Bacterial therapy has attracted increasing attention due to its special mechanism and abundant applications. With the flourishing development of synthetic biology, therapeutic genes have been introduced into engineering bacteria to improve their antitumor efficacy. However, it is difficult to spatiotemporally control the expression of these therapeutic genes at the tumor site in vivo, thereby considerably limiting the application of engineered bacteria in tumor treatment. To resolve this problem, we constructed a temperature-responsive bacterial strain capable of triggering the expression of exogenous genes in a laser-controllable way. Noxa, a pro-apoptotic protein, is chosen to test the expression of exogenous protein and its anti-tumor effect in engineered bacteria upon laser irradiation. Firstly, Noxa was fused to the C-terminus of the bacterial outer membrane protein cytolysin A (ClyA), and then the recombinant gene fragment ClyA-Noxa was inserted into the temperature-sensitive plasmid pBV220 and the recombinant plasmid was transformed into non-pathogenic Escherichia coli MG1655. Thus, we constructed the engineering strain (TRB@Noxa) that could express Noxa on the bacterial surface. TRB@Noxa could target and colonize the tumor tissue without causing notable host toxicity. The bacterial infection triggered thrombosis in the tumor tissue, resulting in the darkness of tumor sites. In a xenograft mouse tumor model, our strategy demonstrated precise tumor targeting and strong tumor inhibition. In conclusion, we successfully constructed a new engineering bacterial strain TRB@Noxa. TRB@Noxa combined with photothermal therapy could arrest tumor growth in the absence of photosensitizers, which represents an appealing method for antitumor therapy in the future.
Escherichia coli/radiation effects* ; Animals ; Humans ; Lasers ; Mice ; Proto-Oncogene Proteins c-bcl-2/biosynthesis* ; Neoplasms/therapy* ; Genetic Engineering ; Cell Line, Tumor ; Escherichia coli Proteins/genetics*

Severe open tibiofibular fractures account for approximately 28.1% of all open fractures. Among them, Gustilo-Anderson type IIIB/C fractures present significant clinical challenges due to associated bone and soft tissue defects, high infection rates, and risk of amputation. Inadequate preoperative assessment may lead to suboptimal emergency surgical planning or intraoperative complications. Historically, external fixation was often preferred, but this approach has been associated with limitations such as restricted joint mobility, delayed bone union, joint stiffness, and disuse osteoporosis, resulting in poor functional recovery. With advancements of debridement techniques, standardization of antibiotic use, and popularization of early soft tissue coverage, early internal fixation has gained broader acceptance. Nevertheless, controversies persist regarding the choice of fixation method, timing of definitive fixation, use of reamed versus unreamed intramedullary nailing, and necessity of fibular fixation. To standardize the diagnosis and early management of severe open tibiofibular fractures, reduce complication rates, and improve functional recovery, the Society of Microsurgery of the Chinese Medical Association organized a panel of domestic experts to develop the Evidence-based guideline for the diagnosis and early fixation of severe open tibiofibular fractures ( version 2025), using evidence-based methodology. The guidelines provided 12 recommendations covering diagnostic and early fixation strategies of severe open tibiofibular fractures, aiming to provide clinicians with scientifically grounded and standardized guidance.

In recent years, the wearable device market has been developing rapidly. Wearable devices with personalized health management and chronic disease monitoring are widely used in daily life by virtue of their powerful performance and convenience. However, with the popularization of these devices, skin adverse reactions caused by prolonged wearable wear are gradually increasing, among which allergic contact dermatitis (ACD) is the most common. Common allergens such as acrylates, methacrylates, rosin, chromium and nickel are widely present in adhesives and device components and are the main causes of ACD. Understanding the presence of potential sensitizers in wearable devices can help in diagnostic patch testing in users experiencing skin reactions caused by the device. Future innovations in wearable device materials will focus on the adoption of safer bonding technologies and biocompatible materials to reduce the risk of allergy. The introduction of new materials brings both development opportunities and challenges. Educating users on proper device usage, identifying specific allergens, selecting hypoallergenic materials, and optimizing device maintenance are important for reducing the risk of ACD.

Severe open tibiofibular fractures account for approximately 28.1% of all open fractures. Among them, Gustilo-Anderson type IIIB/C fractures present significant clinical challenges due to associated bone and soft tissue defects, high infection rates, and risk of amputation. Inadequate preoperative assessment may lead to suboptimal emergency surgical planning or intraoperative complications. Historically, external fixation was often preferred, but this approach has been associated with limitations such as restricted joint mobility, delayed bone union, joint stiffness, and disuse osteoporosis, resulting in poor functional recovery. With advancements of debridement techniques, standardization of antibiotic use, and popularization of early soft tissue coverage, early internal fixation has gained broader acceptance. Nevertheless, controversies persist regarding the choice of fixation method, timing of definitive fixation, use of reamed versus unreamed intramedullary nailing, and necessity of fibular fixation. To standardize the diagnosis and early management of severe open tibiofibular fractures, reduce complication rates, and improve functional recovery, the Society of Microsurgery of the Chinese Medical Association organized a panel of domestic experts to develop the Evidence-based guideline for the diagnosis and early fixation of severe open tibiofibular fractures ( version 2025), using evidence-based methodology. The guidelines provided 12 recommendations covering diagnostic and early fixation strategies of severe open tibiofibular fractures, aiming to provide clinicians with scientifically grounded and standardized guidance.

In recent years, the wearable device market has been developing rapidly. Wearable devices with personalized health management and chronic disease monitoring are widely used in daily life by virtue of their powerful performance and convenience. However, with the popularization of these devices, skin adverse reactions caused by prolonged wearable wear are gradually increasing, among which allergic contact dermatitis (ACD) is the most common. Common allergens such as acrylates, methacrylates, rosin, chromium and nickel are widely present in adhesives and device components and are the main causes of ACD. Understanding the presence of potential sensitizers in wearable devices can help in diagnostic patch testing in users experiencing skin reactions caused by the device. Future innovations in wearable device materials will focus on the adoption of safer bonding technologies and biocompatible materials to reduce the risk of allergy. The introduction of new materials brings both development opportunities and challenges. Educating users on proper device usage, identifying specific allergens, selecting hypoallergenic materials, and optimizing device maintenance are important for reducing the risk of ACD.

Objective:To explore the effects of miR-21-5p exosomes derived from human umbilical cord mesenchymal stem cells on apoptosis of human granular cells.Methods:A granular cell apoptosis model was constructed by treating KGN cells with different concentrations (0 μmol/L, 30 μmol/L, 60 μmol/L, and 100 μmol/L) of phosphoramide nitrogen mustard for 48 h. The mRNA and protein levels of bax and bcl2 were detected using qPCR and Western blotting, respectively. The apoptosis rate was measured using flow cytometry to screen for the optimal concentration of phosphoramide nitrogen mustard for constructing an apoptosis model. Hsa-miR-21-5p overexpression plasmid was used for instantaneously transfecting human umbilical cord mesenchymal stem cells, and the expression level of hsa-miR-21-5p was detected by qPCR. The miR-21-5p exosomes were separated and identified by flow cytometry and electron microscope. Different concentrations (5 μg/mL, 10 μg/mL and 15 μg/mL) of miR-21 exosomes were added into successful KGN cell apoptosis model to overexpress miR-21. The mRNA and protein levels of bax and bcl2 were detected using qPCR and Western blotting, respectively. PKH-26 was used to trace the position of human granular cells. Results:The levels of bax mRNA and protein in KGN cells treated with 60 μmol/L phosphoramide nitrogen mustard were significantly higher than those in the 0 μmol/L phosphoramide nitrogen mustard group (all P<0.001), while the levels of bcl2 mRNA and protein were significantly higher than those in the 0 μmol/L phosphoramide nitrogen mustard group ( P=0.005, P<0.001). The apoptosis rate of KGN cells after 60 μmol/L phosphoramide nitrogen mustard intervention was (38.10±2.90)%, while the apoptosis rate of KGN cells after 30 μmol/L phosphoramide nitrogen mustard intervention was (16.75±2.55)%, they were all significantly higher than that of the 0 μmol/L phosphoramide nitrogen mustard intervention group ( P=0.020, P=0.006). Hsa-miR-21-5p was transiently transfected into human umbilical cord blood mesenchymal stem cells, and the expression of has-miR-21-5p was higher than that in control group detected by qPCR ( P<0.001). The positive rate of surface protein CD9, CD63 and CD81 was 14.9%, 16.4% and 31.4%. The exosome was observed as "tea tray" or "concave hemisphere" by electron microscope. The exosome labeled by PKH-26 entered the granular cells and exerted biological effects. There was no statistically significant difference in bax mRNA expression levels between the 5 μg/mL, 10 μg/mL, and 15 μg/mL empty plasmid exosomes groups and the 60 μmol/L phosphoramide nitrogen mustard group (all P>0.05). However, the expression levels of bax mRNA in the 5 μg/mL, 10 μg/mL, and 15 μg/mL miR-21-5-p exosomes groups were lower than those in the 60 μmol/L phosphoramide nitrogen mustard group ( P=0.008, P=0.003, P<0.001). However, there was no statistically significant difference in the expression of bcl2 mRNA among the groups (all P>0.05). From the perspective of protein levels, there was no statistically significant difference in BAX protein expression between the 5 μg/mL, 10 μg/mL, and 15 μg/mL empty exosomes groups and 60 μmol/L phosphoramide nitrogen mustard group (all P>0.05), while the 5 μg/mL, 10 μg/mL, and 15 μg/mL miR-21-5-p exosomes groups showed a decrease in BAX protein expression compared with the 60 μmol/L phosphoramide nitrogen mustard group, and the differences were statistically significant (all P<0.001). However, there was no statistically significant difference in the expression of BCL2 protein among the intervention groups (all P>0.05). Conclusion:Hsa-miR-21-5p exosomes derived from human umbilical cord blood mesenchymal stem cells can effectively exert the anti-apoptotic effect.

Objective To establish an optimal limiting dose for dose limiting rings placed in the anterior and posterior regions of the neck for reducing head and neck lymphedema under intensity-modulated radiation therapy(IMRT)for early nasopharyngeal carcinoma(NPC)from a dosimetric perspective.Method Fifteen newly diagnosed early-stage nasopharyngeal carcinoma patients who underwent CT localization for radiotherapy at the Cancer Hospital of Guangzhou Medical University from January to September 2022 were included in the study.Each case was designed with five sets of radiotherapy plans.Plan A consisted of conventional unlimited-field plans,while Plans B-E consisted of limited-field plans with dose constraints set at 20,18,16,and 14 Gy,respectively,with the remaining parameters consistent with Plan A.The impact on target coverage and organ-at-risk constraints was evaluated through variance analysis and pairwise multiple comparisons using a randomized block design to determine the optimal dose limits.Results The gradient of 16Gy was determined as the optimal dose limiting cutoff point for achieving the balance between target coverage and organ limiting dose.Compared with the conventional plan,The plans with the placement of a cervical anterior and posterior dose limiting ring(16Gy)did not change the target dose coverage(P>0.05),but only yielded a slight change in the homogeneity index(P<0.05).It did not cause any changes of the dosage in the inner ear,mandible,and brainstem(all P>0.05),but lead to statisti-cally significant reductions in the oral cavity,throat,and thyroid(all P<0.05).It caused a slight increase of the dose in the parotid gland and spinal cord(both P<0.05),but the increased dose was anyhow within the tolerance range.Conclusion The dosimetric investigation determines an optimal dose limit cutoff point for the cervical ante-rior and posterior dose limiting rings.It is expected to provide a design method for IMRT plans to reduce head and neck lymphedema after radiotherapy for early NPC.

Objective:To explore the effects of miR-21-5p exosomes derived from human umbilical cord mesenchymal stem cells on apoptosis of human granular cells.Methods:A granular cell apoptosis model was constructed by treating KGN cells with different concentrations (0 μmol/L, 30 μmol/L, 60 μmol/L, and 100 μmol/L) of phosphoramide nitrogen mustard for 48 h. The mRNA and protein levels of bax and bcl2 were detected using qPCR and Western blotting, respectively. The apoptosis rate was measured using flow cytometry to screen for the optimal concentration of phosphoramide nitrogen mustard for constructing an apoptosis model. Hsa-miR-21-5p overexpression plasmid was used for instantaneously transfecting human umbilical cord mesenchymal stem cells, and the expression level of hsa-miR-21-5p was detected by qPCR. The miR-21-5p exosomes were separated and identified by flow cytometry and electron microscope. Different concentrations (5 μg/mL, 10 μg/mL and 15 μg/mL) of miR-21 exosomes were added into successful KGN cell apoptosis model to overexpress miR-21. The mRNA and protein levels of bax and bcl2 were detected using qPCR and Western blotting, respectively. PKH-26 was used to trace the position of human granular cells. Results:The levels of bax mRNA and protein in KGN cells treated with 60 μmol/L phosphoramide nitrogen mustard were significantly higher than those in the 0 μmol/L phosphoramide nitrogen mustard group (all P<0.001), while the levels of bcl2 mRNA and protein were significantly higher than those in the 0 μmol/L phosphoramide nitrogen mustard group ( P=0.005, P<0.001). The apoptosis rate of KGN cells after 60 μmol/L phosphoramide nitrogen mustard intervention was (38.10±2.90)%, while the apoptosis rate of KGN cells after 30 μmol/L phosphoramide nitrogen mustard intervention was (16.75±2.55)%, they were all significantly higher than that of the 0 μmol/L phosphoramide nitrogen mustard intervention group ( P=0.020, P=0.006). Hsa-miR-21-5p was transiently transfected into human umbilical cord blood mesenchymal stem cells, and the expression of has-miR-21-5p was higher than that in control group detected by qPCR ( P<0.001). The positive rate of surface protein CD9, CD63 and CD81 was 14.9%, 16.4% and 31.4%. The exosome was observed as "tea tray" or "concave hemisphere" by electron microscope. The exosome labeled by PKH-26 entered the granular cells and exerted biological effects. There was no statistically significant difference in bax mRNA expression levels between the 5 μg/mL, 10 μg/mL, and 15 μg/mL empty plasmid exosomes groups and the 60 μmol/L phosphoramide nitrogen mustard group (all P>0.05). However, the expression levels of bax mRNA in the 5 μg/mL, 10 μg/mL, and 15 μg/mL miR-21-5-p exosomes groups were lower than those in the 60 μmol/L phosphoramide nitrogen mustard group ( P=0.008, P=0.003, P<0.001). However, there was no statistically significant difference in the expression of bcl2 mRNA among the groups (all P>0.05). From the perspective of protein levels, there was no statistically significant difference in BAX protein expression between the 5 μg/mL, 10 μg/mL, and 15 μg/mL empty exosomes groups and 60 μmol/L phosphoramide nitrogen mustard group (all P>0.05), while the 5 μg/mL, 10 μg/mL, and 15 μg/mL miR-21-5-p exosomes groups showed a decrease in BAX protein expression compared with the 60 μmol/L phosphoramide nitrogen mustard group, and the differences were statistically significant (all P<0.001). However, there was no statistically significant difference in the expression of BCL2 protein among the intervention groups (all P>0.05). Conclusion:Hsa-miR-21-5p exosomes derived from human umbilical cord blood mesenchymal stem cells can effectively exert the anti-apoptotic effect.

Objective:To analyze of the main influecing factors of mosic embryos during the preimplantation genetic test for chromosomal structural rearrangement (PGT-SR) to avoid the increase of risk of abortion and genetic abnormalities and to improve the diagnostic rate of mosic embryos.Methods:We used a retrospective cohort study to analyze 94 cycles of infertile patients undergoing PGT-SR and 551 cycles of intracytoplasmic sperm injection (ICSI) from January 2018 to December 2019 in the Reproductive Medical Center of the Maternal and Child Health Hospital. The relationship of mosic embryos was analyzed between the age, the number of oocytes, gonadotropin (Gn)/oocyte, the grade of blastocysts and chromosome carrier of different genders by the SPSS21.0 software.Results:In the PGT-SR cycle, single factor analysis found that mosaic embryos were related to age and sperm concentration ( P=0.02, P=0.04), but multivariate logistic regression analysis showed that age ( OR=3.41, 95% CI=1.34-8.66, P=0.01), sperm concentration ( OR=0.41, 95% CI=0.17-0.96, P=0.04) and chromosome carrier of different genders ( OR=2.21, 95% CI=1.04-4.70, P=0.04) were the main factors of embryo mosaicism. Conclusion:Female age, sperm concentration and chromosome carrier of different genders maybe affect the formation of mosaic embryos, providing theoretical basis for selective transfer of mosaic embryos.

Objective:To analyze of the main influecing factors of mosic embryos during the preimplantation genetic test for chromosomal structural rearrangement (PGT-SR) to avoid the increase of risk of abortion and genetic abnormalities and to improve the diagnostic rate of mosic embryos.Methods:We used a retrospective cohort study to analyze 94 cycles of infertile patients undergoing PGT-SR and 551 cycles of intracytoplasmic sperm injection (ICSI) from January 2018 to December 2019 in the Reproductive Medical Center of the Maternal and Child Health Hospital. The relationship of mosic embryos was analyzed between the age, the number of oocytes, gonadotropin (Gn)/oocyte, the grade of blastocysts and chromosome carrier of different genders by the SPSS21.0 software.Results:In the PGT-SR cycle, single factor analysis found that mosaic embryos were related to age and sperm concentration ( P=0.02, P=0.04), but multivariate logistic regression analysis showed that age ( OR=3.41, 95% CI=1.34-8.66, P=0.01), sperm concentration ( OR=0.41, 95% CI=0.17-0.96, P=0.04) and chromosome carrier of different genders ( OR=2.21, 95% CI=1.04-4.70, P=0.04) were the main factors of embryo mosaicism. Conclusion:Female age, sperm concentration and chromosome carrier of different genders maybe affect the formation of mosaic embryos, providing theoretical basis for selective transfer of mosaic embryos.