Gastrointestinal (GI) mucosal injury management remains challenging due to the limited specificity and pronounced adverse effects of conventional therapies. Inspired by the traditional application of carbonized herbs for mucosal healing, this study developed Gardeniae Fructus Carbonisata-derived carbon dots (GFC-CDs) via a facile one-step pyrolysis. GFC-CDs exhibited a unique quasi-spherical nano-topography with abundant oxygen/nitrogen-rich surface passivation, endowing them with robust broad-spectrum radical scavenging capabilities and potent COX-2 inhibitory activity in vitro. In a TNBS-induced zebrafish model of GI mucosal injury, water-bath administered GFC-CDs significantly restored intestinal lumen architecture and profoundly suppressed neutrophil infiltration, outperforming the conventional clinical drug mesalazine. By integrating traditional carbonization wisdom with green nanotechnology, GFC-CDs present a synergistic therapeutic platform addressing both oxidative stress and inflammatory cascades in GI mucosal injury. This work is consistent with, and provides a nanoscale interpretation supportive of, the carbonized-herbs theory of tissue repair, and provides a novel nanomedicine strategy with promising preclinical potential for targeting complex mucosal disorders.

Pediatric-onset ulcerative colitis (UC) is characterized by an aggressive phenotype, with higher rates of pancolitis and more rapid progression to a medically refractory state. After failure of conventional therapies and multiple biologic agents, treatment options are limited and often require surgery. We report the case of a 15-year-old girl with a 5-year history of highly refractory pancolitis-type UC. Previous treatments included mesalazine, salazosulfapyridine, tacrolimus, and three biologic agents (infliximab, vedolizumab, and adalimumab), all of which failed to maintain remission. After ustekinumab initiation, she initially experienced mild improvement but subsequently developed a severe clinical relapse (Pediatric Ulcerative Colitis Activity Index score: 40-50) triggered by Edwardsiella tarda infection. Despite infection resolution and treatment with systemic corticosteroids, her condition remained critical. As adjunctive therapy, intensive granulocyte and monocyte adsorptive apheresis (GMA) was administered twice weekly for 10 sessions, followed by twice monthly for 7 sessions, resulting in rapid symptomatic improvement. Follow-up colonoscopy confirmed complete mucosal healing (Mayo Endoscopic Subscore, 0). Intensive GMA may be a safe and effective adjunct to ustekinumab before its full therapeutic effect is achieved, potentially complementing the anti-inflammatory effects of ustekinumab in refractory pediatric UC and may help avoid colectomy even when multiple drug therapies have failed.

Mesalazine is a recognised cause of drug-induced eosinophilic pneumonia. The condition usually occurs after 2-6 months of therapy, and onset within the first week is rare. A 29-year-old woman with bronchial asthma and newly diagnosed ulcerative colitis was initiated on oral mesalazine. On Day 7, she developed a persistent cough. Three weeks later, imaging revealed a right upper-lobe pulmonary infiltrate, promoting referral for evaluation. Bronchoalveolar lavage and transbronchial cryobiopsy demonstrated marked eosinophilic infiltration, confirming eosinophilic pneumonia. Discontinuation of mesalazine led to rapid clinical and radiographic improvement. Clinical course and exclusion of alternative aetiologies identified mesalazine as the causative drug. This case demonstrates that mesalazine can induce eosinophilic pneumonia within 7 days of initiation.

Organising pneumonia is an increasingly recognised pulmonary manifestation of ulcerative colitis, though nearly all reported cases are attributed to drug-induced aetiology. The 2025 ERS/ATS classification of interstitial pneumonias now explicitly lists ulcerative colitis among secondary causes of cicatricial organising pneumonia, formally recognising a disease-intrinsic mechanism for organising pneumonia in ulcerative colitis. We present a 76-year-old woman with 10-year ulcerative colitis pancolitis on stable mesalamine in biochemical remission (faecal calprotectin 62 μg/g, below the 80 μg/g histological activity threshold) who developed progressive dyspnea. Drug-induced aetiology was systematically excluded: mesalamine had been stable for 10 years, discontinuation produced no improvement, and corticosteroids were required for response. Transbronchial cryobiopsy was initially interpreted as fibrotic non-specific interstitial pneumonia; expert pathology consultation revised the diagnosis to organising pneumonia with Masson bodies, changing management from antifibrotics to corticosteroids, illustrating the clinical consequences of cryobiopsy diagnostic discordance. Bronchoalveolar lavage revealed a neutrophil-predominant profile (42% neutrophils, 3% lymphocytes), atypical for cryptogenic organising pneumonia, which typically shows lymphocytic predominance. This pattern may reflect gut-lung axis immune trafficking in secondary organising pneumonia associated with ulcerative colitis. Concurrent seronegative arthritis was reclassified as ulcerative colitis-associated spondyloarthropathy, removing rheumatoid arthritis-associated interstitial lung disease from the differential. This case extends the sole prior report of organising pneumonia during confirmed ulcerative colitis remission by incorporating biomarker-confirmed remission, systematic drug exclusion, cryobiopsy discordance with treatment-altering consequences and contextualisation within the updated 2025 ERS/ATS classification framework.