No abstract

Nanoparticulas de quitosana (CH) e goma do angico (AG), dopadas com óleo essencial de Lippia sidoides (Ls) foram preparadas e caracterizadas em relação às suas composições, distribuição de tamanho de partículas, estabilidade térmica, bem como as liberações in vitro e in vivo. Os dados obtidos revelaram que as nanopartículas preparadas usando razões Ls:AG variando de 1:2 a 1:20, apresentaram dopagens na faixa de 3,3 a 7,7%, com eficiência de encapsulação entre 16,0 e 77,8%. Os tamanhos de partículas ficaram na faixa de 10-60 nm, com distribuições independentes do teor de óleo incorporado. FTIR revelou a presença de timol, principal componente de Ls. Análises de TGA e DSC mostraram que a incorporação de óleo na matriz resulta em nanopartículas de menor estabilidade térmica. A amostra Ls:AG = 1:10 apresentou um perfil de liberação in vitro mais lento que as demais, exibindo, porém, nos bioensaios, uma maior mortalidade larval.Chitosan (CH) and angico gum (AG) nanoparticles were loaded with essential oil, Lippia sidoides (Ls), being characterized according to their composition, size distribution, Ls:polymer ratio, thermal stability and in vitro and in vivo controlled release. Nanoparticles prepared using Ls:AG ratios of 1:2 to 1:20 had loading values of 3.3 to 7.7%, with encapsulation efficiencies in the range of 16.0 to 77.8%. Particle sizes were in the range of 10-60 nm and size distributions were independent of Ls content, for different Ls:AG ratios. Infrared spectroscopy revealed the presence of thymol in the nanoparticles. TGA and DSC revealed that the degradation temperature of AG-CH nanoparticles decreased with an increase in Ls content. Controlled-release data showed a slower release profile for samples with Ls:AG = 1:10 than for the other samples. Bioassays showed that sample Ls:AG = 1:10 has a greater larvicidal effect, with 85 ± 3% mortality.

Cashew gum (GC) is a polysaccharide whose structural modification has the potential to extend its applications on varied fields such as to the formation of self-organized nanoparticulated systems. In this work, a 2 factorial design was carried out, aiming at evaluation of the influence of the reactional parameters of an acetylation reaction on the final properties of cashew gum. The effects of temperature, reaction time and amount of acetylating agent on the reaction yield and degree of GC acetylation were investigated. Data obtained revealed that the aforementioned parameters influenced both yield and degree of acetylation. Statistical analysis showed that the different derivatives had their variables influenced mainly by temperature and interaction effect between the factors time and quantity of acetylating agent. Acetylated derivatives were obtained with yield higher than 90% and degrees of acetylation above 2.42. Data on the formation of self-organized systems, revealed particle sizes in the range 190-300nm, where smaller particle sizes were obtained for derivatives with acetylation degrees lower than 1.5. Release profiles of Amphotericin-B incorporated in derivative nanoparticles, yielded 70% encapsulation efficiency and long release profiles, corroborating their potential application to delivery of hydrophobic active principles.

No abstract

Stable oil nanocapsules based on acetylated Sterculia striata polysaccharide (ASSP) were produced without the use of a surfactant, and derivatives of ASSP with four different degrees of substitution (DS) were synthesised. The data revealed that only derivatives with high DS were able to produce nanocapsules (NC), which exhibited monomodal size distribution profiles with a Z-average particle size,-potential, and polydispersity index (PDI) that were dependent on ASSP DS and concentration. Nanocapsules were loaded with amphotericin B (AMB) with encapsulation efficiencies (EE%) thatwere dependent on drug and ASSP concentrations and DS. A maximum EE% value of 99.2%was achieved, and the loaded AMBwas found to be in amonomeric form, evenwith a concentration one hundredfold higher than that usually observed for commercial AMB aqueous solutions. Loaded nanocapsules show an in vitro controlled release of AMB. As the monomeric AMB state decreased drug toxicity, ASSP nanocapsules loaded with AMB (NC1.68) have potential for use as a drug delivery system. AMB loaded NC 1.68 keeps its activity against 5 strains of Candida albicans tested.