complete protection against lethal homologous H1N1 challenge in mice despite the route of administration. These findings demonstrate the potential of simian adenovirus type 25-based vectors as a promising candidate for intranasal vaccine development targeting respiratory pathogens. Full article

Background/Objectives: Intramuscular immunization elicits systemic IgG and is the primary route of vaccine administration in humans. However, there is growing interest in utilizing other routes of administration to tailor antibody profiles, increase immunity at primary sites of infection, simplify administration, and eliminate needle waste. Here, we investigated the antibody profiles elicited by immunization with bacteriophage virus-like particle vaccine platforms at various routes of administration. Methods: We chose two model bacteriophage vaccines for investigation: bacteriophage MS2 virus-like particles (VLPs) recombinantly displaying a short, conserved peptide from Chlamydia trachomatis major outer membrane protein (MS2) and bacteriophage Qβ VLPs displaying oxycodone through chemical conjugation (Qβ). We comprehensively characterized the antibodies elicited systemically and at various mucosal sites when the vaccines were administered intramuscularly, intranasally or periocularly with or without an intramuscular prime using various prime/boost schemes. Results: Intranasal and periocular immunization elicited robust mucosal and systemic IgA responses for both MS2 and Qβ. The intramuscular prime followed by intranasal or periocular boosts elicited broad antibody responses, and increased antibodies titers at certain anatomical sites. Conclusions: These findings demonstrate the tractability of bacteriophage VLP-based vaccines in generating specific antibody profiles based on the prime–boost regimen and route of administration. Full article

Background/Objectives: Mucosal vaccines, delivered intranasally or via inhalation, are being studied for respiratory infectious diseases like COVID-19 and influenza. These vaccines aim to provide non-invasive administration and strong immune responses at infection sites, making them a promising area of research. This systematic review and meta-analysis assessed their immunogenicity, safety, and protective efficacy. Methods: The study design was a systematic review and meta-analysis, searching PubMed and Cochrane databases up to 30 May 2025. Inclusion criteria followed the PICOS framework, focusing on mucosal vaccines for COVID-19, influenza, RSV, pertussis, and tuberculosis. Results: A total of 65 studies with 229,614 participants were included in the final analysis. Mucosal COVID-19 vaccines elicited higher neutralizing antibodies compared to intramuscular vaccines (SMD = 2.48, 95% CI: 2.17–2.78 for wild-type; SMD = 1.95, 95% CI: 1.32–2.58 for Omicron), with varying efficacy by route (inhaled VE = 47%, 95% CI: 22–74%; intranasal vaccine VE = 17%, 95% CI: 0–31%). Mucosal influenza vaccines protected children well (VE = 62%, 95% CI: 30–46%, I² = 17.1%), but seroconversion rates were lower than those of intramuscular vaccines. RSV and pertussis vaccines had high seroconversion rates (73% and 52%, respectively). Tuberculosis vaccines were reviewed systemically, exhibiting robust cellular immunogenicity. Safety was comparable to intramuscular vaccines or placebo, with no publication bias detected. Conclusions: Current evidence suggests mucosal vaccines are immunogenic, safe, and protective, particularly for respiratory diseases. This review provides insights for future research and vaccination strategies, though limitations include varying efficacy by route and study heterogeneity. Full article

Central nervous system (CNS) disorders present significant therapeutic challenges due to the limited regenerative capacity of neural tissues, resulting in long-term disability for many patients. Consequently, the development of novel therapeutic strategies is urgently warranted. Stem cell therapies show considerable potential for mitigating brain damage and restoring neural connectivity, owing to their multifaceted properties, including anti-apoptotic, anti-inflammatory, neurogenic, and vasculogenic effects. Recent research has also identified exosomes—small vesicles enclosed by a lipid bilayer, secreted by stem cells—as a key mechanism underlying the therapeutic effects of stem cell therapies, and given their enhanced stability and superior blood–brain barrier permeability compared to the stem cells themselves, exosomes have emerged as a promising alternative treatment for CNS disorders. A key challenge in the application of both stem cell and exosome-based therapies for CNS diseases is the method of delivery. Currently, several routes are being investigated, including intracerebral, intrathecal, intravenous, intranasal, and intra-arterial administration. Intracerebral injection can deliver a substantial quantity of stem cells directly to the brain, but it carries the potential risk of inducing additional brain injury. Conversely, intravenous transplantation is minimally invasive but results in limited delivery of cells and exosomes to the brain, which may compromise the therapeutic efficacy. With advancements in catheter technology, intra-arterial administration of stem cells and exosomes has garnered increasing attention as a promising delivery strategy. This approach offers the advantage of delivering a significant number of stem cells and exosomes to the brain while minimizing the risk of additional brain damage. However, the investigation into the therapeutic potential of intra-arterial transplantation for CNS injury is still in its early stages. In this comprehensive review, we aim to summarize both basic and clinical research exploring the intra-arterial administration of stem cells and exosomes for the treatment of CNS diseases. Additionally, we will elucidate the underlying therapeutic mechanisms and provide insights into the future potential of this approach. Full article

Recombinant vesicular stomatitis virus (rVSV) is a promising viral vaccine vector for addressing the COVID-19 pandemic. Inducing mucosal immunity via the intranasal route is an ideal strategy for rVSV-based vaccines, but it requires extremely stringent safety standards. In this study, we constructed two rVSV variants with amino acid mutations in their M protein: rVSV-M2 with M33A/M51R mutations and rVSV-M4 with M33A/M51R/V221F/S226R mutations, and developed COVID-19 vaccines based on these attenuated vectors. By comparing viral replication capacity, intranasal immunization, intracranial injection, and blood cell counts, we demonstrated that the M protein mutation variants exhibit significant attenuation effects both in vitro and in vivo. Moreover, preliminary investigations into the mechanisms of virus attenuation revealed that these attenuated viruses can induce a stronger type I interferon response while reducing inflammation compared to the wild-type rVSV. We developed three candidate vaccines against SARS-CoV-2 using the wildtype VSV backbone with either wild-type M (rVSV-JN.1) and two M mutant variants (rVSV-M2-JN.1 and rVSV-M4-JN.1). Our results confirmed that rVSV-M2-JN.1 and rVSV-M4-JN.1 retain strong immunogenicity while enhancing safety in hamsters. In summary, the rVSV variants with M protein mutations represent promising candidate vectors for mucosal vaccines and warrant further investigation. Full article

The intranasal delivery of exogenous mitochondria is a potential therapy for Parkinson’s disease (PD). The regulatory mechanisms and effectiveness in genetic models remains uncertain, as well as the impact of modulating the mitochondrial permeability transition pore (mPTP) in grafts. Utilizing UQCRC1 (p.Tyr314Ser) knock-in mice, and a cellular model, this study validated the transplantation of mitochondria with or without cyclosporin A (CsA) preloading as a method to treat mitochondrial dysfunction and improve disease progression through intranasal delivery. Liver-derived mitochondria were labeled with bromodeoxyuridine (BrdU), incubated with CsA to inhibit mPTP opening, and were administered weekly via the nasal route to 6-month-old mice for six months. Both treatment groups showed significant locomotor improvements in open-field tests. PET imaging showed increased striatal tracer uptake, indicating enhanced dopamine synthesis capacity. The immunohistochemical analysis revealed increased neuron survival in the dentate gyrus, a higher number of tyrosine hydroxylase (TH)-positive neurons in the substantia nigra (SN) and striatum (ST), and a thicker granule cell layer. In SN neurons, the function of mitochondrial complex III was reinstated. Additionally, the CsA-accumulated mitochondria reduced more proinflammatory cytokine levels, yet their therapeutic effectiveness was similar to that of unmodified mitochondria. External mitochondria were detected in multiple brain areas through BrdU tracking, showing a 3.6-fold increase in the ST compared to the SN. In the ST, about 47% of TH-positive neurons incorporated exogenous mitochondria compared to 8% in the SN. Notably, GFAP-labeled striatal astrocytes (ASTs) also displayed external mitochondria, while MBP-labeled striatal oligodendrocytes (OLs) did not. On the other hand, fewer ASTs and increased OLs were noted, along with lower S100β levels, indicating reduced reactive gliosis and a more supportive environment for OLs. Intranasally, mitochondrial transplantation showed neuroprotective effects in genetic PD, validating a noninvasive therapeutic approach. This supports mitochondrial recovery and is linked to anti-inflammatory responses and glial modulation. Full article

Donepezil (DPZ) is an Alzheimer’s disease (AD) drug that promotes cholinergic neurotransmission and exhibits excellent acetylcholinesterase (AChE) selectivity. The current oral formulations of DPZ demonstrate decreased bioavailability, attributed to limited drug permeability across the blood–brain barrier (BBB). In order to overcome these limitations, various dosage forms aimed at delivering DPZ have been explored. This discussion will focus on the nose-to-brain (N2B) delivery system, which represents the most promising approach for brain drug delivery. Intranasal (IN) drug delivery is a suitable system for directly delivering drugs to the brain, as it bypasses the BBB and avoids the first-pass effect, thereby targeting the central nervous system (CNS). Currently developed formulations include lipid-based, solid particle-based, solution-based, gel-based, and film-based types, and a systematic review of the N2B research related to these formulations has been conducted. According to the in vivo results, the brain drug concentration 15 min after IN administration was more than twice as high those from other routes of administration, and the direct delivery ratio of the N2B system improved to 80.32%. The research findings collectively suggest low toxicity and high therapeutic efficacy for AD. This review examines drug formulations and delivery methods optimized for the N2B delivery of DPZ, focusing on technologies that enhance mucosal residence time and bioavailability while discussing recent advancements in the field. Full article

Background/Objectives: In this study, we aimed to evaluate probiotics’ clinical efficacy and safety in adults with chronic rhinosinusitis (CRS), and summarize mechanistic evidence related to mucosal immunity and microbiota modulation. Methods: We performed a systematic review and random-effects meta-analysis. MEDLINE, Embase, Scopus, Web of Science, and the Cochrane Library were searched until May 2025. Eligibility: Randomized controlled trials (RCTs) and mechanistic studies investigating probiotics (any strain, dose, or administration route) in adults with CRS were eligible. Primary outcomes included changes in Sino-Nasal Outcome Test (SNOT-20/22) scores and CRS relapse rates. Secondary outcomes were adverse events and mechanistic endpoints. Results: Six studies (four RCTs, n = 337; two mechanistic studies) met the inclusion criteria. Probiotics did not significantly improve SNOT scores compared with the placebo, but trended in that direction (pooled mean difference—2.70; 95% CI −7.12 to 1.72; I² = 0%). Furthermore, probiotic use was associated with a non-significant trend towards fewer CRS relapses (risk ratio 0.41; 95% CI 0.16–1.04; p = 0.06; I² = 48%). Adverse events were mild and comparable to the placebo (risk ratio 0.87; 95% CI 0.33–2.34). Mechanistic data indicated that intranasal Lactococcus lactis W136 might downregulate type 1 inflammatory pathways and modestly increase microbiome diversity. Subgroup analyses (by route, duration, and CRS subtype) revealed no statistically significant effect modifiers, though mechanistic insights suggest possible differences in efficacy based on the CRS endotype and delivery method. Conclusions: Probiotics appear safe and may provide a small, non-significant improvement in CRS symptoms; emerging evidence of reduced relapse rates warrants further investigation through larger, endotype-stratified trials utilizing targeted probiotic strains and optimized delivery methods. Full article

Nocardia, an easily missed but potentially fatal opportunistic pathogen, can lead to serious infections like lung and brain abscesses. Intranasal inoculation (IN) is the traditional approach for constructing a Nocardia-induced pneumonia mice model, while it usually only results in limited local bacterial infection in the lungs. To comprehensively assess infection dynamics across distinct pulmonary inoculation routes in mice models, this study compared the pathogenicity of three different Nocardia farcinica pneumonia models established via IN, intratracheal aerosolization (ITA), and intratracheal instillation (ITI). C57BL/6J mice were infected with N. farcinica through IN, ITA and ITI with comparative analyses of bacterial distribution in lungs, survival rate, weight, bacterial load, inflammatory cytokines, histopathological characteristics and transcriptome differences. The findings suggest that ITA N. farcinica infections caused severer clinical symptoms, higher mortality, pulmonary bacterial load, levels of inflammatory cytokines in bronchoalveolar lavage fluid, and more significant histopathological damage to lungs than IN and ITI. Furthermore, ITA resulted in better lung bacterial distribution and delivery efficiency than ITI and IN. Transcriptome analysis of lungs from N. farcinica infected mice via IN, ITA and ITI revealed significant differential gene expression, whereas ITA route resulted in a larger fold change. ITA provides a more consistent and severe model of N. farcinica pneumonia in mice than IN and ITI, which can make the bacteria more evenly distributed in the lungs, leading to more severe pathological damage and higher mortality rates. In conclusion, ITA is an optimal route for developing animal models of N. farcinica pneumonia infections. Full article

Introduction: Psychomotor agitation represents a complex medical emergency, particularly challenging in prehospital settings. Since March 2020, the incidence of psychomotor agitation has significantly increased. Rationale: Emergency Medical Services (EMS) frequently serve as the first point of contact, bearing the critical responsibility of effectively managing these situations. Objective: This was to assess the feasibility and suitability of the intranasal route for administering pharmacological therapy in the prehospital management of patients experiencing psychomotor agitation. Materials and Methods: An integrative review of the literature was conducted to evaluate the use of the intranasal route for drug administration in patients with psychomotor agitation in prehospital settings. The review was carried out between September 2022 and July 2024. A total of 454 articles were identified, 15 of which met the inclusion criteria. These were supplemented by an additional 10 records, resulting in the analysis of 25 studies. Results: Seventeen studies outlined protocols for managing agitated patients, five described the correct technique for intranasal drug administration, and eleven identified drugs suitable for this route. Conclusions: The intranasal route is a safe, rapid, and accessible method for the pharmacological containment of agitated patients in prehospital settings, particularly for individuals who are uncooperative. Full article

Background/Objectives: Non-invasive central nervous system (CNS) therapies are limited by complex mechanisms and the blood–brain barrier, but nasal delivery offers a promising alternative. The study planned to develop a non-invasive in situ intranasal mucoadhesive thermosensitive gel to deliver CNS-active risperidone via nose-to-brain targeting. Risperidone, a second-generation antipsychotic, has shown efficacy in managing both psychotic and mood-related symptoms. The mucoadhesive gel formulations help to prolong the residence time at the nasal absorption site, thereby facilitating the uptake of the drug. Methods: The poloxamer 407 (18.0% w/v), HPMC K100M and K15M (0.3–0.5% w/v), and benzalkonium chloride (0.1% v/v) were used as thermosensitive polymers, a mucoadhesive agent, and a preservative, respectively, for the development of in situ thermosensitive gel. The developed formulations were evaluated for various parameters. Results: The pH, gelation temperature, gelation time, and drug content were found to be 6.20 ± 0.026–6.37 ± 0.015, 34.25 ± 1.10–37.50 ± 1.05 °C, 1.65 ± 0.30–2.50 ± 0.55 min, and 95.58 ± 2.37–98.03 ± 1.68%, respectively. Furthermore, the optimized F3 formulation showed satisfactory gelling capacity (9.52 ± 0.513 h) and an acceptable mucoadhesive strength (1110.65 ± 6.87 dyne/cm²). Diffusion of the drug through the egg membrane depended on the formulation’s viscosity, and the F3 formulation explained the first-order release kinetics, indicating concentration-dependent drug diffusion with n < 0.45 (0.398) value, indicating the Fickian-diffusion (diffusional case I). The pharmacokinetic study was performed with male Wistar albino rats, and the F3 in situ thermosensitive risperidone gel confirmed significantly (p < 0.05) ~5.4 times higher brain AUC_0–∞ when administered intranasally compared to the oral solution. Conclusions: Based on physicochemical, in vitro, and in vivo parameters, it can be concluded that in situ thermosensitive gel is suitable for administration of risperidone through the nasal route and can enhance patient compliance through ease of application and with less repeated administration. Full article

The incidence of morbidity and mortality in patients who have suffered traumatic brain injury (TBI) is such that novel therapeutic strategies are currently required. There is good evidence that ischaemia is the primary, and sometimes the secondary, cause of brain damage in TBI. This ischaemia may lead to mitochondrial dysfunction, with associated oxidative stress and inflammation, in the pathogenesis of brain injury following head trauma. This, in turn, provides a rationale for the use of supplemental coenzyme Q10 (CoQ10) in the management of TBI, given its key roles in normal mitochondrial function and as an antioxidant and anti-inflammatory agent. In this article, we, therefore, review the use of supplemental CoQ10 in animal models of TBI and its potential application in the management of TBI patients. The problem of blood–brain barrier access is discussed, and how this might be circumvented via the use of an intranasal route to provide direct access of CoQ10 to the brain. In addition, there is evidence that TBI patients have an increased risk of developing cardiac dysfunction and that this may be mediated by aberrant immune action. Given the role of CoQ10 in promoting normal cardiac function and normal immune function, the administration of CoQ10 to prevent cardiovascular complications may improve outcomes in TBI patients. Full article

Background/Objectives: Respiratory syncytial virus (RSV) poses a substantial global health threat, particularly impacting infants and vulnerable pediatric populations through severe respiratory morbidity. Methods: We developed a novel adenoviral vector vaccine platform utilizing chimpanzee adenovirus 68 (AdC68) to deliver prefusion F (pre-F) antigens from RSV subtypes A and B, generating three vaccine candidates: AdC68-A (subtype A), AdC68-B (subtype B), and AdC68-A+B (bivalent formulation). Results: Single intranasal (i.n.) immunization and prime–boost immunizations via intramuscular (i.m.) routes in BALB/c mice induced robust immune activation, with single i.n. administration conferring durable protection evidenced by an 85% reduction in pulmonary viral loads (p < 0.05) at 134 days post-immunization. All vaccine formulations via i.n. single administration elicited potent subtype-specific IgG responses (geometric mean titers 50–12,800) and Th1-polarized cellular immunity (552–1201 IFN-γ+ spot-forming units/10⁶ PBMCs, IgG2a/IgG1 > 1) in bivalent formulation group, while i.m. boosting enhanced cellular responses 3-fold versus prime immunization alone (p < 0.01). Notably, despite undetectable serum-neutralizing antibodies and absent mucosal IgA in bronchoalveolar lavage at 7 days post-i.n. immunization, the sustained viral control highlights non-neutralizing antibody-mediated protective mechanisms. Conclusions: These findings establish the proof-of-concept for adenoviral-vectored intranasal vaccines against RSV, though optimization of humoral response induction and mucosal immunity duration require further investigation. Full article

Neurological symptoms involving the central nervous system (CNS) and peripheral nervous system (PNS) are common complications of acute COVID-19 as well as post-COVID conditions. Most research into these neurological sequalae focuses on the CNS, disregarding the PNS. Guinea pigs were previously shown to be useful models of disease during the SARS-CoV-1 epidemic. However, their suitability for studying SARS-CoV-2 has not been experimentally demonstrated. To assess the suitability of guinea pigs as models for SARS-CoV-2 infection and the impact of SARS-CoV-2 infection on the PNS, and to determine routes of CNS invasion through the PNS, we intranasally infected wild-type Dunkin-Hartley guinea pigs with ancestral SARS-CoV-2 USA-WA1/2020. We assessed PNS sensory neurons (trigeminal ganglia, dorsal root ganglia), autonomic neurons (superior cervical ganglia), brain regions (olfactory bulb, brainstem, cerebellum, cortex, hippocampus), lungs, and blood for viral RNA (RT-qPCR), protein (immunostaining), and infectious virus (plaque assay) at three- and six-days post infection. We show that guinea pigs, which have previously been used as a model of SARS-CoV-1 pulmonary disease, are not susceptible to intranasal infection with ancestral SARS-CoV-2, and are not useful models in assessing neurological impacts of infection with SARS-CoV-2 isolates from the early pandemic. Full article

Background: Allergic rhinitis (AR) is a common disease that requires more convenient, safe, and effective therapy. This study aimed to investigate the therapeutic effect of Forkhead box protein3 (Foxp3) introduced with poly(d,l-lactic-co-glycolic acid) (PLGA) nanoparticles (Foxp3 NPs) in an AR mouse model. Methods: A murine model of allergic rhinitis was established using BALB/c mice through initial sensitization by intraperitoneal administration of ovalbumin (OVA), followed by repeated intranasal OVA challenges. Foxp3 plasmid-loaded PLGA nanoparticles were subsequently administered via either the intranasal or intraperitoneal route to evaluate therapeutic efficacy. Episodes of sneezing and nose rubbing were counted. The serum total IgE, OVA-specific IgE, and cytokine levels in nasal lavage fluid (NALF) were determined by ELISA (Enzyme-Linked ImmunoSorbent Assay). Nasal mucosa from each group were analyzed using protein, reverse transcriptase–polymerase chain reaction (RT-PCR), and histological analyses. Result: Rubbing and sneezing symptoms improved in the Foxp3 NPs intranasal administration group. Foxp3 NPs intranasal administration markedly ameliorated OVA-induced nasal allergic inflammation. The total IgE and OVA-specific IgE serum level and IL-4, IL-13 expression levels of NALF were significantly decreased in the treated Foxp3 NPs group. The histopathological results of nasal mucosa were also normal, with no cellular infiltration and no inflammation in the Foxp3 NPs group. Conclusions: These results suggest that Foxp3 NPs alleviate nasal allergic inflammation and may have therapeutic value in the treatment of AR. Full article