During skin aging, the degeneration of epidermal stem cells (EpiSCs) leads to diminished wound healing capabilities and epidermal disintegration. This study tackles this issue through a comprehensive analysis combining transcriptomics and untargeted metabolomics, revealing age-dependent alterations in the Gpx gene family and arachidonic acid (AA) metabolic networks, resulting in enhanced ferroptosis. Selenomethionine (Se-Met) could enhance GPX4 expression, thereby assisting EpiSCs in countering AA-induced mitochondrial damage and ferroptosis. Additionally, Se-Met demonstrates antioxidative characteristics and extensive ultraviolet absorption. For the sustained and controllable release of Se-Met, it was covalently grafted to UV-responsive GelMA hydrogels via AC-PEG-NHS tethers. The Se-Met@GelMA hydrogel effectively accelerated wound healing in a chronological aging mice model, by inhibiting lipid peroxidation and ferroptosis with augmented GPX4 expression. Moreover, in a photoaging model, this hydrogel significantly mitigated inflammatory responses, extracellular matrix remodeling, and ferroptosis in UV-exposed mice. These characteristics render Se-Met@GelMA hydrogel valuable in practical clinical applications.

Pilonidal sinus disease (PNSD) challenged surgeons for decades. Limberg flap repair (LFR) is a common treatment for PNSD. The purpose of this study was to observe the effect and risk factors of LFR in PNSD. A retrospective study was conducted on the PNSD patients who visited two medical centers and four departments in the People's Liberation Army General Hospital and were taking LFR treatment between 2016 and 2022. The risk factors, the effect of the operation, and complications were observed. The effects of known risk factors on the surgical results were compared. There were 37 PNSD patients: male/female ratio of 35:2, average age: 25.1 ± 7.9 years. Average BMI: 25.2 ± 4.0 kg/m², average wound healing time: 15.4 ± 3.4 days. 30 patients (81.0%) healed in stage one and 7 (16.3%) had postoperative complications. Only 1 patient (2.7%) had a recurrence while others were healed after dressing‐changing. There was no significant difference in age, BMI, preoperative debridement history, preoperative sinus classification, Wound area, Negative pressure drainage tube, prone time (<3d) and treatment effect. Squat defecate and premature defecation were associated with treatment effect, and they were independent predictors of treatment effect in the multivariate analysis. LFR has a stable therapeutic outcome. Compared with other skin flaps, the therapeutic effect of this flap is not significantly different, but the design is simple and is not affected by the known risk factors before operation. However, it is necessary to avoid the influence of two independent risk factors, squatting defecation and premature defecation, on the therapeutic effect.

Background: ¹⁸F-NaF and ^99mTc-MDP are widely used bone imaging tracers, but their comparative uptake in bone versus cartilage is unclear. This study aimed to directly compare these patterns in rats to guide musculoskeletal molecular imaging. Methods: Male Sprague-Dawley rats underwent in vivo and ex vivo radiotracer studies. Tracer uptake (%ID/g) was quantified in bone and cartilage at 30, 60, or 120 min post-injection (¹⁸F-NaF or ^99mTc-MDP), and across different ages. Additional rats received subcutaneous implants of viable or devitalized bone and cartilage; uptake was assessed using PET/CT, autoradiography, and histology. Results: ¹⁸F-NaF showed faster blood/background clearance and higher target-to-background ratios compared to ^99mTc-MDP, especially in weight-bearing joint cartilage. ¹⁸F-NaF uptake in cancellous bone significantly exceeded that of ^99mTc-MDP, whereas ^99mTc-MDP showed higher uptake in knee cartilage. Age-related analysis showed maximal knee cartilage accumulation in aged rats. Histological and cell inactivation studies confirmed that ¹⁸F-NaF uptake reflects both cellular activity and degree of calcification. Conclusions:¹⁸F-NaF demonstrates distinctive, quantifiable uptake in cartilage, dependent on both cellular activity and calcification, and exhibits favorable imaging characteristics versus ^99mTc-MDP for cartilage metabolism. These findings support ¹⁸F-NaF as a promising tool for early diagnosis and therapeutic monitoring of bone and joint disorders, and provide pathophysiological insight into the dynamics of the bone–cartilage interface.