IADR Abstract Archives
Additively Manufactured Constructs Processed by HIP Treatment Enhance Osteoblastic Response
Objectives: Hot isostatic pressure (HIP) treatment is used to increase mechanical properties of additively manufactured (AM) titanium-aluminum-vanadium (Ti6Al4V) implants. Use of AM implants for biomedical applications raises the question of whether cellular response is altered by HIP treatment, especially for implants that undergo further modification of surface roughness via grit-blasting and acid-etching. We used an in vitro human mesenchymal stem cell (MSC) culture model to assess the effects of HIP treatment. MSCs were cultured on 3D AM constructs with either trabecular bone inspired (3DLS) or organized (3DG) geometry that had surfaces modified by grit-blasting and acid-etching.
Methods: 15mm x 6mm Ti6Al4V constructs +/- HIP treatment were fabricated by laser sintering and further modified by grit blasting and acid etching (AB Dental, Ashdod, Israel). MSCs (Lonza) were cultured on these constructs for 7 days in growth media. Bone morphogenetic protein 2 (BMP2), vascular endothelial growth factor (VEGF), and interleukins 6 and 10, as well as osteoblastic markers osteoprotegerin and osteocalcin, were measured in conditioned media. Data were normalized to DNA. Alkaline phosphatase specific activity (ALP), and DNA content were determined in cell lysates (n=6 cultures/variable; Student’s t-test p<0.05).
Results: Osteoblastic markers and soluble factors were comparable in cultures on 3DLS and 3DG constructs not processed by HIP-treatment. HIP-treated 3DLS constructs increased BMP2 compared to HIP-treated 3DG constructs. HIP-treated 3DLS increased production of BMP2 and VEGF, as well as decreased DNA content compared to non-treated 3DLS constructs. MSCs on HIP-treated 3DG constructs had increased ALP activity and BMP2 compared to non-HIP-treated 3DG constructs.
Conclusions: Our data suggest that HIP treatment of Ti6Al4V AM constructs enhances creation of an osteogenic environment and osteoblastic differentiation. MSCs are more sensitive to architecture changes on constructs that have undergone HIP treatment. Thus, use of HIP may provide mechanical and biologic advantages during implant osseointegration and function.
Methods: 15mm x 6mm Ti6Al4V constructs +/- HIP treatment were fabricated by laser sintering and further modified by grit blasting and acid etching (AB Dental, Ashdod, Israel). MSCs (Lonza) were cultured on these constructs for 7 days in growth media. Bone morphogenetic protein 2 (BMP2), vascular endothelial growth factor (VEGF), and interleukins 6 and 10, as well as osteoblastic markers osteoprotegerin and osteocalcin, were measured in conditioned media. Data were normalized to DNA. Alkaline phosphatase specific activity (ALP), and DNA content were determined in cell lysates (n=6 cultures/variable; Student’s t-test p<0.05).
Results: Osteoblastic markers and soluble factors were comparable in cultures on 3DLS and 3DG constructs not processed by HIP-treatment. HIP-treated 3DLS constructs increased BMP2 compared to HIP-treated 3DG constructs. HIP-treated 3DLS increased production of BMP2 and VEGF, as well as decreased DNA content compared to non-treated 3DLS constructs. MSCs on HIP-treated 3DG constructs had increased ALP activity and BMP2 compared to non-HIP-treated 3DG constructs.
Conclusions: Our data suggest that HIP treatment of Ti6Al4V AM constructs enhances creation of an osteogenic environment and osteoblastic differentiation. MSCs are more sensitive to architecture changes on constructs that have undergone HIP treatment. Thus, use of HIP may provide mechanical and biologic advantages during implant osseointegration and function.