Periodontitis, a chronic inflammatory disease driven by plaque biofilm, is a leading cause of tooth loss in adults worldwide. Effective treatment requires not only infection and inflammation control but, more critically, functional regeneration of the periodontal ligament, cementum, and alveolar bone. Periodontal regeneration, however, is a highly ordered, multi-stage biological cascade involving temporally coordinated phases of blood clot formation, inflammatory regulation, tissue formation, and remodeling. Conventional single-drug or mixed-delivery strategies cannot distinguish the distinct demands of each healing phase and fail to replicate this natural rhythm. Sequential controlled-release systems address this gap by delivering multiple bioactive agents (antimicrobials, immunomodulators, and growth factors) in a programmed order tailored to the healing cascade, enabling precise modulation of the periodontal microenvironment and orderly tissue regeneration. This review systematically summarizes advances in these systems, classifying material platforms into four categories: (1) diffusion-barrier and degradation-kinetics systems, including multilayer films, core-shell fibers, porous microspheres, and microneedle arrays; (2) stimuli-responsive systems triggered by pH, matrix metalloproteinases, reactive oxygen species, or exogenous physical stimuli; (3) cell and extracellular vesicle-based systems exploiting the inflammatory tropism of M2 macrophage-derived exosomes for targeted immune reprogramming; and (4) asymmetric structural designs achieving spatiotemporal coordination of physical and biochemical signals through hierarchical architectures. These systems follow an anti-infection/anti-inflammation first, osteogenesis later therapeutic logic, circumventing temporal antagonism among bioactive factors. However, significant challenges hinder clinical translation, including individualized prediction of release kinetics, long-term biocompatibility of carrier materials, material retention under dynamic oral conditions, translational limitations of animal models, and precise regulation of complex factor networks. Future progress will likely depend on multi-responsive and logic-gated systems, deeper integration of biotechnology and immunomodulation, personalized precision medicine, AI-driven material design, and robust clinical translational research.

Anti-glomerular basement membrane (anti-GBM) disease is a rare, aggressive autoimmune condition that typically presents as rapidly progressive glomerulonephritis and can be complicated by pulmonary haemorrhage. The co-occurrence of anti-GBM disease and IgA nephropathy (IgAN) is extremely uncommon, though increasingly recognised as a distinct clinical and pathological entity. We describe a 51-year-old Sudanese man who presented with acute hypoxaemic respiratory failure, haemoptysis, severe anaemia, and acute kidney injury. Testing showed high levels of anti-GBM antibodies, with negative anti-neutrophil cytoplasmic antibodies. Chest imaging revealed diffuse alveolar haemorrhage. Renal biopsy demonstrated crescentic glomerulonephritis with linear IgG staining along the glomerular basement membrane, alongside mesangial deposits dominated by IgA, confirming the presence of both diseases. Treatment included plasma exchange, high-dose corticosteroids, cyclophosphamide, and bronchial artery embolisation, which led to significant respiratory improvement and stabilisation of kidney function. A review of published cases suggests that individuals with this overlap may experience better renal outcomes than those with anti-GBM disease alone, though serious pulmonary-renal symptoms can still occur. This case highlights the need for accurate clinicopathological assessment and prompt initiation of anti-GBM-specific treatment.

Negative pressure pulmonary edema (NPPE) is a rare, life-threatening, yet rapidly reversible complication of acute upper airway obstruction. We present the case of a 17-year-old healthy male who underwent an emergency appendectomy under general anesthesia. Immediately following extubation, he developed severe respiratory distress and desaturation (SpO2 70%) due to presumed glossoptosis and reactive laryngospasm. Despite initial stabilization, he deteriorated in the Post-anesthesia Care Unit, exhibiting hypoxemia and pink frothy sputum. Arterial blood gases confirmed acute respiratory acidosis, while chest radiography revealed diffuse bilateral alveolar opacities. A completely normal point-of-care ultrasound (POCUS) served as a valuable adjunct to effectively rule out cardiogenic edema. The patient was managed conservatively with supplemental oxygen and nebulized bronchodilators, while loop diuretics were deliberately avoided. He showed rapid clinical improvement, weaning to room air within six hours, with complete radiological resolution by the next morning. While NPPE is a recognized complication, the educational novelty of this case lies in highlighting the efficacy of targeted conservative management. It underscores the adjunctive role of POCUS in safely avoiding inappropriate diuresis and emphasizes the paramount need for continuous vigilance following extubation.

Diffuse alveolar hemorrhage (DAH) is a rare but potentially life-threatening pulmonary condition that, while classically linked to autoimmune disorders, can occur in the setting of trauma. We report the case of a 20-year-old male who sustained polytrauma following a road traffic accident and initially had a normal chest radiograph. On the fourth day of hospitalization, he developed acute hypoxemia with new bilateral alveolar infiltrates; high-resolution computed tomography revealed diffuse ground-glass opacities with septal thickening. Bronchoalveolar lavage demonstrated progressively hemorrhagic return across aliquots, confirming DAH. Autoimmune markers were largely negative, and in the absence of systemic features, a multifactorial etiology involving trauma-related injury and anticoagulant use was considered. High-dose intravenous corticosteroids produced rapid clinical and radiological recovery. This case underscores the importance of considering DAH in trauma patients presenting with unexplained hypoxemia and bilateral infiltrates, even without hemoptysis, where early bronchoscopy and prompt treatment can be lifesaving.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne viral infection that can rapidly progress to multiple organ failure with a high mortality rate. Pulmonary involvement has been reported, but the radiologic-pathologic correlation remains poorly understood. We report an autopsy-proven fatal case of SFTS in a 79-year-old man with pre-existing collagen vascular disease-associated interstitial lung disease. Serial chest computed tomography (CT) initially demonstrated subtle peripheral ground-glass opacities that progressively expanded over time. On the final CT examination obtained shortly before death, extensive bilateral consolidation with high attenuation on mediastinal window images was observed, suggestive of pulmonary hemorrhage. The patient developed severe thrombocytopenia, disseminated intravascular coagulation, and respiratory failure and died despite intensive treatment. Autopsy revealed diffuse pulmonary hemorrhage, alveolar septal thickening, focal diffuse alveolar damage with hyaline membrane formation, and prominent hemophagocytosis. Immunohistochemical staining demonstrated numerous SFTS virus-infected cells within the lung tissue. This case highlights the CT findings of pulmonary involvement in fatal SFTS and demonstrates a direct radiologic-pathologic correlation. Our findings suggest that cytokine storm and hemophagocytic syndrome play critical roles in the development of pulmonary hemorrhage and lung injury in SFTS.

Diffuse alveolar hemorrhage (DAH) is a life-threatening pulmonary condition characterized by widespread bleeding into the alveoli, leading to respiratory failure. It can result from various etiologies, including autoimmune disorders, drug reactions, and infections. Here is a rare case of a 37-year-old male who presented with progressive dyspnea, hemoptysis, and hypoxemia. Chest imaging and bronchoscopy confirmed the diagnosis of DAH, while laboratory tests revealed ANCA-associated vasculitis. On diagnosis, the patient with granulomatosis with polyangiitis was initiated on corticosteroids and cyclophosphamide. Early initiation of immunosuppressive therapy and supportive care plays a crucial role in disease management, reducing morbidity in such cases.