There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.
Abstract
A novel method was developed to produce highly porous sponges for potential use in
tissue engineering, without the use of organic solvents. Highly porous sponges of
biodegradable polymers are frequently utilized in tissue engineering both to transplant
cells or growth factors, and to serve as a template for tissue regeneration. The processes
utilized to fabricate sponges typically use organic solvents, but organic residues
remaining in the sponges may be harmful to adherent cells, protein growth factors
or nearby tissues. This report describes a technique to fabricate macroporous sponges
from synthetic biodegradable polymers using high pressure carbon dioxide processing
at room temperature. Solid discs of poly (D,L-lactic-co-glycolic acid) were saturated
with CO2 by exposure to high pressure CO2 gas (5.5 MPa) for 72 h at room temperature.
The solubility of the gas in the polymer was then rapidly decreased by reducing the
CO2 gas pressure to atmospheric levels. This created a thermodynamic instability for
the CO2 dissolved in the polymer discs, and resulted in the nucleation and growth
of gas cells within the polymer matrix. Polymer sponges with large pores (approximately
100 microns) and porosities of up to 93% could be fabricated with this technique.
The porosity of the sponges could be controlled by the perform production technique,
and mixing crystalline and amorphous polymers. Fibre-reinforced foams could also be
produced by placing polymer fibres within the polymer matrix before CO2 gas processing.