A novel technique for the formation of embryoid bodies inside liquid marbles

The significant and inherent limitations associated with commonly used methods of in vitro embryoid body (EB) formation motivate the development of novel, facile, efficient and reproducible techniques. In this study we report the possibility of using ''liquid marbles'' as facile and efficient micro bioreactors for in vitro EB formation. To exploit liquid marbles as micro biological reactors, embryonic stem cells (ES cells) were inoculated into liquid marbles containing embryonic cell growth medium. Herein we show how the confined internal space of a liquid marble, along with the porous and non-adhesive properties of the highly hydrophobic liquid marble shell, can provide the necessary conditions for the formation of uniform EBs inside liquid marbles. Factors such as the powder particle size, the liquid marble volume and the cell seeding density inside each liquid marble were also investigated to evaluate the effects of varying experimental conditions on the efficiency of EB formation within a liquid marble

Preparation and Characterization of Microfiltration Membrane Embedded with Silver Nano-Particles,

ABSTRACT: The microfiltration 0.2 µm Cellulose Acetate (CA) membrane was modified by embedding antibacterial silver nano-particles in the membrane pores. This novel technique was developed to enhance the capability of the microfiltration membrane for removing microorganism including bacteria. The prepared membrane was characterized using Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDS), water contact angle measurement and Differential Scanning Calorimetry (DSC). Membrane performance was elucidated by flux and rejection measurements using water samples from the pond of a public recreational park in Tehran. For rejection capability of the membrane, the availability of filament and c-shaped species of the phyla Actinobacteria and Spirochetas in the permeate side of the membrane was estimated. Contrary to virgin membrane, the modified membrane was able to remove 100% of Actinobacteria and Spirochetas species from the infected water. Moreover, the wettability of the modified membrane was remarkably changed leading to higher water flux. A potential application of the modified Ag-CA membrane is "sterile filtration" of temperature sensitive fluids

Identifying the qualitative components of gamification in the working environment of knowledge-based companies

Although digitization brings important possibilities, implementing its technologies in practice can be challenging. One of the current major developments in this field is to discover the potential of gamification for the empowerment of knowledge-based companies. Based on this, the current research was conducted with the aim of identifying the qualitative components of gamification implementation in the working environment of knowledge-based companies. This research has a qualitative approach, through in-depth semi-structured interviews, it has compiled and validated the conceptual framework with thematic analysis method. The statistical population includes experts and experts of knowledge-based companies, among whom 12 people were selected by purposeful sampling and participated in this study. The number of samples follows the rule of saturation. The findings of the research show that concepts were identified in the form of 4 main themes, including the acceptance process with 2 organizing themes, promotion strategies with 4 organizing themes, development and design strategies with 4 organizing themes, evaluation and implementation platforms with 3 organizing themes Gamification actually provides various possibilities to increase the motivation of employees for knowledge-based activities. But to reveal its potential, it needs a suitable environment

The potential of liquid marbles for biomedical applications: a critical review

Liquid marbles (LM) are freestanding droplets covered by micro/nanoparti- cles with hydrophobic/hydrophilic properties, which can be manipulated as a soft solid. The phenomenon that generates these soft structures is regarded as a different method to generate a superhydrophobic behavior in the liquid/ solid interface without modifying the surface. Several applications for the LM have been reported in very different fields, however the developments for bio- medical applications are very recent. At first, the LM properties are reviewed, namely shell structure, LM shape, evaporation, floatability and robustness. The different strategies for LM manipulation are also described, which make use of magnetic, electrostatic and gravitational forces, ultraviolet and infrared radiation, and approaches that induce LM self-propulsion. Then, very distinc- tive applications for LM in the biomedical field are presented, namely for diagnostic assays, cell culture, drug screening and cryopreservation of mam- malian cells. Finally, a critical outlook about the unexplored potential of LM for biomedical applications is presented, suggesting possible advances on this emergent scientific area. The authors acknowledge funding from the European Research Council grant agreement ERC-2012-ADG 20120216-321266 for project ComplexiTE. N. M. Oliveira acknowledges the financial support from Portuguese Foundation for Science and Technology - FCT (Grant SFRH/BD/73172/2010), from the financial program POPH/FSE from QREN.info:eu-repo/semantics/publishedVersio

Liquid Marble Actuator for Microfluidic Logic Systems

© 2018, The Author(s). A mechanical flip-flop actuator has been developed that allows for the facile re-routing and distribution of liquid marbles (LMs) in digital microfluidic devices. Shaped loosely like a triangle, the actuating switch pivots from one bistable position to another, being actuated by the very low mass and momentum of a LM rolling under gravity (~4 × 10 −6 kg ms −1 ). The actuator was laser-cut from cast acrylic, held on a PTFE coated pivot, and used a PTFE washer. Due to the rocking motion of the switch, sequential LMs are distributed along different channels, allowing for sequential LMs to traverse parallel paths. This distributing effect can be easily cascaded, for example to evenly divide sequential LMs down four different paths. This lightweight, cheap and versatile actuator has been demonstrated in the design and construction of a LM-operated mechanical multiplication device — establishing its effectiveness. The actuator can be operated solely by gravity, giving it potential use in point-of-care devices in low resource areas

Mapping outcomes of liquid marble collisions

© 2019 The Royal Society of Chemistry. Liquid marbles (LMs) have many promising roles in the ongoing development of microfluidics, microreactors, bioreactors, and unconventional computing. In many of these applications, the coalescence of two LMs is either required or actively discouraged, therefore it is important to study liquid marble collisions and establish parameters which enable the desired collision outcome. Recent reports on LM coalescence have focused on either two mobile LMs colliding, or an accelerating LM hitting a sessile LM with a backstop. A further possible scenario is the impact of a mobile LM against a non-supported static LM. This paper investigates such a collision, using high-speed videography for single-frame analysis. Multiple collisions were undertaken whilst varying the modified Weber number (We∗) and offset ratios (X∗). Parameter ranges of 1.0 0.25, and We∗ 1.55 resulted in 100% non-coalescence. Additionally, observations of LMs moving above a threshold velocity of 0.6 m s -1 have revealed a new and unusual deformation. Comparisons of the outcome of collisions whilst varying both the LM volume and the powder grain size have also been made, revealing a strong link. The results of this work provide a deeper understanding of LM coalescence, allowing improved control when designing future collision experiments

Bioactive Hydrogel Marbles

Liquid marbles represented a signifcant advance in the manipulation of fuids as they used particle flms to confne liquid drops, creating a robust and durable soft solid. We exploit this technology to engineering a bioactive hydrogel marble (BHM). Specifcally, pristine bioactive glass nanoparticles were chemically tuned to produce biocompatible hydrophobic bioactive glass nanoparticles (H-BGNPs) that shielded a gelatin-based bead. The designed BHM shell promoted the growth of a bone-like apatite layer upon immersion in a physiological environment. The fabrication process allowed the efcient incorporation of drugs and cells into the engineered structure. The BHM provided a simultaneously controlled release of distinct encapsulated therapeutic model molecules. Moreover, the BHM sustained cell encapsulation in a 3D environment as demonstrated by an excellent in vitro stability and cytocompatibility. The engineered structures also showed potential to regulate a pre-osteoblastic cell line into osteogenic commitment. Overall, these hierarchical nanostructured and functional marbles revealed a high potential for future applications in bone tissue engineering.Portuguese Foundation for Science and Technology − FCT (Grant Nos SFRH/BD/73174/2010 and SFRH/BD/73172/2010, respectively), from the program POPH/FSE from QREN. The authors would like to acknowledge the support of the European Research Council grant agreement ERC-2014-ADG-669858 for project ATLASinfo:eu-repo/semantics/publishedVersio

Tumor inside a pearl drop

The confined internal space of a liquid marble, as well as its porous and non-adhesive shell, offers an attractive application possibility - accommodating living cells inside liquid marbles. Cancer cells in suspension may aggregate to form three dimensional structures, also known as cancer cell spheroids (CCS). In this study, CCS formation inside liquid marble is investigated. This liquid marble application opens significant and novel avenues for biomedical applications and cancer research