Surface modification of poly(lactic acid) nanoparticles by covalent attachment of thiol groups by means of three methods

Details

Serval ID
serval:BIB_22E23F0B270E
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Surface modification of poly(lactic acid) nanoparticles by covalent attachment of thiol groups by means of three methods
Journal
International Journal of Pharmaceutics
Author(s)
Nobs  L., Buchegger  F., Gurny  R., Allemann  E.
ISSN
0378-5173 (Print)
Publication state
Published
Issued date
01/2003
Volume
250
Number
2
Pages
327-37
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Jan 16
Abstract
The aim of the present work was to find a suitable method for the introduction of thiol functions on the surface of poly(DL-lactic acid) (PLA) nanoparticles. Three different approaches were investigated. The modification of the surface involves the activation of PLA carboxylic acid groups followed by the attack of a nucleophile such as cysteine (method #1) or cystamine (method #2 and #3) that provide thiol functions via an amide bond. For the conjugation with cystamine, a second reaction step is required to expose the sulfhydryl function of cystamine that is otherwise protected in a disulfide bond. 1,4-Dithio-DL-threitol (DTT) (method #2) or Tris(2-carboxyethyl)-phosphine hydrochloride (method #3) were evaluated for their ability to reduce this linkage. Method #1 allowed a maximum of 8.5+/-2.8 mmol of thiol functions per mol of PLA to be attached on the surface of the nanoparticles. Method #2 allowed the introduction of a greater number of thiol functions (up to 190+/-15 mmol per mol of PLA). However, this latter method has a major drawback: DTT interacts strongly with the nanoparticle matrix during the reduction step. Method #3 has the advantage over method #2 in that it allowed a significant number of thiol functions to be covalently bound to the particles (up to 107.6+/-0.6 mmol per mol of PLA) without the problem of undesired interaction between DTT and the nanoparticle matrix. The introduction of thiol groups onto the surface of PLA nanoparticles is possible with all three suggested methods. The method #3 provides a straight forward approach for the substitution of carboxylic acid groups with a high number of activated sulfhydryl at the surface of PLA nanoparticles.
Keywords
Lactic Acid/*chemistry Nanotechnology/*methods Polymers/*chemistry Sulfhydryl Compounds/*chemistry Surface Properties/drug effects Technology, Pharmaceutical/*methods
Pubmed
Web of science
Create date
25/01/2008 11:27
Last modification date
20/08/2019 13:00
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