1.Effect of mussel-derived antimicrobial peptide-coated modified prosthesis on prevention of early periprosthetic joint infection and regulation of bone transfer
Bo LIU ; WUHUZI·WULAMU ; Guangzhao ZHU ; Xiaobin GUO ; Ziyue SONG ; Xingbu MENG ; Junjie HU ; Xiaogang ZHANG
Chinese Journal of Tissue Engineering Research 2026;30(2):278-287
BACKGROUND:Periprosthetic joint infection is the most common cause of early failure after total knee replacement.The current methods of preventing periprosthetic joint infection by improving the surface of the prosthesis have limitations to varying degrees.OBJECTIVE:To construct a coating material that can stably improve the surface of the implant,prevent the initial floating bacterial infection of periprosthetic infection,and regulate the bone transfer function around the implant.METHODS:(1)Material preparation:YGF polypeptide(which promotes bone formation),LL-37 polypeptide(with antibacterial properties)and YGF+LL-37 composite peptide were prepared by Fmoc solid phase peptide synthesis technology.The titanium-based materials were immersed in the three polypeptide solutions for 2 hours to obtain YGF coating,LL-37 coating and composite peptide coating coated titanium sheets.(2)In vitro experiment:Uncoated titanium sheets and coated titanium sheets were co-cultured with Escherichia coli(or Staphylococcus aureus)and the colonies were counted by plate method.MC3T3 cells were inoculated on the surface of uncoated titanium sheet and coated titanium sheet,respectively.Alizarin red staining was used to observe the calcium salt deposition on the surface of the material.Western blot assay was used to detect the protein expression of RUNX2,osteocalcin,osteopontin,and bone morphogenetic protein 2.(3)Animal experiment:24 SD rats were randomly divided into three groups:the blank group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal;the control group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension;the experimental group(n=8)was implanted with composite peptide coated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension.After 5 weeks of implantation,micro-CT examination,hematoxylin-eosin staining and immunohistochemical staining of femur specimens were performed.RESULTS AND CONCLUSION:(1)In vitro experiment:Compared with uncoated titanium sheet and YGF coated titanium sheet,LL-37 coated and composite peptide coated titanium sheet could significantly inhibit the growth and reproduction of Escherichia coli and Staphylococcus aureus.Compared with uncoated titanium sheets and LL-37-coated titanium sheets,YGF-coated and composite peptide-coated titanium sheets could promote calcium salt deposition in osteoblasts and increase the protein expression of RUNX2,osteocalcin,osteopontin and bone morphogenetic protein 2.(2)Animal experiment:Micro-CT test showed that the control group had less bone mass than the blank group and the experimental group.Hematoxylin-eosin staining showed that there was a large amount of fibrous tissue around the nail channel in the control group,only a small amount of tissue fibrosis around the nail channel in the blank group,and only a small amount of tissue fibrosis around the nail channel in the experimental group.Immunohistochemical staining showed that the protein expression of interleukin 1β and tumor necrosis factor α in the control group was higher than that in the blank group and the experimental group,and the expression of osteocalcin,RUNX2 and osteopontin in the experimental group was higher than that in the blank group and the control group.(3)The results show that the titanium-based material coated with YGF+LL-37 composite peptide coating has good antibacterial ability and can promote bone transfer around the implant.
2.Differences in scapular kinematics between healthy individuals and rotator cuff tear patients based on biplane X-ray
Zicheng GUO ; Jingyuan MENG ; Jiechao ZHANG ; Li DING ; Xiaoye TANG ; Lichao TIAN ; Yilin WANG ; Yong HE
Chinese Journal of Tissue Engineering Research 2026;30(3):652-660
BACKGROUND:Due to the complex movement of the scapula,which is a six-degree-of-freedom activity in three-dimensional space,it is difficult to measure it accurately using traditional methods.The image and model matching technology based on dual-plane X-ray is a three-dimensional measurement method that has gradually developed and matured in recent years.Two high-speed cameras are used to project and shoot from orthogonal directions.Compared with a single perspective,this method has advantages in observation range and reduction of out-of-plane errors,and is suitable for the study of scapula kinematics.OBJECTIVE:X-ray biplane and image-model registration technology were used to explore the differences in scapular kinematics between normal individuals and patients with rotator cuff tears,providing a basis for the treatment and rehabilitation of rotator cuff tear patients.METHODS:From April 2023 to January 2024,10 patients with normal shoulders and 10 patients with rotator cuff tears who met the inclusion criteria were enrolled from Guanghua Hospital Affiliated to Shanghai University of Traditional Chinese Medicine.The subjects underwent a shoulder CT scan to create a 3D model and a local scapular coordinate system.X-ray biplane images were taken during shoulder abduction with two C-arm machines.The 2D and 3D images were registered to compare scapular kinematic differences between the two groups at 0°,15°,30°,45°,60°,75°,and 90° of abduction,including scapular rotation angle and displacement distance.RESULTS AND CONCLUSION:(1)During shoulder abduction,the scapula of both groups showed upward rotation,but the upward rotation of the rotator cuff tear group was greater than that of the control group,and the difference was significant when the abduction was 30°-90°(P<0.01).At the same time,the scapula internal rotation of both groups gradually increased,but the rotator cuff tear group was significantly greater than the control group when the abduction was 45°-90°(P<0.01).In addition,the anteroposterior tilt of the scapula of the two groups was significantly different when the abduction was 15°-90°(P<0.01).The scapula posterior tilt of the control group gradually increased during abduction,while the scapula of the rotator cuff tear group tilted forward except for a slight posterior tilt at 15°-30° abduction.(2)In terms of displacement,the upward displacement of the rotator cuff tear group was less than that of the control group during abduction,and the difference was significant at 15°-90°(P<0.05),but there was no significant difference in lateral and anterior-posterior displacement between the two groups(P>0.05).(3)Rotator cuff tear can cause scapular dyskinesis,characterized by increased upward rotation,internal rotation,and abnormal forward tilt during shoulder abduction.Identifying and addressing scapular dyskinesis is crucial for treating rotator cuff tear.
3.Pain after total knee arthroplasty:current status and trend analysis
Anqi ZHANG ; Haotian HUA ; Tianyuan CAI ; Zicheng WANG ; Zhuo MENG ; Xiaoqian ZHAN ; Guoqian CHEN
Chinese Journal of Tissue Engineering Research 2026;30(3):795-804
BACKGROUND:The number of patients receiving total knee arthroplasty has been increasing globally each year.Pain management is a crucial aspect following total knee arthroplasty,as effective pain control can facilitate early mobilization,reduce complications,enhance patient satisfaction,and accelerate the rehabilitation process.OBJECTIVE:To construct a visual map of post-total knee arthroplasty pain,understand the international research status and trends in this field,and provide a reference for future studies.METHODS:Relevant research articles on post-total knee arthroplasty pain were retrieved from the CNKI,WanFang Data,and Web of Science core databases,covering the period from January 2000 to December 2023.The CiteSpace software(version 6.2.3)was used to analyze the annual publication output,authors,institutions,countries,keywords,and references.Utilizing R programming language(version 4.4.1),a database was established to create line charts and bar graphs.RESULTS AND CONCLUSION:(1)Our analysis included 3 796 publications,predominantly in Chinese(3 509 articles)with the remainder in English(287 articles).(2)The United States was the most productive country in English literature,with Harvard University leading institutional output.Guangzhou University of Chinese Medicine was the top publishing institution in Chinese literature.(3)Keyword clustering identified"quality of life,""phobia,"and"acupuncture"as emerging focal points in Chinese literature,while"satisfaction"and"psychological factors"were prominent in English literature over the past five years.Co-occurrence and clustering analysis revealed dense internal connections among institutions,authors,and publications,but sparse external collaborations.(4)The study's bias on visualization analysis may have introduced bias by excluding less influential papers.(5)Regarding research hotspots,domestic research emphasized the efficacy and exploration of analgesic methods,in contrast to international research that focused on pain mechanism subtyping and analgesic drug innovation.Future research is expected to trend towards traditional Chinese medicine for postoperative pain,multimodal analgesia,and the investigation and prevention of pain typing mechanisms.
4.Effect of mussel-derived antimicrobial peptide-coated modified prosthesis on prevention of early periprosthetic joint infection and regulation of bone transfer
Bo LIU ; WUHUZI·WULAMU ; Guangzhao ZHU ; Xiaobin GUO ; Ziyue SONG ; Xingbu MENG ; Junjie HU ; Xiaogang ZHANG
Chinese Journal of Tissue Engineering Research 2026;30(2):278-287
BACKGROUND:Periprosthetic joint infection is the most common cause of early failure after total knee replacement.The current methods of preventing periprosthetic joint infection by improving the surface of the prosthesis have limitations to varying degrees.OBJECTIVE:To construct a coating material that can stably improve the surface of the implant,prevent the initial floating bacterial infection of periprosthetic infection,and regulate the bone transfer function around the implant.METHODS:(1)Material preparation:YGF polypeptide(which promotes bone formation),LL-37 polypeptide(with antibacterial properties)and YGF+LL-37 composite peptide were prepared by Fmoc solid phase peptide synthesis technology.The titanium-based materials were immersed in the three polypeptide solutions for 2 hours to obtain YGF coating,LL-37 coating and composite peptide coating coated titanium sheets.(2)In vitro experiment:Uncoated titanium sheets and coated titanium sheets were co-cultured with Escherichia coli(or Staphylococcus aureus)and the colonies were counted by plate method.MC3T3 cells were inoculated on the surface of uncoated titanium sheet and coated titanium sheet,respectively.Alizarin red staining was used to observe the calcium salt deposition on the surface of the material.Western blot assay was used to detect the protein expression of RUNX2,osteocalcin,osteopontin,and bone morphogenetic protein 2.(3)Animal experiment:24 SD rats were randomly divided into three groups:the blank group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal;the control group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension;the experimental group(n=8)was implanted with composite peptide coated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension.After 5 weeks of implantation,micro-CT examination,hematoxylin-eosin staining and immunohistochemical staining of femur specimens were performed.RESULTS AND CONCLUSION:(1)In vitro experiment:Compared with uncoated titanium sheet and YGF coated titanium sheet,LL-37 coated and composite peptide coated titanium sheet could significantly inhibit the growth and reproduction of Escherichia coli and Staphylococcus aureus.Compared with uncoated titanium sheets and LL-37-coated titanium sheets,YGF-coated and composite peptide-coated titanium sheets could promote calcium salt deposition in osteoblasts and increase the protein expression of RUNX2,osteocalcin,osteopontin and bone morphogenetic protein 2.(2)Animal experiment:Micro-CT test showed that the control group had less bone mass than the blank group and the experimental group.Hematoxylin-eosin staining showed that there was a large amount of fibrous tissue around the nail channel in the control group,only a small amount of tissue fibrosis around the nail channel in the blank group,and only a small amount of tissue fibrosis around the nail channel in the experimental group.Immunohistochemical staining showed that the protein expression of interleukin 1β and tumor necrosis factor α in the control group was higher than that in the blank group and the experimental group,and the expression of osteocalcin,RUNX2 and osteopontin in the experimental group was higher than that in the blank group and the control group.(3)The results show that the titanium-based material coated with YGF+LL-37 composite peptide coating has good antibacterial ability and can promote bone transfer around the implant.
5.Differences in scapular kinematics between healthy individuals and rotator cuff tear patients based on biplane X-ray
Zicheng GUO ; Jingyuan MENG ; Jiechao ZHANG ; Li DING ; Xiaoye TANG ; Lichao TIAN ; Yilin WANG ; Yong HE
Chinese Journal of Tissue Engineering Research 2026;30(3):652-660
BACKGROUND:Due to the complex movement of the scapula,which is a six-degree-of-freedom activity in three-dimensional space,it is difficult to measure it accurately using traditional methods.The image and model matching technology based on dual-plane X-ray is a three-dimensional measurement method that has gradually developed and matured in recent years.Two high-speed cameras are used to project and shoot from orthogonal directions.Compared with a single perspective,this method has advantages in observation range and reduction of out-of-plane errors,and is suitable for the study of scapula kinematics.OBJECTIVE:X-ray biplane and image-model registration technology were used to explore the differences in scapular kinematics between normal individuals and patients with rotator cuff tears,providing a basis for the treatment and rehabilitation of rotator cuff tear patients.METHODS:From April 2023 to January 2024,10 patients with normal shoulders and 10 patients with rotator cuff tears who met the inclusion criteria were enrolled from Guanghua Hospital Affiliated to Shanghai University of Traditional Chinese Medicine.The subjects underwent a shoulder CT scan to create a 3D model and a local scapular coordinate system.X-ray biplane images were taken during shoulder abduction with two C-arm machines.The 2D and 3D images were registered to compare scapular kinematic differences between the two groups at 0°,15°,30°,45°,60°,75°,and 90° of abduction,including scapular rotation angle and displacement distance.RESULTS AND CONCLUSION:(1)During shoulder abduction,the scapula of both groups showed upward rotation,but the upward rotation of the rotator cuff tear group was greater than that of the control group,and the difference was significant when the abduction was 30°-90°(P<0.01).At the same time,the scapula internal rotation of both groups gradually increased,but the rotator cuff tear group was significantly greater than the control group when the abduction was 45°-90°(P<0.01).In addition,the anteroposterior tilt of the scapula of the two groups was significantly different when the abduction was 15°-90°(P<0.01).The scapula posterior tilt of the control group gradually increased during abduction,while the scapula of the rotator cuff tear group tilted forward except for a slight posterior tilt at 15°-30° abduction.(2)In terms of displacement,the upward displacement of the rotator cuff tear group was less than that of the control group during abduction,and the difference was significant at 15°-90°(P<0.05),but there was no significant difference in lateral and anterior-posterior displacement between the two groups(P>0.05).(3)Rotator cuff tear can cause scapular dyskinesis,characterized by increased upward rotation,internal rotation,and abnormal forward tilt during shoulder abduction.Identifying and addressing scapular dyskinesis is crucial for treating rotator cuff tear.
6.Prevalence and influencing factors of metabolic syndrome in the population aged 35-75 years in Hubei Province
Peijun ZHANG ; Meng LEI ; Shuzhen ZHU ; Junfeng QI ; Shenghong HAN ; Junlin LI
Journal of Public Health and Preventive Medicine 2026;37(3):80-84
Objective To analyze the prevalence characteristics and influencing factors of metabolic syndrome (MS) in people aged 35-75 years in Hubei Province. Methods The follow-up data from 2016 to 2022 in the early screening and comprehensive intervention project for high-risk cardiovascular population in Hubei Province were collected. SAS 9.4 software was used to conduct 2-test and multivariate logistic regression to analyze the prevalence of MS and its influencing factors. Results Among the 89 199 subjects, 24 757 were affected by MS, with a prevalence rate of 27.75% and a standardized rate of 23.55%. Among the various components of MS, the prevalence of abnormal blood pressure was the highest, at 70.88%, and the standardized rate was 59.32%. Secondly, abnormal blood glucose was 36.26%, and the standardized rate was 30.04%. Central obesity was 33.12%, and the standardized rate was 30.28%. Hypertriglyceridemia was 32.90%, and the standardized prevalence rate was 32.70%. The rate of low HDL-C syndrome was 10.25%, and the standardized rate was 11.67%. The results of multivariate logistic regression analysis showed that the risk of MS increased with age, and the risk of MS in urban residents was lower than that in rural residents (OR=0.835, 95%CI: 0.77-0.886). Administrative and professional workers had a higher risk of MS than farmers (OR=1.313, 95%CI:1.194-1.445). Overweight, obesity, central obesity, history of self-reported hypertension, history of self-reported diabetes, and history of self-reported dyslipidemia were associated with a higher risk of MS, and the differences were statistically significant (P < 0.001). Conclusion The prevalence of MS is high in people aged 35-75 years in Hubei Province. On the basis of comprehensive intervention, focus monitoring should be strengthened to control the risk factors of MS and reduce the risk of cardiovascular and cerebrovascular diseases.
7.The Diversity of Filamentous Morphologies and Magnetic Sensitivity Modulated by Diverse MagR Expression in Bacteria
Ya-Fei CHANG ; Jing ZHANG ; Peng ZHANG ; Xiu-Juan ZHOU ; Meng-Ke WEI ; Tian-Tian CAI ; Pei-Qi HE ; Jun-Feng WANG ; Can XIE
Progress in Biochemistry and Biophysics 2026;53(5):1439-1456
Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe2+), whereas clMagR favors ferric iron (Fe3+) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe2+-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe2+/Fe3+ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.
8.Clinical and epidemiological characteristics of human bocavirus in hospitalized children with acute lower respiratory tract infection at a hospital in Shanghai from 2021 to 2023
Shan ZHANG ; Yujuan HUANG ; Lei SHEN ; Li LIU ; Jie WANG ; Huilin ZHOU ; Leijun MENG ; Tingting CHEN
Shanghai Journal of Preventive Medicine 2026;38(3):193-198
ObjectiveTo investigate the epidemiological and clinical characteristics of human bocavirus (HBoV) in hospitalized children with acute lower respiratory tract infection (ALRTI) at a single-center children’s hospital in Shanghai, thereby providing evidence for the diagnosis, treatment, and prevention of HBoV infection. MethodsA retrospective study was conducted on 19 537 hospitalized children with ALRTI at Shanghai Children’s Hospital from January 2021 to December 2023. Multiplex polymerase chain reaction (PCR) combined with capillary electrophoresis was used to detect HBoV and 12 other common respiratory viruses /atypical pathogens. The positive detection rate, demographic characteristics (sex, age), temporal distribution (year, season) of HBoV, as well as the clinical characteristics of severe and non-severe pneumonia were analyzed. ResultsThe overall HBoV-positive rate was 2.57% (503/19 537), with 59.44% (299/503) being single infections and 40.56% (204/503) being co-infections. The positive detection rate was significantly higher in boys than that in girls (2.78% vs 2.33%, χ²=3.88, P=0.049). The highest infection rate was observed in toddlers, followed by infants (χ²=379.57, P<0.001). The positive rate peaked in 2021 and reached its lowest point in 2023 (χ²=45.49, P<0.001), with epidemics mainly prevalent in summer and autumn. The main clinical symptoms were cough (90.06%, 453/503), fever (75.94%, 382/503), and wheezing (39.96%, 201/503). Children with severe pneumonia showed a higher incidence of wheezing compared with the non-severe group (P<0.001), while underlying diseases and co-infections had no significant association with disease severity (P>0.05). ConclusionHBoV was an important pathogen of ALRTI in children, predominantly affecting infants and toddlers, with higher susceptibility in boys and seasonal peaks in autumn and summer. The main clinical manifestations included cough, fever, and wheezing, with wheezing being more prevalent in children with severe pneumonia.
9.The Diversity of Filamentous Morphologies and Magnetic Sensitivity Modulated by Diverse MagR Expression in Bacteria
Ya-Fei CHANG ; Jing ZHANG ; Peng ZHANG ; Xiu-Juan ZHOU ; Meng-Ke WEI ; Tian-Tian CAI ; Pei-Qi HE ; Jun-Feng WANG ; Can XIE
Progress in Biochemistry and Biophysics 2026;53(5):1439-1456
Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe2+), whereas clMagR favors ferric iron (Fe3+) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe2+-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe2+/Fe3+ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.
10.Evaluation of the Angle Deviation between Pilot Holes and Actual Implanted Pedicle Screw Trajectories in Freehand Pedicle Screw Placement for Thoracolumbar Spine Surgery: The Impact of Tapping and Work Experience
Jie SHAO ; Shaokang HUANG ; Yiping LUO ; Bingkun MENG ; Qunfei YU ; Yi ZHANG ; Wei LI ; Yushu BAI ; Ziqiang CHEN
Clinics in Orthopedic Surgery 2026;18(1):87-95
Background:
To investigate directional deviations between pilot holes and final pedicle screw trajectories in freehand placement and analyze risk factors for misplacement. While pedicle screws are widely used in thoracolumbosacral surgery, directional deviations between pilot holes and final screw trajectories remain understudied as potential risk factors for misplacement.
Methods:
Thirty-three patients undergoing posterior fixation were prospectively enrolled. Inertial measurement units (IMUs) tracked the spatial positions of pedicle finders and screwdrivers via custom software. Surgeons (n = 6) were stratified into senior, middle, and junior groups. Analyzed variables included the use of tapping, surgeon experience, spinal deformity status, screw tip morphology, and surgical parameters.
Results:
Among 198 implanted screws (6.00 ± 2.88/patient), all exhibited trajectory deviations (8.12° ± 3.47°). Tapping significantly reduced deviations (7.23° ± 3.23° vs. 8.87° ± 3.31°, p < 0.01). Senior surgeons achieved smaller deviations (7.34° ± 3.33°) than the middle group (8.60° ± 3.51°, p = 0.039) and junior group (8.68° ± 3.49°, p = 0.022). Multivariate analysis confirmed tapping (p = 0.001) and senior experience (p = 0.023) as protective factors. No significant associations emerged for spinal deformity (8.43° ± 3.73° vs. 7.97° ± 3.35°, p = 0.377), screw tip type (cylindrical, 8.43° ± 3.26° vs. tapered, 8.07 ± 3.51°; p = 0.637), obesity, or surgical position parameters.
Conclusions
Freehand pedicle screw placement consistently produces trajectory deviations from pilot holes, and surgeon experience and tapping are modifiable protective factors. The IMU-based tracking system enables quantitative surgical motion analysis, suggesting its utility for training optimization and technique standardization.


Result Analysis
Print
Save
E-mail