RESUMO
This report characterizes an aqueous isolate (SBD.4) of one of the most broadly used Chinese medicinal herbs, Angelica sinensis, from the perspective of its application in skin and wound care. SBD.4 has been chemically defined and was found to increase the strength of healed wounds in retired breeder (older) rats. Furthermore, the mechanism of action of this Angelica sinensis isolate was tested in the zebrafish angiogenesis model, and in human skin substitutes by DNA microarray, revealing a bioactivity profile consistent with skin repair and regeneration. When combined with several types of wound dressings, SBD.4 increased type I collagen production in human dermal fibroblasts, and when formulated in nanosilver hydrocolloid dressing, it was found effective in chronic ulcer management in humans, demonstrating that botanical high-tech wound dressings can be successfully developed to improve the treatment of chronic lesions in humans.
Assuntos
Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacologia , Úlcera Cutânea/tratamento farmacológico , Cicatrização/efeitos dos fármacos , Indutores da Angiogênese , Animais , Anti-Infecciosos Locais/uso terapêutico , Curativos Hidrocoloides , Células Cultivadas , Colágeno Tipo I/metabolismo , Colágeno Tipo III/metabolismo , Medicamentos de Ervas Chinesas/uso terapêutico , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Perfilação da Expressão Gênica , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Ratos , Ratos Sprague-Dawley , Prata/uso terapêutico , Cicatrização/genética , Peixe-Zebra/fisiologiaRESUMO
Controlled movement of materials or molecules within the nanometer range is essential in many applications of nanotechnology. Here we report the capture, movement, and release of cargo molecules along DNA by a modified form of T7 RNA polymerase (RNAP) in a manner that is controlled by the sequence of the DNA. Using single-molecule methods, we visualize the assembly and manipulation of nanodevices and the ability to harness rotary and linear forces of the RNAP motor.
Assuntos
RNA Polimerases Dirigidas por DNA , Proteínas Motores Moleculares , Nanotecnologia , Proteínas Virais , Sequência de Bases , RNA Polimerases Dirigidas por DNA/química , RNA Polimerases Dirigidas por DNA/metabolismo , Enzimas Imobilizadas , Modelos Moleculares , Proteínas Motores Moleculares/química , Proteínas Motores Moleculares/metabolismo , RNA/genética , RNA/metabolismo , Proteínas Virais/química , Proteínas Virais/metabolismoRESUMO
We have used magnetic tweezers to study in real time chaperone-mediated chromatin assembly/disassembly at the level of single chromatin fibers. We find a strong dependence of the rate of assembly on the exerted force, with strong inhibition of assembly at forces exceeding 10 pN. During assembly, and especially at higher forces, occasional abrupt increases in the length of the fiber were observed, giving a clear indication of reversibility of the assembly process. This result is a clear demonstration of the dynamic equilibrium between nucleosome assembly and disassembly at the single chromatin fiber level.
