Characterization of Polylactic Acid–Polyglycolic Acid Composites for Cartilage Tissue Engineering

Abstract

The objective of this study was to determine the effects of scaffold composition on the physical properties, adhesion, and growth of bovine articular chondrocytes on polylactic acid (PLA)/polyglycolic acid (PGA) composites. Nonwoven meshes of PGA were coated with PLA, using a solvent evaporation technique that resulted in composites with fractional PLA contents ranging from 0 to 68%. The compressive modulus of scaffolds increased linearly with the addition of PLA, ranging from less than 1 kPa for PGA to approximately 20 kPa for scaffolds with 68% PLA content. The characteristic degradation time of these scaffolds also increased from approximately 5 days for 0% PLA to 45 days for 68% PLA. Addition of PLA decreased cell seeding efficiency from 48% for 0% PLA scaffolds to 27% for 68% PLA scaffolds. Cells seeded onto 27% PLA scaffolds increased 3-fold in number over 4 weeks in culture, whereas cells seeded onto 68% PLA increased only 2-fold in number. Scanning electron microscopy indicated that cells attached to PGA appeared flat with many small processes, whereas those attached to PLA were more rounded. These studies provide important information for the design of scaffolds for cartilage tissue engineering.

Tissue Engineering for Tissue and Organ Regeneration

“…The remaining cells were collected and counted. The cell seeding efficiencies of the scaffolds with different PLA contents were calculated based on the formula: (total cell numberremaining cell number)/ total cell number×100% (Moran et al, 2003).…”

“…Polyglycolic acid (PGA) has proven to be one of the most successful scaffolds for cartilage regeneration (Cui et al, 2009;Frenkel, Di, 2004;Heath, Magari, 1996). Cartilage engineered with the PGA scaffold has structure and composition similar to the native tissue, as demonstrated by histological analysis and cartilage specific matrices (Aufderheide, Athanasiou, 2005;Moran et al, 2003;Yan et al, 2009). However, the most widely used form of PGA material in cartilage engineering is unwoven fiber mesh, which is difficult to be initially prepared into a complicated 3D structure and would most likely fail to maintain its original architecture during subsequent in vitro chondrogenesis due to insufficient mechanical support (Gunatillake, Adhikari, 2003;Kim, Mooney, 1998;Moran et al, 2003).…”

Human Ear Cartilage

“…The remaining cells were collected and counted. The cell seeding efficiencies of the scaffolds with different PLA contents were calculated based on the formula: (total cell numberremaining cell number)/ total cell number×100% (Moran et al, 2003). Scanning electron microscopy (SEM): The constructs were cultured in vitro and the attachment and matrix production of the cells on the scaffolds were examined by SEM (Philips XL-30, Amsterdam, Netherlands) after 2 weeks and 8 weeks.…”

“…Polyglycolic acid (PGA) has proven to be one of the most successful scaffolds for cartilage regeneration (Cui et al, 2009;Frenkel, Di, 2004;Heath, Magari, 1996). Cartilage engineered with the PGA scaffold has structure and composition similar to the native tissue, as demonstrated by histological analysis and cartilage specific matrices (Aufderheide, Athanasiou, 2005;Moran et al, 2003;Yan et al, 2009). However, the most widely used form of PGA material in cartilage engineering is unwoven fiber mesh, which is difficult to be initially prepared into a complicated 3D structure and would most likely fail to maintain its original architecture during subsequent in vitro chondrogenesis due to insufficient mechanical support (Gunatillake, Adhikari, 2003;Kim, Mooney, 1998;Moran et al, 2003).…”

Cartilage Tissue Engineering

“…Controls of the physical characteristics of the scaffolds, such as fiber diameter, pore size, and polymer crystallinity can regulate the scaffold degradation rates, which can range from 6-8 weeks in the case of highly porous PGA fibrous mesh to 6-18 months in the case of a highly crystalline PLA [11]. Similarly, the mechanical properties of these scaffolds can be regulated and have been shown to range from 5 kPa [12] to 1 GPa [13].…”