The healing of chronic wounds remains a considerable challenge in clinical trials and imposes severe financial and physiological burdens on patients. Many works are being tried to find ideal clinical promoting wound healing biomaterials. Small bioactive peptides with low cost and easy production, store and transfer become excellent candidates. Here, we identified a novel peptide (named OM-LV20) from skin secretions of odorous frog Odorrana margaretae. The peptide had an amino acid sequence of "LVGKLLKGAVGDVCGLLPIC," contained an intramolecular disulfide bridge at the C-terminus, and was produced by post-translational processing of a 71-residue prepropeptide. Our results showed that OM-LV20 had no direct microbe-killing effects, hemolytic activity, or acute toxicity, but did exhibit weak antioxidant activity.OM-LV20 promoted wound healing against human keratinocytes (HaCaT) and human skin fibroblasts (HSF) in both time-and dose-dependent manners. In addition, it induced the proliferation of HaCaT but not HSF cells. Of note, OM-LV20showed strong wound healing-promoting activity in a mice model of full-thickness skin wound. Our research indicates the cellular and animal level wound healing potential of OM-LV20, and thus provides a novel bioactive peptide template for the development of wound healing agents and medicine.

The objective of this study was to use finite element models to investigate the biomechanics of stable thoracolumbar burst fracture repair using unilateral short-segment fixation and 4 alternate pedicle screw systems.Four posterior pedicle screw systems were compared for unilateral short-segment fixation using finite element models: intermediate bilateral short pedicle screw fixation, intermediate bilateral long pedicle screw fixation, intermediate unilateral short pedicle screw fixation, and intermediate unilateral long pedicle screw fixation. We compared range of motion (ROM), von Mises stresses on the implants, and stress on the intervertebral discs superior and inferior to the injured vertebra during simulated spinal movements.There were no significant differences in ROM, von Mises stress, or intervertebral disc stress among the 4 intermediate pedicle screw fixation techniques for all spinal movements evaluated. In addition, there were no consolidated trends depicting beneficial differences between the short and long screw models, or between the unilateral and bilateral screw models.ROM, von Mises stress, and intervertebral disc stress are the same across the 4, posterior short-segment fixation techniques evaluated using finite element models. The simplest technique—posterior short segment fixation combined with intermediate unilateral short pedicle screw fixation—is a feasible treatment strategy for stable thoracolumbar fracture.

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OBJECTIVE:To evaluate the correlation between the severity of intervertebral disc injury and the anteroposterior type of thoracolumbar vertebral fractures.METHODS:Fifty-six cases of thoracolumbar vertebral fractures treated in our trauma center from October 2012 to October 2013 were included in this study. The fractures were classified by the anteroposterior classification, whereas the severity of intervertebral disc injury was evaluated using magnetic resonance imaging. The Spearman correlation coefficient was used to analyze the correlation between the severity of intervertebral disc injury and the anteroposterior type of thoracolumbar fractures, whereas a χ2 test was adopted to measure the variability between different fracture types and upper and lower adjacent disc injuries.RESULTS:The Spearman correlation coefficients between fracture types and the severity of the upper and lower adjacent disc injuries were 0.739 (PU<0.001) and 0.368 (PL=0.005), respectively. It means that the more complex Arbeitsgemeinschaft für Osteosynthesefragen (AO) classifications are the disc injury is more severe. There was also a significant difference in the severity of injury between the upper and lower adjacent discs near the fractured vertebrae (p<0.001).CONCLUSIONS:In thoracolumbar spinal fractures, the severity of the adjacent intervertebral disc injury is positively correlated with the anteroposterior fracture type. The injury primarily involves intervertebral discs near the fractured end plate, with more frequent and severe injuries observed in the upper than in the lower discs. The presence of intervertebral disc injury, along with its severity, may provide useful information during the clinical decision-making process.