title: Chitosan glutamate nanoparticles for protein delivery: development and effect on prolidase stability.
abstract: OBJECTIVE
  To evaluate the feasibility of exploiting ultrasonication coupled with ionotropic gelation in order to prepare tripolyphosphate (TPP)-chitosan glutamate nanoparticles suitable for the delivery of the enzyme prolidase.
  
  
  METHODS
  All the parameters for the preparation of TPP-chitosan nanoparticles in terms of components weight ratio, ultrasonication conditions and time-saving nanoparticles recovery conditions were optimized. The best formulation was loaded with the prolidase. All the nanoparticles were characterized in terms of morphology, size, polydispersity, zeta-potential, yield of the process and encapsulation efficiency. The in-vitro activity of the prolidase was assessed by capillary electrophoresis (CE).
  
  
  CONCLUSIONS
  A TPP to chitosan weight ratio of 0.2:1 combined with one ultrasonication cycle (4 min using the probe-type sonifier at 75% power) obtained well-formed nanoparticles of spherical shape, mean size of approximately 365 nm (polydispersity index 0.3) and a + 17.94 mV zeta potential. A satisfactory prolidase encapsulation efficiency (43%) was obtained with a yield of the preparation process of approximately 55%. In vitro study of activity of prolidase, as free enzyme or released from chitosan nanoparticles, highlighted the ability of chitosan to stabilize the enzyme during all the steps of the preparation process and to modulate the enzyme activity up to 48 h.
authors.affiliation: Department of Pharmaceutical Chemistry, University of Pavia, Pavia, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Colonna
authors.forename: Bice
authors.initials: B
authors.lastname: Conti
authors.forename: Paola
authors.initials: P
authors.lastname: Perugini
authors.forename: Franca
authors.initials: F
authors.lastname: Pavanetto
authors.forename: Tiziana
authors.initials: T
authors.lastname: Modena
authors.forename: Rossella
authors.initials: R
authors.lastname: Dorati
authors.forename: Ida
authors.initials: I
authors.lastname: Genta
mesh_terms: D048271:Chitosan / Q000737:chemistry*; D004150:Dipeptidases / Q000378:metabolism*; D004337:Drug Carriers; D004795:Enzyme Stability; D018698:Glutamic Acid / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D013379:Substrate Specificity
chemical_list: D004337:Drug Carriers; D018698:Glutamic Acid; D048271:Chitosan; D004150:Dipeptidases; C022449:proline dipeptidase