Doxorubicin loaded dual pH- and thermo-responsive magnetic nanocarrier for combined magnetic hyperthermia and targeted controlled drug delivery applications

Magnetic nanocarriers have attracted increasing attention for multimodal cancer therapy due to the possibility to deliver heat and drugs locally. The present study reports the development of magnetic nanocomposites (MNCs) made of an iron oxide core and a pH- and thermo-responsive polymer shell, that can be used as both hyperthermic agent and drug carrier. The conjugation of anticancer drug doxorubicin (DOX) to the pH- and thermo-responsive MNCs via acid-cleavable imine linker provides advanced features for the targeted delivery of DOX molecules via the combination of magnetic targeting, and dual pH- and thermo-responsive behaviour which offers spatial and temporal control over the release of DOX. The iron oxide cores exhibit a superparamagnetic behaviour with a saturation magnetization around 70 emu g(-1). The MNCs contained 8.1 wt% of polymer and exhibit good heating properties in an alternating magnetic field. The drug release experiments confirmed that only a small amount of DOX was released at room temperature and physiological pH, while the highest drug release of 85.2% was obtained after 48 h at acidic tumour pH under hyperthermia conditions (50 °C). The drug release kinetic followed Korsmeyer-Peppas model and displayed Fickian diffusion mechanism. From the results obtained it can be concluded that this smart magnetic nanocarrier is promising for applications in multi-modal cancer therapy, to target and efficiently deliver heat and drug specifically to the tumour.

Successful Treatment of Hepatitis C in Renal Transplant Recipients With Direct-Acting Antiviral Agents

The direct-acting antivirals (DAAs) constitute an emerging group of small molecule inhibitors that effectively treat hepatitis C virus (HCV) infection, a common comorbidity in end-stage renal disease patients. To date, there are no data to guide use of these agents in kidney transplant patients. The authors collected data from 20 consecutive kidney recipients treated with interferon-free treatment regimens for HCV at their center: 88% were infected with genotype 1; 50% had biopsy-proved advanced hepatic fibrosis on their most recent liver biopsy preceding treatment (Metavir stage 3 fibrosis [F3] or F4); and 60% had failed treatment pretransplantation with interferon-based therapy. DAA treatment was initiated a median of 888 days after renal transplantation. All patients cleared the virus while on therapy, and 100% have achieved a sustained virologic response at 12 weeks after completion of DAA therapy. The most commonly used regimen was sofosbuvir 400 mg daily in combination with simeprevir 150 mg daily. However, four different treatment approaches were used, with comparable results. The DAAs were well tolerated, and less than half of patients required calcineurin inhibitor dose adjustment during treatment. Eradication of HCV infection with DAAs is feasible after kidney transplantation with few treatment-related side effects.

Copper Complex in Poly(vinyl chloride) as a Nitric Oxide-Generating Catalyst for the Control of Nitrifying Bacterial Biofilms

In this study, catalytic generation of nitric oxide by a copper(II) complex embedded within a poly(vinyl chloride) matrix in the presence of nitrite (source of nitric oxide) and ascorbic acid (reducing agent) was shown to effectively control the formation and dispersion of nitrifying bacteria biofilms. Amperometric measurements indicated increased and prolonged generation of nitric oxide with the addition of the copper complex when compared to that with nitrite and ascorbic acid alone. The effectiveness of the copper complex-nitrite-ascorbic acid system for biofilm control was quantified using protein analysis, which showed enhanced biofilm suppression when the copper complex was used in comparison to that with nitrite and ascorbic acid treatment alone. Confocal laser scanning microscopy (CLSM) and LIVE/DEAD staining revealed a reduction in cell surface coverage without a loss of viability with the copper complex and up to 5 mM of nitrite and ascorbic acid, suggesting that the nitric oxide generated from the system inhibits proliferation of the cells on surfaces. Induction of nitric oxide production by the copper complex system also triggered the dispersal of pre-established biofilms. However, the addition of a high concentration of nitrite and ascorbic acid to a pre-established biofilm induced bacterial membrane damage and strongly decreased the metabolic activity of planktonic and biofilm cells, as revealed by CLSM with LIVE/DEAD staining and intracellular adenosine triphosphate measurements, respectively. This study highlights the utility of the catalytic generation of nitric oxide for the long-term suppression and removal of nitrifying bacterial biofilms.

Antimicrobial surfaces to prevent healthcare-associated infections: a systematic review

Contamination of the healthcare environment with pathogenic organisms contributes to the burden of healthcare-associated infection (HCAI). Antimicrobial surfaces are designed to reduce microbial contamination of healthcare surfaces. We aimed to determine whether antimicrobial surfaces prevent HCAI, transmission of antibiotic-resistant organisms (AROs), or microbial contamination, we conducted a systematic review of the use of antimicrobial surfaces in patient rooms. Outcomes included HCAI, ARO, and quantitative microbial contamination. Relevant databases were searched. Abstract review, full text review, and data abstraction were performed in duplicate. Risk of bias was assessed using the Cochrane Effective Practice and Organization Care (EPOC) Group risk of bias assessment tool and the strength of evidence determined using Grading of Recommendations Assessment, Development and Evaluation (GRADE). Eleven studies assessed the effect of copper (N = 7), silver (N = 1), metal-alloy (N = 1), or organosilane-treated surfaces (N = 2) on microbial contamination. Copper surfaces demonstrated a median (range) reduction of microbial contamination of <1 log10 (<1 to 2 log10). Two studies addressed HCAI/ARO incidence. An RCT of copper surfaces in an ICU demonstrated 58% reduction in HCAI (P = 0.013) and 64% reduction in ARO transmission (P = 0.063) but was considered low-quality evidence due to improper randomization and incomplete blinding. An uncontrolled before-after study evaluating copper-impregnated textiles in a long-term care ward demonstrated 24% reduction in HCAI but was considered very-low-quality evidence based on the study design. Copper surfaces used in clinical settings result in modest reductions in microbial contamination. One study of copper surfaces and one of copper textiles demonstrated reduction in HCAI, but both were at high risk of bias.

Altered mesenchymal niche cells impede generation of normal hematopoietic progenitor cells in leukemic bone marrow

Degeneration of normal hematopoietic cells is a shared feature of malignant diseases in the hematopoietic system. Previous studies have shown the exhaustion of hematopoietic progenitor cells (HPCs) in leukemic marrow, whereas hematopoietic stem cells (HSCs) remain functional upon relocation to non-leukemic marrow. However, the underlying cellular mechanisms, especially the specific niche components that are responsible for the degeneration of HPCs, are unknown. In this study, we focused on murine bone mesenchymal stem cells (MSCs) and their supporting function for normal hematopoietic cells in Notch1-induced acute T-cell lymphocytic leukemia (T-ALL) mice. We demonstrate that the proliferative capability and differentiation potential of T-ALL MSCs were impaired due to accelerated cellular senescence. RNA-seq analysis revealed significant transcriptional alterations in leukemic MSCs. After co-cultured with the MSCs from T-ALL mice, a specific inhibitory effect on HPCs was defined, whereas in vivo repopulating potential of normal HSCs was not compromised. Furthermore, osteoprotegerin was identified as a cytokine to improve the function of T-ALL MSCs and to enhance normal HPC output via the p38/ERK pathway. Therefore, this study reveals a novel cellular mechanism underlying the inhibition of HPC generation in T-ALL. Leukemic MSCs may serve as a cellular target for improving normal hematopoietic regeneration therapeutically.

Protocol for a multicentre randomiSed controlled TRial of IntraVEnous immunoglobulin versus standard therapy for the treatment of transverse myelitis in adults and children (STRIVE)

INTRODUCTION

Transverse myelitis (TM) is an immune-mediated disorder of the spinal cord which causes motor and sensory disturbance and limited recovery in 50% of patients. Standard treatment is steroids, and patients with more severe disease appear to respond to plasma exchange (PLEX). Intravenous immunoglobulin (IVIG) has also been used as an adjunct to steroids, but evidence is lacking. We propose the first randomised control trial in adults and children, to determine the benefit of additional treatment with IVIG.

METHODS AND ANALYSIS

170 adults and children aged over 1 year with acute first episode TM or neuromyelitis optica (with myelitis) will be recruited over a 2.5-year period and followed up for 12 months. Participants randomised to the control arm will receive standard therapy of intravenous methylprednisolone (IVMP). The intervention arm will receive the above standard therapy, plus additional IVIG. Primary outcome will be a 2-point improvement on the American Spinal Injury Association (ASIA) Impairment scale at 6 months postrandomisation by blinded assessors. Additional secondary and tertiary outcome measures will be collected: ASIA motor and sensory scales, Kurtzke expanded disability status scale, International Spinal Cord Injury (SCI) Bladder/Bowel Data Set, Client Services Receipt Index, Pediatric Quality of Life Inventory, EQ-5D, SCI Pain and SCI Quality of Life Data Sets. Biological samples will be biobanked for future studies. After 6-months' follow-up of the first 52 recruited patients futility analysis will be carried out. Health economics analysis will be performed to calculate cost-effectiveness. After 6 months' recruitment futility analysis will be performed.

ETHICS AND DISSEMINATION

Research Ethics Committee Approval was obtained: 14/SC/1329. Current protocol: v3.0 (15/01/2015). Study findings will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBERS

This study is registered with EudraCT (REF: 2014-002335-34), Clinicaltrials.gov (REF: NCT02398994) and ISRCTN (REF: 12127581).

Fetal magnetocardiography (fMCG) to monitor cardiac time intervals in fetuses at risk for isoimmune AV block

OBJECTIVE

The objective of this report is to detect cardiac time intervals (CTIs) in fetuses exposed to SSA/Ro-SSB/La antibodies in relation to gestational age (GA) and fetal weight and compared them with a control cohort.

METHODS

Fetal magnetocardiography (fMCG) recordings were conducted on a biomagnetic device dedicated to obstetrical measurement starting in the second trimester. Fetal cardiac time intervals of 87 healthy fetuses of normal gestation (control group) were compared to 11 fetuses exposed to maternal SSA/Ro-SSB/La antibodies (study group).

RESULTS

fCTIs were analyzed starting at 17 weeks of GA. Atrial and ventricular depolarization times increased with GA in both groups. PQ segments were significantly longer in the study group (50.8 ms vs. 60.2 ms; p < 0.001) independent of GA or fetal weight. PQ segment prolongation was more obvious in the study group prior to 30 weeks of GA.

CONCLUSION

PQ segment prolongation can be interpreted as early AV-node involvement caused by maternal SSA/Ro-SSB/La antibodies. The age dependency of the PQ segment should be taken into account in further studies.