RESUMEN
Herein we demonstrate a bioinspired method involving macromolecular assembly of anionic polypeptide with cationic peptide-oligomer that allows for in situ encapsulation of antibiotics like tetracycline in CaCO3 microstructure. In a single step one-pot process, the encapsulation of the drug occurs under desirable environmentally benign conditions resulting in drug loaded CaCO3 microspheres. While this tetracycline-loaded sample exhibits pH dependent in vitro drug-release profile and excellent antibacterial activity, the encapsulated drug or the dye-conjugated peptide emits fluorescence suitable for optical imaging and detection, thereby making it a multitasking material. The efficacy of tetracycline loaded calcium carbonate microspheres as pH dependent drug delivery vehicles is further substantiated by performing cell viability experiments using normal and cancer cell lines (in vitro). Interestingly, the pH-dependent drug release enables selective cytotoxicity toward cancer cell lines as compared to the normal cells, thus having the potential for further development of therapeutic applications.
Asunto(s)
Antibacterianos/química , Carbonato de Calcio , Sistemas de Liberación de Medicamentos , Liberación de Fármacos , Concentración de Iones de Hidrógeno , MicroesferasRESUMEN
Herein, we present an environmentally benign method capable of mineralization and deposition of nanomaterials to introduce antibacterial functionalities into cotton fabrics under mild conditions. Similar to the way in which many naturally occurring biominerals evolve around the living organism under ambient conditions, this technique enables flexible substrates like the cotton fabric to be coated with inorganic-based functional materials. Specifically, our strategy involves the use of long-chain polyamines known to be responsible in certain biomineralization processes, to nucleate, organize, and deposit nanostructured ZnO on cotton bandage in an aqueous solution under mild conditions of room temperature and neutral pH. The ZnO-coated cotton bandages as characterized by SEM, confocal micro-Raman spectroscopy, XRD, UV-DRS, and fluorescence microscopy demonstrate the importance of polyamine in generating a stable and uniform coating of spindle-shaped ZnO particles on individual threads of the fabric. As the coating process requires only mild conditions, it avoids any adverse effect on the thermal and mechanical properties of the substrate. Furthermore, the ZnO particles on cotton fabric show efficient antibacterial activity against both gram-positive and gram-negetive bacteria. Therefore, the developed polyamine mediated bioinspired coating method provides not only a facile and "green" synthesis for coating on flexible substrate but also the fabrication of antibacterial enabled materials for healthcare applications.
Asunto(s)
Antibacterianos/farmacología , Minerales/química , Nanoestructuras , Textiles , Óxido de Zinc/química , Microscopía Electrónica de Rastreo , Difracción de Rayos XRESUMEN
Prevention is the best resistance management strategy in integrated vector control programs. Combined use of insecticides of different classes that interact synergistically and show multi-site actions within the insect is recognized as a potential key strategy to be implemented even before the onset of resistance. The present study is aimed at harvesting the benefits of synergism between the wild-type Bacillus thuringiensis subsp. israelensis-H14 (Bti) and Bacillus sphaericus-2362 (Bs) strains by evaluating six different combinations of mixtures toxic to Aedes and Culex mosquito larvae. Isobolographic analysis was performed to distinguish the synergistic combinations of Bti and Bs, followed by determination of the degree of synergism through synergy and improvement factors. Furthermore, the speed of activity of Bs when combined with Bti is studied by histopathological investigations on the fate of midgut muscles of mosquito larvae upon exposure to individual wild-type strains as well as their mixtures.
Asunto(s)
Aedes/microbiología , Bacillus/patogenicidad , Culex/microbiología , Interacciones Microbianas , Animales , Bacillus thuringiensis/patogenicidad , Tracto Gastrointestinal/patología , Histocitoquímica , Larva/microbiología , Control de Mosquitos/métodos , Control Biológico de Vectores/métodos , Análisis de SupervivenciaRESUMEN
Three-component coupling of aldehyde, indole and kojic acid has been achieved using a catalytic amount of InCl(3) under solvent free conditions to produce a novel series of 2-substituted aryl(indolyl)kojic acid derivatives in good yields and with high selectivity. These compounds are found to exhibit potent antifungal properties.
Asunto(s)
Antibacterianos/síntesis química , Antifúngicos/síntesis química , Indio/química , Indoles/química , Pironas/química , Aldehídos/química , Antibacterianos/química , Antibacterianos/farmacología , Antifúngicos/química , Antifúngicos/farmacología , Catálisis , Pruebas de Sensibilidad Microbiana , Pironas/síntesis química , Pironas/farmacologíaRESUMEN
2-Chloro-5-methylpyridine-3-olefin derivatives (3a-e) have been synthesized from 2-chloro-5-methylnicotinaldehyde (1) and studied their photochemical E (trans)-->Z (cis) isomerization upon direct irradiation and triplet sensitized excitation for the first time. The triplet sensitized excitations of the compounds yielded high Z (4a-e) isomer composition, whereas the direct excitation results in less Z (4a-e) isomer composition, indicating triplet pathway is very efficient in converting the E (trans)-->Z (cis) isomer. Thus synthesized E (3a-c and 3e) and generated Z (4a-c and 4e) isomers were tested for antimicrobial activity. Antifungal activity of these pyridine derivatives are closely comparable to the standard used.
Asunto(s)
Alquenos/química , Alquenos/farmacología , Antiinfecciosos/química , Antiinfecciosos/farmacología , Piridinas/química , Piridinas/farmacología , Bacterias/efectos de los fármacos , Hongos/efectos de los fármacos , Isomerismo , Fotoquímica , Relación Estructura-ActividadRESUMEN
Indazole regioisomers such as 3-amino-4-(trifluoromethyl)-6-phenyl-1H-indazole-7-carbonitrile 1 and 3-amino-6-(trifluoromethyl)-4-phenyl-1H-indazole-7-carbonitrile 2 were independently reacted with formaldehyde followed by unsymmetrical, symmetrical and cyclic electron rich olefins in presence of GdCl(3) as catalyst and obtained pyrimidine fused indazole derivatives 3 and 4, respectively. The reaction is found to be concerted and an exclusive product is formed. Representative examples of compounds 3 and 4 were screened against Gram-positive, Gram-negative bacteria and fungal species such as yeast and filamentous fungi in vitro. Compound 3f showed significant activity against all species of Gram-positive and Gram-negative bacteria, whereas compounds 3h and 4a showed the least activity with reference to penicillin as well as streptomycin. Similarly compound 3c showed promising activity against yeast and filamentous fungi whereas compound 3f is inactive at the maximum concentration of 150 microg/mL.