Microfluidics for 3D Cell and Tissue Cultures: Microfabricative and Ethical Aspects Updates.

The necessity to improve in vitro cell screening assays is becoming ever more important. Pharmaceutical companies, research laboratories and hospitals require technologies that help to speed up conventional screening and therapeutic procedures to produce more data in a short time in a realistic and reliable manner. The design of new solutions for test biomaterials and active molecules is one of the urgent problems of preclinical screening and the limited correlation between in vitro and in vivo data remains one of the major issues. The establishment of the most suitable in vitro model provides reduction in times, costs and, last but not least, in the number of animal experiments as recommended by the 3Rs (replace, reduce, refine) ethical guiding principles for testing involving animals. Although two-dimensional (2D) traditional cell screening assays are generally cheap and practical to manage, they have strong limitations, as cells, within the transition from the three-dimensional (3D) in vivo to the 2D in vitro growth conditions, do not properly mimic the real morphologies and physiology of their native tissues. In the study of human pathologies, especially, animal experiments provide data closer to what happens in the target organ or apparatus, but they imply slow and costly procedures and they generally do not fully accomplish the 3Rs recommendations, i.e., the amount of laboratory animals and the stress that they undergo must be minimized. Microfluidic devices seem to offer different advantages in relation to the mentioned issues. This review aims to describe the critical issues connected with the conventional cells culture and screening procedures, showing what happens in the in vivo physiological micro and nano environment also from a physical point of view. During the discussion, some microfluidic tools and their components are described to explain how these devices can circumvent the actual limitations described in the introduction.

Intrinsically High Capacity of Animal Cells From a Symbiotic Cnidarian to Deal With Pro-Oxidative Conditions.

The cnidarian-dinoflagellate symbiosis is a mutualistic intracellular association based on the photosynthetic activity of the endosymbiont. This relationship involves significant constraints and requires co-evolution processes, such as an extensive capacity of the holobiont to counteract pro-oxidative conditions induced by hyperoxia generated during photosynthesis. In this study, we analyzed the capacity of Anemonia viridis cells to deal with pro-oxidative conditions by in vivo and in vitro approaches. Whole specimens and animal primary cell cultures were submitted to 200 and 500 µM of H2O2 during 7 days. Then, we monitored global health parameters (symbiotic state, viability, and cell growth) and stress biomarkers (global antioxidant capacity, oxidative protein damages, and protein ubiquitination). In animal primary cell cultures, the intracellular reactive oxygen species (ROS) levels were also evaluated under H2O2 treatments. At the whole organism scale, both H2O2 concentrations didn't affect the survival and animal tissues exhibited a high resistance to H2O2 treatments. Moreover, no bleaching has been observed, even at high H2O2 concentration and after long exposure (7 days). Although, the community has suggested the role of ROS as the cause of bleaching, our results indicating the absence of bleaching under high H2O2 concentration may exculpate this specific ROS from being involved in the molecular processes inducing bleaching. However, counterintuitively, the symbiont compartment appeared sensitive to an H2O2 burst as it displayed oxidative protein damages, despite an enhancement of antioxidant capacity. The in vitro assays allowed highlighting an intrinsic high capacity of isolated animal cells to deal with pro-oxidative conditions, although we observed differences on tolerance between H2O2 treatments. The 200 µM H2O2 concentration appeared to correspond to the tolerance threshold of animal cells. Indeed, no disequilibrium on redox state was observed and only a cell growth decrease was measured. Contrarily, the 500 µM H2O2 concentration induced a stress state, characterized by a cell viability decrease from 1 day and a drastic cell growth arrest after 7 days leading to an uncomplete recovery after treatment. In conclusion, this study highlights the overall high capacity of cnidarian cells to cope with H2O2 and opens new perspective to investigate the molecular mechanisms involved in this peculiar resistance.

Biosensors to Monitor Cell Activity in 3D Hydrogel-Based Tissue Models.

Three-dimensional (3D) culture models have gained relevant interest in tissue engineering and drug discovery owing to their suitability to reproduce in vitro some key aspects of human tissues and to provide predictive information for in vivo tests. In this context, the use of hydrogels as artificial extracellular matrices is of paramount relevance, since they allow closer recapitulation of (patho)physiological features of human tissues. However, most of the analyses aimed at characterizing these models are based on time-consuming and endpoint assays, which can provide only static and limited data on cellular behavior. On the other hand, biosensing systems could be adopted to measure on-line cellular activity, as currently performed in bi-dimensional, i.e., monolayer, cell culture systems; however, their translation and integration within 3D hydrogel-based systems is not straight forward, due to the geometry and materials properties of these advanced cell culturing approaches. Therefore, researchers have adopted different strategies, through the development of biochemical, electrochemical and optical sensors, but challenges still remain in employing these devices. In this review, after examining recent advances in adapting existing biosensors from traditional cell monolayers to polymeric 3D cells cultures, we will focus on novel designs and outcomes of a range of biosensors specifically developed to provide real-time analysis of hydrogel-based cultures.

In Vitro Studies on Nasal Formulations of Nanostructured Lipid Carriers (NLC) and Solid Lipid Nanoparticles (SLN).

The nasal route has been used for many years for the local treatment of nasal diseases. More recently, this route has been gaining momentum, due to the possibility of targeting the central nervous system (CNS) from the nasal cavity, avoiding the blood-brain barrier (BBB). In this area, the use of lipid nanoparticles, such as nanostructured lipid carriers (NLC) and solid lipid nanoparticles (SLN), in nasal formulations has shown promising outcomes on a wide array of indications such as brain diseases, including epilepsy, multiple sclerosis, Alzheimer's disease, Parkinson's disease and gliomas. Herein, the state of the art of the most recent literature available on in vitro studies with nasal formulations of lipid nanoparticles is discussed. Specific in vitro cell culture models are needed to assess the cytotoxicity of nasal formulations and to explore the underlying mechanism(s) of drug transport and absorption across the nasal mucosa. In addition, different studies with 3D nasal casts are reported, showing their ability to predict the drug deposition in the nasal cavity and evaluating the factors that interfere in this process, such as nasal cavity area, type of administration device and angle of application, inspiratory flow, presence of mucoadhesive agents, among others. Notwithstanding, they do not preclude the use of confirmatory in vivo studies, a significant impact on the 3R (replacement, reduction and refinement) principle within the scope of animal experiments is expected. The use of 3D nasal casts to test nasal formulations of lipid nanoparticles is still totally unexplored, to the authors best knowledge, thus constituting a wide open field of research.

Biomimetic synthesis of functional silver nanoparticles using hairy roots of Panax ginseng for wheat pathogenic fungi treatment.

Presently, multifunctional silver nanoparticles (AgNPs) show a rapid growth in various commercial applications, leading to increasing demand for new eco-friendly manufacturing technologies. An array of genetic engineering tools can be used to increase the yield in the production of AgNPs using various biological systems. The present study reports a green chemistry approach for the biological synthesis of AgNPs using extracts from non-transformed callus, rolC-transgenic callus and hairy roots of Panax ginseng and an evaluation of their efficacy against crop-damaging fungal pathogens. All types of ginseng cell lines promote the reduction of silver nitrate and formation of spherical AgNPs with an average diameter of 50-90 nm. Notably, hairy root extract possessed the maximal reduction potential among the studied cell lines probably due to higher secondary metabolite content. The biosynthesized nanoparticles were highly toxic against several wheat fungal pathogens including Fusarium graminearum, F. avenaceum, F. poae, and F. sporotrichioides, which are associated with fusarium head blight disease in cereals. Furthermore, the antifungal activity of nanosilver was successfully utilized for surface sterilization of infected wheat kernels without any negative effect on seed germination capability.

An Interpenetrating Alginate/Gelatin Network for Three-Dimensional (3D) Cell Cultures and Organ Bioprinting.

Crosslinking is an effective way to improve the physiochemical and biochemical properties of hydrogels. In this study, we describe an interpenetrating polymer network (IPN) of alginate/gelatin hydrogels (i.e., A-G-IPN) in which cells can be encapsulated for in vitro three-dimensional (3D) cultures and organ bioprinting. A double crosslinking model, i.e., using Ca2+ to crosslink alginate molecules and transglutaminase (TG) to crosslink gelatin molecules, is exploited to improve the physiochemical, such as water holding capacity, hardness and structural integrity, and biochemical properties, such as cytocompatibility, of the alginate/gelatin hydrogels. For the sake of convenience, the individual ionic (i.e., only treatment with Ca2+) or enzymatic (i.e., only treatment with TG) crosslinked alginate/gelatin hydrogels are referred as alginate-semi-IPN (i.e., A-semi-IPN) or gelatin-semi-IPN (i.e., G-semi-IPN), respectively. Tunable physiochemical and biochemical properties of the hydrogels have been obtained by changing the crosslinking sequences and polymer concentrations. Cytocompatibilities of the obtained hydrogels are evaluated through in vitro 3D cell cultures and bioprinting. The double crosslinked A-G-IPN hydrogel is a promising candidate for a wide range of biomedical applications, including bioartificial organ manufacturing, high-throughput drug screening, and pathological mechanism analyses.

Phytochemical Screening of Callus and Cell Suspensions Cultures of Thevetia peruviana

Abstract Thevetia peruviana is an ornamental shrub grown-up in many tropical region of the world. This plant produces secondary metabolites with biological properties of interest for the pharmaceutical industry. The objective was to determine the secondary metabolites profile of callus and cell suspension cultures of T. peruviana and compare them with those from explant (fruit pulp). Extracts in 50% aqueous ethanol and ethyl acetate were prepared. The phytochemical analysis was performed using standard chemical tests and thin layer chromatography. In addition, total phenolic and flavonoids compounds (TPC and TFC), total cardiac glycosides (TCG) and total antioxidant activity (TAA) was determined during the cell suspension growth. Phenolic chemical profile was also analyzed by high performance liquid chromatography (HPLC). Common metabolites (alkaloids, amino acids, antioxidants, cardiac glycosides, leucoanthocyanidins, flavonoids, phenols, sugars and triterpenes) were detected in all samples. The maximum production of extracellular TCG, TPC, TFC and TAA in cells suspensions were at 6-12 days; in contrast, intracellular content was relatively constant during the exponential grown phase (0 to 12-days). HPLC analysis detected one compound with retention time at 11.6 min; this compound was tentatively identified as dihydroquercetin, a flavonoid with anti-cancer properties. These results provide evidence on the utility of the in vitro cell cultures of T. peruviana for valuable pharmaceutical compounds production.

EVALUACIÓN DE LA RESPUESTA DE CULTIVOS CELULARES DE (Fouquieria splendens ssp. breviflora) fouquieriaceae BAJO ESTRES HÍDRICO / Assessment of (Fouquieria splendens ssp. breviflora) Cell Cultures Response Under Water Stress

RESUMEN Los cultivos de células vegetales son sistemas experimentales homogéneos altamente controlables que permiten el estudio de adaptaciones bajo condiciones de estrés hídrico, sin la interferencia de los diferentes tejidos y estados del desarrollo vegetal. Una aproximación para comprender esas adaptaciones, es la aparición de proteínas inducidas, resultado de la alteración en la expresión génica. El presente trabajo analizó la respuesta de cultivos de células de Fouquieria splendens ssp. breviflora, expuestos a ácido abscísico (ABA), mediante la caracterización electroforética en cantidad y calidad de las proteínas inducibles de estrés. Se registraron polipéptidos de bajo peso molecular (< 35kDa), comunes bajo la exposición a 10 mM, seguida la asociación con 20 y 30 mM de ABA, quedando aislada la respuesta de la condición de células en cultivo sin la presencia de éste.

ABSTRACT Plant cell cultures are homogenous experimental systems, highly controllable that allow the study of short and large water stress adaptations without the interference of the different tissues and development ofplants. An approach to understand these adaptations is through the presence of induced proteins; as a result of changes in genetic expression. This work analyze the response of Fouquieria splendens ssp. breviflora cell cultures exposed to abscisic acid (ABA), through the electrophoretic characterization of quantity and quality of stress induced proteins. There were recorded low molecular weight polypeptides (< 35kDa), common in experiments under ABA 10mM, followed by the association with 20 and 30mM ABA conditions, with a particularly response of cell cultures without the stress agent.

Effects of chitosan on the protein profile of grape cell culture subcellular fractions.

Grapevine is a large source of healthy polyphenols for human diet, and red table-grapes and wines are the main source of stilbenes. These compounds are important both in the plant defence system and for human health. In the present study, Vitis vinifera cv. Barbera cell cultures were treated with 50 µg/mL chitosan and proteomic analyses on soluble and membrane subcellular fractions were performed against suitable controls. Three soluble stilbene synthase protein spots, four stilbene synthase spots in the microsomal fraction and four spots of membrane ATPase subunits were identified, the accumulation of which was modulated in response to chitosan treatment. Present proteomic and immunolocalisation data seem to provide evidence supporting the hypothesis that a stilbene biosynthetic multi-enzyme complex is associated with the intracellular membrane. In addition, proteomic analyses showed a general decrease in the accumulation of proteins belonging to different primary metabolism pathways, both in the soluble and membrane fractions. In particular, energy, sugar and amino acid metabolisms were down-regulated as a consequence of chitosan and acetic acid treatments. These metabolic modifications could lead to a consistent change in the profile and amount of metabolites stored in grape berries, with consequent effects on taste, flavour, organoleptic and nutraceutical properties of derived food products.

Citotoxicidad in vitro de extractos laticiferos de Calotropis procera (Aiton) W.T. Aiton y Pedilanthus tithymaloides (L.) Poit / In vitro cytotoxicity of laticifers extracts from Calotropis procera (Aiton) WT and Pedilanthus tithymaloides (L) Poit

In order to assess the anticancer action of extracts obtained by latex from Calotropis procera and Pedilanthus tithymaloides, samples were collected from adult plants. Soluble proteins were extracted with 16 uL of 50 mM sodium acetate pH 5/ug integral latex and centrifugation at 16,000 x g for 15 min, the supernatant was named "latex crude extract" (LCE). The "latex methanolic extract" (LME) was obtained on dried latex. Both extracts were tested in vitro by cytotoxic and cytostatic activity in Jurkat cell cultures. Cellular viability, proliferation, necrosis and apoptosis were evaluated. LCE and LME of C. procera were found with cytotoxic and cytostatic activity after 24 incubation hours (p < 0,05) with doses from 1ug/mL. The LCE and LME of P. tithymaloides presented cytotoxic effect (p < 0,05) from 50 ug/mL and from 1ug/mL, respectively.

Con el objetivo de evaluar el potencial anticanceroso de extractos de látex de Calotropis procera y Pedilanthus tithymaloides se colectaron muestras de plantas adultas. Las proteínas solubles fueron extraídas con 16 uL de acetato de sodio 50 mM pH 5/ug de látex integral y centrifugación a 16.000 x g durante 15 min, denominándose al sobrenadante “extracto crudo de látex” (ECL). El “extracto metanólico de látex” (EML) se obtuvo sobre látex deshidratado. Ambos extractos fueron probados en su actividad citotóxica y citostática in vitro sobre cultivos de células Jurkat. Se realizaron estudios de viabilidad, proliferación, necrosis y apoptosis celular. El ECL y el EML de C. procera presentaron actividad citotóxica y citostática después de 24 y 48 horas de incubación (p < 0,05) con dosis desde 1 ug/mL. Los ECL y EML de P. tithymaloides presentaron efectos citotóxicos (p < 0,05) a partir de 50 ug/mL y desde 1 ug/mL respectivamente.