**Acknowledgements**

one could clearly identify the kinetoplast and nucleus cell, but no significant morphological

In the case of the colonies exposed to NR/NZF nanocomposite samples (Figure 13 (b)), one can identify a linear decrease in intensity of the logarithmic phase, depending of increasing concentration of nanoparticles, indicating that the presence of such nanoparticles difficult culture protein consumption and cell division by the parasite. However, a slight reduction (lower than 20%) can still be noticeable to the generation time of the colonies. With a smaller amount of parasites in culture and limited capacity of nutritional consumption in the envi‐ ronment, there is a smaller stationary phase and a fall phase greater than that of control colonies

Comparing the morphological characteristics of the parasites exposed to NR/NZF-5phr nanocomposites with colony control parasites [43, 44], there is a clear morphological difference in cell design. Control parasites has elongated cell bodies, while for parasites in contact with

Whereas both types of nanoparticles have nanometric sizes, the first factor to justify the identified differences is that the sum of factors such as differences in crystallinity, surface area, micro-deformations of the crystal lattice, cell volume and especially chemical composition that generate surface characteristics particular to each nanoparticle type is responsible for the differences noted in each colony. However, intrinsic interactions between cells and magnetic/ ferroelectric nanoparticle properties, which would help to explain the high specificity exhib‐ ited by nanoparticles against leishmaniasis parasites and not against mammalian cells can not

Modified polyol method was used in the chemical synthesis of potassium strontium niobate ferroelectric oxide with stoichiometry KSr2Nb5O15 and of nickel zinc ferrite paramagnetic oxide, stoichiometry Ni0, 5Zn0, 5Fe2O4. Single-phase ceramic phases with average crystallite size in nanometric scale were obtained. Using XRD and AFM essays, average crystallite size and particle surface parameters could be determined, mainly. We employed a method for the preparation of functional composites and nanocomposites based on vulcanized natural rubber, grounded in the dry mixing of the constituents using a open chamber mixing. A vulcanization system based on sulfur (S8), suitable for natural rubber and ceramic nanoparticles was used. The development of a potential application for composites and nanocomposites based on vulcanized natural rubber was started and the preliminary results are encouraging, namely: use of paramagnetic and ferroelectric nanocomposites as modulating agents of the develop‐

differences were observed, confirming the similarity of the curves in Figure 13 (a).

than the sample and exposed to natural rubber samples.

436 Leishmaniasis - Trends in Epidemiology, Diagnosis and Treatment

be discarded, although less likely.

ment of colonies of *Leishmania braziliensis* parasites.

**4. Conclusions**

NR/NZF-5phr, the cell body has approximately a circular shape.

The authors would want to acknowledge the Brazilian research agencies FAPESP, CAPES and CNPq for financial support, the graduate program of Materials Science and Technolo‐ gy, Carlos Gomes Barbosa-Filho and Dr. Josué de Moraes for the biological tests, Dr. José Antonio de Saja-Saéz, Prof. Dr. Miguel-Ángel Rodrigues-Pérez and Dr. Marcos Augusto de Lima Nobre for the scientific discussions and also Dr. Ricardo F. Aroca and Ariel Guer‐ rero for the AFM measurements.
