title: Natural extracts into chitosan nanocarriers for rosmarinic acid drug delivery.
abstract: BACKGROUND
  Nanotechnology can be applied to deliver and protect antioxidants in order to control the oxidative stress phenomena in several chronic pathologies. Chitosan (CS) nanoparticles are biodegradable carriers that may protect antioxidants with potent biological activity such as rosmarinic acid (RA) in Salvia officinalis (sage) and Satureja montana (savory) extracts for safe and innovative therapies.
  
  
  OBJECTIVE
  Development and characterization of CS nanoparticles as a stable and protective vehicle to deliver RA for medical applications using natural extracts as sage and savory.
  
  
  METHODS
  Antioxidant-CS based nanoparticles were prepared by ionic gelation with sodium tripolyphosphate (TPP), at pH 5.8 with a mass ratio of 7:1 (CS:TPP), with a theoretical antioxidant-CS loading of 40-50%. The nanoparticles were then characterized by different methods such as photon correlation spectroscopy, laser Doppler anemometry, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR), high-performance liquid chromatographic (HPLC), association efficiency, and antioxidant activity.
  
  
  CONCLUSIONS
  Individual and small sizing nanoparticles, around 300 nm, were obtained. SEM confirmed smooth and spherical nanoparticles after freeze-drying. No chemical interactions were found between antioxidants and CS, after encapsulation, by DSC and FTIR. The association efficiency was 51.2% for RA (with 40% loading) and 96.1 and 98.2% for sage and savory nanoparticles, respectively (both with 50% loading). Antioxidant activity values were higher than 0.0348 eq [Asc. Ac.] g/L/g extract and 0.4251 µmol/eq Trolox/g extract.
  
  
  CONCLUSIONS
  The extracts under study are promising vehicles for RA drug delivery in CS nanocarriers.
authors.affiliation: Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Porto , Porto , Portugal .
authors.forename: Sara Baptista
authors.initials: SB
authors.lastname: da Silva
authors.forename: Manuela
authors.initials: M
authors.lastname: Amorim
authors.forename: Pedro
authors.initials: P
authors.lastname: Fonte
authors.forename: Raquel
authors.initials: R
authors.lastname: Madureira
authors.forename: Domingos
authors.initials: D
authors.lastname: Ferreira
authors.forename: Manuela
authors.initials: M
authors.lastname: Pintado
authors.forename: Bruno
authors.initials: B
authors.lastname: Sarmento
mesh_terms: D048271:Chitosan / Q000008:administration & dosage* / Q000737:chemistry; D002934:Cinnamates / Q000008:administration & dosage* / Q000737:chemistry; D053630:Depsides / Q000008:administration & dosage* / Q000737:chemistry; D016503:Drug Delivery Systems / Q000379:methods; D053758:Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry; D010316:Particle Size; D010936:Plant Extracts / Q000008:administration & dosage* / Q000737:chemistry / Q000302:isolation & purification; D027543:Salvia officinalis; D031362:Satureja; D000097123:Rosmarinic Acid
chemical_list: D048271:Chitosan; D002934:Cinnamates; D053630:Depsides; D010936:Plant Extracts; D000097123:Rosmarinic Acid
keywords: Antioxidants; oxidative diseases; pharmaceutical nanosystems; polymeric nanoparticles