title: A novel biomaterial for osteotropic drug nanocarriers: synthesis and biocompatibility evaluation of a PLGA-ALE conjugate.
abstract: OBJECTIVE
  Osteotropic drug-delivery systems have been proposed as a means to provide drugs with affinity to bone tissues. Drugs or proteins have been linked chemically to bone-seeking agents, such as bisphosphonates (BPs); alternatively, drug-loaded nanoparticles have been used to target specific tissues, such as tumor areas. In our current research, these approaches were merged by synthesizing a novel bone-seeking polymer conjugate, from which targetable nanoparticles can be produced.
  
  
  METHODS
  An amino-BP, alendronate (ALE) was bound covalently to a biodegradable polymer, poly(lactic-co-glycolide) (PLGA), containing a free end carboxylic group. Blood compatibility and cytotoxicity were assessed in vitro.
  
  
  CONCLUSIONS
  By a classical solvent-evaporation method, nanoparticles with a mean size of 200-300 nm were prepared from the conjugate; sterilization was achieved by gamma-irradiation, confirming their potential as injectable drug nanocarriers. Owing to the presence of the BP residue, PLGA-ALE nanoparticles were adsorbed onto hydroxyapatite to a higher extent than pure PLGA nanoparticles. The PLGA-ALE conjugate did not induce either hemolysis or alterations of the plasmatic phase of coagulation, or cytotoxic effects on endothelial cells and trabecular osteoblasts.
  
  
  CONCLUSIONS
  The prepared conjugate represents a novel biomaterial that is able to provide nanoparticles, which can be further loaded with drugs, such as anticancer agents, and addressed to osteolytic or other bone diseases.
authors.affiliation: Department of Pharmaceutical Sciences, Città Universitaria, Università degli Studi di Catania, Catania, Italy. r.pignatello@unict.it
authors.forename: Rosario
authors.initials: R
authors.lastname: Pignatello
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Cenni
authors.forename: Dorotea
authors.initials: D
authors.lastname: Micieli
authors.forename: Caterina
authors.initials: C
authors.lastname: Fotia
authors.forename: Manuela
authors.initials: M
authors.lastname: Salerno
authors.forename: Donatella
authors.initials: D
authors.lastname: Granchi
authors.forename: Sofia
authors.initials: S
authors.lastname: Avnet
authors.forename: Maria G
authors.initials: MG
authors.lastname: Sarpietro
authors.forename: Francesco
authors.initials: F
authors.lastname: Castelli
authors.forename: Nicola
authors.initials: N
authors.lastname: Baldini
mesh_terms: D019386:Alendronate / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry*; D002478:Cells, Cultured; D004337:Drug Carriers / Q000737:chemistry*; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008855:Microscopy, Electron, Scanning; D015394:Molecular Structure; D053758:Nanoparticles / Q000737:chemistry*; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D001672:Biocompatible Materials; D004337:Drug Carriers; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D019386:Alendronate