RESUMEN

The effects of crosslinking density, polymer concentration and monomer ratio on the mechanical properties (tensile and compressive properties) of biocompatible clay/P(MEO2MA-co-OEGMA) nanocomposite (NC) hydrogels were investigated. These novel NC hydrogels, composed of inorganic/organic networks, were prepared via in-situ free radical polymerization. The results showed that with increasing inorganic crosslinking agent, i.e. clay concentration, an increase in the tensile strength, elongation at break and compressive strength was observed. Similarly, with increasing polymer concentration, the tensile strength and compressive strength of the NC hydrogels increased while the elongation at break decreased. Increasing the molar concentration of OEGMA in the comonomer led to an increase in the tensile strength of the NC hydrogels but a reduction in the compressive strength. Moreover, clay/P(MEO2MA-co-OEGMA) NC hydrogels presented good biocompatibility bolstering their application as tissue engineering scaffolds.

Asunto(s)

Silicatos de Aluminio/análisis , Materiales Biocompatibles/análisis , Hidrogeles/análisis , Nanocompuestos/análisis , Arcilla , Fuerza Compresiva , Polímeros , Resistencia a la Tracción , Andamios del Tejido

RESUMEN

In vivo MEO2 MA@MEO2 MA-co-OEGMA-CuS-DOX (G-CuS-DOX) nanocapsules increase the temperature of tumors from room temperature to 57 °C due to the photothermal effect under irradiation from a 915-nm laser. When the temperature exceeds 42 °C, photothermal therapy of G-CuS-DOX is switched on. Simultaneously, higher temperatures (>LCST, 42 °C) induce volume shrinkage of G-CuS-DOX in vivo, leading to the controllable release of the anticancer drug DOX. If the NIR laser is switched off, both therapy effects are interrupted immediately.

Asunto(s)

Antineoplásicos/administración & dosificación , Carcinoma Hepatocelular/terapia , Hipertermia Inducida , Neoplasias Hepáticas/terapia , Terapia por Luz de Baja Intensidad/métodos , Nanocápsulas , Animales , Antineoplásicos/farmacocinética , Carcinoma Hepatocelular/diagnóstico por imagen , Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/secundario , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/efectos de la radiación , Terapia Combinada , Doxorrubicina/administración & dosificación , Doxorrubicina/farmacocinética , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/secundario , Ratones , Nanocápsulas/química , Trasplante de Neoplasias , Carga Tumoral/efectos de los fármacos , Carga Tumoral/efectos de la radiación , Agua/química

RESUMEN

Novel thermosensitive nanocomposite (NC) hydrogels consisting of organic/inorganic networks are prepared via in situ free radical polymerization of 2-(2-methoxyethoxy) ethyl methacrylate (MEO2 MA) and oligo(ethylene glycol) methacrylate (OEGMA) in the presence of inorganic cross-linker clay in aqueous solution. The obtained clay/P(MEO2 MA-co-OEGMA) hydrogels exhibit double volume phase transition temperatures, an upper critical solution temperature (UCST), and a lower critical solution temperature (LCST), which can be controlled between 5 and 85 °C by varying the fraction of OEGMA units and the weight percentage of cross-linker clay. These new types of NC hydrogels with excellent reversible thermosensitivity are promising for temperature-sensitive applications such as smart optical switches.

Asunto(s)

Hidrogeles/química , Metacrilatos/química , Nanocompuestos/química , Polímeros/química , Temperatura , Silicatos de Aluminio/química , Arcilla , Radicales Libres/química , Transición de Fase , Polimerizacion , Soluciones/química

RESUMEN

Near-infrared (NIR) laser-induced photothermal ablation (PTA) therapy has great potential to revolutionize conventional therapeutic approaches for cancers, and a prerequisite is to obtain biocompatible and efficient photothermal agents. Herein, we have developed hydrophilic W18O49 nanowires with average lengths of about 800 nm (abbreviated as W18O49-800 NWs) as an efficient photothermal agent, which are prepared by the solvothermal synthesis-simultaneous PEGylation/exfoliation/breaking two-step route. These W18O49-800 NWs exhibit stronger NIR photoabsorption than short nanowires with average lengths of about 50 nm (abbreviated as W18O49-50 NWs) that are prepared via a solvothermal one-step route. Under irradiation of 980 nm with a safe intensity of 0.72 W cm-2, the aqueous dispersion of W18O49-800 NWs (1.0 mg mL-1) exhibits the temperature elevation by 35.2 °C in 5 min; which is a 37.5% increase compared to that (by 25.6 °C) from W18O49-50 NWs (1.0 mg mL-1). More importantly, under 980 nm laser irradiation (0.72 W cm-2) for 10 min, in vivo cancer cells can be efficiently ablated by the photothermal effects of W18O49-800 NWs. Therefore, these W18O49-800 NWs can be used as a more efficient and promising photothermal nanoagent for the ablation of cancer cells in vivo.

RESUMEN

A new type of nanocomposite hydrogels based on covalent cross-linked interactions with excellent mechanical properties and good stability has been prepared by using in situ free-radical polymerization; polystyrene nanoparticles with photo-activity are used as the cross-linking agent.