Aptamer-gelatin composite material for prolonging PDGF-BB release

Abstract

Platelet-derived growth factor-BB (PDGF-BB) is a promising molecule with a range of medical applications. However, the very rapid delivery of this growth factor may render treatment ineffective. A delivery system that is able to prolong the release rate is therefore required. In this study, a composite was fabricated from gelatin type IV and an aptamer. The aptamer worked as a binding ligand for PDGF-BB and was shown to slow the release rate. An inverted-tube test showed that the phase transition temperature of the gelatin increased in line with the gelatin concentration and in the presence of the coupling reagents N,N’- dicyclohexylcarbodiimide and N-hydroxysuccinimide. Binding functionality of the aptamer was confirmed by surface plasmon resonance spectrometry. Rheological measurements indicated that the incorporation had no effect on the mechanical properties of the composite. The degradation of the composite and the kinetic release of the target proteins were investigated. The gelatin was shown to gradually dissolve in the release medium. The rate of PDGF-BB release from the aptamer-gelatin composite was significantly slower than from the native gelatin. This novel composite has potential applications in a range of PDGF-BB-related treatments.

Keywords

• gelatin
• aptamer
• composite
• pdgf-bb
• protein release