DODAB:MO versus novel liposomes for protein delivery: comparing toxicity and encapsulation efficiency

UID/BIA/04050/2019, funded by national funds through the FCT IP, and project FUN2CYT: Harnessing the potential for biomedical applications of pleiotropic cytokines LIF and oncostatin M (PTDC/BTM-MAT/30568/2017, POCI-01-0145-FEDER-030568) supported by POCI through FEDER and FCT IPinfo:eu-repo/semantics/publishedVersio

Counter ions and constituents combination affect DODAX: MO nanocarriers toxicity in vitro and in vivo

Liposomes have received extensive attention as nanocarriers for bioactive compounds due to their good biocompatibility, possibility of targeting and incorporation of hydrophilic and hydrophobic compounds. Although generally considered as safe, detailed knowledge of the effects induced in cells and tissues with which they interact is still underexplored. The aim of this study is to gain insight into the toxicity profile of dioctadecyldimethylammonium (DODAX) : monoolein(MO) liposomes (X is bromide or chloride), previously validated for gene therapy, by evaluating the effect of the counter ions Br− or Cl−, and of the cationic : neutral lipid molar fraction, both in vitro and in vivo. Effects on cellular metabolism and proliferation, plasma membrane integrity, oxidative stress, mitochondrial membrane potential dysfunction and ability to trigger apoptosis and necrosis were evaluated in a dose-/time-dependent manner in normal human skin fibroblasts. Also, newly fertilized zebrafish zygotes were exposed to liposomes, permitting a fast-track evaluation of the morphophysiological modifications. In vitro data showed that only very high doses of DODAX : MO induce apoptosis and necrosis, inhibit cell proliferation, and affect the metabolism and plasma membrane integrity of fibroblasts in a dose-/time-dependent manner. Furthermore, liposomes affected mitochondrial function, increasing ROS accumulation and disturbing mitochondrial membrane potential. DODAC-based liposomes were consistently more toxic when compared to DODAB-based formulations; furthermore, the inclusion of MO was found to reduce toxicity, in contrast to liposomes with cationic DODAX only, especially in DODAB : MO (1 : 2) nanocarriers. These results were corroborated, in a holistic approach, by cytotoxicity profiling in five additional human cell lines, and also with the zebrafish embryotoxicity testing, which constitutes a sensitive and informative tool and accurately extends cell-based assays.This work was supported by the strategic programme UID/BIA/ 04050/2013 (POCI-01-0145-FEDER-007569) funded by national funds through the FCT I.P. and by the ERDF through the COMPETE2020 – Programa Operacional Competitividade e Internacionalização (POCI); by FEDER through POFCCOMPETE; and by national funds from FCT through PEstC/FIS/UI0607/2013 (CFUM) and PTDC/QUI/69795/2006. Ana Oliveira held the scholarship, SFRH/BD/68588/2010. Marisa P. Sárria holds a Marie Curie COFUND fellowship funding from the European Union’s7 th Framework Programme for research, technological development and demonstration under grant agreement 600375. The authors are grateful to the technical support of Marinnova – Marine and Environmental Innovation, Technology and Services, a R&I company anchored to the Centre of Marine and Environmental Research (CIIMAR – University of Porto, Portugal), focused at providing innovative services and products in the field of marine and environmental sciences

A systematic review and critical analysis of the role of graphene-based nanomaterials in cancer theranostics

Many graphene-based materials (GBNs) applied to therapy and diagnostics (theranostics) in cancer have been developed. Most of them are hybrid combinations of graphene with other components (e.g., drugs or other bioactives, polymers, and nanoparticles) aiming toward a synergic theranostic effect. However, the role of graphene in each of these hybrids is sometimes not clear enough and the synergic graphene effect is not proven. The objective of this review is to elaborate on the role of GBNs in the studies evaluated and to compare the nanoformulations in terms of some of their characteristics, such as therapeutic outcomes and toxicity, which are essential features for their potential use as bionanosystems. A systematic review was carried out using the following databases: PubMed, Scopus, and ISI Web of Science (2013–2018). Additional studies were identified manually by consulting the references list of relevant reviews. Only English papers presenting at least one strategy for cancer therapy and one strategy for cancer diagnostics, and that clearly show the role of graphene in theranostics, were included. Data extraction and quality assessment was made by reviewer pairings. Fifty-five studies met the inclusion criteria, but they were too heterogeneous to combine in statistical meta-analysis. Critical analysis and discussion of the selected papers are presented.This research was funded by Fundação para a Ciência e Tecnologia (FCT) in the framework of the Strategic Funding UID/FIS/04650/2013 and in the ambit of the project POCI-01-0145-FEDER-032651. E.F. acknowledges the scholarship CFUM BI-10/2018 - UID/FIS/04650/2013.info:eu-repo/semantics/publishedVersio

Drug biophysical profiling using lipid-based colloidal nanosystems and human serum albumin as biomimetic interfaces

The development of new drugs is a highly complex and expensive process, so it is crucial that less promising compounds are rejected early in the discovery phase before progressing to more expensive phases. This scenario impels researchers to refine and speed up the drug discovery process and to seek tools to support decisions related to modifications of the drug chemical structure to improve drugs’ properties and thus increase the probability of success in the process of drug discovery. [1], [2] In the drug discovery process it should be considered that in physiological environment there will be reciprocal interactions between drugs and biological interfaces, such as cell membranes or plasma proteins, and from those interactions different pharmacokinetic profiles can be achieved. [3] Thus, it is important to develop in vitro high throughput methods to evaluate the pharmaceutical profile, consisting in measuring properties such as permeability, lipophilicity, plasma protein binding, and biophysical changes of the membranes, which in turn affect other properties, such as the bioavailability of a drug and its pharmacokinetic profile. [4] Herein, the characterization of a newly synthesized drug (MIT-3) will be based on the measurement of fundamental biophysical properties, which allow inferring about its ADMET profile (absorption, distribution, excretion and toxicity at the membrane level). For this purpose, lipid-based colloidal nanosystems of different compositions were prepared as membrane mimetic models and several biophysical techniques were applied: derivative spectroscopy; quenching of steady-state and time-resolved fluorescence; quenching of intrinsic fluorescence of human serum albumin; synchronous fluorescence; dynamic and electrophoretic light scattering, differential scanning calorimetry and small and wide angle x-ray diffraction. The application of these techniques allowed to predict that MIT-3 has an ubiquitous location at the membrane level, presenting good membrane permeability and a good distribution in the therapeutic target. However, it is also predicted bioaccumulation with distribution in non-therapeutic targets and under conditions of prolonged exposure the drug may cause membrane toxicity as concluded by the impairment of membrane biophysical properties. It is also possible to conclude that the biophysical techniques and the biomimetic models used, constitute a toolbox of strategies for the future evaluation of other drugs.This work was supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/FIS/04650/2013. We also acknowledge PEstC/QUI/UI0081/2013, NORTE-01-0145-FEDER-000028 and PTDC/DTP-FTO/2433/2014. F. Cagide and S. Benfeito are thankful for the pos-doctoral and doctoral grants (SFRH/BPD/74491/2010 and SFRH/BD/99189/2013 respectively). Marlene Lúcio acknowledges the exploratory project funded by FCT with the reference IF/00498/2012. Eduarda Fernandes acknowledges COMPETE 2020 “Programa Operacional Competitividade e internacionalização”.info:eu-repo/semantics/publishedVersio

Graphene-Based Nanosystems: Versatile Nanotools for Theranostics and Bioremediation

Since its revolutionary discovery in 2004, graphene— a two-dimensional (2D) nanomaterial consisting of single-layer carbon atoms packed in a honeycomb lattice— was thoroughly discussed for a broad variety of applications including quantum physics, nanoelectronics, energy efficiency, and catalysis. Graphene and graphene-based nanomaterials (GBNs) have also captivated the interest of researchers for innovative biomedical applications since the first publication on the use of graphene as a nanocarrier for the delivery of anticancer drugs in 2008. Today, GBNs have evolved into hybrid combinations of graphene and other elements (e.g., drugs or other bioactive compounds, polymers, lipids, and nanoparticles). In the context of developing theranostic (therapeutic + diagnostic) tools, which combine multiple therapies with imaging strategies to track the distribution of therapeutic agents in the body, the multipurpose character of the GBNs hybrid systems has been further explored. Because each therapy and imaging strategy has inherent advantages and disadvantages, a mixture of complementary strategies is interesting as it will result in a synergistic theranostic effect. The flexibility of GBNs cannot be limited to their biomedical applications and, these nanosystems emerge as a viable choice for an indirect effect on health by their future use as environmental cleaners. Indeed, GBNs can be used in bioremediation approaches alone or combined with other techniques such as phytoremediation. In summary, without ignoring the difficulties that GBNs still present before being deemed translatable to clinical and environmental applications, the purpose of this chapter is to provide an overview of the remarkable potential of GBNs on health by presenting examples of their versatility as nanotools for theranostics and bioremediation

European Society of Vascular Surgery (ESVS) guidelines. Invasive treatment for carotid stenosis: indications, techniques

Europejskie Towarzystwo Chirurgii Naczyniowej (ESVS) zgromadziło grupę ekspertów zajmujących się patologią tętnic szyjnych (CAD) w celu stworzenia uaktualnionych wytycznych dotyczących inwazyjnego leczenia zwężenia tętnicy szyjnej. Zalecenia oceniano, przypisując im odpowiedni poziom dowodów. Wykonanie endarterektomii tętnicy szyjnej (CEA) zaleca się u pacjentów z objawami, u których zwężenie jest większe niż 50%, jeśli częstość występowania udaru mózgu/zgonu w okresie okołooperacyjnym wynosi mniej niż 6% [A]; najlepiej, aby CEA wykonano w ciągu 2 tygodni od wystąpienia ostatnich objawów [A]. Zabieg ten zaleca się także u mężczyzn, u których nie stwierdza się objawów, w wieku poniżej 75 rż., ze zwężeniem wynoszącym 70–99%, jeśli częstość występowania udaru mózgu/zgonu w okresie okołooperacyjnym wynosi mniej niż 3% [A]. Korzyści z przeprowadzenia CEA u kobiet, u których nie występują objawy, są istotnie mniejsze niż u mężczyzn [A], dlatego wykonanie tego zabiegu powinno rozważać się tylko u młodszych kobiet bez dodatkowych obciążeń. Preferuje się przeprowadzanie angioplastyki z użyciem łaty nad pierwotnym zamknięciem tętnicy [A]. Przed zabiegiem CEA, w jego trakcie i po nim chorym należy zalecić stosowanie kwasu acetylosalicylowego w dawce dobowej 75–325 mg i terapię statynami [A]. Zabieg stentowania tętnicy szyjnej (CAS) powinno się wykonywać jedynie u pacjentów, u których przeprowadzenie zabiegu CEA wiąże się z dużym ryzykiem, w dużych ośrodkach o udokumentowanym małym ryzyku wystąpienia zgonu i udaru mózgu w okresie okołooperacyjnym lub w ramach randomizowanych kontrolowanych badań klinicznych [C]. Zabieg CAS należy wykonywać, stosując jednocześnie podwójne leczenie przeciwpłytkowe z użyciem kwasu acetylosalicylowego i klopidogrelu [A]. Wykorzystanie systemów protekcji mózgu prawdopodobnie jest korzystne [C]. Acta Angiol 2010; 16, 4: 190–21

A Bayesian Modelling of Wildfires in Portugal

In the last decade wildfires became a serious problem in Portugal due to different issues such as climatic characteristics and nature of Portuguese forest. In order to analyse wildfire data, we employ beta regression for modelling the proportion of burned forest area, under a Bayesian perspective. Our main goal is to find out fire risk factors that influence the proportion of area burned and what may make a forest type susceptible or resistant to fire. Then, we analyse wildfire data in Portugal during 1990-1994 through Bayesian beta models t

Lipid-based Nanocarriers for siRNA Delivery: Challenges, Strategies and the Lessons Learned from the DODAX: MO Liposomal System

The possibility of using the RNA interference (RNAi) mechanisms in gene therapy was one of the scientific breakthroughs of the last century. Despite the extraordinary therapeutic potential of this approach, the need for an efficient gene carrier is hampering the translation of the RNAi technology to the clinical setting. Although a diversity of nanocarriers has been described, liposomes continue to be one of the most attractive siRNA vehicles due to their relatively low toxicity, facilitated siRNA complexation, high transfection efficiency and enhanced pharmacokinetic properties. This review focuses on RNAi as a therapeutic approach, the challenges to its application, namely the nucleic acids’ delivery process, and current strategies to improve therapeutic efficacy. Additionally, lipid-based nanocarriers are described, and lessons learned from the relation between biophysical properties and biological performance of the dioctadecyldimethylammonium:monoolein (DODAX: MO) system are explored. Liposomes show great potential as siRNA delivery systems, being safe nanocarriers to protect nucleic acids in circulation, extend their half-life time, target specific cells and reduce off-target effects. Nevertheless, several issues related to delivery must be overcome before RNAi therapies reach their full potential, namely target-cell specificity and endosomal escape. Understanding the relationship between biophysical properties and biological performance is an essential step in the gene therapy field.This work was further supported by FEDER through POFC-COMPETE and by national funds from Fundacao para a Ciencia e a Tecnologia (FCT), through the projects PEst-OE/BIA/UI4050/2014 (CBMA) and PEst-C/FIS/UI0607/2013 (CFUM). Ana Oliveira was the recipient of a FCT scholarship (SFRH/BD/68588/2010). The authors would also like to acknowledge Andre Seixas Pereira for all the assistance with figures and graphs.info:eu-repo/semantics/publishedVersio