Fluctuations in plasma adrenocorticotropic hormone concentration may predict the onset of immune checkpoint inhibitor-related hypophysitis.

Immune checkpoint inhibitor (ICI)-related hypophysitis (RH) is a common immune-related adverse event. The early detection of ICI-RH prevents life-threatening adrenal insufficiency. However, good predictors of secondary adrenal insufficiency in ICI-RH have not yet been reported. We hypothesized that fluctuations in serum adrenocorticotropic hormone (ACTH) and cortisol levels occur similarly to those in thyroid-stimulating hormone and thyroid hormone (thyroxine and triiodothyronine) levels in ICI-related thyroiditis. Here, we sought to test this hypothesis. Patients who used ICI and had a history of measurement of serum ACTH and cortisol concentrations were retrieved from electronic medical records, and those with a history of glucocorticoid use were excluded from the analysis. We evaluated fluctuations in serum ACTH and cortisol concentrations and the development of ICI-RH. For patients with ICI-RH, data at three points (before ICI administration (pre), maximum ACTH concentration (peak), and onset of ICI-RH) were analyzed to evaluate hormone fluctuations. A total of 202 patients were retrieved from the medical record. Forty-three patients were diagnosed with ICI-RH. Twenty-six out of 43 patients had sufficient data to evaluate fluctuations in serum ACTH and cortisol concentrations and no history of glucocorticoid use. ACTH concentrations changed from 37.4 (29.9-48.3) (pre) to 64.4 (46.5-106.2) (peak) pg/mL (1.72-fold increase, p=0.0026) in the patients with ICI-RH before the onset. There were no differences in cortisol concentrations between the pre and peak values in patients with ICI-RH. We also evaluated the fluctuations in serum ACTH and cortisol levels in patients who did not receive ICI-RH (62 cases). However, elevation of serum ACTH levels was not observed in patients without ICI-RH, suggesting that transient elevation of serum ACTH levels is a unique phenomenon in patients with ICI-RH. In conclusion, serum ACTH levels were transiently elevated in some patients with ICI-RH before the onset of secondary adrenal insufficiency. Monitoring the ACTH levels and their fluctuations may help predict the onset of ICI-RH.

Lens capsule pathological characteristics in cases of intraocular lens dislocation with atopic dermatitis.

PURPOSE: To explore lens capsule pathological characteristics in intraocular lens (IOL) dislocation following cataract surgery in patients with atopic dermatitis (AD). SETTING: University hospital department of ophthalmology. DESIGN: Case series with clinicopathological correlations. METHODS: Lens capsules and surrounding tissues excised during surgery from eyes with AD (AD group) and eyes without AD (non-AD group) with IOL dislocation were histologically evaluated. Hematoxylin and eosin staining was used to assess abnormal changes in lens epithelial cells (LECs). Masson's trichrome staining distinguished the fibrous metaplasia around the lens capsule into high- and low-density fibrosis. Capsular splitting (thinning) was identified in both stained preparations. RESULTS: The IOL dislocation morphology in the AD group (10 eyes of 10 patients) included 7 cases of capsular bag dislocation (CBD) and 3 cases of dead bag syndrome (DBS), with an average duration to IOL dislocation of 11.5±5.6 years. All patients in the non-AD group (12 eyes of 12 patients) had CBD, averaging 10.2±5.7 years to dislocation. Abnormal LECs, low-density fibrosis, and capsular splitting were observed in 9 (90), 9 (90), and 6 (60) of the patients in the AD group, respectively, compared to 6 (50), 3 (25), and 2 (18), respectively, in the non-AD group (Total n(%)). CONCLUSIONS: Compared to the non-AD group, the AD group exhibited higher frequencies of morphological changes in LECs, low-density fibrosis around the lens capsule, and capsular splitting characteristics of DBS. These results suggest lens epithelial cells degeneration and increased lens capsule fragility occurred in patients with AD.

Optical Biopsies Using Probe-Based Confocal Laser Endomicroscopy for Autoimmune Pulmonary Alveolar Proteinosis.

INTRODUCTION: Increasing numbers of cases of mild asymptomatic pulmonary alveolar proteinosis (PAP) are being reported with the recent increase in chest computed tomography (CT). Bronchoscopic diagnosis of mild PAP is challenging because of the patchy distribution of lesions, which makes it difficult to obtain sufficient biopsy samples. Additionally, the pathological findings of mild PAP, particularly those that differ from severe PAP, have not been fully elucidated. This study aimed to clarify the pathological findings of mild PAP and the usefulness of optical biopsy using probe-based confocal laser endomicroscopy (pCLE). METHODS: We performed bronchoscopic optical biopsy using pCLE and tissue biopsy in 5 consecutive patients with PAP (three with mild PAP and two with severe PAP). We compared the pCLE images of mild PAP with those of severe PAP by integrating clinical findings, tissue pathology, and chest CT images. RESULTS: pCLE images of PAP showed giant cells with strong fluorescence, amorphous substances, and thin alveolar walls. Images of affected lesions in mild PAP were equivalent to those obtained in arbitrary lung lesions in severe cases. All 3 patients with mild PAP spontaneously improved or remained stable after ≥3 years of follow-up. Serum autoantibodies to granulocyte-macrophage colony-stimulating factor were detected in all 5 cases. CONCLUSION: Optical biopsy using pCLE can yield specific diagnostic findings, even in patients with mild PAP. pCLE images of affected areas in mild and severe PAP showed similar findings, indicating that the dysfunction level of pathogenic alveolar macrophages in affected areas is similar between both disease intensities.

Outer layer of Vb neurons in medial entorhinal cortex project to hippocampal dentate gyrus in mice.

Entorhinal cortical (EC)-hippocampal (HPC) circuits are crucial for learning and memory. Although it was traditionally believed that superficial layers (II/III) of the EC mainly project to the HPC and deep layers (V/VI) receive input from the HPC, recent studies have highlighted the significant projections from layers Va and VI of the EC into the HPC. However, it still remains unknown whether Vb neurons in the EC provide projections to the hippocampus. In this study, using a molecular marker for Vb and retrograde tracers, we identified that the outer layer of Vb neurons in the medial EC (MEC) directly project to both dorsal and ventral hippocampal dentate gyrus (DG), with a significant preference for the ventral DG. In contrast to the distribution of DG-projecting Vb cells, anterior thalamus-projecting Vb cells are distributed through the outer to the inner layer of Vb. Furthermore, dual tracer injections revealed that DG-projecting Vb cells and anterior thalamus-projecting Vb cells are distinct populations. These results suggest that the roles of MEC Vb neurons are not merely limited to the formation of EC-HPC loop circuits, but rather contribute to multiple neural processes for learning and memory.

Effects of the Cortisol Milieu on Tumor-Infiltrating Immune Cells in Corticotroph Tumors.

CONTEXT: Corticotrophs are susceptible to lymphocyte cytotoxicity, as seen in hypophysitis, suggesting that an immunological approach may be a potential strategy for corticotroph-derived tumors. OBJECTIVE: We aimed to clarify whether corticotroph tumors that induce hypercortisolemia (ACTHomas) could be targets for immunotherapy. METHODS: Tumor-infiltrating immune cells were immunohistochemically analyzed. ACTHomas were compared with other pituitary tumors, and further divided into 3 different cortisol-exposed milieus: Naïve (ACTHomas without preoperative treatment), Met (ACTHomas with preoperative metyrapone), and SCA (silent corticotroph adenomas). A 3-dimensional cell culture of resected tumors was used to analyze the effects of immune checkpoint inhibitors. RESULTS: The number of tumor-infiltrating lymphocytes (TILs) was low in ACTHomas. Among these, the number of CD8+ cells was lower in ACTHomas than in both somatotroph and gonadotroph tumors (both P < .01). Then we compared the differences in TILs among Naïve, Met, and SCA. The number of CD4+ cells, but not CD8+ cells, was higher in both Met and SCA than in Naïve. Next, we investigated tumor-associated macrophages, which could negatively affect T cell infiltration. The numbers of CD163+ and CD204+ cells were positively associated with cortisol levels. Moreover, tumor size was positively correlated with the number of CD204+ cells. CONCLUSION: We found the possibility that ACTHomas were immunologically cold in a cortisol-independent manner. In contrast, the tumor infiltration of CD4+ cells and M2-macrophages were associated with the cortisol milieu. Future studies are needed to validate these results and develop effective immunotherapy while considering the cortisol milieu.

The combination of doxazosin and metyrosine as a preoperative treatment for pheochromocytomas and paragangliomas.

PURPOSE: Preoperative medical management is critical to prevent intraoperative cardiovascular complications in patients with pheochromocytomas and paragangliomas (PPGLs). Initial treatment involves α-adrenergic receptor blockers. However, while the routine use of metyrosine alongside these blockers is not strongly recommended due to a lack of evidence supporting its efficacy and associated safety concerns, there are previous studies on combination therapy with phenoxybenzamine and metyrosine. There are few reports on combination therapy with the selective α1-adrenergic receptor blocker doxazosin. Therefore, we investigated this combination treatment, which theoretically can affect perioperative outcomes in patients with PPGLs. To our knowledge, this is the first such study. METHODS: This retrospective single-center observational study involved 51 patients who underwent surgical resection of PPGLs at Kobe University Hospital between 2014 and 2022. All patients received doxazosin at maximum doses. Fourteen patients received concomitant metyrosine, while 37 received doxazosin alone. Their perioperative outcomes were compared. RESULTS: No severe event, such as acute coronary syndrome, was observed in either group. Intraoperatively, the doxazosin + metyrosine group exhibited a lower median minimum systolic blood pressure (56 [54-60] vs. 68 [59-74] mmHg, P = 0.03) and required lower median remifentanil (P = 0.04) and diltiazem (P = 0.02) doses than the doxazosin-alone group. CONCLUSION: The combination of metyrosine and doxazosin as a preoperative treatment for PPGLs affects intraoperative circulatory hemodynamics, such as a reduced occurrence of blood pressure elevation during surgery. Further research is necessary to identify patients who will benefit most from this combination treatment.

Controllable Chiral Light Generation and Vortex Field Investigation Using Plasmonic Holes Revealed by Cathodoluminescence.

Control of the angular momentum of light is a key technology for next-generation nano-optical devices and optical communications, including quantum communication and encoding. We propose an approach to controllably generate circularly polarized light from a circular hole in a metal film using an electron beam by coherently exciting transition radiation and light scattering from the hole through surface plasmon polaritons. The circularly polarized light generation is confirmed by fully polarimetric four-dimensional cathodoluminescence mapping, where angle-resolved spectra are simultaneously obtained. The obtained intensity and Stokes maps show clear interference fringes as well as almost fully circularly polarized light generation with controllable parities by the electron beam position. By applying this approach to a three-hole system, a vortex field with a phase singularity is visualized in the middle of three holes.

The aortic knob index as a novel predictor of new-onset atrial fibrillation after off-pump coronary artery bypass grafting.

PURPOSE: To validate the predictive value of the aortic knob index for identifying new-onset postoperative atrial fibrillation (POAF) after off-pump coronary artery bypass grafting (OPCAB). METHODS: Among 156 patients who underwent isolated OPCAB, 138 consecutive patients without a history of atrial fibrillation were enrolled in this retrospective observational cohort study. The patients were divided into two groups based on the development of POAF. We compared the baseline clinical characteristics; preoperative radiographic characteristics of the aorta, including aortic knob measurements; and perioperative data, between the groups. Logistic regression analysis was performed to identify the predictors of new-onset POAF. RESULTS: New-onset POAF developed in 35 (25.4%) patients. Multivariate logistic regression analysis revealed that the aortic knob index was an independent predictor of POAF and yielded that the risk of POAF increased by 1.85 times when the aortic knob index increased by 0.1 (odds ratio, 1.853; confidence interval, 1.326-2.588; P < 0.001). Receiver operating characteristic analysis revealed that an aortic knob index of 1.364 constituted a cutoff value for new-onset POAF with 80.0% sensitivity and 65.0% specificity. CONCLUSIONS: The aortic knob index on preoperative chest radiography was a significant and independent predictor of new-onset POAF following OPCAB.

Mitochondrial-targeting effector RsIA_CtaG/Cox11 in Rhizoctonia solani AG-1 IA has two functions: plant immunity suppression and cell death induction mediated by a rice cytochrome c oxidase subunit.

Rhizoctonia solani AG-1 IA causes a necrotrophic rice disease and is a serious threat to rice production. To date, only a few effectors have been characterized in AG-1 IA. We previously identified RsIA_CtaG/Cox11 and showed that infiltration of the recombinant protein into rice leaves caused disease-like symptoms. In the present study, we further characterized the functionality of RsIA_CtaG/Cox11. RsIA_CtaG/Cox11 is an alternative transcript of cytochrome c oxidase copper chaperone Cox11 that starts from the second AUG codon, but contains a functional secretion signal peptide. RNA interference with RsIA_CtaG/Cox11 reduced the pathogenicity of AG-1 IA towards rice and Nicotiana benthamiana without affecting its fitness or mycelial morphology. Transient expression of the RsIA_CtaG/Cox11-GFP fusion protein demonstrated the localization of RsIA_CtaG/Cox11 to mitochondria. Agro-infiltration of RsIA_CtaG/Cox11 into N. benthamiana leaves inhibited cell death by BAX and INF1. In contrast to rice, agro-infiltration of RsIA_CtaG/Cox11 did not induce cell death in N. benthamiana. However, cell death was observed when it was coinfiltrated with Os_CoxVIIa, which encodes a subunit of cytochrome c oxidase. Os_CoxVIIa appeared to interact with RsIA_CtaG/Cox11. The cell death triggered by coexpression of RsIA_CtaG/Cox11 and Os_CoxVIIa is independent of the leucine-rich repeat receptor kinases BAK1/SOBIR1 and enhanced the susceptibility of N. benthamiana to AG-1 IA. Two of the three evolutionarily conserved cysteine residues at positions 25 and 126 of RsIA_CtaG/Cox11 were essential for its immunosuppressive activity, but not for cell death induction. This report suggests that RsIA_CtaG/Cox11 appears to have a dual role in immunosuppression and cell death induction during pathogenesis.

A case of meningoencephalitis caused by multisystem inflammatory syndrome in adult SARS-CoV-2 infection.

A 37-year-old woman was hospitalized with fever and consciousness disturbance. She showed systemic inflammation with stress cardiomyopathy. Brain computed tomography showed diffuse brain edema. Cerebrospinal fluid (CSF) findings revealed markedly elevated cerebrospinal fluid pressure with pleocytosis, elevated protein, and elevated interleukin 6. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nicking enzyme amplification reaction test using a nasopharyngeal swab was positive, and the patient was diagnosed with SARS-CoV-2 infection. From the negative result of the CSF SARS-CoV-2 polymerase chain reaction test and no findings of bacterial or viral infection, we diagnosed meningoencephalitis by multisystem inflammation syndrome in adults (MIS-A). Intravenous methylprednisolone pulse therapy improved her symptoms and brain edema. There have been no cases of MIS-A with meningoencephalitis, and no initial treatment strategy has been established, especially in emergency cases of suspected MIS-A. The present case suggested Early intravenous methylprednisolone pulse with anti-coronaviral therapies after the exclusion of bacterial infection would be useful in suspected MIS-A with emergent meningoencephalitis cases.

Newer parameters of the octreotide test in patients with acromegaly.

PURPOSE: Predicting the therapeutic effects of first-generation somatostatin receptor ligands (fg-SRLs) is important when assessing or planning effective treatment strategies in patients with acromegaly. The oft-used maximum growth hormone (GH) suppression rate parameter of the octreotide test has a suboptimal predictive value. Therefore, this study explored newer parameters of the octreotide test for predicting the therapeutic effect of long-acting fg-SRLs. METHODS: In this single-center retrospective study, the octreotide test parameters and the therapeutic effects of fg-SRL at 3 months were investigated in 45 consecutive treatment-naïve patients with acromegaly between April 2008 and March 2023. Additionally, the relationship between the octreotide test parameters and the therapeutic effects of fg-SRLs was investigated. Tumor shrinkage was evaluated based on changes in the longitudinal diameter of the macroadenomas. The area GH suppression rate-time under the curve (AUC) and the time to nadir GH level were calculated and compared with the maximum GH suppression rate. RESULTS: The AUC estimated reductions in serum insulin-like growth factor I, and tumor shrinkage. The time to nadir GH level predicted tumor shrinkage more robustly than the maximum GH suppression rate in patients with macroadenoma. CONCLUSION: The AUC and time to nadir GH level may potentially be newer parameters of the octreotide test for estimating the therapeutic effect of fg-SRLs.

Dual biologics for severe asthma and atopic dermatitis: Synopsis of two cases and literature review.

The efficacy and safety of the combination of biologic therapies remain unclear with an ineffective and insufficient single biologic for managing asthma. Herein, we report two cases using dual biologics for severe asthma and atopic dermatitis. A 52-year-old male patient who received dupilumab and mepolizumab, benralizumab, or tezepelumab, followed by bronchial thermoplasty, and a 41-year-old male patient who received dupilumab and omalizumab, both experienced improved asthma and atopic dermatitis. To date, 38 cases are using dual biologics for severe asthma. The success rate was 84%, with no major adverse effects. We report the first case of severe asthma receiving dual biologics with tezepelumab and furthermore bronchial thermoplasty, and comprehensive literature review on dual biologics. Dual biologics may be an effective treatment method for severe asthma, requiring further investigation.

Piezo1 channel causes lens sclerosis via transglutaminase 2 activation.

Presbyopia is caused by age-related lenticular hardening, resulting in near vision loss, and it occurs in almost every individual aged ≥50 years. The lens experiences mechanical pressure during for focal adjustment to change its thickness. As lenticular stiffening results in incomplete thickness changes, near vision is reduced, which is known as presbyopia. Piezo1 is a mechanosensitive channel that constantly senses pressure changes during the regulation of visual acuity, and changes in Piezo1 channel activity may contribute to presbyopia. However, no studies have reported on Piezo1 activation or the onset of presbyopia. To elucidate the relevance of Piezo1 activation and cross-linking in the development of presbyopia, we analysed the function of Piezo1 in the lens. The addition of Yoda1, a Piezo1 activator, induced an increase in transglutaminase 2 (TGM2) mRNA expression and activity through the extra-cellular signal-regulated kinase (ERK) 1/2 and c-Jun-NH2-terminal kinase1/2 pathways. In ex vivo lenses, Yoda1 treatment induced γ-crystallin cross-linking via TMG2 activation. Furthermore, Yoda1 eye-drops in mice led to lenticular hardening via TGM2 induction and activation in vivo, suggesting that Yoda1-treated animals could serve as a model for presbyopia. Our findings indicate that this presbyopia-animal model could be useful for screening drugs for lens-stiffening inhibition.

Optogenetic activation of dopamine D1 receptors in island cells of medial entorhinal cortex inhibits temporal association learning.

A critical feature of episodic memory formation is to associate temporally segregated events as an episode, called temporal association learning. The medial entorhinal cortical-hippocampal (EC-HPC) networks is essential for temporal association learning. We have previously demonstrated that pyramidal cells in the medial EC (MEC) layer III project to the hippocampal CA1 pyramidal cells and are necessary for trace fear conditioning (TFC), which is an associative learning between tone and aversive shock with the temporal gap. On the other hand, Island cells in MECII, project to GABAergic neurons in hippocampal CA1, suppress the MECIII input into the CA1 pyramidal cells through the feed-forward inhibition, and inhibit TFC. However, it remains unknown about how Island cells activity is regulated during TFC. In this study, we report that dopamine D1 receptor is preferentially expressed in Island cells in the MEC. Optogenetic activation of dopamine D1 receptors in Island cells facilitate the Island cell activity and inhibited hippocampal CA1 pyramidal cell activity during TFC. The optogenetic activation caused the impairment of TFC memory recall without affecting contextual fear memory recall. These results suggest that dopamine D1 receptor in Island cells have a crucial role for the regulation of temporal association learning.

Enteral tube nutrition for geriatric post-stroke dysphagia evaluation (ENGE) score to evaluate the risk of dysphagia after acute ischemic stroke.

BACKGROUND: Post-stroke dysphagia (PSD) is a common complication after stroke. Early PSD prediction is essential for patient stratification for intensive oral intake rehabilitation. We aimed to develop a PSD prediction score using clinical data obtained at admission. METHODS: We examined consecutive patients with acute ischemic stroke between 2018 and 2019. The dysphagia status 14 days after admission was assessed using the Functional Oral Intake Scale (FOIS). PSD was defined as FOIS 1-3, which represents tube-dependent nutrition. Using multivariable logistic regression analysis, we constructed the Enteral tube Nutrition for Geriatric post-stroke dysphagia Evaluation (ENGE) score. The discriminative performance of the ENGE score was analyzed by receiver operating curve analysis. The reproducibility of the ENGE score was validated using patient data in 2020. RESULTS: PSD developed in 84 of 488 patients (median age 78 years; 57% males). The ENGE score ranged from 0 to 6, with 1 point assigned for older age (≥78 years), 1 for high premorbid modified Rankin Scale (mRS) (≥1), 3 for high NIHSS score (≥12), and 1 for low serum albumin (<3.0 mg/dl). The area under the curve (AUC) of the ENGE score for discriminating PSD was 0.88 (95% confidence interval [CI] 0.83-0.92), and a score of 3 or more had a higher positive likelihood ratio. In the validation cohort, the AUC of the ENGE score for PSD was 0.85 (95% CI 0.78-0.91), which was similar to the derivation cohort (p = 0.491). CONCLUSIONS: The ENGE score predicts severe PSD after acute ischemic stroke with good reproducibility.

Recovery from indomethacin-induced gastrointestinal bleeding by treatment with teprenone.

BACKGROUND: Gastrointestinal injuries caused by nonsteroidal anti-inflammatory drugs (NSAIDs) is a serious side effect in patients with rheumatoid arthritis (RA). However, effective therapeutic strategies have yet to be established. In this study, we investigated the therapeutic effects of teprenone (TEP), a gastric mucosal protective drug, on NSAID-induced gastrointestinal injuries in rats with RA (AA rats). METHODS: Gastrointestinal injury was induced by oral administration of indomethacin (IMC), a typical NSAID. TEP was orally administered after IMC-induced gastrointestinal bleeding, and the stomach, jejunum, and ileum were excised. RESULTS: On day 14 of IMC administration, lesion areas in the stomach, jejunum, and ileum were significantly larger in AA rats than in normal rats. When TEP was orally administered to AA rats, the lesion areas in the stomach, jejunum, and ileum significantly decreased compared with those in control rats (IMC-induced AA rats). Therefore, we measured NOS2 mRNA and NO levels, which were significantly decreased in rats with IMC-induced AA after treatment with TEP. CONCLUSIONS: These results suggest that the oral administration of TEP may be useful for the treatment of NSAID-induced gastrointestinal injuries in patients with RA.

Eustachian Valve-Enhanced Paradoxical Cerebral Embolism: A Case Report.

Cryptogenic stroke includes many suspicious embolic causes that do not fulfill the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification criteria. Atrial fibrillation (AF) is one of the major hidden causes of cryptogenic stroke, and an implantable loop recorder (ILR) is widely used for detecting AF. Herein, we report a case of paradoxical cerebral embolism due to a large Eustachian valve with large PFO under no molecular complete remission (CR) of acute monocytic leukemia (AMoL). A 75-year-old man arrived at our emergency room because of aphasia and right hemiparesis. He had a history of two cryptogenic strokes and implanted ILR. Magnetic resonance imaging showed left middle cerebral artery occlusion with slight acute ischemic lesion. The red clot was retrieved by mechanical thrombectomy, and complete recanalization was achieved. We checked ILR, but there was no AF. Transesophageal echocardiography revealed a large patent foramen ovale (PFO) and the large Eustachian valve in the right atrium. Although obvious deep vein thrombosis (DVT) was not detected in venous ultrasonography of the lower extremities, Wilms' tumor 1 messenger ribonucleic acid (WT1mRNA) expression level was high, and AMoL was considered to be not in molecular CR, suggesting a high risk of thrombosis to the large Eustachian valve. From large PFO and no molecular CR of AMoL, we diagnosed him with paradoxical cerebral embolism. Ruling out of AF by ILR and other etiologies, such as aortic or carotid atherosclerosis and pulmonary shunt, also supported the diagnosis of paradoxical cerebral embolism. Even in the absence of obvious DVT, paradoxical cerebral embolism should be considered in cases of a large Eustachian valve and PFO with a hypercoagulable state.

Therapeutic Effects of Hydrogel Formulations Incorporating Troxipide Nanoparticles on Oral Mucositis in Hamsters.

Purpose: Medical therapies, such as the use of anti-inflammatory agents, are commonly used for the treatment of oral mucositis (OM). However, these treatments have limited efficacy in treating severe cases of OM. In this study, we aimed to develop a carbopol gel incorporating troxipide (TRO) nanoparticles and methylcellulose (TRO-NP gel) and demonstrate its efficacy in accelerating wound healing in a hamster model of OM (OM model) induced by acetic acid injection. Methods: TRO nanoparticles were prepared using bead milling. The crystalline form was determined by powder X-ray diffraction, and the particle size was measured using a NanoSight LM10 instrument. The drug release was determined using a Franz diffusion cell, and the hamsters injected with acetic acid were selected to evaluate the therapeutic effect of OM. Results: After preparing TRO nanoparticles, we observed a mixture of crystals and amorphous TRO, and the particle size of TRO in the TRO-NP gel ranged from 50 to 280 nm. The TRO-NP gel exhibited a more uniform TRO distribution and viscosity compared to the Carbopol gel containing TRO microparticles (TRO-MP gel). However, the solubility of TRO was comparable in both TRO-MP and TRO-NP gels. The TRO-NP gel released a higher amount of TRO than that from the TRO-MP gel, with detectable release of TRO nanoparticles. TRO levels in the cheek pouches of hamsters treated with TRO-NP gel were higher than those treated with TRO-MP gel. The increased TRO levels in the cheek pouches of hamsters treated with TRO-NP gel were attenuated by treatment with 40 µM dynasore, an inhibitor of clathrin-dependent endocytosis (CME). Moreover, the therapeutic effect of the TRO-NP gel was superior to that of the TRO-MP gel in the hamster model of OM. Conclusion: We have designed a TRO-NP gel, and this gel showed excellent TRO delivery into the cheek pouch tissue through the CME pathway. Moreover, the TRO-NP gel treatment enhanced wound healing after acetic acid injection.