Instability of membranes containing ionizable cationic lipids: Effects of the repulsive range of headgroups and tail structures.

The stability of membranes formed by ionizable cationic lipids, which constitute the primary components in lipid nanoparticles capable of endosomal escape, is explored using coarse-grained dissipative particle dynamics. Three types of ionizable model lipids with different tail structures are considered. Endosome acidification causes the ionization of lipids, leading to an increased repulsive range between their headgroups. When electrostatic repulsion is modeled as a conservative force with a long-range cutoff distance (rc,HH), the membrane and vesicle experience a loss of structural integrity and develop holes as rc,HH is beyond a critical value, which varies with the tail structure. When Coulombic repulsion is explicitly incorporated and intensified, a fully ionized lipid membrane undergoes a loss of structural integrity, displaying a qualitative similarity to the effect observed with the increase in rc,HH on the membrane stability. Qualitatively similar results are obtained for partially ionized membranes as the fraction of charged lipids increases. The stability of a mixed lipid membrane containing both ionizable and conventional lipids is also investigated. The disruption of the bilayer structure occurs for a sufficiently high charged fraction. The membrane instability can be attributed to the decrease in the packing parameter, which significantly deviates from unity as the interaction range increases.

One-step Fabrication of Physical Eutectogel with Recyclability: Crystalline Domain Regulation Induced by Microgels.

HYPOTHESIS: Despite their non-volatility, low cost, and recyclability, physical eutectogels' appeal is hindered by the intricate fabrication process and the involvement of hazardous chemicals. The network of polyvinyl alcohol (PVA) in deep eutectic solvent (choline chloride and glycerol) might be developed by the addition of microgels of polyacrylic acid (Carbopol). EXPERIMENTS: Hydrogen-bond interactions between Carbopol and PVA are revealed through Fourier-transform infrared spectroscopy. The impact of microgels on crystalline domains and the polymer network can be observed using X-ray diffraction and scanning electron microscopy. The physical properties of the eutectogel, including mechanical strength and ionic conductivity, are investigated as well. Finally, the strain-sensing ability and remarkable recyclability of the eutectogel are demonstrated. FINDINGS: The physical eutectogel can be obtained through a one-step fabrication process using only green and low-cost materials. It demonstrates robust strength (1.02 MPa) and remarkable stretchability (1000 % strain). This is attributed to the uniform dispersion of PVA crystalline domains within the deep eutectic solvent, facilitated by the hydrogen bonds and space restriction effects between PVA and Carbopol. Furthermore, the physical eutectogel with recyclability can consistently generate electrical resistance signals, highlighting its potential as a reliable strain sensor.

Partial decellularization eliminates immunogenicity in tracheal allografts.

There is currently no suitable autologous tissue to bridge large tracheal defects. As a result, no standard of care exists for long-segment tracheal reconstruction. Tissue engineering has the potential to create a scaffold from allografts or xenografts that can support neotissue regeneration identical to the native trachea. Recent advances in tissue engineering have led to the idea of partial decellularization that allows for the creation of tracheal scaffolds that supports tracheal epithelial formation while preserving mechanical properties. However, the ability of partial decellularization to eliminate graft immunogenicity remains unknown, and understanding the immunogenic properties of partially decellularized tracheal grafts (PDTG) is a critical step toward clinical translation. Here, we determined that tracheal allograft immunogenicity results in epithelial cell sloughing and replacement with dysplastic columnar epithelium and that partial decellularization creates grafts that are able to support an epithelium without histologic signs of rejection. Moreover, allograft implantation elicits CD8+ T-cell infiltration, a mediator of rejection, while PDTG did not. Hence, we establish that partial decellularization eliminates allograft immunogenicity while creating a scaffold for implantation that can support spatially appropriate airway regeneration.

Ag NPs-coated polyurethane sponge as a water filter for removal of toxic metal ions at high concentrations.

Heavy metal ions are toxic to humans, plants, and marine life, making it crucial to eliminate them from water. This study reports the development of a new nanocomposite material (Alg@Ag/PU) that involves modifying silver nanoparticles (Ag NPs) with alginate (Alg) and coating them onto a polyurethane sponge (PU) for removing heavy metal ions. The successful coating of Alg@Ag NPs onto PU due to their strong chemical binding was confirmed by morphology and size characterization. Batch experiments were conducted to evaluate the removal efficiency of heavy metal ions at high concentrations (∼100 mg/L). The maximum adsorption amount was achieved within 6 h, and the highest removal efficiency was obtained at pH values between 6 and 7. Furthermore, the Alg@Ag/PU nanocomposite demonstrated excellent recyclability for metal ion removal even after 5 cycles. In summary, this work developed a simple and cost-effective method for producing an environmentally-friendly nanocomposite material for the efficient removal of heavy metal ions.

Novel prosthetic ligament repair of a shoulder luxation in a cat using a bone anchor and ligament prosthesis.

Case summary: A 7-year-old male castrated Ragdoll cat was presented for chronic shoulder instability after a previous medial luxation of the right shoulder. Upon examination, there was palpable instability of the glenohumeral joint and an increased abduction angle. Surgical stabilisation was elected due to lameness and instability after closed reduction, rest and medical management. A low-profile bone-anchor and a ligament prosthesis were used to stabilise the glenohumeral joint with minimal disruption to the cat's natural shoulder stabilisers. Clinical signs resolved after surgery and the cat remained non-symptomatic at the 12-month follow-up. Relevance and novel information: Feline shoulder luxation is rarely described in the veterinary literature. To the authors' knowledge, this is the first report describing stabilisation of the glenohumeral joint in a cat using a bone anchor and a ligament prosthesis.

Acute Hemodynamics in the Fontan Circulation: Open-Label Study of Vasopressin.

OBJECTIVE: To describe the acute hemodynamic effect of vasopressin on the Fontan circulation, including systemic and pulmonary pressures and resistances, left atrial pressure, and cardiac index. DESIGN: Prospective, open-label, nonrandomized study (NCT04463394). SETTING: Cardiac catheterization laboratory at Lucile Packard Children's Hospital, Stanford. PATIENTS: Patients 3-50 years old with a Fontan circulation who were referred to the cardiac catheterization laboratory for hemodynamic assessment and/or intervention. INTERVENTIONS: A 0.03 U/kg IV (maximum dose 1 unit) bolus of vasopressin was administered over 5 minutes, followed by a maintenance infusion of 0.3 mU/kg/min (maximum dose 0.03 U/min). MEASUREMENTS AND MAIN RESULTS: Comprehensive cardiac catheterization measurements before and after vasopressin administration. Measurements included pulmonary artery, atrial, and systemic arterial pressures, oxygen saturations, and systemic and pulmonary flows and resistances. There were 28 patients studied. Median age was 13.5 (9.1, 17) years, and 16 (57%) patients had a single or dominant right ventricle. Following vasopressin administration, systolic blood pressure and systemic vascular resistance (SVR) increased by 17.5 (13.0, 22.8) mm Hg ( Z value -4.6, p < 0.001) and 3.8 (1.8, 7.5) Wood Units ( Z value -4.6, p < 0.001), respectively. The pulmonary vascular resistance (PVR) decreased by 0.4 ± 0.4 WU ( t statistic 6.2, p < 0.001), and the left atrial pressure increased by 1.0 (0.0, 2.0) mm Hg ( Z value -3.5, p < 0.001). The PVR:SVR decreased by 0.04 ± 0.03 ( t statistic 8.1, p < 0.001). Neither the pulmonary artery pressure (median difference 0.0 [-1.0, 1.0], Z value -0.4, p = 0.69) nor cardiac index (0.1 ± 0.3, t statistic -1.4, p = 0.18) changed significantly. There were no adverse events. CONCLUSIONS: In Fontan patients undergoing cardiac catheterization, vasopressin administration resulted in a significant increase in systolic blood pressure, SVR, and left atrial pressure, decrease in PVR, and no change in cardiac index or pulmonary artery pressure. These findings suggest that in Fontan patients vasopressin may be an option for treating systemic hypotension during sedation or general anesthesia.

Imbibition Dynamics in a U-Groove Microchannel with Sudden Enlargement.

Imbibition dynamics in a rectangular U-groove that is connected to a sudden enlargement and complicated by the presence of Concus-Finn (CF) filaments is investigated using many-body dissipative particle dynamics. For open-ended sudden enlargement, four flow types are identified and depend on the contact angle θy, the critical angle θf associated with the occurrence of CF filaments, and the critical angle θc associated with the occurrence of main flow. First, for θy > θf and θy > θc, the corner flow is absent, and the main flow stops at the end of the small U-groove. Second, for θc > θy > θf, the corner flow vanishes, but the main flow occurs. Third, for θf > θy > θc, the corner flow takes place in the large U-groove, but the main flow is still absent. Fourth, for θy < θf and θy < θc, both the corner and main flows appear in the large U-groove. Additionally, the flow dynamics is greatly influenced by the length of the large U-groove (le). For closed-ended sudden enlargement, similar findings can be obtained. However, the outcome of the third case is altered for sufficiently small le, and the sudden enlargement can eventually be filled.

Regeneration of tracheal neotissue in partially decellularized scaffolds.

Extensive tracheal injury or disease can be life-threatening but there is currently no standard of care. Regenerative medicine offers a potential solution to long-segment tracheal defects through the creation of scaffolds that support the generation of healthy neotissue. We developed decellularized tracheal grafts (PDTG) by removing the cells of the epithelium and lamina propria while preserving donor cartilage. We previously demonstrated that PDTG support regeneration of host-derived neotissue. Here, we use a combination of microsurgical, immunofluorescent, and transcriptomic approaches to compare PDTG neotissue with the native airway and surgical controls. We report that PDTG neotissue is composed of native tracheal cell types and that the neoepithelium and microvasculature persisted for at least 6 months. Vascular perfusion of PDTG was established within 2 weeks and the graft recruited multipotential airway stem cells that exhibit normal proliferation and differentiation. Hence, PDTG neotissue recapitulates the structure and function of the host trachea and has the potential to regenerate.

Physical activity and mental health in children and youth during COVID-19: a systematic review and meta-analysis.

BACKGROUND: The coronavirus disease (COVID-19) and universal mitigation strategies have fundamentally affected peoples' lives worldwide, particularly during the first two years of the pandemic. Reductions in physical activity (PA) and increased mental health (MH) problems among children and youth have been observed. This systematic review and meta-analysis investigated the relationship between physical activity (PA) and mental health (MH) among children and youth during the COVID-19 pandemic. METHODS: Four electronic databases (EMBASE, PsycINFO, PubMed, and Web of Science) were systematically searched to identify studies that (1) examined the relationship between PA and MH among children and youth (aged 2-24 years old) and (2) were published in peer-reviewed journals in English between January 2020 and December 2021. Relationships between PA and two MH aspects (i.e., negative and positive psychological responses) among children and youth at different age ranges and those with disabilities or chronic conditions (DCC) were synthesized. Meta-analyses were also performed for eligible studies to determine the pooled effect size. RESULTS: A total of 58 studies were eventually included for variable categorization, with 32 eligible for meta-analyses. Our synthesis results showed that greater PA participation was strongly related to lower negative psychological responses (i.e., anxiety, depression, stress, insomnia, fatigue, and mental health problems) and higher positive psychological responses (i.e., general well-being and vigor) in children and youth during COVID-19. The pattern and strength of relations between PA and MH outcomes varied across age ranges and health conditions, with preschoolers and those with DCC receiving less attention in the existing research. Meta-analysis results showed that the magnitude of associations of PA with negative (Fisher's z = - 0.198, p < 0.001) and positive (Fisher's z = 0.170, p < 0.001) psychological responses among children and youth was weak. These results were linked to age of participants, study quality, and reporting of PA-related information. CONCLUSIONS: PA participation and MH among children and youth deteriorated during the COVID-19 pandemic and were closely associated with each other. For the post-COVID-19 era, additional research on age- and health condition-specific relationships between PA and MH outcomes from a comprehensive perspective is warranted. (Word count: 344 words).

Serum proteome profiles in cats with chronic enteropathies.

BACKGROUND: Serum protein biomarkers are used to diagnose, monitor treatment response, and to differentiate various forms of chronic enteropathies (CE) in humans. The utility of liquid biopsy proteomic approaches has not been examined in cats. HYPOTHESIS/OBJECTIVES: To explore the serum proteome in cats to identify markers differentiating healthy cats from cats with CE. ANIMALS: Ten cats with CE with signs of gastrointestinal disease of at least 3 weeks duration, and biopsy-confirmed diagnoses, with or without treatment and 19 healthy cats were included. METHODS: Cross-sectional, multicenter, exploratory study with cases recruited from 3 veterinary hospitals between May 2019 and November 2020. Serum samples were analyzed and evaluated using mass spectrometry-based proteomic techniques. RESULTS: Twenty-six proteins were significantly (P < .02, ≥5-fold change in abundance) differentially expressed between cats with CE and controls. Thrombospondin-1 (THBS1) was identified with >50-fold increase in abundance in cats with CE (P < 0.001) compared to healthy cats. CONCLUSIONS AND CLINICAL IMPORTANCE: Damage to the gut lining released marker proteins of chronic inflammation that were detectable in serum samples of cats. This early-stage exploratory study strongly supports THBS1 as a candidate biomarker for chronic inflammatory enteropathy in cats.

Jammed Microgels in Deep Eutectic Solvents as a Green and Low-Cost Ink for 3D Printing of Reliable Auxetic Strain Sensors.

Additive manufacturing is a promising technique for offering novel functionality to various materials by creating three-dimensional (3D) structures. However, the development of sustainable synthesis processes for 3D printing inks or 3D-printed materials remains a major challenge. In this work, a simple two-step mixing approach is developed to prepare a 3D printing ink from green, low-cost, and low-toxicity materials [commercial Carbopol and deep eutectic solvents (DESs)]. A small weight fraction of Carbopol can impart desired rheological properties to the DES used in the 3D printing ink and also can significantly enhance the stretchability of eutectogels up to 2500% strain. The 3D-printed auxetic structure shows a negative Poisson's ratio (within 100% strain), high stretchability (300%), high sensitivity (gauge factor of 3.1), good moisture resistance, and sufficient transparency. It can detect human motion with high skin comfort and breathability. The results of this work highlight a green, low-cost, and energy-saving strategy to fabricate conductive microgel-based inks for 3D printing of wearable devices.

Single-cell multiomic analysis identifies a HOX-PBX gene network regulating the survival of lymphangioleiomyomatosis cells.

Lymphangioleiomyomatosis (LAM) is a rare, progressive lung disease that predominantly affects women. LAM cells carry TSC1/TSC2 mutations, causing mTORC1 hyperactivation and uncontrolled cell growth. mTORC1 inhibitors stabilize lung function; however, sustained efficacy requires long-term administration, and some patients fail to tolerate or respond to therapy. Although the genetic basis of LAM is known, mechanisms underlying LAM pathogenesis remain elusive. We integrated single-cell RNA sequencing and single-nuclei ATAC-seq of LAM lungs to construct a gene regulatory network controlling the transcriptional program of LAM cells. We identified activation of uterine-specific HOX-PBX transcriptional programs in pulmonary LAMCORE cells as regulators of cell survival depending upon HOXD11-PBX1 dimerization. Accordingly, blockage of HOXD11-PBX1 dimerization by HXR9 suppressed LAM cell survival in vitro and in vivo. PBX1 regulated STAT1/3, increased the expression of antiapoptotic genes, and promoted LAM cell survival in vitro. The HOX-PBX gene network provides promising targets for treatment of LAM/TSC mTORC1-hyperactive cancers.

Microstructural Dynamics of Polymer Melts during Stretching: Radial Size Distribution.

The transient elongational viscosity ηe(t) of the polymer melt is known to exhibit strain hardening, which depends on the strain rate ε˙. This phenomenon was elucidated by the difference of chain stretching in the entanglement network between extension and shear. However, to date, the microscopic evolution of polymer melt has not been fully statistically analyzed. In this work, the radial size distributions P(Rg,t) of linear polymers are explored by dissipative particle dynamics during the stretching processes. In uniaxial extensional flow, it is observed that the mean radius of gyration R¯g(t) and standard deviation σ(t) remain unchanged until the onset of strain hardening, corresponding to linear viscoelasticity. Both R¯g and σ rise rapidly in the non-linear regime, and bimodal size distribution can emerge. Moreover, the onset of strain hardening is found to be insensitive to the Hencky strain (ε˙Ht) and chain length (N).

Serum proteome of dogs with chronic enteropathy.

BACKGROUND: Chronic enteropathy (CE) is common in dogs and can occur with multiple etiologies including food-responsive enteropathy (FRE) and idiopathic inflammatory bowel disease (IBD). HYPOTHESIS/OBJECTIVE: To study the protein profile and pathway differences among dogs with FRE, IBD, and healthy controls using serum proteome analysis. ANIMALS: Nine CE dogs with signs of gastrointestinal disease and histologically confirmed chronic inflammatory enteropathy and 16 healthy controls. METHODS: A cross-sectional study with cases recruited from 2 veterinary hospitals between May 2019 and November 2020 was performed. Serum samples were analyzed using mass spectrometry-based proteomic techniques. RESULTS: Proteomic profiles showed marked variation in relative protein abundances. Forty-five proteins were significantly (P ≤ .01) differentially expressed among the dogs with CE and controls with ≥2-fold change in abundance. The fold change of dogs with IBD normalized to controls was more pronounced for the majority of proteins than that seen in the dogs with FRE normalized to control dogs. Proteins involving reactive oxygen species, cytokine activation, acute phase response signaling, and lipid metabolism were altered in dogs with CE. CONCLUSIONS AND CLINICAL IMPORTANCE: Cytokine alterations, acute phase response signaling, and lipid metabolism are likely involved in pathogenesis of CE. Although there are insufficient current data to justify the use of proteomic biomarkers for assessment of CE in dogs, our study identifies potential candidates.

Behavior Analysis With Integrated Visual-Motor Tracking for Developmental Coordination Disorder.

Developmental coordination disorder (DCD) is a motor learning disability with a prevalence of 5%-6% in school-aged children, which may seriously affect the physical and mental health of affected children. Behavior analysis of children helps explore the mechanism of DCD and develop better diagnosis protocols. In this study, we investigate the behavioral pattern of children with DCD in the gross movement using a visual-motor tracking system. First, visual components of interest are detected and extracted using a series of intelligent algorithms. Then, the kinematic features are defined and calculated to describe the children behavior, including eye movement, body movement, and interacting object trajectory. Finally, statistical analysis is conducted both between groups with different motor coordination abilities and between groups with different task outcomes. The experimental results show that groups of children with different coordination abilities differ significantly both in the duration of eye gaze focusing on the target and in the degree of concentration during aiming, which can serve as behavioral markers to distinguish children with DCD. This finding also provides precise guidance for the interventions for children with DCD. In addition to increasing the amount of time spent on concentrating, we should focus on improving children's attention levels.

Successful Early Neovascularization in Composite Tracheal Grafts.

OBJECTIVE: Long-segment tracheal defects require tissue replacement for successful reconstruction. Rapid revascularization is imperative to maintain graft function. We previously showed that partially decellularized tracheal grafts (PDTG) and composite tracheal grafts (CTG; PDTG supported by a 3-dimensionally printed external splint) regenerate respiratory epithelium and may support the regeneration of endothelial cells (CD31+). However, the capability of graft endothelial cells to organize or contribute to tracheal revascularization remains unclear. In this study, we quantified endothelial cells (CD31+) and neovessel formation in PDTG and CTG. We hypothesize that PDTG and CTG support tracheal neovascularization to a similar extent as surgical (syngeneic tracheal graft [STG]) and native trachea (NT) controls. STUDY DESIGN: The animal study, a randomized control trial. SETTING: Center for Regenerative Medicine, Nationwide Children's Hospital. METHODS: PDTG was created via an established decellularization protocol. Segmental tracheal reconstruction was performed with STG, PDTG, or CTG using a mouse microsurgical model. NT was used as a nonsurgical control. At 1 month, mice were euthanized, grafts harvested, sectioned, and stained with CD31 and hematoxylin and eosin. Neovessel formation was quantified by the number of formed blood vessels in the lamina propria and vessel size (vessel/graft area, mm2 ). RESULTS: Decellularization eliminated all endothelial cells and there were no perfused vessels at implantation. At 1 month, PDTG and CTG supported neovessel formation with tubular vessels lined with endothelial cells. There was no difference in the number or size of vessels compared to controls. CONCLUSION: PDTG and CTG support tracheal endothelial cell regeneration and neovessel formation. Future directions to assess the function, kinetics, and distribution of graft neovessels are needed.

A fast machine-learning-guided primer design pipeline for selective whole genome amplification.

Addressing many of the major outstanding questions in the fields of microbial evolution and pathogenesis will require analyses of populations of microbial genomes. Although population genomic studies provide the analytical resolution to investigate evolutionary and mechanistic processes at fine spatial and temporal scales-precisely the scales at which these processes occur-microbial population genomic research is currently hindered by the practicalities of obtaining sufficient quantities of the relatively pure microbial genomic DNA necessary for next-generation sequencing. Here we present swga2.0, an optimized and parallelized pipeline to design selective whole genome amplification (SWGA) primer sets. Unlike previous methods, swga2.0 incorporates active and machine learning methods to evaluate the amplification efficacy of individual primers and primer sets. Additionally, swga2.0 optimizes primer set search and evaluation strategies, including parallelization at each stage of the pipeline, to dramatically decrease program runtime. Here we describe the swga2.0 pipeline, including the empirical data used to identify primer and primer set characteristics, that improve amplification performance. Additionally, we evaluate the novel swga2.0 pipeline by designing primer sets that successfully amplify Prevotella melaninogenica, an important component of the lung microbiome in cystic fibrosis patients, from samples dominated by human DNA.

Selective whole-genome amplification reveals population genetics of Leishmania braziliensis directly from patient skin biopsies.

In Brazil, Leishmania braziliensis is the main causative agent of the neglected tropical disease, cutaneous leishmaniasis (CL). CL presents on a spectrum of disease severity with a high rate of treatment failure. Yet the parasite factors that contribute to disease presentation and treatment outcome are not well understood, in part because successfully isolating and culturing parasites from patient lesions remains a major technical challenge. Here we describe the development of selective whole genome amplification (SWGA) for Leishmania and show that this method enables culture-independent analysis of parasite genomes obtained directly from primary patient skin samples, allowing us to circumvent artifacts associated with adaptation to culture. We show that SWGA can be applied to multiple Leishmania species residing in different host species, suggesting that this method is broadly useful in both experimental infection models and clinical studies. SWGA carried out directly on skin biopsies collected from patients in Corte de Pedra, Bahia, Brazil, showed extensive genomic diversity. Finally, as a proof-of-concept, we demonstrated that SWGA data can be integrated with published whole genome data from cultured parasite isolates to identify variants unique to specific geographic regions in Brazil where treatment failure rates are known to be high. SWGA provides a relatively simple method to generate Leishmania genomes directly from patient samples, unlocking the potential to link parasite genetics with host clinical phenotypes.

Upregulation of acid ceramidase contributes to tumor progression in tuberous sclerosis complex.

Tuberous sclerosis complex (TSC) is characterized by multisystem, low-grade neoplasia involving the lung, kidneys, brain, and heart. Lymphangioleiomyomatosis (LAM) is a progressive pulmonary disease affecting almost exclusively women. TSC and LAM are both caused by mutations in TSC1 and TSC2 that result in mTORC1 hyperactivation. Here, we report that single-cell RNA sequencing of LAM lungs identified activation of genes in the sphingolipid biosynthesis pathway. Accordingly, the expression of acid ceramidase (ASAH1) and dihydroceramide desaturase (DEGS1), key enzymes controlling sphingolipid and ceramide metabolism, was significantly increased in TSC2-null cells. TSC2 negatively regulated the biosynthesis of tumorigenic sphingolipids, and suppression of ASAH1 by shRNA or the inhibitor ARN14976 (17a) resulted in markedly decreased TSC2-null cell viability. In vivo, 17a significantly decreased the growth of TSC2-null cell-derived mouse xenografts and short-term lung colonization by TSC2-null cells. Combined rapamycin and 17a treatment synergistically inhibited renal cystadenoma growth in Tsc2+/- mice, consistent with increased ASAH1 expression and activity being rapamycin insensitive. Collectively, the present study identifies rapamycin-insensitive ASAH1 upregulation in TSC2-null cells and tumors and provides evidence that targeting aberrant sphingolipid biosynthesis pathways has potential therapeutic value in mechanistic target of rapamycin complex 1-hyperactive neoplasms, including TSC and LAM.

Association of Vibrotactile Biofeedback With Reduced Ergonomic Risk for Surgeons During Tonsillectomy.

Importance: Work-related musculoskeletal disorders are common among otolaryngologists and can be associated with decreased productivity, missed workdays, and reduced quality of life. Ergonomic risk for surgeons is elevated during common otolaryngology procedures; current ergonomic interventions lack the ability to provide real-time feedback. The ability to quantify and mitigate ergonomic risk during surgery may reduce work-related musculoskeletal disorders. Objective: To quantify the association of vibrotactile biofeedback with intraoperative ergonomic risk to surgeons during tonsillectomy. Design, Setting, and Participants: This cross-sectional study was conducted between June 2021 and October 2021 at a freestanding tertiary care children's hospital and included 11 attending pediatric otolaryngologists. Data analysis was conducted from August to October 2021. Interventions: Real-time quantification of ergonomic risk during tonsillectomy and the use of a vibrotactile biofeedback posture monitor. Main Outcomes and Measures: Association of vibrotactile biofeedback with objective measures of ergonomic risk. Assessment tools included the Rapid Upper Limb Assessment, craniovertebral angle, and time spent in an at-risk posture. Results: Eleven surgeons (mean [SD] age 42 [7] years; 2 women [18%]) performed 126 procedures with continuous posture monitoring in the presence (80 [63%]) and absence (46 [37%]) of vibrotactile biofeedback. No complications or delays associated with the device were reported. Intraoperative vibrotactile biofeedback was associated with improved Rapid Upper Limit Assessment neck, trunk, and leg scores by 0.15 (95% CI, 0.05-0.25), improved craniovertebral angle by 1.9 (95% CI, 0.32-3.40), and decreased overall time spent in an at-risk posture by 30% (95% CI, 22%-39%). Conclusions and Relevance: The results of this cross-sectional study suggest that use of a vibrotactile biofeedback device to quantify and mitigate ergonomic risk for surgeons is feasible and safe while performing surgery. Vibrotactile biofeedback was associated with reduced ergonomic risk during tonsillectomy and may have a role in improving surgical ergonomics and preventing work-related musculoskeletal disorders.