Controllable Surface Modification of Poly(lactic-co-glycolic acid) (PLGA) by Hydrolysis or Aminolysis I:  Physical, Chemical, and Theoretical Aspects

Abstract

While biodegradable, biocompatible polyesters such as poly (lactic-co-glycolic acid) (PLGA) are popular materials for the manufacture of tissue engineering scaffolds, their surface properties are not particularly suitable for directed tissue growth. Although a number of approaches to chemically modify the PLGA surface have been reported, their applicability to soft tissue scaffolds, which combine large volumes, complex shapes, and extremely fine structures, is questionable. In this paper, we describe two wet-chemical methods, base hydrolysis and aminolysis, to introduce useful levels of carboxylic acid or primary and secondary amine groups, respectively, onto the surface of PLGA with minimal degradation. The effects of temperature, concentration, pH, and solvent type on the kinetics of these reactions are studied by following changes in the wettability of the PLGA using contact angle measurements. In addition, the treated surfaces are studied using X-ray photoelectron spectroscopy (XPS) to determine the effect on the surface chemical structure. Furthermore, we show using XPS analysis that these carboxyl and amine groups are readily activated to allow the covalent attachment of biological macromolecules.

Tuneable surface modification of PLGA nanoparticles carrying new antitubercular drug candidate

“…The activation and chemical coupling [9,10] yields a stable layer but is accompanied by partial degradation of the polyester. The PEG-containing triblock copolymer (Pluronic) proved to be an efficient surface modifier which can be applied in a blend form since it is miscible with PLGA in a certain concentration range depending on their composition [11][12][13].…”

Protein adsorption onto polyester surfaces: Is there a need for surface activation?

“…Alternatively, aminolysis may be employed to introduce primary and secondary amine groups on the surface. 21,24 The effects of temperature, pH, concentration of the substances, and cell seeding density were studied to optimize the conditions for cell adhesion and cell growth. There is, however, conflicting data in the literature regarding whether modified biodegradable polyesters can encourage cell adhesion and cell growth.…”

Amino-functionalized poly(L-lactide) lamellar single crystals as a valuable substrate for delivery of HPV16-E7 tumor antigen in vaccine development

“…This reaction can provide the lamella surface not just with amino groups but with hydroxyl functionalities as well, without producing any hydrolysis side reaction. 29 The aminolysis reaction conditions chosen in this study (0.1 g/mL TEPA solution in isopropanol, 10 minutes at 55°C), did not change the single crystal morphology or surface roughness, as shown by SEM images of well dispersed PLLA sc and APLLA sc lamellae, obtained from a diluted isopropanol suspension ( Figure 1A and B). In contrast, more drastic reaction conditions (such as longer reaction time, and a higher temperature and amine concentration) brought about a reduction in the lamellar lateral dimension or weakening of the crystal structure with lamellar fragmentation in subsequent treatments (data not shown).…”