Successful lung transplantation in genetic methionyl-tRNA synthetase-related alveolar proteinosis/lung fibrosis without recurrence under methionine supplementation: Medium-term outcome in 4 cases.

Pulmonary alveolar proteinosis (PAP) results from the accumulation of lipoproteinaceous material in the alveoli and alveolar macrophages, and can be associated with pulmonary fibrosis, with a need for lung transplantation (LTx). Causes of PAP are autoimmune (90%-95%), secondary (5%), or hereditary (<1%). Patients with hereditary PAP are generally not considered for isolated LTx, due to the high probability of recurrence after LTx, and only a challenging scenario with sequential LTx followed by hematopoietic stem cell transplantation (HSCT) was reported as successful. Recently, a new genetic cause of PAP linked to mutations in the methionyl-tRNA synthetase (MARS) gene has been reported, with a highly variable clinical presentation. Because clinical correction of the defective MARS activity with methionine supplementation has been reported in nontransplanted children, we reassessed the feasibility of LTx for candidates with MARS-related PAP/fibrosis. We report 3 cases of LTx performed for MARS-related pulmonary alveolar proteinosis-pulmonary fibrosis without recurrence under methionine supplementation, whereas another fourth case transplanted without supplementation had fatal PAP recurrence. These results suggest the effectiveness of methionine in correcting defective MARS activity and also looking for this very rare diagnosis in case of unclassified PAP/fibrosis. It argues for not excluding the feasibility of isolated LTx in patients with MARS mutation.

Acute respiratory failure due to pulmonary exacerbation in children with cystic fibrosis admitted in a pediatric intensive care unit: outcomes and factors associated with mortality.

BACKGROUND: Children with advanced pulmonary disease due to cystic fibrosis (CF) are at risk of acute respiratory failure due to pulmonary exacerbations leading to their admission to pediatric intensive care units (PICU). The objectives of this study were to determine short and medium-term outcomes of children with CF admitted to PICU for acute respiratory failure due to pulmonary exacerbation and to identify prognosis factors. METHODS: This retrospective monocentric study included patients less than 18 years old admitted to the PICU of a French university hospital between 2000 and 2020. Cox proportional hazard regression methods were used to determine prognosis factors of mortality or lung transplant. RESULTS: Prior to PICU admission, the 29 patients included (median age 13.5 years) had a severe lung disease (median Forced Expiratory Volume in 1 s percentage predicted at 29%). Mortality rates were respectively 17%, 31%, 34%, 41% at discharge and at 3, 12 and 36 months post-discharge. Survival rates free of lung transplant were 34%, 32%, 24% and 17% respectively. Risk factors associated with mortality or lung transplant using the univariate analysis were female sex and higher pCO2 and chloride levels at PICU admission, and following pre admission characteristics: home respiratory and nutritional support, registration on lung transplant list and Stenotrophomonas Maltophilia bronchial colonization. CONCLUSION: Children with CF admitted to PICU for acute respiratory failure secondary to pulmonary exacerbations are at high risk of death, both in the short and medium terms. Lung transplant is their main chance of survival and should be considered early.

Monoclonal antibody-mediated neutralization of SARS-CoV-2 in an IRF9-deficient child.

We describe an unvaccinated child at risk for life-threatening COVID-19 due to an inherited deficiency of IRF9, which governs ISGF-3-dependent responses to type I and III interferons (IFN). She was admitted, with a high nasal SARS-CoV-2 load on day 1 of upper respiratory tract infection. She was viremic on day 2 and received casirivimab and imdevimab. Her clinical manifestations and viremia disappeared on days 3 and 4, respectively. Circulating SARS-CoV-2 virus induced the expression of IFN-stimulated genes in leukocytes on day 1, whereas the secretion of blood type I IFNs, which peaked on day 4, did not. Antibody-mediated SARS-CoV-2 neutralization is, therefore, sufficient to overcome a deficiency of antiviral IFNs.

Children's views on artificial intelligence and digital twins for the daily management of their asthma: a mixed-method study.

New technologies enable the creation of digital twin systems (DTS) combining continuous data collection from children's home and artificial intelligence (AI)-based recommendations to adapt their care in real time. The objective was to assess whether children and adolescents with asthma would be ready to use such DTS. A mixed-method study was conducted with 104 asthma patients aged 8 to 17 years. The potential advantages and disadvantages associated with AI and the use of DTS were collected in semi-structured interviews. Children were then asked whether they would agree to use a DTS for the daily management of their asthma. The strength of their decision was assessed as well as the factors determining their choice. The main advantages of DTS identified by children were the possibility to be (i) supported in managing their asthma (ii) from home and (iii) in real time. Technical issues and the risk of loss of humanity were the main drawbacks reported. Half of the children (56%) were willing to use a DTS for the daily management of their asthma if it was as effective as current care, and up to 93% if it was more effective. Those with the best computer skills were more likely to choose the DTS, while those who placed a high value on the physician-patient relationship were less likely to do so.   Conclusions: The majority of children were ready to use a DTS for the management of their asthma, particularly if it was more effective than current care. The results of this study support the development of DTS for childhood asthma and the evaluation of their effectiveness in clinical trials. What is Known: • New technologies enable the creation of digital twin systems (DTS) for children with asthma. • Acceptance of these DTSs by children with asthma is unknown. What is New: • Half of the children (56%) were willing to use a DTS for the daily management of their asthma if it was as effective as current care, and up to 93% if it was more effective. •Children identified the ability to be supported from home and in real time as the main benefits of DTS.

NTPDase1/CD39 Ectonucleotidase Is Necessary for Normal Arterial Diameter Adaptation to Flow.

NTPDase1/CD39, the major vascular ectonucleotidase, exerts thrombo-immunoregulatory function by controlling endothelial P2 receptor activation. Despite the well-described release of ATP from endothelial cells, few data are available regarding the potential role of CD39 as a regulator of arterial diameter. We thus investigated the contribution of CD39 in short-term diameter adaptation and long-term arterial remodeling in response to flow using Entpd1-/- male mice. Compared to wild-type littermates, endothelial-dependent relaxation was modified in Entpd1-/- mice. Specifically, the vasorelaxation in response to ATP was potentiated in both conductance (aorta) and small resistance (mesenteric and coronary) arteries. By contrast, the relaxing responses to acetylcholine were supra-normalized in thoracic aortas while decreased in resistance arteries from Entpd1-/- mice. Acute flow-mediated dilation, measured via pressure myography, was dramatically diminished and outward remodeling induced by in vivo chronic increased shear stress was altered in the mesenteric resistance arteries isolated from Entpd1-/- mice compared to wild-types. Finally, changes in vascular reactivity in Entpd1-/- mice were also evidenced by a decrease in the coronary output measured in isolated perfused hearts compared to the wild-type mice. Our results highlight a key regulatory role for purinergic signaling and CD39 in endothelium-dependent short- and long-term arterial diameter adaptation to increased flow.

A role for ceruloplasmin in the control of human glioblastoma cell responses to radiation.

BACKGROUND: Glioblastoma (GB) is the most common and most aggressive malignant brain tumor. In understanding its resistance to conventional treatments, iron metabolism and related pathways may represent a novel avenue. As for many cancer cells, GB cell growth is dependent on iron, which is tightly involved in red-ox reactions related to radiotherapy effectiveness. From new observations indicating an impact of RX radiations on the expression of ceruloplasmin (CP), an important regulator of iron metabolism, the aim of the present work was to study the functional effects of constitutive expression of CP within GB lines in response to beam radiation depending on the oxygen status (21% O2 versus 3% O2). METHODS AND RESULTS: After analysis of radiation responses (Hoechst staining, LDH release, Caspase 3 activation) in U251-MG and U87-MG human GB cell lines, described as radiosensitive and radioresistant respectively, the expression of 9 iron partners (TFR1, DMT1, FTH1, FTL, MFRN1, MFRN2, FXN, FPN1, CP) were tested by RTqPCR and western blots at 3 and 8 days following 4 Gy irradiation. Among those, only CP was significantly downregulated, both at transcript and protein levels in the two lines, with however, a weaker effect in the U87-MG, observable at 3% O2. To investigate specific role of CP in GB radioresistance, U251-MG and U87-MG cells were modified genetically to obtain CP depleted and overexpressing cells, respectively. Manipulation of CP expression in GB lines demonstrated impact both on cell survival and on activation of DNA repair/damage machinery (γH2AX); specifically high levels of CP led to increased production of reactive oxygen species, as shown by elevated levels of superoxide anion, SOD1 synthesis and cellular Fe2 + . CONCLUSIONS: Taken together, these in vitro results indicate for the first time that CP plays a positive role in the efficiency of radiotherapy on GB cells.

Primary seminal vesicle epithelioid smooth muscle neoplasm of uncertain biologic potential.

We present the case of a 73-year-old male patient who presented with obstructive urinary symptoms, pelvic pressure, and hematuria. CT imaging revealed a heterogenous prostate enlargement, and MRI demonstrated the mass to be arising from the seminal vesicle. Prostate biopsies showed benign tissue. Surgical excision was completed and pathology revealed it to be an epithelioid smooth muscle neoplasm of uncertain biologic potential. This is only the second known case of such a seminal vesicle tumour. As soft tissue sarcomas of the seminal vesicle emerge in the literature, we may develop a better understanding of their biologic behaviour and prognostic potential.

Assessing the indirect effects of COVID-19 on healthcare delivery, utilization and health outcomes: a scoping review.

BACKGROUND: The COVID-19 pandemic and global efforts to contain its spread, such as stay-at-home orders and transportation shutdowns, have created new barriers to accessing healthcare, resulting in changes in service delivery and utilization globally. The purpose of this study is to provide an overview of the literature published thus far on the indirect health effects of COVID-19 and to explore the data sources and methodologies being used to assess indirect health effects. METHODS: A scoping review of peer-reviewed literature using three search engines was performed. RESULTS: One hundred and seventy studies were included in the final analysis. Nearly half (46.5%) of included studies focused on cardiovascular health outcomes. The main methodologies used were observational analytic and surveys. Data were drawn from individual health facilities, multicentre networks, regional registries, and national health information systems. Most studies were conducted in high-income countries with only 35.4% of studies representing low- and middle-income countries (LMICs). CONCLUSION: Healthcare utilization for non-COVID-19 conditions has decreased almost universally, across both high- and lower-income countries. The pandemic's impact on non-COVID-19 health outcomes, particularly for chronic diseases, may take years to fully manifest and should be a topic of ongoing study. Future research should be tied to system improvement and the promotion of health equity, with researchers identifying potentially actionable findings for national, regional and local health leadership. Public health professionals must also seek to address the disparity in published data from LMICs as compared with high-income countries.

Multisensory integration and behavioral stability.

Information coming from multiple senses, as compared to a single one, typically enhances our performance. The multisensory improvement has been extensively examined in perception studies, as well as in tasks involving a motor response like a simple reaction time. However, how this effect extends to more complex behavior, typically involving the coordination of movements, such as bimanual coordination or walking, is still unclear. A critical element in achieving motor coordination in complex behavior is its stability. Reaching a stable state in the coordination pattern allows to sustain complex behavior over time (e.g., without interruption or negative consequences, like falling). This study focuses on the relation between stability in the coordination of movement patterns, like walking, and multisensory improvement. Participants walk with unimodal and audio-tactile metronomes presented either at their preferred rate or at a slower walking rate, the instruction being to synchronize their steps to the metronomes. Walking at a slower rate makes gait more variable than walking at the preferred rate. Interestingly however, the multimodal stimuli enhance the stability of motor coordination but only in the slower condition. Thus, the reduced stability of the coordination pattern (at a slower gait rate) prompts the sensorimotor system to capitalize on multimodal stimulation. These findings provide evidence of a new link between multisensory improvement and behavioral stability, in the context of ecological sensorimotor task.

Wildlife consumption of neonicotinoid-treated seeds at simulated seed spills.

The most likely route of exposure to high concentrations of neonicotinoids capable of producing lethal or sublethal effects in birds and mammals is consumption of treated seeds. We placed trail cameras at simulated seed spills to document wildlife consuming treated seeds during the spring planting season. We simulated 4 types of spills, corn treated with 2 concentrations of clothiandin (0.50 or 0.25 mg/seed), corn treated with thiamethoxam (0.25 mg/seed), and soybean treated with imidacloprid (0.15 mg/seed). We documented 16 species of birds and 14 species of mammals eating neonicotinoid-treated seeds at spills. Of these, we quantified consumption of treated seeds by 12 species of birds and 13 species of mammals. Birds and mammals did not consume enough seeds to exceed published LD50s in related taxa, but most species did consume enough seeds to reach or exceed thresholds for sublethal effects based on currently available studies. Birds and mammals did not increase the amount of seeds consumed over time, as would be expected if responsive to the concentration of neonicotinoids on seeds, but more birds and mammals consumed seeds over time, as a proportion of the number at spills each day. More birds also consumed seeds after a soaking rain event, which likely reduced the amount of treatment on the seeds. Importantly, wildlife are consuming seeds while neonicotinoids are still concentrated on seeds. Our findings indicate that previously held assumptions about the safety of neonicotinoid seed treatments for vertebrate wildlife need to be revisited.

Evaluation of neurobehavioral abnormalities and immunotoxicity in response to oral imidacloprid exposure in domestic chickens (Gallus gallus domesticus).

Domestic chickens (Gallus gallus domesticus) were exposed to imidacloprid by gavage once daily for 7 consecutive days at 0, 0.03, 0.34, 3.42, 10.25, and 15.5 mg/kg/day (n = 20 per group; 5 6-week-old males, 5 6-week-old females, 5 9-week-old males, and 5 9-week-old females). The severity and duration of neurobehavioral abnormalities were recorded. Components of the innate and adaptive immune system were assessed with 7 standard functional assays. Temporary neurobehavioral abnormalities were observed in a dose-dependent manner, including muscle tremors, ataxia, and depressed mentation. Based upon mean clinical severity scores, the no observed adverse effect level (NOAEL) was 3.42 mg/kg/day, and the lowest observed adverse effect level (LOAEL) was 10.25 mg/kg/day. The effective dose value for the presence of any neurobehavioral abnormalities in 50% of the test group (ED50) was 4.62 ± 0.98 mg/kg/day. The ED50 for an adjusted score that included both severity and duration of neurobehavioral abnormalities was 11.24 ± 9.33 mg/kg/day. These ED50 values are equivalent to a 1 kg bird ingesting 29 or 70 imidacloprid treated soybean seeds respectively. Immunotoxicity was not documented, possible causes include the assays were insensitive, relevant immune functions were not examined, or imidacloprid is not immunotoxic at this dosing schedule in this species. Neurobehavioral abnormalities were a more sensitive indicator of the sublethal effects of imidacloprid than immunotoxicity.

Loss of vascular expression of nucleoside triphosphate diphosphohydrolase-1/CD39 in hypertension.

Ectonucleoside triphosphate diphosphohydrolase-1, the major vascular/immune ectonucleotidase, exerts anti-thrombotic and immunomodulatory actions by hydrolyzing extracellular nucleotides (danger signals). Hypertension is characterized by vascular wall remodeling, endothelial dysfunction, and immune infiltration. Here our aim was to investigate the impact of arterial hypertension on CD39 expression and activity in mice. Arterial expression of CD39 was determined by reverse transcription quantitative real-time PCR in experimental models of hypertension, including angiotensin II (AngII)-treated mice (1 mg/kg/day, 21 days), deoxycorticosterone acetate-salt mice (1% salt and uninephrectomy, 21 days), and spontaneously hypertensive rats. A decrease in CD39 expression occurred in the resistance and conductance arteries of hypertensive animals with no effect on lymphoid organs. In AngII-treated mice, a decrease in CD39 protein levels (Western blot) was corroborated by reduced arterial nucleotidase activity, as evaluated by fluorescent (etheno)-ADP hydrolysis. Moreover, serum-soluble ADPase activity, supported by CD39, was significantly decreased in AngII-treated mice. Experiments were conducted in vitro on vascular cells to determine the elements underlying this downregulation. We found that CD39 transcription was reduced by proinflammatory cytokines interleukin (IL)-1ß and tumor necrosis factor alpha on vascular smooth muscle cells and by IL-6 and anti-inflammatory and profibrotic cytokine transforming growth factor beta 1 on endothelial cells. In addition, CD39 expression was downregulated by mechanical stretch on vascular cells. Arterial expression and activity of CD39 were decreased in hypertension as a result of both a proinflammatory environment and mechanical strain exerted on vascular cells. Reduced ectonucleotidase activity may alter the vascular condition, thus enhancing arterial damage, remodeling, or thrombotic events.

Central Role of P2Y6 UDP Receptor in Arteriolar Myogenic Tone.

OBJECTIVE: Myogenic tone (MT) of resistance arteries ensures autoregulation of blood flow in organs and relies on the intrinsic property of smooth muscle to contract in response to stretch. Nucleotides released by mechanical strain on cells are responsible for pleiotropic vascular effects, including vasoconstriction. Here, we evaluated the contribution of extracellular nucleotides to MT. APPROACH AND RESULTS: We measured MT and the associated pathway in mouse mesenteric resistance arteries using arteriography for small arteries and molecular biology. Of the P2 receptors in mouse mesenteric resistance arteries, mRNA expression of P2X1 and P2Y6 was dominant. P2Y6 fully sustained UDP/UTP-induced contraction (abrogated in P2ry6(-/-) arteries). Preventing nucleotide hydrolysis with the ectonucleotidase inhibitor ARL67156 enhanced pressure-induced MT by 20%, whereas P2Y6 receptor blockade blunted MT in mouse mesenteric resistance arteries and human subcutaneous arteries. Despite normal hemodynamic parameters, P2ry6(-/-) mice were protected against MT elevation in myocardial infarction-induced heart failure. Although both P2Y6 and P2Y2 receptors contributed to calcium mobilization, P2Y6 activation was mandatory for RhoA-GTP binding, myosin light chain, P42-P44, and c-Jun N-terminal kinase phosphorylation in arterial smooth muscle cells. In accordance with the opening of a nucleotide conduit in pressurized arteries, MT was altered by hemichannel pharmacological inhibitors and impaired in Cx43(+/-) and P2rx7(-/-) mesenteric resistance arteries. CONCLUSIONS: Signaling through P2 nucleotide receptors contributes to MT. This mechanism encompasses the release of nucleotides coupled to specific autocrine/paracrine activation of the uracil nucleotide P2Y6 receptor and may contribute to impaired tissue perfusion in cardiovascular diseases.

Walking to a multisensory beat.

Living in a complex and multisensory environment demands constant interaction between perception and action. In everyday life it is common to combine efficiently simultaneous signals coming from different modalities. There is evidence of a multisensory benefit in a variety of laboratory tasks (temporal judgement, reaction time tasks). It is less clear if this effect extends to ecological tasks, such as walking. Furthermore, benefits of multimodal stimulation are linked to temporal properties such as the temporal window of integration and temporal recalibration. These properties have been examined in tasks involving single, non-repeating stimulus presentations. Here we investigate the same temporal properties in the context of a rhythmic task, namely audio-tactile stimulation during walking. The effect of audio-tactile rhythmic cues on gait variability and the ability to synchronize to the cues was studied in young adults. Participants walked with rhythmic cues presented at different stimulus-onset asynchronies. We observed a multisensory benefit by comparing audio-tactile to unimodal stimulation. Moreover, both the temporal window of integration and temporal recalibration mediated the response to multimodal stimulation. In sum, rhythmic behaviours obey the same principles as temporal discrimination and detection behaviours and thus can also benefit from multimodal stimulation.

Inflammatory rebound and postinfectious inflammatory response in children with pleural infection: A single-center retrospective study.

INTRODUCTION: As pleural inflammation plays a central role in pleural infection (PI), corticosteroids are increasingly being considered as a potential therapy. However, the timing of treatment and the identification of patients who might benefit most remain unresolved. The aim of this study was therefore to investigate the inflammatory trajectories of children with PI. METHODS: This retrospective single-center study included children aged 3 months to 17 years and 11 months hospitalized for PI due to Streptococcus pyogenes, Streptococcus pneumonia, and Staphylococcus aureus over 10 years. An inflammatory rebound was defined biologically as a reincrease in C-reactive protein (CRP) of at least 50 mg/L after an initial decrease in CRP of at least 50 mg/L. RESULTS: We included 53 cases of PI, including 16 due to S. pyogenes, 27 due to S. pneumonia, and 10 due to S. aureus. An inflammatory rebound occurred in 20 patients (38%) after a median of 4.5 (3-6) days. This inflammatory rebound occurred in 9 (56%) children with S. pyogenes, 8 (30%) children with S. pneumonia, and 3 (30%) children with S. aureus. Children with an inflammatory rebound also had a higher rate of persistent fever after Day 7 and a longer length of stay (p = .01 for both). CONCLUSION: We postulate that the inflammatory rebound identified in nearly 40% of our patients corresponds to an early postinfectious inflammatory response, and thus that corticosteroids may be most beneficial for children with PI if administered early (between Days 2 and 5).

Global Emergency Medicine: A Scoping Review of the Literature from 2022.

OBJECTIVE: The objective was to identify the highest quality global emergency medicine (GEM) research published in 2022. The top articles are compiled in a comprehensive list of all the year's GEM articles and narrative summaries are performed on those included. METHODS: A systematic PubMed search was conducted to identify all GEM articles published in 2022 and included a manual supplemental screen of 11 organizational websites for gray literature (GRAY). A team of trained reviewers and editors screened all identified titles and abstracts, based on three case definition categories: disaster and humanitarian response (DHR), emergency care in resource-limited settings (ECRLS), and emergency medicine development (EMD). Articles meeting these definitions were independently scored by two reviewers using rubrics for original research (OR), review (RE) articles, and GRAY. Articles that scored in the top 5% from each category as well as the overall top 5% of articles were included for narrative summary. RESULTS: The 2022 search identified 58,510 articles in the main review, of which 524 articles screened in for scoring, respectively, 30% and 18% increases from last year. After duplicates were removed, 36 articles were included for narrative summary. The GRAY search identified 7755 articles, of which 33 were scored and one was included for narrative summary. ECRLS remained the largest category (27; 73%), followed by DHR (7; 19%) and EMD (3; 8%). OR articles remained more common than RE articles (64% vs. 36%). CONCLUSIONS: The waning of the COVID-19 pandemic has not affected the continued growth in GEM literature. Articles related to prehospital care, mental health and resilience among patients and health care workers, streamlining pediatric infectious disease care, and disaster preparedness were featured in this year's review. The continued lack of EMD studies despite the global growth of GEM highlights a need for more scholarly dissemination of best practices.

Brain intratumoural astatine-211 radiotherapy targeting syndecan-1 leads to durable glioblastoma remission and immune memory in female mice.

BACKGROUND: Glioblastoma (GB), the most aggressive brain cancer, remains a critical clinical challenge due to its resistance to conventional treatments. Here, we introduce a locoregional targeted-α-therapy (TAT) with the rat monoclonal antibody 9E7.4 targeting murine syndecan-1 (SDC1) coupled to the α-emitter radionuclide astatine-211 (211At-9E7.4). METHODS: We orthotopically transplanted 50,000 GL261 cells of murine GB into the right striatum of syngeneic female C57BL/6JRj mice using stereotaxis. After MRI validation of tumour presence at day 11, TAT was injected at the same coordinates. Biodistribution, efficacy, toxicity, local and systemic responses were assessed following application of this protocol. The 9E7.4 monoclonal antibody was labelled with iodine-125 (125I) for biodistribution and with astatine-211 (211At) for the other experiments. FINDINGS: The 211At-9E7.4 TAT demonstrated robust efficacy in reducing orthotopic tumours and achieved improved survival rates in the C57BL/6JRj model, reaching up to 70% with a minimal activity of 100 kBq. Targeting SDC1 ensured the cerebral retention of 211At over an optimal time window, enabling low-activity administration with a minimal toxicity profile. Moreover, TAT substantially reduced the occurrence of secondary tumours and provided resistance to new tumour development after contralateral rechallenge, mediated through the activation of central and effector memory T cells. INTERPRETATION: The locoregional 211At-9E7.4 TAT stands as one of the most efficient TAT across all preclinical GB models. This study validates SDC1 as a pertinent therapeutic target for GB and underscores 211At-9E7.4 TAT as a promising advancement to improve the treatment and quality of life for patients with GB. FUNDING: This work was funded by the French National Agency for Research (ANR) "France 2030 Investment Plan" Labex Iron [ANR-11-LABX-18-01], The SIRIC ILIAD [INCa-DGOS-INSERM-18011], the French program "Infrastructure d'Avenir en Biologie-Santé" (France Life Imaging) [ANR-11-INBS-0006], the PIA3 of the ANR, integrated to the "France 2030 Investment Plan" [ANR-21-RHUS-0012], and support from Inviscan SAS (Strasbourg, France). It was also related to: the ANR under the frame of EuroNanoMed III (project GLIOSILK) [ANR-19-ENM3-0003-01]; the "Région Pays-de-la-Loire" under the frame of the Target'In project; the "Ligue Nationale contre le Cancer" and the "Comité Départemental de Maine-et-Loire de la Ligue contre le Cancer" (CD49) under the frame of the FusTarG project and the "Tumour targeting, imaging and radio-therapies network" of the "Cancéropôle Grand-Ouest" (France). This work was also funded by the Institut National de la Santé et de la Recherche Médicale (INSERM), the University of Nantes, and the University of Angers.

Polymer-lipid hybrid nanomedicines to deliver siRNA in and against glioblastoma cells.

Small interfering RNA (siRNA) holds great potential to treat many difficult-to-treat diseases, but its delivery remains the central challenge. This study aimed at investigating the suitability of polymer-lipid hybrid nanomedicines (HNMeds) as novel siRNA delivery platforms for locoregional therapy of glioblastoma. Two HNMed formulations were developed from poly(lactic-co-glycolic acid) polymer and a cationic lipid: 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) or 3ß-[N-(N',N'-dimethylaminoethane)-carbamoyl]cholesterol (DC-Chol). After characterization of the HNMeds, a model siRNA was complexed onto their surface to form HNMed/siRNA complexes. The physicochemical properties and siRNA binding ability of complexes were assessed over a range of nitrogen-to-phosphate (N/P) ratios to optimize the formulations. At the optimal N/P ratio of 10, complexes effectively bound siRNA and improved its protection from enzymatic degradation. Using the NIH3T3 mouse fibroblast cell line, DOTAP-based HNMeds were shown to possess higher cytocompatibility in vitro over the DC-Chol-based ones. As proof-of-concept, uptake and bioefficacy of formulations were also assessed in vitro on U87MG human glioblastoma cell line expressing luciferase gene. Complexes were able to deliver anti-luciferase siRNA and induce a remarkable suppression of gene expression. Noteworthy, the effect of DOTAP-based formulation was not only about three-times higher than DC-Chol-based one, but also comparable to lipofectamine model transfection reagent. These findings set the basis to exploit this nanosystem for silencing relevant GB-related genes in further in vitro and in vivo studies.