Video Experimental Relacionado
Updated: May 5, 2026
09:09
Visualizing Diffusional Dynamics of Gold Nanorods on Cell Membrane using Single Nanoparticle Darkfield Microscopy
Published on: March 5, 2021
4.3K
Observación del comportamiento de agregación dinámica en micro y nanopartículas térmicamente sensibles mediante
Anshu Agarwal1, Benjamin G Bobay2, Matthew L Becker1,3,4,5
1Thomas Lord Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, United States.
Journal of the American Chemical Society
|March 7, 2025
Resumen
Los investigadores desarrollaron nuevos polímeros termorresponsivos para la administración de medicamentos. Estos polímeros se autoensamblan en nanopartículas o micropartículas, y la espectroscopia de RMN ordenada por difusión (DOSY) cuantifica su comportamiento de agregación.
Área de la Ciencia:
- Química de los polímeros
- Ciencias de los materiales
- Nanotecnología
Sus antecedentes:
- Los sistemas de administración de fármacos sensibles a estímulos mejoran la protección de la carga, el tiempo de circulación y la liberación controlada.
- Los métodos de caracterización cuantitativa son cruciales para traducir estos sistemas complejos a aplicaciones clínicas.
Objetivo del estudio:
- Desarrollar poliéster degradable y térmicamente sensible para la administración de fármacos.
- Caracterizar el comportamiento de autoensamblaje y la formación de partículas de estos polímeros.
- Utilización de la espectroscopia de RMN ordenada por difusión (DOSY) para el análisis cuantitativo.
Principales métodos:
- Copolimerización de apertura de anillo de anhídrido maleico y epóxido funcionalizado con oligo (etilenglicol).
- Ajuste del tamaño de las partículas (nano vs. micropartículas) mediante la selección de diferentes iniciadores de polímeros.
- Utilizando la espectroscopia de RMN ordenada por difusión (DOSY) con estándares de polietilenglicol para la calibración del peso molecular y la determinación del número de agregación.
Principales resultados:
- Los poliésteres termorresponsivos sintetizados con una temperatura de solución crítica más baja (LCST) para autoensamblaje sintonizable.
- Las nanopartículas obtenidas (aprox. 162 nm) y las micropartículas (aprox. Formación basada en la elección del iniciador.
- DOSY monitoreó con éxito el autoensamblaje del polímero y cuantificó los números de agregación en soluciones acuosas a diferentes temperaturas.
Conclusiones:
- Desarrollo de nuevos polímeros térmoresponsables adecuados para la administración de fármacos sensibles a estímulos.
- Demostró la utilidad de DOSY como herramienta cuantitativa para caracterizar el autoensamblaje y la agregación de polímeros en solución.
- Los hallazgos facilitan el avance de los sistemas complejos de administración de fármacos hacia el uso clínico.
Más Videos Relacionados
08:17Probing Structural and Dynamic Properties of Trafficking Subcellular Nanostructures by Spatiotemporal Fluctuation Spectroscopy
Published on: August 16, 2021
1.8K
08:48High-Resolution Neutron Spectroscopy to Study Picosecond-Nanosecond Dynamics of Proteins and Hydration Water
Published on: April 28, 2022
1.7K
Videos de Conceptos Relacionados
01:13¹H NMR: Complex Splitting
1.7K
A proton M that is coupled to a proton X results in doublet signals for M. However, NMR-active nuclei can be simultaneously coupled to more than one nonequivalent nucleus. When M is coupled to a second proton A, such as in styrene oxide, each peak in the doublet is split into another doublet.
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...
1.7K
01:02¹H NMR: Interpreting Distorted and Overlapping Signals
1.3K
Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
1.3K
00:52¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
995
At room temperature, the chair conformer of cyclohexane undergoes rapid ring flipping between two equivalent chair conformers at a rate of approximately 105 times per second. These two chair conformers are in equilibrium. The rapid ring flipping results in the interconversion of the axial proton to an equatorial proton and an equatorial to the axial proton. Such interconversions are too rapid and cannot be detected on the NMR timescale. Hence, the NMR spectrometer cannot distinguish between the...
995
01:08NMR Spectroscopy: Spin–Spin Coupling
3.5K
The spin state of an NMR-active nucleus can have a slight effect on its immediate electronic environment. This effect propagates through the intervening bonds and affects the electronic environments of NMR-active nuclei up to three bonds away; occasionally, even farther. This phenomenon is called spin–spin coupling or J-coupling. Coupling interactions are mutual and result in small changes in the absorption frequencies of both nuclei involved. While nuclei of the same element are involved...
3.5K
01:25Applications Of NMR In Biology
3.3K
Nuclear magnetic resonance (NMR) spectroscopy is a very valuable analytical technique for researchers. It has been used for more than 50 years as an analytical tool. F. Bloch and E. Purcell formulated NMR in 1946 and won the 1952 Nobel Prize in Physics for their work. Biological macromolecules such as proteins, nucleic acids, lipids, and organic molecules including pharmaceutical compounds, can be studied using this versatile tool that exploits the magnetic properties of certain nuclei.
3.3K
01:16Other Nuclides: 31P, 19F, 15N NMR
891
Many organic, inorganic, and biological molecules contain spin-half nuclei such as nitrogen-15, fluorine-19, and phosphorus-31. As a result, NMR studies of these nuclei have found extensive applications in chemical and biological research.
While fluorine-19 and phosphorous-31 have high natural abundances (100%) and positive gyromagnetic ratios, nitrogen-15 has a low natural abundance and a negative gyromagnetic ratio. However, nitrogen-15 is still preferred over nitrogen-14 (which has a...
While fluorine-19 and phosphorous-31 have high natural abundances (100%) and positive gyromagnetic ratios, nitrogen-15 has a low natural abundance and a negative gyromagnetic ratio. However, nitrogen-15 is still preferred over nitrogen-14 (which has a...
891