Manufacture and characterization of chitosan/PLGA nanoparticles nanocomposite buccal films.

Oral bioavailability of C-glycosyl flavonoid enriched fraction of Cecropia glaziovii (EFF-Cg) is limited due to its chemical complexity. The purpose of this study is the prospective evaluation of chitosan buccal films impregnated with EFF-Cg-loaded nanospheres as a drug delivery system for labial herpes treatment or for buccal administration. EFF-Cg-loaded PLGA nanospheres were prepared by double emulsion solvent evaporation technique. Nanoparticles were embedded into buccoadhesive chitosan films in different concentrations in order to obtain nanocomposite films. Films were characterized in term of morphology, mechanical properties and water absorption test. Furthermore a cytotoxicity assay was analyzed to evaluate the biocompatibility of systems. The results obtained from these analyses revealed that nanocomposite films present transparent appearance in all composition and Scanning Electron Microscopy (SEM) images show a continuous and compact section structure. Compared to the control film, mechanical responses of nanocomposites presented lower tensile strength values and no significant effect on the elongation at break. Dynamic Mechanical Analysis (DMA) tests indicated that increasing of NP concentration caused decreased stiffness and an increased of glass transition temperature values. Direct cytotoxicity test shows that nanoparticles and chitosan films not induce cytotoxic effect. Given the promising results, the study concludes that the developed buccal film impregnated with EFF-Cg-loaded nanospheres could be a promising approach for effective delivery of EFF-Cg.

In vitro antiherpes effect of C-glycosyl flavonoid enriched fraction of Cecropia glaziovii encapsulated in PLGA nanoparticles.

In this work is reported a novel and promising approach for the preparation of C-glycosylflavonoid enriched fraction of Cecropia glaziovii (EFF-Cg) loaded PLGA nanoparticles (NP) with antiherpes properties. The purpose of this study was to evaluate and to compare the effect of two nonionic surfactants (poloxamer 188 (PLU) and polyvinyl alcohol (PVA)), and also an emulsion stabilized by solid particles of cellulose nanocrystal (CNC) in place of surfactants. The characterization of these nanoparticles was in terms of size, polydispersity index, zeta potential, morphology, thermogravimetric analysis (TGA), loading capacity and percent yield. Since TGA analysis revealed thermo stability especially for NP-PLU, this formulation was selected for the evaluation of drug release profile, cytotoxicity and antiherpes activity. The drug delivery profile demonstrated a sustained release through the polymer structure and a significant reduction of the polymer molecular weight at 21-day period. The cytotoxicity of these nanoparticles was determined on Vero cells, and the selected formulation did not exhibit cytotoxicity even at the highest tested concentration. The results demonstrated a potential antiherpetic effect of the EFF-Cg loaded NP at 48h of testing. In summary, EFF-Cg loaded NP exhibited a promising system for the effective drug delivery in the treatment of herpes infections.

Use of alginate, chitosan and cellulose nanocrystals as emulsion stabilizers in the synthesis of biodegradable polymeric nanoparticles.

Biopolymeric nanoparticles (NPs) based on a biodegradable poly(DL-Lactide-co-Glycolide) PLGA copolymer matrix combined with alginate, chitosan and nanostructured cellulose crystals as three different natural emulsion stabilizers, were synthesized by a double emulsion (water/oil/water) method with subsequent solvent evaporation. The morphological, thermal, chemical and rheological properties of the novel designed NPs and the effect of the different emulsion stabilizers used during the synthesis were deeply investigated in order to optimize the synthesis procedure and the development of biodegradable nanoparticles coated with natural polymers. The morphological analysis of the produced nanoparticles showed that all the different formulations presented a spherical shape with smooth surface. Infrared spectroscopy investigations showed that the PLGA copolymer maintained its backbone structure and confirmed the presence of chitosan, alginate and cellulose nanocrystals (CNC) on the nanoparticle surface. The obtained results suggest that PLGA nanoparticles with CNC as emulsion stabilizer might represent promising formulations opening new perspective in the field of self-assembly of biodegradable nanomaterials for medical and pharmaceutical applications.

Protein encapsulation in biodegradable polymeric nanoparticles: morphology, fluorescence behaviour and stem cell uptake.

The synthesis and characterization of new biodegradable polymeric NPs loaded with bovine serum albumin marked with fluorescein isothiocyanate (FITC-BSA) is reported. The protein is encapsulated in poly(D,L-lactide-co-glycolide) (PLGA) NPs by the double emulsion method with subsequent solvent evaporation. The NPs display a spherical shape with a narrow size distribution and no aggregation is observed after drying. Steady-state and time-resolved fluorescence measurements appear to be a sensitive method to investigate the protein environment on the nanometer-scale. Finally, FITC-BSA-loaded NPs are rapidly internalized in stem cells. Interestingly, 25% cells were slightly positive after 28 days.