title: Enhanced surface attachment of protein-type targeting ligands to poly(lactide-co-glycolide) nanoparticles using variable expression of polymeric acid functionality.
abstract: The density of reactive carboxyl groups on the surface of poly(lactide-co-glycolide) (PLGA) nanoparticles (NP) was modulated using a combination of high-molecular weight (MW) encapped and low MW non-encapped PLGA. Carboxyl groups were activated using carbodiimide chemistry and conjugated to bovine serum albumin and a model polyclonal antibody. Activation of carboxyl groups in solution-phase PLGA prior to NP formation was compared with a postformation activation of peripheral carboxyl groups on intact NP. Activation before or after NP formation did not influence conjugation efficiency to NP prepared using 100% of the low-MW PLGA. The effect of steric stabilization using poly(vinyl alcohol) reduced conjugation of a polyclonal antibody from 62 microg/(mg NP) to 32 microg/(mg NP), but enhanced particulate stability. Increasing the amount of a high-MW PLGA also reduced conjugation, with the activation postformation still superior to the preformation approach. Drug release studies showed that high proportions of high-MW PLGA in the NP produced a longer sustained release profile of a model drug (celecoxib). It can be concluded that activating intact PLGA NP is superior to activating component parts prior to NP formation. Also, high MW PLGA could be used to prolong drug release, but at the expense of conjugation efficiency on to the NP surface.
authors.affiliation: School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, United Kingdom. p.mccarron@qub.ac.uk
authors.forename: Paul A
authors.initials: PA
authors.lastname: McCarron
authors.forename: Waleed M
authors.initials: WM
authors.lastname: Marouf
authors.forename: Ryan F
authors.initials: RF
authors.lastname: Donnelly
authors.forename: Chris
authors.initials: C
authors.lastname: Scott
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry / Q000378:metabolism; D001672:Biocompatible Materials / Q000737:chemistry; D002417:Cattle; D000068579:Celecoxib; D004337:Drug Carriers / Q000737:chemistry; D016503:Drug Delivery Systems; D004355:Drug Stability; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry*; D008024:Ligands; D008422:Materials Testing; D015394:Molecular Structure; D008970:Molecular Weight; D053758:Nanoparticles / Q000737:chemistry*; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry*; D011720:Pyrazoles / Q000737:chemistry / Q000378:metabolism; D013449:Sulfonamides / Q000737:chemistry / Q000378:metabolism; D013499:Surface Properties
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D001672:Biocompatible Materials; D004337:Drug Carriers; D008024:Ligands; D011108:Polymers; D011720:Pyrazoles; D013449:Sulfonamides; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D000068579:Celecoxib