Permeabilización de biomembranas con péptidos policatiónicos y pulsos eléctricos
- Autores: Diego Alejandro Ortiz Mejía
- Directores de la Tesis: Víctor Lemehsko (dir. tes.)
- Lectura: En la Universidad Nacional de Colombia (UNAL) ( Colombia ) en 2020
- Idioma: español
- Materias:
- Enlaces
- Tesis en acceso abierto en: repositorio.unal.edu.co
- Resumen
Amphipathic polycationic peptides represent the Antimicrobial system of humans, animals and plants, their ability to permeabilize, in a potential way, the pathogenic microorganisms of plasma membrane is peculiar. The objective of this work was the evaluation of the possibility to increase permeabilization of biomembranes by amphipathic polycationic peptides and electrical pulses. An electroporator for biological samples and an electroporation cell were designed, which allow for the monitoring of permeabilization of live cells in real time, measuring transmittance, dispersion of light and temperature (patent # 14245762 approved, 2017). Plasma membrane permeabilization in red blood cells was performed with electrical pulses; bipolar pulses reached permeabilization between 4 to 31% of the result for bimonopolar pulses, this indicates that in the case of bipolar pulses, there is an effect of cancellation in the permeabilization by the second pulse, opposite in polarity, to the first pulse. Red blood cells permeabilization by polycationic peptides wasn’t significant, but applying both, with bimonopolar electrical pulses, the increase was significant (synergistic effect). Permeabilization cancellation effect in cell suspension was observed with polycationic peptides and bipolar electrical pulses. Between 4 and 14% of the permeabilization achieved if the pulses are bimonopolar. The cancellation degree with the second pulse of the opposite polarity decreases with increasing time between the first and the second pulse, in the case of bipolar pulses. Additionally, the modulation of the permeabilization of red blood cells with osmotic pressure, or with the surface potential of the membrane was shown. Cell permeabilization with polycationic peptides and electrical pulses is significantly increased in the hypotonic incubation medium, for example bimonopolar pulses and BTM-P4 peptide, it can reach up to 2,8 times more permeabilization than in the case of an isotonic incubation medium. The permeabilization of the cells is also greater if there is an increase in the negative surface potential of the 4 membrane, for example, with bimonopolar pulses and an increase in the negative surface potential with deoxycholate, there is 1,8 times more permeabilization of the cells. The results obtained demonstrate the possibility of activity increasing of polycationic peptides and modulating the degree and time of cell permeabilization by changing characteristics of the electrical pulses.
