Biological Efficacy of Modified Structure of Polymer Surfaces for Bone Substitute
Hydroxyapatite (HA) coatings were introduced onto Poly L-lactic Acid (PLLA) polymer in a controlled manner by immobilized urease method with a shortened precipitation time. Osteoblastic-like cellular responses to the composite were examined in terms of cell proliferation, differentiation and cell morphology, as well as the expression of bone-associated genes. The cells exhibited higher cellular proliferation at 2 and 4 days on the HA/PLLA composite compared to PLLA scaffold, while no significant difference was observed later at 6 days. The alkaline phosphatase (ALP) activity by cells at 7 days was statistically higher on HA/PLLA scaffold than on PLLA. Moreover, the gene expression of ALP and osteocalcin (OC) was up regulated on HA/PLLA composite by RT-PCR analysis. The preliminary study suggested that the use of the controlled modification of hydroxyapatite coating on PLLA scaffold to produce HA/PLLA composite might enhance cellular activity, indicating the potential use for bone substitute in tissue engineering.
Xingdong Zhang, Xudong Li, Hongsong Fan, Xuanyong Liu
Z. J. Pan et al., "Biological Efficacy of Modified Structure of Polymer Surfaces for Bone Substitute", Key Engineering Materials, Vols. 330-332, pp. 707-710, 2007