Donut-like MOFs of copper/nicotinic acid and composite hydrogels with superior bioactivity for rh-bFGF delivering and skin wound healing.

BACKGROUND: Skin injury and the resultant defects are common clinical problems, and usually lead to chronic skin ulcers and even life-threatening diseases. Copper, an essential trace element of human body, has been reported to promote the regeneration of skin by stimulating proliferation of endothelial cell and enhance angiogenesis. RESULTS: Herein, we have prepared a new donut-like metal-organic frameworks (MOF) of copper-nicotinic acid (CuNA) by a simple solvothermal reaction. The rough surface of CuNA is beneficial for loading/release basic fibroblast growth factor (bFGF). The CuNAs with/without bFGF are easily processed into a light-responsive composite hydrogel with GelMA, which not only show excellent mechanical properties, but also display superior biocompatibility, antibacterial ability and bioactivity. Moreover, in the in vivo full-thickness defect model of skin wound, the resultant CuNA-bFGF@GelMA hydrogels significantly accelerate the wound healing, by simultaneously inhibiting the inflammatory response, promoting the new blood vessels formation and the deposition of collagen and elastic fibers. CONCLUSIONS: Considering the superior biocompatibility, antibacterial ability and bioactivity, the CuNA and its composite light-responsive hydrogel system will be promising in the applications of skin and even other tissue regeneration.

Poly(acrylic acid)-modified Fe3O4 microspheres for magnetic-targeted and pH-triggered anticancer drug delivery.

Monodisperse poly(acrylic acid)-modified Fe(3)O(4) (PAA@Fe(3)O(4)) hybrid microspheres with dual responses (magnetic field and pH) were successfully fabricated. The PAA polymer was encapsulated into the inner cavity of Fe(3)O(4) hollow spheres by a vacuum-casting route and photo-initiated polymerization. TEM images show that the samples consist of monodisperse porous spheres with a diameter around 200 nm. The Fe(3)O(4) spheres, after modification with the PAA polymer, still possess enough space to hold guest molecules. We selected doxorubicin (DOX) as a model drug to investigate the drug loading and release behavior of as-prepared composites. The release of DOX molecules was strongly dependent on the pH value due to the unique property of PAA. The HeLa cell-uptake process of DOX-loaded PAA@Fe(3)O(4) was observed by confocal laser scanning microscopy (CLSM). After being incubated with HeLa cells under magnet magnetically guided conditions, the cytotoxtic effects of DOX-loaded PAA@Fe(3)O(4) increased. These results indicate that pH-responsive magnetic PAA@Fe(3)O(4) spheres have the potential to be used as anticancer drug carriers.

Multifunctional core-shell structured nanocarriers for synchronous tumor diagnosis and treatment in vivo.

Multifunctional, mesoporous, silica-coated upconversion luminescent/magnetic NaGdF4:Yb/Er@NaGdF4:Yb@mSiO2-PEG (referred to as UCNPS; PEG=polyethylene glycol) nanocomposites were fabricated through a phase-transfer-assisted surfactant-templating coating process, followed by hydrophilic polymer (PEG) functionalization to improve the stability and biocompatibility. The UCNP core imparts the nanomaterials with luminescence and magnetic properties for simultaneous upconversion optical and magnetic resonance (MR) imaging, whereas the mesoporous shell affords the nanomaterials the ability to load the anticancer drug doxorubicin. Proof-of-principle in vitro and in vivo experiments are presented to demonstrate that the resultant composite nanomaterials can serve as nanotheranostics for synchronous upconversion luminescence/MR dual modal imaging and anticancer drug delivery; this finally realizes the integration of diagnostics and the treatment of cancers.