Jaime A. Ramirez, William P.D. Figueiredo, Joao Francisco C. Vale, Isabela D. Metzker, Rafael G. Santos, Matheus S. Mattos, Elizabeth R.S. Camargos and David A. Lowther
– This paper aims to investigate the electroporation phenomenon in a single cell exposed to ultra short (μs) and high voltage (kV) electric pulses.
Abstract
Purpose
This paper aims to investigate the electroporation phenomenon in a single cell exposed to ultra short (μs) and high voltage (kV) electric pulses.
Design/methodology/approach
The problem is addressed by two complementary approaches. First, numerical simulations based on an asymptotic approximation derived from the Smoluchowski theory are used to calculate the pore generation, growth and size evolution at the membrane of a spherical cell model, immersed in a suspension medium and consisting of cytoplasm and membrane. The numerical calculations are solved using the finite difference method. Second, an in vitro experiment with LLC-MK2 cells is carried out in which electroporation was monitored with molecules of propidium iodide. This part also comprehended the design and manufacturing of a portable electric pulse generator capable of providing rectangular pulses with amplitude of 1,000 V and duration in the range of 1-μs to 100-μs. The pulse generator is composed of three modules: a high voltage DC source, a control module, and an energy storage and high voltage switching.
Findings
The numerical simulations considered a 5-μm radius cell submitted to a 500 kV/m rectangular electric pulse for 1-μs. The results indicate the formation of around 3,500 pores at the cell membrane, most of them, around 950, located at the poles of the cell aligned to the applied electric pulse, with radii sizes varying from 0.5-nm to 13-nm. The in vitro experiment considered exposition of LLC-MK2 cells to pulses of 200 V, 500 V, and 700 V, and 1-μs. Images from fluorescence microscopy exhibit the LLC-MK2 cells with intense red, a strong evidence of the electroporation.
Originality/value
The work presents a thorough study of the electroporation phenomenon combining two complementary approaches, a rigorous numerical simulation and a detailed in vitro experiment.
Details
Keywords
Iara Sibele Silva, Patrícia Bernardes, Felipe Diniz Ramalho, Petr Iakovlevitch Ekel, Carlos Augusto Paiva da Silva Martins and Matheus Pereira Libório
The purpose of this paper is to present the innovation management program (IMP) (FAZ Program) and analyze its results according to the public policy goals that support it…
Abstract
Purpose
The purpose of this paper is to present the innovation management program (IMP) (FAZ Program) and analyze its results according to the public policy goals that support it (Pró-Inova) suggesting improvements.
Design/methodology/approach
Intensive-direct-observation method in 43 companies; systematic data gathering and analysis (172 meeting documents); and innovation maturity diagnostics in 30 companies between August 2013 and May 2016.
Findings
The FAZ Program success rate according to the Pró-Inova goals achieved 81 percent. The percentage of completion of FAZ activities decreases during its implementation from 100 percent (strategic module) to 74 percent (management module) and ending at 46 percent (project module). The maturity for innovation of these committees/teams is decisive for those percentages. Companies whose maturity for innovation of the strategic committee and the organizational team are above average or excellent have, respectively, 1.8 and 1.7 times greater probability of implementing the program successfully.
Research limitations/implications
The FAZ Program represents only 4 percent of the programs supported by Pró-Inova. The innovative products, processes and businesses produced by the FAZ Program implementation are not measured. These innovations usually happen several years after an innovative management models implementation.
Practical implications
The maturity for innovation diagnosis is useful both to evaluate the company’s innovation capacity and to predict its chances of implementing the program successfully. Adjusting the structure of the model (e.g. PDCA cycle for the organizational module) and improving the program’s implementation (e.g. ensure management module resources and maturity for innovation capacity) can increase the program’s success rate.
Originality/value
Previous research works on IMPs supported by Pro-Inova focus on describing their methodology or benefits. The results allow answering what and how one of these programs offers in a return to the public innovation support received.