RESUMO
New nanoparticles containing biomaterials are emerging as versatile active platforms in a great number of applications, for example, as skin substitutes and therapeutic media. The present study describes the preparation of silver nanoparticles (AgNPs) embedded in agarose films and the impact of calcium ascorbate in the formation of ANPs as well as in the final properties of the films. Colloidal AgNPs were synthetized by two chemical reduction routes: (i) applying calcium ascorbate and NaBH4 and (ii) applying only NaBH4. AgNPs synthetized using NaBH4 showed sizes ranging from 5 to 18â¯nm while AgNPs were calcium ascorbate was used showed micrometer from 164 to 955â¯nm size. Films were prepared in three formulations: agarose control film (A1); agaroseâ¯+â¯AgNPs without calcium ascorbate (A2) and agaroseâ¯+â¯AgNPs with calcium ascorbate (A3). The characterization of films by SEM and EDS showed agarose agglomerates in A2 and unreacted calcium ascorbate crystals on surface of A3. Thus, the presence of calcium ascorbate influenced the properties of A3 film. In addition, the antimicrobial analysis showed a silver particles release dependence on the film composition and only the A3 presented activity against Staphylococcus aureus. The results found in this study open an important way for development of new biomaterials, economically competitive, and with medical application.
Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Ácido Ascórbico/química , Nanopartículas Metálicas/química , Sefarose/química , Prata/química , Prata/farmacologia , Antibacterianos/síntese química , Técnicas de Química Sintética , Testes de Sensibilidade Microbiana , Staphylococcus aureus/efeitos dos fármacosRESUMO
Several 5-arylidene-4-thioxo-thiazolidine-2-ones (3a-n) were synthesized and evaluated as antimicrobial agents against representative strains, including multidrug-resistant strains of clinical isolates. Also, the antiproliferative activity was evaluated against two human carcinoma cell lines (NCI-H292 and HEp-2). The compounds containing the 5-arylidene subunit presented greater antimicrobial activities against Gram positive bacteria, including the multidrug-resistant clinical isolates, than the 4-thioxo-thiazolidine-2-one. Important SAR information was also gathered, such as the contribution of thiocarbonyl attached at 4-position on the thiazolidine heterocyclic for antimicrobial properties. None of the derivatives exhibited significant antiproliferative activity against the human carcinoma cell lines.
