In vivo study of 2D PHA matrices of different chemical compositions: tissue reactions and biodegradations

Abstract

Matrices based on resorbable polyhydroxyalkanoates (PHAs) of five types {a homopolymer of 3-hydroxybutyric acid, copolymers of 3-hydroxybutyric and 4-hydroxybutyric acids [P(3HB/4HB)], 3-hydroxybutyric and 3-hydroxyvaleric acids [P(3HB/3HV)], 3-hydroxybutyric and 3-hydroxyhexanoic acids [P(3HB/3HHx)]} have been constructed and characterised. No significant differences have been found in tissue response to implantation of these PHAs. Non-coarse fibrous capsules that formed around PHA matrices reached their maximum thickness (60–90 μm) 90 days after implantation; by day 180, the average thickness of the capsules had decreased by 1·5–2·3 times. The number of foreign body giant cells, resorbing PHAs, remained high. In vivo biodegradation behaviour of polymer matrices is related to the chemical composition of the PHA. Matrices prepared from copolymers P(3HB/4HB) and P(3HB/3HHx) exhibited the fastest degradation rates. P3HB/3HV matrices were degraded more slowly, and P3HB matrices were the most durable. In the PHA matrices that were degraded more slowly, giant cell reaction developed later.

Keywords:

• PHA
• Polyhydroxyalkanoates
• Biocompatibility
• Implantation
• Tissue response
• Biodegradation

Acknowledgements

The study was supported by the project initiated by the Government of the Russian Federation (decree no. 220 of 09·04·2010) for governmental support of scientific research conducted under the guidance of leading scientists at Russian institutions of higher learning (agreement no. 11.G34·31·0013) and the Program of Integrated Research of the Presidium of SB RAS (project no. 96).