Interactions between Magnetic Nanowires and Living Cells : Uptake, Toxicity and Degradation

We report on the uptake, toxicity and degradation of magnetic nanowires by NIH/3T3 mouse fibroblasts. Magnetic nanowires of diameters 200 nm and lengths comprised between 1 {\mu}m and 40 {\mu}m are fabricated by controlled assembly of iron oxide ({\gamma}-Fe2O3) nanoparticles. Using optical and electron microscopy, we show that after 24 h incubation the wires are internalized by the cells and located either in membrane-bound compartments or dispersed in the cytosol. Using fluorescence microscopy, the membrane-bound compartments were identified as late endosomal/lysosomal endosomes labeled with lysosomal associated membrane protein (Lamp1). Toxicity assays evaluating the mitochondrial activity, cell proliferation and production of reactive oxygen species show that the wires do not display acute short-term (< 100 h) toxicity towards the cells. Interestingly, the cells are able to degrade the wires and to transform them into smaller aggregates, even in short time periods (days). This degradation is likely to occur as a consequence of the internal structure of the wires, which is that of a non-covalently bound aggregate. We anticipate that this degradation should prevent long-term asbestos-like toxicity effects related to high aspect ratio morphologies and that these wires represent a promising class of nanomaterials for cell manipulation and microrheology.Comment: 21 pages 12 figure

Attenuated total reflection-FT-IR spectroscopic imaging of protein crystallization

Protein crystallization is of strategic and commercial relevance in the post-genomic era because of its pivotal role in structural proteomics projects. Although protein structures are crucial for understanding the function of proteins and to the success of rational drug design and other biotechnology applications, obtaining high quality crystals is a major bottleneck to progress. The major means of obtaining crystals is by massive-scale screening of a target protein solution with numerous crystallizing agents. However, when crystals appear in these screens, one cannot easily know if they are crystals of protein, salt, or any other molecule that happens to be present in the trials. We present here a method based on Attenuated Total Reflection (ATR)-FT-IR imaging that reliably identifies protein crystals through a combination of chemical specificity and the visualizing capability of this approach, thus solving a major hurdle in protein crystallization. ATR-FT-IR imaging was successfully applied to study the crystallization of thaumatin and lysozyme in a high-throughput manner, simultaneously from six different solutions. This approach is fast as it studies protein crystallization in situ and provides an opportunity to examine many different samples under a range of conditions

Two-photon dual imaging platform for in vivo monitoring cellular oxidative stress in liver injury

Oxidative stress reflects an imbalance between reactive oxygen species (ROS) and antioxidants, which has been reported as an early unifying event in the development and progression of various diseases and as a direct and mechanistic indicator of treatment response. However, highly reactive and short-lived nature of ROS and antioxidant limited conventional detection agents, which are influenced by many interfering factors. Here, we present a two-photon sensing platform for in vivo dual imaging of oxidative stress at the single cell-level resolution. This sensing platform consists of three probes, which combine the turn-on fluorescent transition-metal complex with different specific responsive groups for glutathione (GSH), hydrogen peroxide (H2O2) and hypochlorous acid (HOCl). By combining fluorescence intensity imaging and fluorescence lifetime imaging, these probes totally remove any possibility of crosstalk from in vivo environmental or instrumental factors, and enable accurate localization and measurement of the changes in ROS and GSH within the liver. This precedes changes in conventional biochemical and histological assessments in two distinct experimental murine models of liver injury. The ability to monitor real-time cellular oxidative stress with dual-modality imaging has significant implications for high-accurate, spatially configured and quantitative assessment of metabolic status and drug response

A chemically modified antibody mediates complete eradication of tumours by selective disruption of tumour blood vessels

These results reinforce the concept that vascular shutdown can induce a curative avalanche of tumour cell death. Immuno-photodynamic therapy may be particularly indicated for squamous cell carcinoma of the skin, which we show to be strongly positive for markers of angiogenesis

Targeting tissue factor on tumour cells and angiogenic vascular endothelial cells by factor VII-targeted verteporfin photodynamic therapy for breast cancer in vitro and in vivo in mice

<p>Abstract</p> <p>Background</p> <p>The objective of this study was to develop a ligand-targeted photodynamic therapy (tPDT) by conjugating factor VII (fVII) protein with photosensitiser verteporfin in order to overcome the poor selectivity and enhance the effect of non-targeted PDT (ntPDT) for cancer. fVII is a natural ligand for receptor tissue factor (TF) with high affinity and specificity. The reason for targeting receptor TF for the development of tPDT is that TF is a common but specific target on angiogenic tumour vascular endothelial cells (VEC) and many types of tumour cells, including solid tumours and leukaemia.</p> <p>Methods</p> <p>Murine factor VII protein (mfVII) containing a mutation (Lys341Ala) was covalently conjugated via a cross linker EDC with Veterporfin (VP) that was extracted from liposomal Visudyne, and then free VP was separated by Sephadex G50 spin columns. fVII-tPDT using mfVII-VP conjugate, compared to ntPDT, was tested <it>in vitro </it>for the killing of breast cancer cells and VEGF-stimulated VEC and <it>in vivo </it>for inhibiting the tumour growth of breast tumours in a mouse xenograft model.</p> <p>Results</p> <p>We showed that: (i) fVII protein could be conjugated with VP without affecting its binding activity; (ii) fVII-tPDT could selectively kill TF-expressing breast cancer cells and VEGF-stimulated angiogenic HUVECs but had no side effects on non-TF expressing unstimulated HUVEC, CHO-K1 and 293 cells; (iii) fVII targeting enhanced the effect of VP PDT by three to four fold; (iii) fVII-tPDT induced significantly stronger levels of apoptosis and necrosis than ntPDT; and (iv) fVII-tPDT had a significantly stronger effect on inhibiting breast tumour growth in mice than ntPDT.</p> <p>Conclusions</p> <p>We conclude that the fVII-targeted VP PDT that we report here is a novel and effective therapeutic with improved selectivity for the treatment of breast cancer. Since TF is expressed on many types of cancer cells including leukaemic cells and selectively on angiogenic tumour VECs, fVII-tPDT could have broad therapeutic applications for other solid cancers and leukaemia.</p

ЭФФЕКТИВНОСТЬ И БЕЗОПАСНОСТЬ НОВОГО РОССИЙСКОГО НЕНУКЛЕОЗИДНОГО ИНГИБИТОРА ОБРАТНОЙ ТРАНСКРИПТАЗЫ ЭЛСУЛЬФАВИРИНА В ПЕРВОЙ ЛИНИИ ЛЕЧЕНИЯ ВИЧ-ИНФЕКЦИИ В КОМБИНАЦИИ С ДВУМЯ НУКЛЕОЗИДНЫМИ/НУКЛЕОТИДНЫМИ ИНГИБИТОРАМИ ОБРАТНОЙ ТРАНСКРИПТАЗЫ – ИССЛЕДОВАНИЕ 96 НЕДЕЛЬ

A randomized multicenter 96-week study of an elsulfavirine (ESV),  non-nucleoside reverse transcriptase inhibitor (NNRTI) of novel  generation, in combination with 2 nucleoside/ nucleotide reverse  transcriptase inhibitors (NRTIs) was conducted in naive HIV adult  patients, divided by 2 parts: 1) partially blind comparative to  efavirenz (EFV) 48-week study, 2) open-label observational study  during additional 48 weeks. High virological and immunological  effectiveness maintained during the study: proportion of patients  with HIV RNA &lt;50 copies/ml in 48 weeks achieved 81,6%, in 96  weeks – 83,9% (MITT-analysis) and 91% (if patients withdrawn from the study due to other reasons not related to treatment were excluded). No resistance mutations were found in patients with viral  replication blips (HIV RNA 50-1300 copies/ml). CD4+-lymphocytes  count was increased by 187,5 at week 48 and 251,0 cells/mcl at  week 96. Good tolerability and safety were confirmed during second year of treatment: no additional safety data which could influence  benefit/risk ratio were recorded as well as withdrawal from the  treatment due to adverse events. Serious adverse events, connected with treatment, allergic reactions were not registered during the whole 96-week study. Conclusion. Results of the 96-week study confirm earlier data from  48-week study on high efficacy and safety of ESV. Based on these  data ESV was included into “National recommendations on  dispensary follow-up and treatment of patients with HIV-infection” as the first-line ART regime in combination with 2 NRTIs.Проведено многоцентровое рандомизированное исследование элсульфавирина (ESV) –  ненуклеозидного ингибитора обратной транскриптазы (ННИОТ) нового поколения в  комбинации с 2 нуклеотидными/нуклеозидными ингибиторами обратной транскриптазы  (НИОТ) у взрослых пациентов с ВИЧ-инфекцией, ранее не получавших АРТ, длительностью  96 недель, состоявшее из 2 этапов: 1) частично слепое, сравнительное с эфавирензом (EFV) исследование – 48 недель, 2) открытое наблюдательное исследование – дополнительные 48 недель. Наблюдалась высокая вирусологическая и иммунологическая эффективность  лечения, устойчивая в течение 96 недель: доля пациентов с неопределяемым уровнем РНК  ВИЧ &lt;50 копий/мл через 48 недель составила 81,6%, через 96 недель – 83,9% (MITT- анализ) и 91% (без учета пациентов, выбывших по не связанным с лечением причинам). Ни  в одном случае всплесков репликации вируса (РНК ВИЧ от 50 до 1300 копий/мл) не  выявлено мутаций резистентности ВИЧ к препаратам. Прирост медианы количества CD4+- лимфоцитов через 48 недель составил 187,5 клеток/мкл, через 96 недель – 251,0 клетку/ мкл. Подтверждена хорошая переносимость и безопасность лечения в течение второго года  исследования: не выявлено каких-либо новых значимых данных в отношении безопасности,  негативно влияющих на соотношение польза/риск, не зарегистрировано  случаев отмены лечения из-за нежелательных явлений. На протяжении 96 недель не  зарегистрированы серьезные нежелательные явления, связанные с приемом препарата,  аллергические реакции. Заключение. Результаты 96-недельного исследования подтверждают полученные ранее  (по итогам 48 недель применения) данные о высокой эффективности и безопасности  элсульфавирина. На основании полученных результатов элсульфавирин включен в «Национальные рекомендации по диспансерному наблюдению и лечению больных ВИЧ- инфекцией» в качестве режима первой линии АРТ в комбинации с 2 препаратами группы НИОТ