Conflict of interest

high-density regions are representing the region formed by the lipid membrane, which in this case is presented as the region with the highest concentration (in yellow) in the four cases. In addition, in the four cases, they present a redder region in the center of the map; this indicates that the density of the lipids is lower, as expected. Density maps also show that the nanoliposome is stable for 4.8 μs of simulation, since the lecithin molecules do not spread throughout the simulation box nor do they collapse in the aqueous core to form a micelle; this was possible thanks to the previous analysis where we found the optimal concentration of

Mean size of the nanoliposome and encapsulation efficiency (EE) as a function of concentration of capsaicin.

Concentration of capsaicin (Mn) Size (nm) (nm) EE (%) (%) 17.95 0.46 96.27 0.69 18.01 0.61 96.93 0.36 17.90 0.21 96.81 0.35 17.97 0.16 96.94 0.25

In our previous study [31], we observed the formation of a nanoliposome based on lecithin was carried out with approximately 7000 molecules of lecithin, but in that study, the presence of natural polymers such as chitosan was included, a

In this chapter, simulations at the mesoscopic scale were used to systematically study the self-assembly of liposomes and their potential applications toward the delivery of drugs. The advantages offered by the mesoscopic methods such as DPD over other simulation methods such as MD were exposed; additionally, the acceleration that the DPD simulations have achieved through the new GPUs technologies was also covered. With these technologies, we show simulations in the microsecond scale with a system composed of 150,000 particles in the process of self-assembly of liposomes. We show the optimal conditions for the formation of liposomes in function of the lecithin concentration to achieve a good capsaicin encapsulation. Our percentage of EE obtained is quite acceptable with respect to experimental

Derived from the results obtained in the density maps of Figure 4, we proceeded to make an analysis on the encapsulation efficiency (EE). It has been reported that both size and EE are key variables in the preparation of liposomes [47]. However, these variables are difficult to control at the laboratory level even with sophisticated experimental equipment. Computational tools such as DPD are ideal for guiding experiments. The size and EE for the system analyzed in this work are show in Table 2. EE is obtained from the following equation: EE = ((CapsT CapsF)/CapsT) 100, where CapsT is the total concentration of capsaicin in the system and CapsF is the free capsaicin in solution. The percentage of EE for the capsaicin obtained in this work was of 96%, which is very close to that reported experimentally of 92% [48], besides, is very similar to the obtained percentage in our previous study, where the presence of chitosan polymer was included [31].

lecithin molecules in the self-assembly process.

component that is not present in these simulations.

measurements and simulation studies of similar systems.

4. Conclusions

64

Table 2.

Liposomes - Advances and Perspectives

The authors declare that they have no competing interests.
