Full text
| |
| Author(s): |
Elias Antonio Berni Neto
Total Authors: 1
|
| Document type: | Doctoral Thesis |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Química |
| Defense date: | 2014-06-26 |
| Examining board members: |
Nelson Eduardo Duran Caballero;
Oswaldo Luiz Alves;
René Alfonso Nome Silva;
Leonardo Fernandes Fraceto;
Caue Ribeiro de Oliveira
|
| Advisor: | Nelson Eduardo Duran Caballero |
| Abstract | |
Brazil plays a pivotal role in livestock market, moving around R$ 164 billions per year. However, this market shows yet some difficulties, mainly related to the health of animals being the main pathologies which affect the ectoparasites such as Boophilus microplus that generates losses of US$ 4 billion per year, and bovine mastitis (inflammation of the udders of cows) caused by microorganisms such as Staphylococcus aureus and Escherichia coli, that generates losses in the amounts of US$ 185 per cow per year. For this reason the drug release was chosen as an alternative to increase the effectiveness of acaricides and drugs used against bovine mastitis. Using polymeric nanoparticles of poly (?-caprolactone) (PCL) coated with the polymer chitosan, and synthesized by displacement solvent technique was possible to increase both stability and solubility assets as well as decreasing its toxicity against 3T3 cells. In this work, 4 different systems were studied, QS_PCLnp (without assets), QS_PCLnp_vio (containing the active violacein) QS_PCLnp_ami (containing the active amitraz) and QS_PCLnp_flu (containing the active fluazuron). The QS_PCLnp_vio system showed a size of 260±10 nm and surface charge of +30±2 mV, with a final concentration of 180 mg mL-1 of violacein and efficiency of 91±1% for a loading capacity of 11±1% compared with PCL mass, this system were being tested against the bacteria S. aureus and E. coli against bovine mastitis. The QS_PCLnp_ami system shows a size of 275±30 nm and surface charge of +43±7 mV, with a final concentration of 1.0 mg mL-1 of amitraz, and an efficiency of 77±1% for a loading capacity of 39±1 % compared with PCL mass, while QS_PCLnp_flu shows a size of 295±35 nm and surface charge of +44±10 mV and 0.5 mg ml-1 of fluazuron, which gave an efficiency of 89±1% for a loading capacity of 22±1% compared with PCL mass. Both system QS_PCLnp_ami and QS_PCLnp_flu were used against B. microplus. All systems shows molecularly dispersed active compound in the polymer matrix of PCL inside and the surface layer of chitosan influencing the steric stability of nanoparticles in pH above 7. All systems were stable in saline concentration of 1.25 mol L-1 of NaCl and with temperature increase up to 50°C. In the study of mastitis, the QS_PCLnp_vio system showed greater activity against S. aureus, while the pure violacein is more effective against E. coli. This result motivates a study of a hybrid system contain QS_PCLnp_vio and pure violacein. In the case of B. microplus tick were used QS_PCLnp_ami and QS_PCLnp_flu together, which provided a lower dose of the active fluazuron than commercially practiced, leaving the animal free of ticks for a period of 28 days, requiring larger spaces between the bathing those currently practiced nowadays (AU) | |
| FAPESP's process: | 10/20257-8 - "Synthesis and characterization of polymeric micro/nanoparticle encapsulating amitraz and fluazuron." |
| Grantee: | Elias Antonio Berni Neto |
| Support Opportunities: | Scholarships in Brazil - Doctorate |