Efficient Loading and Controlled Release of Benzophenone-3 Entrapped into Self-Assembling Nanogels
Abstract:Benzophenone-3 (BZ-3), was successfully entrapped into nanogels prepared by a simple one-step method based on selfassembly of two water soluble polymers: a hydrophobically modified dextran (MD) and a β-Cyclodextrin polymer (pβ-CD). Isothermal titration microcalorimetry (ITC) and phase solubility experiments were performed at 4, 25 or 37°C to investigate the interaction of the hydrophobic BZ-3 with MD and pβ-CD. The BZ-3 entrapment efficiency, yield of nanogels formation, particle size, and BZ-3 release were also evaluated. BZ-3/pβ-CD interaction was characterized by association constants K= 5180 M-1 and K´= 2700 M-1, as determined by phase solubility and ITC experiments, respectively. Differences obtained in association constants values were discussed critically. Results indicate that both K and K´ decrease with increase in temperature. The strong interactions between BZ-3 and pβ-CD were characterized by a negative enthalpy change ( H) with entropic contribution (T S). Monodisperse nanogels were produced with an entrapment up to 75 % and yield up 84 %. BZ-3 was firmly entrapped into nanogels, as only the dilution of the nanogels led to its release. This system provides an advantage for sunscreen formulation to prevent systemic penetration of BZ-3. The ‘green’ (solvent free) preparation method, and the possibility of unlimited storage after freeze drying makes these nanogels valuable candidates for the entrapment of sun screen agents.
Keywords: CDs; MD; Nanogels; QELS; Temperature; UV rays; centrifugation; cyclodextrins; drug loading; enthalpy; entropy; inclusion complexes; isothermal titration microcalorimetry; modified dextran; nanogel; permeability; photo-sensitivity; photoprotection; solubilization; sunscreen; sunscreen agents; supernatant; thermodynamic
Document Type: Research Article
Publication date: December 1, 2010
- Current Nanoscience publishes authoritative reviews and original research reports, written by experts in the field on all the most recent advances in nanoscience and nanotechnology. All aspects of the field are represented including nano- structures, synthesis, properties, assembly and devices. Applications of nanoscience in biotechnology, medicine, pharmaceuticals, physics, material science and electronics are also covered. The journal is essential to all involved in nanoscience and its applied areas.