Sensory Nerve Regulation via H3K27 Demethylation Revealed in Akermanite Composite Microspheres Repairing Maxillofacial Bone Defect.

Maxillofacial bone defects exhibit intricate anatomy and irregular morphology, presenting challenges for effective treatment. This study aimed to address these challenges by developing an injectable bioactive composite microsphere, termed D-P-Ak (polydopamine-PLGA-akermanite), designed to fit within the defect site while minimizing injury. The D-P-Ak microspheres biodegraded gradually, releasing calcium, magnesium, and silicon ions, which, notably, not only directly stimulated the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) but also activated sensory nerve cells to secrete calcitonin gene-related peptide (CGRP), a key factor in bone repair. Moreover, the released CGRP enhanced the osteogenic differentiation of BMSCs through epigenetic methylation modification. Specifically, inhibition of EZH2 and enhancement of KDM6A reduced the trimethylation level of histone 3 at lysine 27 (H3K27), thereby activating the transcription of osteogenic genes such as Runx2 and Osx. The efficacy of the bioactive microspheres in bone repair is validated in a rat mandibular defect model, demonstrating that peripheral nerve response facilitates bone regeneration through epigenetic modification. These findings illuminated a novel strategy for constructing neuroactive osteo-inductive biomaterials with potential for further clinical applications.

Characteristics, Treatment, and Prognosis of Pediatric Symphyseal/Parasymphyseal-Condylar Fractures.

BACKGROUND: Pediatric condylar fractures combined with symphyseal or parasymphyseal fractures are common but challenging to manage. The authors present fracture characteristics, propose a treatment algorithm, and evaluate the treatment prognosis of pediatric symphyseal/parasymphyseal-condylar fractures. METHODS: A retrospective review was conducted on pediatric patients who underwent treatment for symphyseal/parasymphyseal-condylar fractures in a trauma center between January of 2006 and January of 2021. Demographic and fracture characteristics were recorded. Complications and functional evaluations, including maximum interincisal opening, Helkimo anamnestic index, and clinical dysfunction index, were assessed after at least 1 year of follow-up. RESULTS: After screening, 104 participants met the inclusion criteria. Among them, 50.96% received open reduction and internal fixation for symphyseal/parasymphyseal fractures and closed treatment for condylar fractures, 45.19% were treated by liquid diet and functional exercise, and the remaining 3.85% with severe malocclusion were treated with the assistance of orthodontic appliances. During follow-up, the average maximum interincisal opening of the patients increased from 17 ± 6.29 mm to 41.64 ± 6.33 mm. No subjective symptoms were observed in 86.54% of the patients and 79.81% showed no or mild clinical symptoms. Except for 1 patient who developed temporomandibular joint ankylosis, no other severe complication was reported. Postfracture remodeling of the nonfractured condyle was noted in 3 cases. CONCLUSIONS: Pediatric symphyseal/parasymphyseal-condylar fractures present unique biomechanical and anatomic challenges that require special consideration during management. In this study, satisfactory functional prognosis was achieved following implementation of the treatment algorithm. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Salt tolerance evaluation and mini-core collection development in Miscanthus sacchariflorus and M. lutarioriparius.

Marginal lands, such as those with saline soils, have potential as alternative resources for cultivating dedicated biomass crops used in the production of renewable energy and chemicals. Optimum utilization of marginal lands can not only alleviate the competition for arable land use with primary food crops, but also contribute to bioenergy products and soil improvement. Miscanthus sacchariflorus and M. lutarioriparius are prominent perennial plants suitable for sustainable bioenergy production in saline soils. However, their responses to salt stress remain largely unexplored. In this study, we utilized 318 genotypes of M. sacchariflorus and M. lutarioriparius to assess their salt tolerance levels under 150 mM NaCl using 14 traits, and subsequently established a mini-core elite collection for salt tolerance. Our results revealed substantial variation in salt tolerance among the evaluated genotypes. Salt-tolerant genotypes exhibited significantly lower Na+ content, and K+ content was positively correlated with Na+ content. Interestingly, a few genotypes with higher Na+ levels in shoots showed improved shoot growth characteristics. This observation suggests that M. sacchariflorus and M. lutarioriparius adapt to salt stress by regulating ion homeostasis, primarily through enhanced K+ uptake, shoot Na+ exclusion, and Na+ sequestration in shoot vacuoles. To evaluate salt tolerance comprehensively, we developed an assessment value (D value) based on the membership function values of the 14 traits. We identified three highly salt-tolerant, 50 salt-tolerant, 127 moderately salt-tolerant, 117 salt-sensitive, and 21 highly salt-sensitive genotypes at the seedling stage by employing the D value. A mathematical evaluation model for salt tolerance was established for M. sacchariflorus and M. lutarioriparius at the seedling stage. Notably, the mini-core collection containing 64 genotypes developed using the Core Hunter algorithm effectively represented the overall variability of the entire collection. This mini-core collection serves as a valuable gene pool for future in-depth investigations of salt tolerance mechanisms in Miscanthus.