Restoring implant fixation strength in osteoporotic bone with a hydrogel locally delivering zoledronic acid and bone morphogenetic protein 2. A longitudinal in vivo microCT study in rats

Osteoporosis poses a major public health challenge, and it is characterized by low bone mass, deterioration of the microarchitecture of bone tissue, causing a consequent increase in bone fragility and susceptibility to fractures and complicating bone fixation, particularly screw implantation. In the present study, our aim was to improve implant stability in osteoporotic bone using a thermoresponsive hyaluronan hydrogel (HA-pNIPAM) to locally deliver the bisphosphonate zoledronic acid (ZOL) to prevent bone resorption and bone morphogenetic protein 2 (BMP2) to induce bone formation. Adult female Wistar rats (n = 36) were divided into 2 treatment groups: one group of SHAM-operated animals and another group that received an ovariectomy (OVX) to induce an osteoporotic state. All animals received a polyetheretherketone (PEEK) screw in the proximal tibia. In addition, subgroups of SHAM or OVX animals received either the HA-pNIPAM hydrogel without or with ZOL/BMP2, placed into the defect site prior to screw implantation. Periprosthetic bone and implant fixation were monitored using longitudinal in vivo microCT scanning post-operatively and at 3, 6, 9, 14, 20 and 28 days. Histological assessment was performed post-mortem. Our data showed that pure hydrogel has no impact of implant fixation The ZOL/BMP2-hydrogel significantly increased bone-implant contact and peri-implant bone fraction, primarily through reduced resorption. STATEMENT OF CLINICAL SIGNIFICANCE: Local delivery of ZOL and BMP2 using a biocompatible hydrogel improved implant stability in osteoporotic bone. This approach could constitute a potent alternative to systemic drug administration and may be useful in avoiding implant loosening in clinical settings.

Correlative montage parallel array cryo-tomography for in situ structural cell biology

Imaging large fields of view while preserving high-resolution structural information remains a challenge in low-dose cryo-electron tomography. Here we present robust tools for montage parallel array cryo-tomography (MPACT) tailored for vitrified specimens. The combination of correlative cryo-fluorescence microscopy, focused-ion-beam milling, substrate micropatterning, and MPACT supports studies that contextually define the three-dimensional architecture of cells. To further extend the flexibility of MPACT, tilt series may be processed in their entirety or as individual tiles suitable for sub-tomogram averaging, enabling efficient data processing and analysis.

Micro-porous PLGA/β-TCP/TPU scaffolds prepared by solvent-based 3D printing for bone tissue engineering purposes

The 3D printing process of fused deposition modelling is an attractive fabrication approach to create tissue-engineered bone substitutes to regenerate large mandibular bone defects, but often lacks desired surface porosity for enhanced protein adsorption and cell adhesion. Solvent-based printing leads to the spontaneous formation of micropores on the scaffold's surface upon solvent removal, without the need for further post processing. Our aim is to create and characterize porous scaffolds using a new formulation composed of mechanically stable poly(lactic-co-glycol acid) and osteoconductive β-tricalcium phosphate with and without the addition of elastic thermoplastic polyurethane prepared by solvent-based 3D-printing technique. Large-scale regenerative scaffolds can be 3D-printed with adequate fidelity and show porosity at multiple levels analysed via micro-computer tomography, scanning electron microscopy and N2 sorption. Superior mechanical properties compared to a commercially available calcium phosphate ink are demonstrated in compression and screw pull out tests. Biological assessments including cell activity assay and live-dead staining prove the scaffold's cytocompatibility. Osteoconductive properties are demonstrated by performing an osteogenic differentiation assay with primary human bone marrow mesenchymal stromal cells. We propose a versatile fabrication process to create porous 3D-printed scaffolds with adequate mechanical stability and osteoconductivity, both important characteristics for segmental mandibular bone reconstruction.

Rehabilitation post-COVID-19: cross-sectional observations using the Stanford Hall remote assessment tool

INTRODUCTION

The multisystem COVID-19 can cause prolonged symptoms requiring rehabilitation. This study describes the creation of a remote COVID-19 rehabilitation assessment tool to allow timely triage, assessment and management. It hypotheses those with post-COVID-19 syndrome, potentially without laboratory confirmation and irrespective of initial disease severity, will have significant rehabilitation needs.

METHODS

Cross-sectional study of consecutive patients referred by general practitioners (April-November 2020). Primary outcomes were presence/absence of anticipated sequelae. Binary logistic regression was used to test association between acute presentation and post-COVID-19 symptomatology.

RESULTS

155 patients (n=127 men, n=28 women, median age 39 years, median 13 weeks post-illness) were assessed using the tool. Acute symptoms were most commonly shortness of breath (SOB) (74.2%), fever (73.5%), fatigue (70.3%) and cough (64.5%); and post-acutely, SOB (76.7%), fatigue (70.3%), cough (57.4%) and anxiety/mood disturbance (39.4%). Individuals with a confirmed diagnosis of COVID-19 were 69% and 63% less likely to have anxiety/mood disturbance and pain, respectively, at 3 months.

CONCLUSIONS

Rehabilitation assessment should be offered to all patients suffering post-COVID-19 symptoms, not only those with laboratory confirmation and considered independently from acute illness severity. This tool offers a structure for a remote assessment. Post-COVID-19 programmes should include SOB, fatigue and mood disturbance management.

Surgical technique and comparison of autologous cancellous bone grafts from various donor sites in rats

Autologous cancellous bone graft is the gold standard in large bone defect repair. However, studies using autologous bone grafting in rats are rare. To determine the feasibility of autologous cancellous bone graft harvest from different anatomical donor sites (humerus, ilium, femur, tibia, and tail vertebrae) in rats and compare their suitability as donor sites, a total of 13 freshly euthanized rats were used to describe the surgical technique, determine the cancellous bone volume and microstructure, and compare the cancellous bone collected quantitatively and qualitatively. It was feasible to harvest cancellous bone grafts from all five anatomical sites with the humerus and tail being more surgically challenging. The microstructural analysis using micro-computed tomography showed a significantly lower bone volume fraction, bone mineral density, and trabecular thickness of the humerus and iliac crest compared to the femur, tibia, and tail vertebrae. The harvested weight and volume did not differ between the donor sites. All donor sites apart from the femur yielded primary osteogenic cells confirmed by the presence of alkaline phosphatase and Alizarin Red S stain. Bone samples from the iliac crest showed the most consistent outgrowth of osteoprogenitor cells. In conclusion, the tibia and iliac crest may be the most favorable donor sites considering the surgical approach. However, due to the differences in microstructure of the cancellous bone and the consistency of outgrowth of osteoprogenitor cells, the donor sites may have different healing properties, that need further investigation in an in vivo study.

Changing characteristics of post-COVID-19 syndrome: Cross-sectional findings from 458 consultations using the Stanford Hall remote rehabilitation assessment tool

BACKGROUND

In the UK, there have been multiple waves of COVID-19, with a five-tier alert system created to describe the transmission rate and appropriate restrictions. While acute mortality decreased, there continued to be a significant morbidity, with individuals suffering from persistent, life-restricting symptoms for months to years afterwards. A remote rehabilitation tool was created at the Defence Medical Rehabilitation Centre (DMRC) Stanford Hall to assess post-COVID-19 symptoms and their impact on the UK military.This study aims to understand changes in post-COVID-19 syndrome between wave 1 and wave 2, identify interactions between alert level and symptoms and investigate any predictive nature of acute symptoms for postacute symptomology in a young, physically active population.

METHODS

Cross-sectional study of 458 consecutive remote rehabilitation assessments performed at DMRC Stanford Hall between 2 April 2020 and 29 July 2021. Consultations were coded, anonymised, and statistical analysis was performed to determine associations between acute and postacute symptoms, and between symptoms, alert levels and waves.

RESULTS

435 assessments were eligible; 174 in wave 1 and 261 in wave 2. Post-COVID-19 syndrome prevalence reduced from 43% to 2% between the waves. Acutely, widespread pain was more prevalent in wave 2 (p<0.001). Postacutely, there was increased anxiety (p=0.10) in wave 1 and increased sleep disturbance (p<0.001), memory/concentration issues (p<0.001) and shortness of breath/cough (p=0.017) in wave 2. Increasing alert level was associated with increased postacute symptom prevalence (p=0.046), with sleep disturbance increasing at higher alert level (p=0.016). Acute symptoms, including fatigue, sleep disturbance and myalgia, were associated with multiple postacute symptoms.

CONCLUSIONS

This study reports the overall prevalence and symptom burden in the UK military in the first two waves of COVID-19. By reporting differences in COVID-19 in different waves and alert level, this study highlights the importance of careful assessment and contextual understanding of acute and postacute illnesses for individual management plans.

Standard in vitro evaluations of engineered bone substitutes are not sufficient to predict in vivo preclinical model outcomes

Understanding the optimal conditions required for bone healing can have a substantial impact to target the problem of non-unions and large bone defects. The combination of bioactive factors, regenerative progenitor cells and biomaterials to form a tissue engineered (TE) complex is a promising solution but translation to the clinic has been slow. We hypothesized the typical material testing algorithm used is insufficient and leads to materials being mischaracterized as promising. In the first part of this study, human bone marrow - derived mesenchymal stromal cells (hBM-MSCs) were embedded in three commonly used biomaterials (hyaluronic acid methacrylate, gelatin methacrylate and fibrin) and combined with relevant bioactive osteogenesis factors (dexamethasone microparticles and polyphosphate nanoparticles) to form a TE construct that underwent in vitro osteogenic differentiation for 28 days. Gene expression of relevant transcription factors and osteogenic markers, and von Kossa staining were performed. In the second and third part of this study, the same combination of TE constructs were implanted subcutaneously (cell containing) in T cell-deficient athymic Crl:NIH-Foxn1^rnu rats for 8 weeks or cell free in an immunocompetent New Zealand white rabbit calvarial model for 6 weeks, respectively. Osteogenic performance was investigated via MicroCT imaging and histology staining. The in vitro study showed enhanced upregulation of relevant genes and significant mineral deposition within the three biomaterials, generally considered as a positive result. Subcutaneous implantation indicates none to minor ectopic bone formation. No enhanced calvarial bone healing was detected in implanted biomaterials compared to the empty defect. The reasons for the poor correlation of in vitro and in vivo outcomes are unclear and needs further investigation. This study highlights the discrepancy between in vitro and in vivo outcomes, demonstrating that in vitro data should be interpreted with extreme caution. In vitro models with higher complexity are necessary to increase value for translational studies. STATEMENT OF SIGNIFICANCE: Preclinical testing of newly developed biomaterials is a crucial element of the development cycle. Despite this, there is still significant discrepancy between in vitro and in vivo test results. Within this study we investigate multiple combinations of materials and osteogenic stimulants and demonstrate a poor correlation between the in vitro and in vivo data. We propose rationale for why this may be the case and suggest a modified testing algorithm.

Virtual family physician care during COVID-19: a mixed methods study using health administrative data and qualitative interviews

BACKGROUND

The onset of the COVID-19 pandemic necessitated a rapid shift in primary health care from predominantly in-person to high volumes of virtual care. The pandemic afforded the opportunity to conduct a deep regional examination of virtual care by family physicians in London and Middlesex County, Ontario, Canada that would inform the foundation for virtual care in our region post-pandemic.

OBJECTIVES

(1) to determine volumes of in-person and virtual family physicians visits and characteristics of the family physicians and patients using them during the early COVID-19 pandemic; (2) to determine how virtual visit volumes changed over the pandemic, compared to in-person; and (3) to explore family physicians' experience in virtual visit adoption and implementation.

METHODS

We conducted a concurrent mixed-methods study of family physicians from March to October 2020. The quantitative component examined mean weekly number of total, in-person and virtual visits using health administrative data. Differences in outcomes according to physician and practice characteristics for pandemic periods were compared to pre-pandemic. The qualitative study employed Constructivist Grounded Theory, conducting semi-structured family physicians interviews; analyzing data iteratively using constant comparative analysis. We mapped themes from the qualitative analysis to quantitative findings.

RESULTS

Initial volumes of patients decreased, driven by fewer in-person visits. Virtual visit volumes increased dramatically; family physicians described using telephone almost entirely. Rural family physicians reported video connectivity issues. By early second wave, total family physician visit volume returned to pre-pandemic volumes. In-person visits increased substantially; family physicians reported this happened because previously scarce personal protective equipment became available. Patients seen during the pandemic were older, sicker, and more materially deprived.

CONCLUSION

These results can inform the future of virtual family physician care including the importance of continued virtual care compensation, the need for equitable family physician payment models, and the need to attend to equity for vulnerable patients. Given the move to virtual care was primarily a move to telephone care, the modality of care delivery that is acceptable to both family physicians and their patients must be considered.

Evaluating the effect of a scalable cancer-navigation program on total cost of care

4

Background: Cancer-patient navigation programs have been shown to reduce total cost of care while improving outcomes. Previous research has focused on navigation programs embedded within a single institution or a single network of practices. We explore whether an independent cancer-patient navigation program deployed in collaboration with a Medicare Advantage (MA) plan can demonstrate similar cost savings when deployed across a wide variety of practice settings in the state of New Jersey. Methods: We conducted a retrospective observational study to determine the per member per month (PMPM) total cost of care (TCOC) difference between cancer patients with and without a navigation intervention provided by Thyme Care, a technology-enabled virtual cancer-navigation platform. The team, staffed by both lay-health workers and nurses, was assigned members of a single MA plan’s population in NJ beginning on March 2, 2021. Patients with a cancer-specific ICD-10 code who received systemic antineoplastic therapy were eligible for the program. The navigation team coordinated care, addressed barriers to care, facilitated goals of care discussions, and conducted proactive and reactive symptom assessment. The cadence of the symptom assessment was determined by both patient and disease-specific criteria. Concerning responses were triaged to the patient’s oncology team the same day. The study period was from January 1, 2018 to June 13, 2022. The primary outcome was TCOC excluding part D drug spend. We compared TCOC for patients who received the intervention to a control group of eligible individuals that were matched using propensity scores derived from clinical and demographic covariates. We used a repeated measure generalized linear model to estimate the monthly effect of navigation on TCOC. Additionally, we conducted a monte-carlo sensitivity analysis to provide an upper and lower bound on the cost savings. Results: Of 4,172 eligible members, 662 were in the treatment group (across 25 community practices and 45 hospital based practices) and 3,510 were in the control group (across 58 community practices and 73 hospitals). The propensity matching resulted in 188 members in both the treatment and the control group (376 total). The mean TCOC declined $459 more PMPM for the navigated group compared to the non-navigated group. The sensitivity analysis suggested a plausible range of $209-708 PMPM savings in the intervention group. Conclusions: This is the first study to demonstrate that a cancer-navigation program can reduce overall costs when deployed in collaboration with a health plan across a wide geography and range of practice types.

Interleukin-1 receptor antagonist enhances the therapeutic efficacy of a low dose of rhBMP-2 in a weight-bearing rat femoral defect model

In the clinical treatment of fractures, rhBMP-2 administration is associated with a well-established profile of side-effects, including osteolysis and ectopic bone formation, which are driven by pro-inflammatory processes triggered by the use of high doses. Immunomodulatory strategies could minimize the incidence of side-effects by enabling the use of lower, and safer, rhBMP-2 doses. This study investigated whether interleukin-1 receptor antagonist (IL-1Ra) can enhance the therapeutic efficacy of a low dose of rhBMP-2 in a weight-bearing femoral fracture healing model. Exogenous IL-1Ra, in combination with rhBMP-2, was delivered using a collagen-hydroxyapatite scaffold (CHA) to attenuate IL-1β produced in response to fracture. Femoral defects were treated with CHA scaffolds alone, or loaded with IL-1Ra (2.5 µg), rhBMP-2 (1 µg), IL-1Ra (2.5 µg) in combination with rhBMP-2 (1 µg). Bone healing was assessed over 14 weeks in comparison to control groups, empty defect, and a higher dose of rhBMP-2 (5 µg), which were recently demonstrated to lead to non-union, and successful bridging of the defect, respectively. The combination of IL-1Ra and rhBMP-2 led to significantly faster early bone formation, at both week 4 and 6, compared to a low dose of rhBMP-2 alone. By 14 weeks, the combination of IL-1Ra and a rhBMP-2 promoted full bridging of femurs, which were 3-fold more mechanically reliable compared to the femurs treated with a low dose of rhBMP-2 alone. Taken together, this study demonstrates that IL-1Ra can significantly enhance femoral bone healing when used in combination with a low dose of rhBMP-2. STATEMENT OF SIGNIFICANCE: Enabling the use of lower and safer doses of rhBMP-2, a potent inducer of bone formation, is of clinical relevance in orthopaedic medicine. In this study, the immunomodulatory interleukin-1 receptor antagonist (IL-1Ra) was investigated for its capacity to enhance the therapeutic efficacy of rhBMP-2 when used at lower doses in a weight-bearing femoral fracture healing model. The combination of IL-1Ra and rhBMP-2 led to significantly faster early bone formation, and resulted in more mechanically reliable healed femurs, compared to a low dose of rhBMP-2 alone. This demonstrates for the first time in a rat long bone healing model that IL-1Ra can significantly enhance bone healing when used in combination with a low dose of rhBMP-2.

People-Powered Research and Experiential Learning: Unravelling Hidden Biodiversity

Globally, thousands of institutions house nearly three billion scientific collections offering unparallelled resources that contribute to both science and society. For herbaria alone - facilities housing dried plant collections - there are over 3,000 herbaria worldwide with an estimated 350 million specimens that have been collected over the past four centuries. Digitisation has greatly enhanced the use of herbarium data in scientific research, impacting diverse research areas, including biodiversity informatics, global climate change, analyses using next-generation sequencing technologies and many others. Despite the entrance of herbaria into a new era with enhanced scientific, educational and societal relevance, museum specimens remain underused. Natural history museums can enhance learning and engagement in science, particularly for school-age and undergraduate students. Here, we outline a novel approach of a natural history museum using touchscreen technology that formed part of an interactive kiosk in a temporary museum exhibit on biological specimens. We provide some preliminary analysis investigating the efficacy of the tool, based on the Zooniverse platform, in an exhibit environment to engage patrons in the collection of biological data. We conclude there is great potential in using crowd‐sourced science, coupled with online technology to unlock data and information from digital images of natural history specimens themselves. Sixty percent of the records generated by community scientists (citizen scientists) were of high enough quality to be utilised by researchers. All age groups produced valid, high quality data that could be used by researchers, including children (10 and under), teens and adults. Significantly, the paper outlines the implementation of experiential learning through an undergraduate mathematics course that focuses on projects with actual data to gain a deep, practical knowledge of the subject, including observations, the collection of data, analysis and problem solving. We here promote an intergenerational model including children, high school students, undergraduate students, early career scientists and senior scientists, combining experiential learning, museum patrons, researchers and data derived from natural history collections. Natural history museums with their dual remit of education and collections-based research can play a significant role in the field of community engagement and people-powered research. There also remains much to investigate on the use of interactive displays to help learners interpret and appreciate authentic research. We conclude with a brief insight into the next phase of our ongoing people-powered research activities developed and designed by high school students using the Zooniverse platform.

Family physician virtual care during COVID-19 in London-Middlesex, Ontario, Canada: a mixed methods exploration

Context: On March 14, 2020, the Ontario, Canada health insurance plan approved COVID-19 physician virtual billing codes; family physicians (FPs) rapidly adopted a new model of care. Virtual care may remain post-pandemic; however, its future should be informed by evidence that considers access and continuity. Objective: 1) to determine FP virtual visit volumes and patient characteristics and 2) to explore FPs' perspectives on virtual visit adoption and implementation. Study Design: Mixed methods: Secondary analysis of health administrative (HA) data and semi-structured qualitative interviews with FPs. Setting or Dataset: London and Middlesex County, Ontario, Canada. HA data through ICES, Ontario entity holding data. Population studied: FPs and their patients. Outcome Measures: Volumes of FP in-person and virtual visits during early pandemic; characteristics of patients receiving care; FPs' perspectives on adopting and delivering virtual care. Results: Overall visit volume dropped by 36% during first wave, recovered to pre-pandemic levels by October 2020. Sharp in-person visit drop of 73% and virtual visit uptake from 0.08% of total visits to 57% within two weeks of March 2020. FPs described this initial drop in volume as patients not seeking care and practices lacking PPE. The move to virtual care was largely to telephone visits. Patient characteristics compared to pre-pandemic, the proportion seeking care were older (46 vs 50 years), more vulnerable (38% vs 41%), and more multimorbidity (33% vs 41%). This was consistent with FP reports that healthier patients stayed away, routine care deferred, sicker patients needed to be seen. FPs believed most vulnerable patients had access to care but cautioned highly vulnerable such as those homeless did not have cell phone access or a safe place to receive calls. Rural FPs reported access issues because of lack of high-speed internet. FPs attributed success of virtual care to the continuity in relationships they had with patients that were established in person pre-pandemic. Conclusions: FPs moved rapidly to virtual care. FP offices remained open despite PPE concerns but overall volumes dropped initially. Vulnerable and sicker patients received care but FPs expressed concern for highly vulnerable and rural residents. FPs believed they could offer patient-centred care over the phone but indicated the importance of maintaining in-person care to build relationships.

Development and characterization of a predictive microCT-based non-union model in Fischer F344 rats

INTRODUCTION

Non-unions remain a clinical problem and are characterised by the failure to heal after a defined period of time. Current preclinical non-union models apply a wide variety of techniques to diminish intrinsic healing potential deviating from the clinical situation. The aim of this study was to develop and characterise a non-union model in rats using internal plate fixation without the need for additional healing insults, whereby bone healing can be longitudinally assessed using microCT. It was hypothesized that healing/non-unions can be accurately predicted at early time points by microCT.

MATERIALS AND METHODS

Female, skeletally mature Fischer F344 rats received a 2 mm or 1 mm femoral osteotomy, stabilized with either a 2 mm thick plate or a 1.25 mm thick plate. Healing was monitored by microCT over 14 weeks and histological analysis at euthanasia. The mechanical environment was characterised using finite element (FE) modelling and biomechanical testing.

RESULTS

The majority of animals receiving the 2 mm thick plate displayed poor healing responses in both the 2 mm and 1 mm defect size groups. Bone and cartilage formation were markedly improved using the 1.25 mm thick plate. MicroCT could accurately predict bone forming capacity at early time points (3-4 weeks).

CONCLUSIONS

The 2 mm thick plating system confers poor healing responses in female Fischer F344 rats, comparable to atrophic non-unions. By reducing plate thickness to increase interfragmentary strain within the defect site healing is improved, leading to borderline healing situations or increased abundance of cartilage tissue present in the defect site with ultimate failure to bridge the defect (hypertrophic non-union). Furthermore, microCT can reliably identify delayed/non-healing animals within 4 weeks, thereby allowing their selective targeting for the testing of novel, clinically relevant treatment strategies in different clinical situations aimed at restoring impaired bone healing.

747 THE DIAGNOSIS AND MANAGEMENT OF HYPERKALAEMIA IN MEDICAL AND ELDERLY CARE INPATIENTS AT A DISTRICT GENERAL HOSPITAL

Introduction

Severe hyperkalaemia is a dangerous and potentially life-threatening condition. Despite this knowledge, the incidence of hyperkalaemia in hospital inpatients remains high. On review of the acute management of hyperkalaemia at Croydon University Hospital, only 50% of medical and elderly care inpatients were managed correctly in line with hospital guidelines, and 50% of surveyed doctors did not feel confident managing acute hyperkalaemia—highlighting an urgent requirement for improvement. The project objectives were to improve management in line with hospital guidelines, overall prescription accuracy and the confidence of junior doctors in managing acute hyperkalaemia.

Methods

Two PDSA cycles; cycle one involved teaching sessions to doctors and the creation and circulation of information posters. Cycle two involved the development and implementation of a new electronic order prescription set for the management of acute hyperkalaemia.

Results

Post-intervention results showed an improvement in the correct management of hyperkalaemia from 50% to 80%. Prescription accuracy improved from 90% to 100%. Doctors reported an improvement in their overall confidence from 50% to 64%. Sub-group analysis identified no post-intervention improvement in the correct management of hyperkalaemia in care of the elderly (COTE, &gt;80 years) patients. COTE patients were also less likely to be managed correctly (45% vs 57%) and to have accurate prescriptions (71% vs 100%). However, prescription accuracy did improve in the COTE group (50% to 100%).

Conclusion

This project achieved its initial objectives. However, COTE patients were less likely to be managed correctly. This may be secondary to being more complex patients, having multiple co-morbidities or significant polypharmacy, which may further contribute to hyperkalaemia. Doctors may feel less confident suspending or modifying medications in these cases and seek input from specialist teams prior to doing so. Future interventions will focus on delivering teaching sessions on hyperkalaemia in complex cases to improve confidence and understanding.

Clinically relevant preclinical animal models for testing novel cranio-maxillofacial bone 3D-printed biomaterials

Bone tissue engineering is a rapidly developing field with potential for the regeneration of craniomaxillofacial (CMF) bones, with 3D printing being a suitable fabrication tool for patient‐specific implants. The CMF region includes a variety of different bones with distinct functions. The clinical implementation of tissue engineering concepts is currently poor, likely due to multiple reasons including the complexity of the CMF anatomy and biology, and the limited relevance of the currently used preclinical models. The ‘recapitulation of a human disease’ is a core requisite of preclinical animal models, but this aspect is often neglected, with a vast majority of studies failing to identify the specific clinical indication they are targeting and/or the rationale for choosing one animal model over another. Currently, there are no suitable guidelines that propose the most appropriate animal model to address a specific CMF pathology and no standards are established to test the efficacy of biomaterials or tissue engineered constructs in the CMF field. This review reports the current clinical scenario of CMF reconstruction, then discusses the numerous limitations of currently used preclinical animal models employed for validating 3D‐printed tissue engineered constructs and the need to reduce animal work that does not address a specific clinical question. We will highlight critical research aspects to consider, to pave a clinically driven path for the development of new tissue engineered materials for CMF reconstruction.

NHS Health Check programme: a rapid review update

OBJECTIVE

To update a rapid review published in 2017, which evaluated the NHS Health Check programme.

METHODS

An enlarged body of evidence was used to readdress six research objectives from a rapid review published in 2017, relating to the uptake, patient experiences and effectiveness of the NHS Health Check programme. Data sources included MEDLINE, PubMed, Embase, Health Management Information Consortium (HMIC), Cumulative Index of Nursing and Allied Health Literature (CINAHL), Global Health, PsycINFO, the Cochrane Library, NHS Evidence, Google Scholar, Google, ClinicalTrials.gov and the ISRCTN registry, Web of Science, Science Citation Index, The Cochrane Library, NHS Evidence, OpenGrey and hand searching article reference lists. These searches identified records from between January 1996 and December 2019. Screening, data extraction and quality appraisal using the Critical Appraisals Skills Programme checklists were performed in duplicate. Grading of Recommendations Assessment, Development and Evaluations was implemented. Data were synthesised narratively.

RESULTS

697 studies were identified, and 29 new studies included in the review update. The number of published studies on the uptake, patient experiences and effectiveness of the NHS Health Check programme has increased by 43% since the rapid review published in 2017. However, findings from the original review remain largely unchanged. NHS Health Checks led to an overall increase in the detection of raised risk factors and morbidities including diabetes mellitus, hypertension, raised blood pressure, cholesterol and chronic kidney disease. Individuals most likely to attend the NHS Health Check programme included women, persons aged ≥60 years and those from more socioeconomically advantaged backgrounds. Opportunistic invitations increased uptake among men, younger persons and those with a higher deprivation level.

CONCLUSIONS

Although results are inconsistent between studies, the NHS Health Check programme is associated with increased detection of heightened cardiovascular disease risk factors and diagnoses. Uptake varied between population subgroups. Opportunistic invitations may increase uptake.

Community investment interventions as a means for decarceration: A scoping review

There is growing support to reverse mass incarceration in the United States, especially in the wake of the COVID-19 pandemic. Little is known about what types and scale of community investments are most effective to support mass decarceration. Using a public health prevention framework, we conducted a scoping review to examine community-based programs that reduced criminal legal involvement. We searched PubMed, Embase and three EBSCO databases from 1990 through September 2019 for all experimental or quasi-experimental studies testing interventions pertaining to education, housing, healthcare, employment, or social support services and how they affected an individual's criminal legal outcomes. Our review identified 53 studies that demonstrated the efficacy of early childhood educational interventions and nurse-family partnership programs, post-secondary education for incarcerated students, navigation programs linking incarcerated people to community resources, and peer support upon release to reduce criminal legal system exposure. In concert with legislative action to end mass incarceration, additional research is needed to test interventions designed to achieve mass decarceration which cross multiple domains, interrogate community-level impacts and ascertain long-term outcomes.

Recommendations on pregnancy, childbirth and aftercare in epidermolysis bullosa: a consensus-based guideline

Linked Comment:A.W. Lucky and E. Pope. Br J Dermatol 2022; 186:602–603.

Plain language summary available online

Titanium Wear Particles Exacerbate S. epidermidis-Induced Implant-Related Osteolysis and Decrease Efficacy of Antibiotic Therapy

Total joint arthroplasty (TJA) surgeries are common orthopedic procedures, but bacterial infection remains a concern. The aim of this study was to assess interactions between wear particles (WPs) and immune cells in vitro and to investigate if WPs affect the severity, or response to antibiotic therapy, of a Staphylococcus epidermidis orthopedic device-related infection (ODRI) in a rodent model. Biofilms grown on WPs were challenged with rifampin and cefazolin (100 µg/mL) to determine antibiotic efficacy. Neutrophils or peripheral blood mononuclear cells (PBMCs) were incubated with or without S. epidermidis and WPs, and myeloperoxidase (MPO) and cytokine release were analyzed, respectively. In the ODRI rodent model, rats (n = 36) had a sterile or S. epidermidis-inoculated screw implanted in the presence or absence of WPs, and a subgroup was treated with antibiotics. Bone changes were monitored using microCT scanning. The presence of WPs decreased antibiotic efficacy against biofilm-resident bacteria and promoted MPO and pro-inflammatory cytokine production in vitro. WPs exacerbated osteolytic responses to S. epidermidis infection and markedly reduced antibiotic efficacy in vivo. Overall, this work shows that the presence of titanium WPs reduces antibiotic efficacy in vitro and in vivo, induces proinflammatory cytokine release, and exacerbates S. epidermidis-induced osteolysis.

Challenges adopting next-generation sequencing in community oncology practice

PURPOSE OF REVIEW

We are in an exhilarating time in which innovations exist to help reduce the impact of cancer for individuals, practitioners and society. Innovative tools in cancer genomics can optimize decision-making concerning appropriate drugs (alone or in combination) to cure or prolong life. The genomic characterization of tumours can also give direction to the development of novel drugs. Next-generation tumour sequencing is increasingly becoming an essential part of clinical decision-making, and, as such, will require appropriate coordination for effective adoption and delivery.

RECENT FINDINGS

There are several challenges that will need to be addressed if we are to facilitate cancer genomics as part of routine community oncology practice. Recent research into this novel testing paradigm has demonstrated the barriers are at the individual level, while others are at the institution and societal levels.

SUMMARY

This article, based on the authors' experience in community oncology practice and summary of literature, describes these challenges so strategies can be developed to address these challenges to improve patient outcomes.

Fracture biomechanics influence local and systemic immune responses in a murine fracture-related infection model

Biomechanical stability plays an important role in fracture healing, with unstable fixation being associated with healing disturbances. A lack of stability is also considered a risk factor for fracture-related infection (FRI), although confirmatory studies and an understanding of the underlying mechanisms are lacking. In the present study, we investigate whether biomechanical (in)stability can lead to altered immune responses in mice under sterile or experimentally inoculated conditions. In non-inoculated C57BL/6 mice, instability resulted in an early increase of inflammatory markers such as granulocyte-colony stimulating factor (G-CSF), keratinocyte chemoattractant (KC) and interleukin (IL)-6 within the bone. When inoculated with Staphylococcus epidermidis, instability resulted in a further significant increase in G-CSF, IL-6 and KC in bone tissue. Staphylococcus aureus infection led to rapid osteolysis and instability in all animals and was not further studied. Gene expression measurements also showed significant upregulation in CCL2 and G-CSF in these mice. IL-17A was found to be upregulated in all S. epidermidis infected mice, with higher systemic IL-17A cell responses in mice that cleared the infection, which was found to be produced by CD4+ and γδ+ T cells in the bone marrow. IL-17A knock-out (KO) mice displayed a trend of delayed clearance of infection (P=0.22, Fisher’s exact test) and an increase in interferon (IFN)-γ production. Biomechanical instability leads to a more pronounced local inflammatory response, which is exaggerated by bacterial infection. This study provides insights into long-held beliefs that biomechanics are crucial not only for fracture healing, but also for control of infection.

Summary: Physical movement between bone fragments after a fracture influence healing, and are shown here, for the first time, to influence immune responses and infection.

The non-steroidal anti-inflammatory drug carprofen negatively impacts new bone formation and antibiotic efficacy in a rat model of orthopaedic-device-related infection

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used for pain management during recovery from orthopaedic surgery. NSAID use is associated with increased risk of bone healing complications but it is currently unknown whether NSAIDs increase the risk of developing an orthopaedic-device-related infection (ODRI) and/or affects its response to antibiotic therapy. The present study aimed to determine if administration of the NSAID carprofen [a preferential cyclooxygenase-2 (COX-2) inhibitor] negatively affected Staphylococcus epidermidis (S. epidermidis) bone infection, or its subsequent treatment with antibiotics, in a rodent ODRI model. Sterile or S. epidermidis-contaminated screws (~ 1.5 x 10⁶ CFU) were implanted into the proximal tibia of skeletally mature female Wistar rats, in the absence or presence of daily carprofen administration. A subset of infected animals received antibiotics (rifampicin plus cefazolin) from day 7 to 21, to determine if carprofen affected antibiotic efficacy. Bone changes were monitored using in vivo µCT scanning and histological analysis. The risk of developing an infection with carprofen administration was assessed in separate animals at day 9 using a screw contaminated with 10² CFU S. epidermidis. Quantitative bacteriological analysis assessed bacterial load at euthanasia. In the 28-day antibiotic treatment study, carprofen reduced osteolysis but markedly diminished reparative bone formation, although total bacterial load was not affected at euthanasia. Antibiotic efficacy was negatively affected by carprofen (carprofen: 8/8 infected; control: 2/9 infected). Finally, carprofen increased bacterial load and diminished bone formation following reduced S. epidermidis inoculum (10² CFU) at day 9. This study suggests that NSAIDs with COX-2 selectivity reduce antibiotic efficacy and diminish reparative responses to S. epidermidis ODRI.

559 IDENTIFYING PATIENTS WITH MOOD DISORDER FOLLOWING ADMISSION WITH HIP FRACTURE WITH A VIEW TO STARTING TREATMENT & PROVIDE ADVICE

Introduction

The signs of depression in the elderly often go unnoticed. The MDT at RSCH observed that low mood could negatively impact on patient’s recovery, affecting pain thresholds and leading to poor engagement with rehabilitation. Proactive identification and management of mood disorder is an important part of CGA, but not routinely performed. The aim of this QI project is to improve identification and management of mood disorder in patients over 65 years admitted to RSCH with hip fractures by introducing a standardised assessment tool to guide appropriate interventions.

Method

Notes of patients with hip fracture admitted over a four-month period were retrospectively reviewed to establish if patients were screened for low mood. A mood screening tool, Cornell Score, was chosen and implemented by OT’s and junior doctors over a four-month period. Those identified with depression or probable depression were issued verbal advice, an information leaflet and follow-up arranged.

Results

Ninety-eight patients were included in the retrospective cohort; There was no indication that mood was considered or assessed at any point during admission. During the four-month prospective period, 86 patients (96%) were screened for low mood; 9% had major depression and 16% probable depression. Feedback from our occupational therapists and doctors was positive, with the tool being easy to use in patients with or without cognitive impairment. Much of the assessment could be incorporated into initial assessment or in gaining collateral history. Anecdotally, considering patients psychological well-being had a positive impact on inpatient therapy sessions guided the MDT in supporting the patient appropriately.

Conclusion

Implementation of a standardised and validated mood screening tool enabled us to identify that a quarter (25%) of the patients had, or probably had depression. This allowed us to intervene with simple measures such as verbal advice and an information leaflet and consider pharmacological intervention where appropriate.

An Exopolysaccharide Produced by Bifidobacterium longum 35624® Inhibits Osteoclast Formation via a TLR2-Dependent Mechanism

The probiotic Bifidobacterium longum subsp. longum 35624® (B. longum 35624®), with its surface exopolysaccharide (EPS624), has previously been demonstrated to induce immunoregulatory responses in the host and may, therefore, be a novel approach to prevent bone loss in inflammatory conditions such as post-menopausal osteoporosis (PMO). The aim of this study was to investigate the effect of EPS624 on osteoclast and osteoblast differentiation and to assess the potential of B. longum 35624® to prevent bone loss in vivo. In vitro cell assays were used to assess the impact of EPS624 on osteoclast and osteoblast differentiation. The potential of two probiotic B. longum 35624® strains, including an EPS-deficient strain, for preventing ovariectomy (Ovx)-induced bone loss was assessed in a murine model. EPS624 prevented osteoclast formation from murine bone marrow precursors under both normal and TNFα-induced inflammatory conditions and modestly increased mineralized matrix deposition in osteogenic cell cultures. However, in the presence of an anti-TLR2 blocking antibody, or in MyD88^-/- osteoclast precursors, the inhibitory effect of EPS624 on osteoclast formation was diminished or completely prevented, respectively. Moreover, EPS624 induced IL-10 production in osteoclast precursors in a TLR2-dependent manner, although IL-10 was dispensable in the EPS624-mediated inhibition of osteoclast formation. In addition, EPS624-producing B. longum 35624® partially prevented bone loss in Ovx mice when administered by oral gavage. This study introduced EPS624 as a potential anti-resorptive therapy, although optimal in vivo delivery of the probiotic strain for treating low-grade inflammatory diseases such as PMO remains to be determined.

Gut microbial-derived short-chain fatty acids and bone: a potential role in fracture healing

Bone healing complications such as delayed healing or non-union affect 5-10 % of patients with a long-bone fracture and lead to reduced quality of life and increased health-care costs. The gut microbiota and the metabolites they produce, mainly short-chain fatty acids (SCFAs), have been shown to impact nearly all organs of the human body including bone. SCFAs show broad activity in positively influencing bone healing outcomes either by acting directly on cell types involved in fracture healing, such as osteoblasts, osteoclasts, chondrocytes and fibroblasts, or indirectly, by shaping an appropriate anti-inflammatory and immune regulatory response. Due to the ability of SCFAs to influence osteoblast and osteoclast differentiation, SCFAs may also affect the integration of orthopaedic implants in bone. In addition, SCFA-derivatives have already been used in a variety of tissue engineering constructs to reduce inflammation and induce bone tissue production. The present review summarises the current knowledge on the role of the gut microbiota, in particular through the action of SCFAs, in the individual stages of bone healing and provides insights into how SCFAs may be utilised in a manner beneficial for fracture healing and surgical reconstruction.

Impact of low bone mass and antiresorptive therapy on antibiotic efficacy in a rat model of orthopedic device-related infection

A significant proportion of orthopedic devices are implanted in osteoporotic patients, but it is currently unclear how estrogen deficiency and/or exposure to antiresorptive bisphosphonates (BPs) influence orthopedic device-related infection (ODRI), or response to therapy. The aim of this study is to characterize the bone changes resulting from Staphylococcus epidermidis infection in a rodent ODRI model and to determine if ovariectomy (OVX) or BP treatment influences the infection or the success of antibiotic therapy. A sterile or S. epidermidis-contaminated screw was implanted into the proximal tibia of skeletally mature female Wistar rats (n = 6-9 per group). Bone changes were monitored over 28 days using in vivo micro-computed tomography scanning. OVX was performed 12 weeks before screw implantation. The BP zoledronic acid (ZOL) was administered 4 days before screw insertion. A combination antibiotic regimen (rifampin plus cefazolin) was administered from Days 7-21. In skeletally healthy animals, S. epidermidis induced marked changes in bone, with peak osteolysis occurring at Day 9 and woven bone deposition and periosteal mineralization from Day 14 onwards. Antibiotic therapy cleared the infection in the majority of animals (2/9 infected) but did not affect bone responses. OVX did not affect the pattern of infection-induced changes in bone, nor bacterial load, but reduced antibiotic efficacy (5/9 infected). ZOL treatment did not protect from osteolysis in OVX animals, or further affect antibiotic efficacy (5/9 infected) but did significantly increase the bacterial load. This study suggests that both BPs and OVX can influence host responses to bone infections involving S. epidermidis.

Non-viral Gene Delivery of Interleukin-1 Receptor Antagonist Using Collagen-Hydroxyapatite Scaffold Protects Rat BM-MSCs From IL-1β-Mediated Inhibition of Osteogenesis

Although most bone fractures typically heal without complications, a small proportion of patients (≤10%) experience delayed healing or potential progression to non-union. Interleukin-1 (IL-1β) plays a crucial role in fracture healing as an early driver of inflammation. However, the effects of IL-1β can impede the healing process if they persist long after the establishment of a fracture hematoma, making it a promising target for novel therapies. Accordingly, the overall objective of this study was to develop a novel gene-based therapy that mitigates the negative effects of IL-1β-driven inflammation while providing a structural template for new bone formation. A collagen-hydroxyapatite scaffold (CHA) was used as a platform for the delivery of nanoparticles composed of pDNA, encoding for IL-1 receptor antagonist (IL-1Ra), complexed to the robust non-viral gene delivery vector, polyethyleneimine (PEI). Utilizing pDNA encoding for Gaussia luciferase and GFP as reporter genes, we found that PEI-pDNA nanoparticles induced a transient gene expression profile in rat bone marrow-derived mesenchymal stromal cells (BM-MSCs), with a transfection efficiency of 14.8 ± 1.8% in 2D. BM-MSC viability was significantly affected by PEI-pDNA nanoparticles as evaluated using CellTiter Blue; however, after 10 days in culture this effect was negligible. Transfection with PEI-pIL-1Ra nanoparticles led to functional IL-1Ra production, capable of antagonizing IL-1β-induced expression of secreted embryonic alkaline phosphatase from HEK-Blue-IL-1β reporter cells. Sustained treatment with IL-1β (0.1, 1, and 10 ng/ml) had a dose-dependent negative effect on BM-MSC osteogenesis, both in terms of gene expression (Alpl and Ibsp) and calcium deposition. BM-MSCs transfected with PEI-IL-1Ra nanoparticles were found to be capable of overcoming the inhibitory effects of sustained IL-1β (1 ng/ml) treatments on in vitro osteogenesis. Ultimately, IL-1Ra gene-activated CHA scaffolds supported mineralization of BM-MSCs under chronic inflammatory conditions in vitro, demonstrating potential for future therapeutic applications in vivo.

Using e-cigarettes for smoking cessation: evaluation of a pilot project in the North West of England

AIMS

E-cigarettes have been advocated as an effective smoking cessation intervention, with evidence indicating that they are substantially less harmful than conventional cigarettes. As a result, a pilot to encourage people to swap from conventional cigarettes to e-cigarettes was conducted in 2018 in a socially deprived area in the North West of England. This evaluation highlights the key findings from the pilot.

METHODS

An analysis of secondary data at 4 weeks (n = 1022) was undertaken to predict those who used solely used e-cigarettes (i.e. had quit tobacco, as confirmed by a carbon monoxide test, CO < 10 ppm) from baseline characteristics, using chi-square tests and logistic regression. Baseline data were demographics, smoking levels and service provider type.

RESULTS

Of the 1022 participants who engaged with the pilot 614 were still engaged at 4 weeks, of whom 62% had quit; quitting was more likely in younger participants (aged 18-24) and less likely in those who were sick and disabled. Of those who still smoked tobacco at week 4 (n = 226), smoking had reduced from a baseline of 19.1 cigarettes/day to 8.7. Overall, 37% (381) of those initially enrolled were confirmed to be using an e-cigarette on its own at follow-up. Successful quit was associated with occupation (unemployed, 33% vs intermediate, 47%, p = .023) and residing in the less deprived quintiles of deprivation (50% vs 34% in the most deprived quintile, p = .016).

CONCLUSIONS

Making the conservative assumption that all those not in contact at 4 weeks were still smoking tobacco, for every five people entering the scheme, three people stayed on the programme and reduced their cigarette smoking and one person cut out tobacco altogether. E-cigarettes appear to be an effective nicotine replacement therapy; however, further research is required to determine whether e-cigarette users are more likely to reduce their overall nicotine consumption in the longer term.

Current Concepts of Osteomyelitis: From Pathologic Mechanisms to Advanced Research Methods

Osteomyelitis is an inflammation of the bone and bone marrow that is most commonly caused by a Staphylococcus aureus infection. Much of our understanding of the underlying pathophysiology of osteomyelitis, from the perspective of both host and pathogen, has been revised in recent years, with notable discoveries including the role played by osteocytes in the recruitment of immune cells, the invasion and persistence of S. aureus in submicron channels of cortical bone, and the diagnostic role of polymorphonuclear cells in implant-associated osteomyelitis. Advanced in vitro cell culture models, such as ex vivo culture models or organoids, have also been developed over the past decade, and have become widespread in many fields, including infectious diseases. These models better mimic the in vivo environment, allow the use of human cells, and can reduce our reliance on animals in osteomyelitis research. In this review, we provide an overview of the main pathologic concepts in osteomyelitis, with a focus on the new discoveries in recent years. Furthermore, we outline the value of modern in vitro cell culture techniques, with a focus on their current application to infectious diseases and osteomyelitis in particular.

Humoral Factors From Musculoskeletal Polytrauma Patients Impair Antibacterial Responses Of Neutrophils In vitro

Polytrauma is associated with increased risk of sepsis, but the risk for implant infection is less clear. Neutrophil antibacterial responses are significantly reduced in polytrauma patients (n= 9, ISS≥15) for at least 5 days compared to healthy controls. Reduced neutrophil activity could influence implant infection in addition to sepsis.

Harmonizing analytical chemistry and clinical epidemiology for human biomonitoring studies. A case-study of plastic product chemicals in urine

There is an interdisciplinary interface between analytical chemistry and epidemiology studies with respect to the design, execution, and analysis of environmental epidemiology cohorts and studies. Extracting meaningful results linking chemical exposure to human health outcomes begins at study design and spans the entire workflow. Here we discuss analytical experimental design from an exposure science perspective, and propose a reporting checklist for the design of human biomonitoring studies. We explain key analytical chemistry concepts of blanks and limits of reporting and present a case series of plastic product chemical exposure in prenatal urine specimens from the Barwon Infant Study.

Snus: a compelling harm reduction alternative to cigarettes

Snus is an oral smokeless tobacco product which is usually placed behind the upper lip, either in a loose form or in portioned sachets, and is primarily used in Sweden and Norway. The purpose of this review is to examine the reported effects of snus use in relation to specified health effects, namely lung cancer, cardiovascular disease, pancreatic cancer, diabetes, oral cancer and non-neoplastic oral disease. The review also examines the harm reduction potential of snus as an alternative to cigarettes by comparing the prevalence of snus use and cigarette smoking, and the reported incidence of tobacco-related diseases across European Union countries. The scientific literature generally indicates that the use of snus is not a significant risk factor for developing lung cancer, cardiovascular disease, pancreatic cancer or oral cancer. Studies investigating snus use and diabetes have reported that high consumption of snus (estimated as being four or more cans per week) may be associated with a higher risk of developing diabetes or components of metabolic syndrome; however, overall results are not conclusive. Snus use is associated with the presence of non-neoplastic oral mucosal lesions which are reported to heal rapidly once use has stopped. The most recent Eurobarometer data from 2017 reported that Sweden had the lowest prevalence of daily cigarette use in the European Union at 5% whilst daily "oral tobacco" use was reported to be 20%. European data published by the World Health Organisation in 2018 indicated that Sweden had the lowest rate of tobacco-related mortality and the lowest incidence of male lung cancer. Overall, prevalence statistics and epidemiological data indicate that the use of snus confers a significant harm reduction benefit which is reflected in the comparatively low levels of tobacco-related disease in Sweden when compared with the rest of Europe. The available scientific data, including long-term population studies conducted by independent bodies, demonstrates that the health risks associated with snus are considerably lower than those associated with cigarette smoking.

Nursing teamwork in the care of older people: A mixed methods study

Healthcare is increasingly complex and requires the ability to adapt to changing demands. Teamwork is essential to delivering high quality care and is central to nursing. The aims of this study were to identify the processes that underpin nursing teamwork and how these affect the care of older people, identify the relationship between perceived teamwork and perceived quality of care, and explore in depth the experience of working in nursing teams. The study was carried out in three older people's wards in a London teaching hospital. Nurses and healthcare assistants completed questionnaires (n = 65) on known dynamics of teamwork (using the Nursing Teamwork Survey) together with ratings of organisational quality (using an adapted AHRQ HSPS scale). A sample (n = 22; 34%) was then interviewed about their perceptions of care, teamwork and how good outcomes are delivered in everyday work. Results showed that many care difficulties were routinely encountered, and confirmed the importance of teamwork (e.g. shared mental models of tasks and team roles and responsibilities, supported by leadership) in adapting to challenges. Perceived quality of teamwork was positively related to perceived quality of care. Work system variability and the external environment influenced teamwork, and confirmed the importance of team adaptive capacity. The CARE model shows the centrality of teamwork in adapting to variable demand and capacity to deliver care processes, and the influence of broader system factors on teamworking.

Development of bone seeker-functionalised microspheres as a targeted local antibiotic delivery system for bone infections

Objective

Bone infections are challenging to treat because of limited capability of systemic antibiotics to accumulate at the bone site. To enhance therapeutic action, systemic treatments are commonly combined with local antibiotic-loaded materials. Nevertheless, available drug carriers have undesirable properties, including inappropriate antibiotic release profiles and nonbiodegradability. To alleviate such limitations, we aim to develop a drug delivery system (DDS) for local administration that can interact strongly with bone mineral, releasing antibiotics at the infected bone site.

Methods

Biodegradable polyesters (poly (ε-caprolactone) or poly (D,l-lactic acid)) were selected to fabricate antibiotic-loaded microspheres by oil in water emulsion. Antibiotic release and antimicrobial effects on Staphylococcus aureus were assessed by zone of inhibition measurements. Microsphere bone affinity was increased by functionalising the bisphosphonate drug alendronate to the microsphere surface using carbodiimide chemistry. Effect of bone targeting microspheres on bone homeostasis was tested by looking at the resorption potential of osteoclasts exposed to the developed microspheres.

Results

In vitro, the antibiotic release profile from the microspheres was shown to be dependent on the polymer used and the microsphere preparation method. Mineral binding assays revealed that microsphere surface modification with alendronate significantly enhanced interaction with bone-like materials. Additionally, alendronate functionalised microspheres did not differentially affect osteoclast mineral resorption in vitro, compared with nonfunctionalised microspheres.

Conclusion

We report the development and characterisation of a DDS which can release antibiotics in a sustained manner. Surface-grafted alendronate groups enhanced bone affinity of the microsphere construct, resulting in a bone targeting DDS.

The Translational Potential of this Article

The DDS presented can be loaded with hydrophobic antibiotics, representing a potential, versatile and biodegradable candidate to locally treat bone infection.

Identification of the Identical Human Mutation in ACVR1 in 2 Cats With Fibrodysplasia Ossificans Progressiva

Two domestic shorthair cats, 1 intact female and 1 intact male, presented with progressive limb lameness and digital deformities at 4 and 6 months of age. Stiffness and swelling of the distal thoracic and pelvic limb joints progressed to involve hip and shoulder joints, resulting in reduced mobility. Radiographs in both cats and computed tomography of the male cat revealed ankylosing, polyarticular deposits of extracortical heterotopic bone spanning multiple axial and appendicular joints, extending into adjacent musculotendinous tissues. All findings supported fibrodysplasia ossificans progressiva (FOP), a disorder characterized by toe malformations and progressive heterotopic ossification in humans. In both cats, molecular analyses revealed the same heterozygous mutation in the activin A receptor type I (ACVR1) gene that occurs in humans with FOP. Several reports of heterotopic ossification in cats exist, but this is the first one to identify clinical FOP in 2 cats with the identical mutation that occurs in >95% of humans with FOP.

Physical and ecological effects of rehabilitating the geothermally influenced Waikite Wetland, New Zealand

Pressure to optimise land use and to maximise the economic viability of land has had a detrimental impact on wetlands worldwide. Rehabilitating wetlands has been identified by resource managers as increasingly important to enhance environmental values and restore ecosystem functions that may have been lost through developments effecting wetlands. This paper investigates rehabilitating a geothermally influenced wetland that had been drained and used for grazing stock. The Waikite Wetland (New Zealand) is a relatively unique wetland because the primary water source to the wetland has a significant geothermal water component. This results in the area hosting populations of rare flora and fauna that are significant to New Zealand. A range of management actions that included diverting a geothermal stream back into the wetland, blocking drains, pest control, weed control, native plantings, fencing and building a weir to increase water levels were used to rehabilitate the wetland. This was done to promote thermotolerant vegetation growth, restore wetland water levels and minimise pest plant species re-establishing while minimising the effects on geothermal surface features and allowing indigenous wetland vegetation to re-establish. Physical, chemical and vegetation monitoring show that management actions have increased thermotolerant vegetation growth in the wetland while having a small potential impact on geothermal discharges into the wetland. Increasing the water level in the wetland appears to be helping control plant pest species close to the weir, but has also made sensitive vegetation growing close to the waterways more susceptible to flooding caused by high-intensity rainfall events.

Personality and prescription drug use/misuse among first year undergraduates

Emerging adults (18-25 year olds) endorse the highest rates of prescription drug misuse. Attending college or university may confer additional risk. Previous research suggests that personality is an important predictor of many addictive behaviours. Four traits have been consistently implicated: anxiety sensitivity, hopelessness, sensation seeking, and impulsivity. Published studies on personality as a predictor of prescription drug abuse are limited, however, by a primary focus on overall prescription drug use, inconsistent operationalisation of misuse, and failure to control for alcohol use. Sample sizes have been small and non-specific. We sought to better understand how personality predicted the overall use, the medically-sanctioned use, and the misuse of prescription sedatives/tranquilizers, opioids, and stimulants. A large (N = 1755) sample of first year Canadian undergraduate students (mean age = 18.6 years; 68.9% female) was used. We predicted that: anxiety sensitivity would be related to sedatives/tranquilizers, hopelessness to opioids, sensation seeking to stimulants, and impulsivity to all three. Save for the impulsivity to opioid use path, predictions were fully supported in our "any use" model. For medically-sanctioned use: anxiety sensitivity predicted sedative/tranquilizers, hopelessness predicted opioids, and impulsivity predicted stimulants. For misuse: anxiety sensitivity (marginally) predicted sedatives/tranquilizers, sensation seeking predicted stimulants, and impulsivity predicted all three. Our models support using personality-matched interventions. Specifically, results suggest targeting anxiety sensitivity for sedative/tranquilizer misuse, sensation seeking for stimulant misuse, and impulsivity for unconstrained prescription drug misuse. Interventions with early coping skills that pertain to all four traits might be useful for preventing prescription drug uptake and later misuse.