Synergy between Laminin-Derived Elastin-like Polypeptides (LELPs) Optimizes Cell Spreading.

A major component of the extracellular matrix (ECM), laminins, modulates cells via diverse receptors. Their fragments have emerging utility as components of "ECM-mimetics" optimized to promote cell-based therapies. Recently, we reported that a bioactive laminin peptide known as A99 enhanced cell binding and spreading via fusion to an elastin-like polypeptide (ELP). The ELP "handle" serves as a rapid, noncovalent strategy to concentrate bioactive peptide mixtures onto a surface. We now report that this strategy can be further generalized across an expanded panel of additional laminin-derived elastin-like polypeptides (LELPs). A99 (AGTFALRGDNPQG), A2G80 (VQLRNGFPYFSY), AG73 (RKRLQVQLSIRT), and EF1m (LQLQEGRLHFMFD) all promote cell spreading while showing morphologically distinct F-actin formation. Equimolar mixtures of A99:A2G80-LELPs have synergistic effects on adhesion and spreading. Finally, three of these ECM-mimetics promote the neurite outgrowth of PC-12 cells. The evidence presented here demonstrates the potential of ELPs to deposit ECM-mimetics with applications in regenerative medicine, cell therapy, and tissue engineering.

Pharmacokinetic model of human exposure to ciprofloxacin through consumption of fish.

Fluoroquinolones are broad-spectrum antibiotics that accumulate in the environment. To assess human exposure through the food chain, we developed a pharmacokinetic model of fluoroquinolone accumulation in fish and a human pharmacokinetic model to predict gastrointestinal concentrations of ciprofloxacin, a common fluoroquinolone, following consumption of fish. At 70 ng/L ciprofloxacin, the average in North American surface waters, the fish steady-state concentration was calculated to be 7.5 × 10-6 µg/g. Upon human consumption of the FDA-recommended portion of 113 g of fish containing this ciprofloxacin level, the predicted human intestinal concentration was 2 × 10-6 µg/mL. At 4 × 106 ng/L (4 µg/mL) ciprofloxacin, the highest recorded environmental measurement, these numbers were 0.42 µg/g in fish and 0.1 µg/mL in the human intestine. Thus, based on the ciprofloxacin MIC for E. coli of 0.13 µg/mL, background environmental ciprofloxacin levels are unlikely to be problematic, but environmental pollution can result in high intestinal levels that may cause gut dysbiosis and antibiotic resistance.

Noncovalent Conjugation of OVA323 to ELP Micelles Increases Immune Response.

Subunit vaccines would benefit from a safe particle-based adjuvant. Elastin-like polypeptide (ELP)-based micelles are interesting candidate adjuvants due to their well-defined size and easy modification with protein-based cargo. Coiled coils can facilitate noncovalent modifications, while potentially enhancing antigen delivery through interaction with cell membranes. ELP micelles comprise ELP diblock copolymers that self-assemble above a critical micelle temperature. In this study, an amphiphilic ELP was conjugated to peptide "K", which forms a heterodimeric coiled-coil complex with peptide "E". Self-assembled "covalent" micelles containing ELP-OVA323 (i.e., model antigen OVA323 conjugated to ELP), "coiled-coil" micelles containing ELP-K/E-OVA323 and "hybrid" micelles containing ELP-K and ELP-OVA323 were shown to be monodisperse and spherical. Dendritic cells (DCs) were exposed to all micelle compositions, and T-cell proliferation was investigated. The presence of ELP-K enhanced micelle uptake and subsequent DC maturation, resulting in enhanced CD4+ T-cell proliferation, which makes ELPs with coiled coil-associated antigens a promising vaccine platform.

Steric stabilization of bioactive nanoparticles using elastin-like polypeptides.

Elastin-like polypeptides (ELP) are versatile, thermo-responsive polymers that can be conjugated to virtually any therapeutic cargo. Derived from short amino-acid sequences and abundant in humans, certain ELPs display low immunogenicity. Substrates for endogenous proteases, ELPs are biodegradable and thus, are candidate biomaterials. Peptides and proteins can be directly coupled with ELPs through genetic engineering, while other polymers and small molecules can be appended through covalent bioconjugation or non-covalent complexation. ELPs that phase separate at physiological temperatures can form the core of nano assemblies; however, ELPs that remain soluble can sterically stabilize the corona of a variety of nanoparticles. Nanoparticles with ELPs at their corona promote colloids with favorable pharmacokinetic (PK) properties that enables therapeutic efficacy with intermittent administration. This review highlights a comprehensive spectrum of ELP fusions shown to stabilize the solubility, and sometimes bioactivity, of their cargo - with a focus on biophysical properties that underlie their therapeutic effects.

Pediatric vehicular heatstroke: An analysis of 296 cases from the National Fatality Review Case Reporting System.

OBJECTIVES: To explore the National Fatality Review Case Reporting System (NFR-CRS) as a new data source to (1) characterize pediatric vehicular heatstroke (PVH) deaths among children <15 years of age reviewed by Child Death Review teams, and (2) identify factors independently associated with common PVH scenarios and incident locations. METHODS: Data for 2005-2019 were used to characterize 296 PVH deaths. Frequencies and percentages were calculated to describe child, supervisor, and incident characteristics. Multiple logistic regression with and without imputation were carried out to identify factors associated with the two outcomes of interest: PVH scenario (left in vehicle vs. gained access) and incident place (supervisor workplace vs. other locations). Odds ratios and 95% confidence intervals (OR, 95% CI) were calculated. RESULTS: Most children had been left unattended in vehicles (N = 225, 76.0%) and 13.5% (N = 40) had gained access independently. Children were most often male (N = 168, 56.8%), non-Hispanic White (N = 131, 44.3%), and <2 years of age (N = 172, 58.1%). Disability or chronic illness was noted for 4.7% (N = 14), 13.9% (N = 41) had a history of maltreatment, and 6.1% (N = 18) an open CPS case at the time of incident. Children left unattended were more likely to be <2 years of age (adjusted imputed OR 26.7, CI 7.3-97.2) and less likely to have an open CPS case (0.2, 0.0-0.4) and for the incident to occur at home (0.2, 0.1-0.9) compared to children who gained access. PVH deaths occurring at the supervisor's workplace were more likely to be <2 years of age (6.2, 2.4-15.8), to have occurred on a weekday (5.9, 1.7-20.9), and to have been supervised by their parent at the incident time (2.7, 1.1-6.7) compared to other locations. CONCLUSIONS: The results align with previous PVH findings and added new information on child race/ethnicity, CPS action, disability/chronic illness, and maltreatment. With the exception of parents being more likely to be the supervisor in incidents occurring at home, which was expected, neither supervisor characteristics nor child race/ethnicity or sex were independently significant in multiple regression, suggesting that PVH is pervasive and that education campaigns should be similarly broad.

Additive and non-additive genetic variance in juvenile Sitka spruce (Picea sitchensis Bong. Carr).

Many quantitative genetic models assume that all genetic variation is additive because of a lack of data with sufficient structure and quality to determine the relative contribution of additive and non-additive variation. Here the fractions of additive (fa) and non-additive (fd) genetic variation were estimated in Sitka spruce for height, bud burst and pilodyn penetration depth. Approximately 1500 offspring were produced in each of three sib families and clonally replicated across three geographically diverse sites. Genotypes from 1525 offspring from all three families were obtained by RADseq, followed by imputation using 1630 loci segregating in all families and mapped using the newly developed linkage map of Sitka spruce. The analyses employed a new approach for estimating fa and fd, which combined all available genotypic and phenotypic data with spatial modelling for each trait and site. The consensus estimate for fa increased with age for height from 0.58 at 2 years to 0.75 at 11 years, with only small overlap in 95% support intervals (I95). The estimated fa for bud burst was 0.83 (I95=[0.78, 0.90]) and 0.84 (I95=[0.77, 0.92]) for pilodyn depth. Overall, there was no evidence of family heterogeneity for height or bud burst, or site heterogeneity for pilodyn depth, and no evidence of inbreeding depression associated with genomic homozygosity, expected if dominance variance was the major component of non-additive variance. The results offer no support for the development of sublines for crossing within the species. The models give new opportunities to assess more accurately the scale of non-additive variation. Supplementary Information: The online version contains supplementary material available at 10.1007/s11295-023-01627-5.

αB-Crystallin Peptide Fused with Elastin-like Polypeptide: Intracellular Activity in Retinal Pigment Epithelial Cells Challenged with Oxidative Stress.

BACKGROUND: Oxidative stress-induced retinal degeneration is among the main contributing factors of serious ocular pathologies that can lead to irreversible blindness. αB-crystallin (cry) is an abundant component of the visual pathway in the vitreous humor, which modulates protein and cellular homeostasis. Within this protein exists a 20 amino acid fragment (mini-cry) with both chaperone and antiapoptotic activity. This study fuses this mini-cry peptide to two temperature-sensitive elastin-like polypeptides (ELP) with the goal of prolonging its activity in the retina. METHODS: The biophysical properties and chaperone activity of cry-ELPs were confirmed by mass spectrometry, cloud-point determination, and dynamic light scattering 'DLS'. For the first time, this work compares a simpler ELP architecture, cry-V96, with a previously reported ELP diblock copolymer, cry-SI. Their relative mechanisms of cellular uptake and antiapoptotic potential were tested using retinal pigment epithelial cells (ARPE-19). Oxidative stress was induced with H2O2 and comparative internalization of both cry-ELPs was made using 2D and 3D culture models. We also explored the role of lysosomal membrane permeabilization by confocal microscopy. RESULTS: The results indicated successful ELP fusion, cellular association with both 2D and 3D cultures, which were enhanced by oxidative stress. Both constructs suppressed apoptotic signaling (cleaved caspase-3); however, cry-V96 exhibited greater lysosomal escape. CONCLUSIONS: ELP architecture is a critical factor to optimize delivery of therapeutic peptides, such as the anti-apoptotic mini-cry peptide; furthermore, the protection of mini-cry via ELPs is enhanced by lysosomal membrane permeabilization.

Biomimetic SARS-CoV-2 Spike Protein Nanoparticles.

COVID-19 is an infectious respiratory disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This virus contains a crucial coat protein that engages with target cells via a receptor binding domain (RBD) on its spike protein. To better study the RBD and its therapeutic opportunities, we genetically engineered a simple fusion with a thermo-responsive elastin-like polypeptide (ELP). These fusions express in Escherichia coli at a high yield in the soluble fraction and were easily purified using ELP-mediated phase separation (79 mg/L culture). Interestingly, they assembled peptide-based nanoparticles (Rh = 71.4 nm), which was attributed to oligomerization of RBDs (25.3 kDa) counterbalanced by steric stabilization by a soluble ELP (73.4 kDa). To investigate their biophysical properties, we explored the size, shape, and binding affinity for the human angiotensin-converting enzyme 2 (hACE2) and cellular uptake. Biomimetic nanoparticles such as these may enable future strategies to target the same cells, tissues, and cell-surface receptors as those harnessed by SARS-CoV-2.

Bet v 1-displaying elastin-like polypeptide nanoparticles induce a strong humoral and weak CD4+ T-cell response against Bet v 1 in a murine immunogenicity model.

There is growing concern about the toxicity of colloidal aluminum salts used as adjuvants in subcutaneous allergen immunotherapy (SCIT). Therefore, alternative adjuvants and delivery systems are being explored to replace alum in SCIT. We applied micellar elastin-like polypeptides (ELPs), a type of self-assembling protein, to replace alum as vaccine adjuvant in birch pollen SCIT. ELP and an ELP-Bet v 1 fusion protein were expressed in E. coli and purified by immuno-affinity chromatography and inverse-transition cycling (ITC). Nanoparticles self-assembled from ELP and a 9:1 ELP/ELP-Bet v 1 mixture were characterized by using dynamic light scattering and atomic force microscopy. Allergenicity was assessed by measuring mediator release from rat basophilic leukemia cells transformed with the human FcϵR1 and sensitized with sera derived from human birch pollen allergic patients. Humoral and T-cell immunity were investigated by immunizing naïve mice with the ELP/ELP-Bet v 1 nanoparticles or alum-adsorbed Bet v 1, both containing 36 µg Bet v 1. ELP and ELP/ELP-Bet v 1 self-assembled at 37°C into spherically shaped micelles with a diameter of ~45 nm. ELP conjugation made Bet v 1 hypo-allergenic (10-fold). Compared to alum-adsorbed Bet v 1, ELP/ELP-Bet v 1 nanoparticles induced stronger IgG responses with an earlier onset. Additionally, ELP/ELP-Bet v 1 did not induce Th2 skewing cytokines and IgE. The hypoallergenic character and strong humoral immune response in the absence of a Th2-skewing T-cell response make ELP-based nanoparticles a promising candidate to replace alum in SCIT.

[18F]Sodium fluoride PET-MRI detects increased metabolic bone response to whole-joint loading stress in osteoarthritic knees.

OBJECTIVE: Altered joint function is a hallmark of osteoarthritis (OA). Imaging techniques for joint function are limited, but [18F]sodium fluoride (NaF) PET-MRI may assess the acute joint response to loading stresses. [18F]NaF PET-MRI was used to study the acute joint response to exercise in OA knees, and compare relationships between regions of increased uptake after loading and structural OA progression two years later. METHODS: In this prospective study, 10 participants with knee OA (59 ± 8 years; 8 female) were scanned twice consecutively using a PET-MR system and performed a one-legged squat exercise between scans. Changes in tracer uptake measures in 9 bone regions were compared between knees that did and did not exercise with a mixed-effects model. Areas of focally large changes in uptake between scans (ROIfocal, ΔSUVmax > 3) were identified and the presence of structural MRI features was noted. Five participants returned two years later to assess structural change on MRI. RESULTS: There was a significant increase in [18F]NaF uptake in OA exercised knees (SUV P < 0.001, KiP = 0.002, K1P < 0.001) that differed by bone region. CONCLUSION: There were regional differences in the acute bone metabolic response to exercise and areas of focally large changes in the metabolic bone response that might be representative of whole-joint dysfunction.

Pediatric Battery-Related Emergency Department Visits in the United States: 2010-2019.

OBJECTIVES: To describe the epidemiology of battery-related emergency department (ED) visits among children aged <18 years in the United States from 2010 to 2019 and compare with previous study findings. METHODS: Data on ED visits were obtained from the National Electronic Injury Surveillance System. Using narrative descriptions and diagnosis codes, battery-related cases were coded into four exposure routes: (1) ingestion, (2) mouth exposure, (3) ear insertion, and (4) nasal insertion. RESULTS: An estimated 70 322 (95% confidence interval: 51 275-89 369) battery-related ED visits among children aged <18 years occurred during the study period, or 9.5 per 100 000 children annually. Button batteries were implicated in 84.7% of visits where battery type was described. A statistically significant increase in the ED visit rate occurred from 2010 to 2017 (P = .03), followed by a nonstatistically significant decrease from 2017 to 2019. The ED visit rate was highest among children aged ≤5 years compared with those 6 to 17 years (24.5 and 2.2 per 100 000 children, respectively). The mean patient age was 3.2 years (95% confidence interval: 2.9-3.4). Ingestions accounted for 90.0% of ED visits, followed by nasal insertions (5.7%), ear insertions (2.5%), and mouth exposures (1.8%). CONCLUSIONS: Pediatric battery-related ED visit rates continued to significantly increase from 2010 to 2017, with children aged ≤5 years having the highest rates. Prevention efforts have not significantly reduced injury rates; therefore, regulatory efforts are needed. Ultimately, hazard reduction or elimination through safer button battery design is critical and should be adopted by the battery industry.

Hydra-Elastin-like Polypeptides Increase Rapamycin Potency When Targeting Cell Surface GRP78.

Rapalogues are powerful therapeutic modalities for breast cancer; however, they suffer from low solubility and dose-limiting side effects. To overcome these challenges, we developed a long-circulating multiheaded drug carrier called 5FA, which contains rapamycin-binding domains linked with elastin-like polypeptides (ELPs). To target these "Hydra-ELPs" toward breast cancer, we here linked 5FA with four distinct peptides which are reported to engage the cell surface form of the 78 kDa glucose-regulated protein (csGRP78). To determine if these peptides affected the carrier solubility, this library was characterized by light scattering and mass spectrometry. To guide in vitro selection of the most potent functional carrier for rapamycin, its uptake and inhibition of mTORC1 were monitored in a ductal breast cancer model (BT474). Using flow cytometry to track cellular association, it was found that only the targeted carriers enhanced cellular uptake and were susceptible to proteolysis by SubA, which specifically targets csGRP78. The functional inhibition of mTOR was monitored by Western blot for pS6K, whereby the best carrier L-5FA reduced mTOR activity by 3-fold compared to 5FA or free rapamycin. L-5FA was further visualized using super-resolution confocal laser scanning microscopy, which revealed that targeting increased exposure to the carrier by ∼8-fold. This study demonstrates how peptide ligands for GRP78, such as the L peptide (RLLDTNRPLLPY), may be incorporated into protein-based drug carriers to enhance targeting.

Protein and polypeptide mediated delivery to the eye.

Hybrid or recombinant protein-polymers, peptide-based biomaterials, and antibody-targeted therapeutics are widely explored for various ocular conditions and vision correction. They have been noted for their potential biocompatibility, potency, adaptability, and opportunities for sustained drug delivery. Unique to peptide and protein therapeutics, their production by cellular translation allows their precise modification through genetic engineering. To a greater extent than drug delivery to other systems, delivery to the eye can benefit from the combination of locally-targeted administration and protein-based specificity. Consequently, a range of delivery platforms and administration methods have been exploited to address the ocular delivery of peptide and protein biomaterials. This review discusses a sample of preclinical and clinical opportunities for peptide-based drug delivery to the eye.

Supra-lacrimal protein-based carriers for cyclosporine A reduce Th17-mediated autoimmunity in murine model of Sjögren's syndrome.

Sjögren's syndrome (SS) is a multifactorial autoimmune disease with principal symptoms including inflammation and loss of function of lacrimal glands (LG) and salivary glands. While glandular infiltrates includes both B- and T-cells, CD4+ T cells are strongly implicated. Utilizing the male non-obese diabetic (NOD) mouse model of SS, this work: 1) identifies clinically-relevant elevations in cytokines (IL-17A, IL-2) in LG-derived CD4+ T cells; and 2) explores tissue-specific immunosuppression of SS using a novel protein-based drug carrier to concentrate cyclosporine A (CsA) directly in the LG. As a potent immunosuppressant, topical ophthalmic CsA is approved for dry eye disorders; however, it cannot effectively resolve inflammation due to limited accumulation in the LG. Systemic CsA has dose-limiting side effects that also limit its ability to block LG inflammation. Using elastin-like polypeptides (ELPs) fused genetically to cyclophilin, the intracellular cognate receptor of CsA, this manuscript reports a sustained-release formulation of CsA that maintains therapeutic drug concentrations in the LG and extends intervals between doses. This formulation blocked both in vitro Th17 cell differentiation and IL-17A secretion. In vivo treatment significantly decreased the abundance of Th17.1 cells, a helper cell population sharing phenotypes of both Th17 and Th1, in the LG of diseased NOD mice. Treatment with even a single dose of the sustained-release formulation was effective enough to improve basal levels of tear production. Thus, this sustained-release formulation suppressed local LG inflammation driven through IL-17 dependent pathways, while improving ocular surface function.

Subchondral bone changes after joint distraction treatment for end stage knee osteoarthritis.

OBJECTIVE: Increased subchondral cortical bone plate thickness and trabecular bone density are characteristic of knee osteoarthritis (OA). Knee joint distraction (KJD) is a joint-preserving knee OA treatment where the joint is temporarily unloaded. It has previously shown clinical improvement and cartilage regeneration, indicating reversal of OA-related changes. The purpose of this research was to explore 3D subchondral bone changes after KJD treatment using CT imaging. DESIGN: Twenty patients were treated with KJD and included to undergo knee CT imaging before, one, and two years after treatment. Tibia and femur segmentation and registration to canonical surfaces were performed semi-automatically. Cortical bone thickness and trabecular bone density were determined using an automated algorithm. Statistical parametric mapping (SPM) with two-tailed F-tests was used to analyze whole-joint changes. RESULTS: Data was available of 16 patients. Subchondral cortical bone plate thickness and trabecular bone density were higher in the weight-bearing region of the most affected compartment (MAC; mostly medial). Especially the MAC showed a decrease in thickness and density in the first year after treatment, which was sustained towards the second year. CONCLUSIONS: KJD treatment results in bone changes that include thinning of the subchondral cortical bone plate and decrease of subchondral trabecular bone density in the first two years after treatment, potentially indicating a partial normalization of subchondral bone.

Intracellular Dynamin Elastin-like Polypeptides Assemble into Rodlike, Spherical, and Reticular Dynasomes.

Dynamin (DNM) is a family of large GTPases possessing a unique mechanical ability to "pinch" off vesicles entering cells. DNM2 is the most ubiquitously expressed member of the DNM family. We developed a novel tool based on elastin-like polypeptide (ELP) technology to quickly, precisely, and reversibly modulate the structure of DNM2. ELPs are temperature-sensitive biopolymers that self-assemble into microdomains above sharp transition temperatures. When linked together, DNM2 and a temperature-sensitive ELP fusion organize into a range of distinct temperature-dependent structures above a sharp transition temperature, which were not observed with wild-type DNM2 or a temperature-insensitive ELP fusion control. The structures comprised three different morphologies, which were prevalent at different temperature ranges. The size of these structures was influenced by an inhibitor of the DNM2 GTPase activity, dynasore; furthermore, they appear to entrap co-expressed cytosolic ELPs. Having demonstrated an unexpected diversity of morphologically distinct structures, DNM2-ELP fusions may have applications in the exploration of dynamin-dependent biology.

[18F]NaF PET-MRI provides direct in-vivo evidence of the association between bone metabolic activity and adjacent synovitis in knee osteoarthritis: a cross-sectional study.

OBJECTIVE: Synovitis is hypothesized to play a role in the development and growth of osteophytes. Our objectives were to use hybrid positron emission tomography-magnetic resonance imaging (PET-MRI) to (1) determine whether synovitis adjacent to peripheral bone subregions with increased metabolic activity is greater than adjacent to regions without increased metabolic activity and (2) assess the association between subregional bone metabolic activity and adjacent synovitis. DESIGN: We recruited 11 participants (22 knees) with a diagnosis of OA in at least one knee. Simultaneous bilateral knee PET-MRI was performed. We quantified bone metabolic activity using the radiotracer [18F]sodium fluoride ([18F]NaF) with calculation of maximum standardized uptake values (SUVmax). Synovitis was quantified using dynamic contrast-enhanced MRI with calculation of Ktrans. Bone subregions were coded as osteophyte (OP), focal increased [18F]NaF uptake without osteophyte (FIU), or normal (no osteophyte or FIU). We used robust linear mixed effects models to assess differences in adjacent Ktrans between different subregion types and to assess association between Ktrans and adjacent SUVmax. RESULTS: 94 OPs were detected (59 MOAKS grade 1, 30 grade 2, 5 grade 3), along with 28 FIU and 18 normal subregions. Ktrans was higher adjacent to FIU (adjusted mean [95% CI] = 0.06 [0.03,0.09]) and OPs (0.08 [0.05,0.11]) when compared to normal bone subregions (0.03 [0.00,0.09]). PET SUVmax was positively associated with adjacent Ktrans (ß[95% CI] = 0.018 [0.008,0.027]). CONCLUSIONS: Synovitis is more intense adjacent to peripheral bone regions with increased metabolic activity than those without, although there is some overlap. Subregional bone metabolic activity is positively associated with intensity of adjacent synovitis.

Musculoskeletal radiology training in the UK: a national survey by the British Society of Skeletal Radiologists.

AIM: To identify the standard of core and subspecialist musculoskeletal (MSK) training across deaneries in the UK. MATERIALS AND METHODS: An online survey of 46 questions with responses in Likert scale or dichotomous formats was distributed to members of the Society of Radiologists in training, British Society of Skeletal Radiologists (BSSR), Training Programme Directors and the Royal College of Radiologists (RCR) Junior Radiology Forum representatives for national training schemes across the country. Responses were analysed descriptively with narrative analysis of free-text comments. RESULTS: One hundred and seventy-eight participants completed the survey. Forty-six percent (81/178) were core trainees (ST1-3), 47% (84/178) were subspecialist trainees, and 7% (13/178) were newly qualified consultants (<2 years in post). All (178/178) of the participants had a dedicated MSK rotation, with a duration of ≥3 months in 76% (136/178). Only one-third received a dedicated period in MSK ultrasound and only 60% (107/178) had been actively involved in interventional procedures during their training. Overall, 21% (37/178) and 42% (75/178) of participants rated the quality of their MSK training as excellent and good, respectively. The majority (93%, 168/178) thought that MSK training could be improved, especially for ultrasound (62%, 110/178) and interventional computed tomography (CT) or fluoroscopy (57%, 101/178). CONCLUSIONS: There are inconsistencies in MSK training offered in the UK. Although the majority of trainees are satisfied, there were gaps and potential threats to the quality of training. MSK training is witnessing substantial demand from trainees and workforce strategists necessitating tactical investments to standardise and enhance its quality.