title: Arginine end-functionalized poly(L-lysine) dendrigrafts for the stabilization and controlled release of insulin.
abstract: Second generation biodegradable poly(l-lysine) dendrigrafts functionalized with 12-48 arginine end-groups interact, at physiological pH, with insulin affording dendrigraft/insulin complexes as established by dynamic light scattering, ζ-potential, circular dichroism and isothermal titration calorimetry. Binding occurs in two steps; at low dendrigraft/insulin molar ratios (< or = 0.07) interaction is accompanied with the endothermic dissociation of insulin dimers, while at higher molar ratios, complexation of insulin monomers with dendrigraft derivatives occurs exothermically. High levels of insulin complexation efficiencies (>99%) were determined for all derivatives. Stabilization of complexed insulin against enzymatic degradation by trypsin and α-chymotrypsin is observed especially for the highly arginine end-functionalized dendrigrafts. Insulin release rates in simulated intestinal fluid are being controlled by the number of arginine end-groups and released insulin retains its conformation.
authors.affiliation: Institute of Physical Chemistry, NCSR Demokritos, 15310 Aghia Paraskevi, Attiki, Greece.
authors.forename: Zili
authors.initials: Z
authors.lastname: Sideratou
authors.forename: Nikoletta
authors.initials: N
authors.lastname: Sterioti
authors.forename: Dimitris
authors.initials: D
authors.lastname: Tsiourvas
authors.forename: Leto-Aikaterini
authors.initials: LA
authors.lastname: Tziveleka
authors.forename: Angelos
authors.initials: A
authors.lastname: Thanassoulas
authors.forename: George
authors.initials: G
authors.lastname: Nounesis
authors.forename: Constantinos M
authors.initials: CM
authors.lastname: Paleos
mesh_terms: D001120:Arginine / Q000737:chemistry*; D050091:Dendrimers / Q000138:chemical synthesis / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007328:Insulin / Q000737:chemistry*; D015394:Molecular Structure; D011107:Polylysine / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D050091:Dendrimers; D007328:Insulin; D011107:Polylysine; D001120:Arginine