Impact of non-thermal plasma surface modification on porous calcium hydroxyapatite ceramics for bone regeneration

• Published in: PloS one 2018-03, Vol.13 (3), p.e0194303-e0194303
• Main Authors: Moriguchi, Yu, Lee, Dae-Sung, Chijimatsu, Ryota, Thamina, Khair, Masuda, Kazuto, Itsuki, Dai, Yoshikawa, Hideki, Hamaguchi, Satoshi, Myoui, Akira
• Format: Article
• Language: English
• Subjects: Biocompatibility; Biology and Life Sciences; Biomedical materials; Bone growth; Bone marrow; Bone surgery; Bones; Calcium; CAT scans; Cell proliferation; Ceramics; Computed tomography; Dielectric barrier discharge; Differentiation (biology); Engineering and Technology; Engineering schools; Hydrophilicity; Hydroxyapatite; Hydroxyapatites; Implantation; Medical research; Medicine; Medicine and Health Sciences; Mesenchyme; Optimization; Osteoblastogenesis; Osteoconduction; Oxygen; Photoelectron spectroscopy; Photoelectrons; Physical Sciences; Physiochemistry; Plasma; Properties; Regeneration; Regeneration (physiology); Research and Analysis Methods; Spectroscopy; Spectrum analysis; Stem cells; Surface treatment; Surgery; Surgical implants; Thermal plasmas; Tissue engineering; Transplants & implants; University graduates; X ray photoelectron spectroscopy; X-ray spectroscopy
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0194303

In the physiochemical sciences, plasma is used to describe an ionized gas. Previous studies have implicated plasma surface treatment in the enhancement of hydrophilicity of implanted musculoskeletal reconstructive materials. Hydroxyapatite (HA) ceramics, widely used in bone tissue regeneration, have made great advancements to skeletal surgery. In the present study, we investigate the impact of low-pressure plasma on the interconnected porous calcium hydroxyapatite (IP-CHA) both in vitro and in vivo. Our results indicate that dielectric barrier discharge (DBD) plasma, when used with oxygen, can augment the hydrophilicity of non-porous HA surfaces and the osteoconductivity of the IP-CHA disc via increased water penetration of inner porous structures, as demonstrated through microfocus computed tomography (μCT) assay. In vivo implantation of plasma-treated IP-CHA displayed superior bone ingrowth than untreated IP-CHA. Though plasma-treated IP-CHA did not alter osteoblast cell proliferation, it accelerated osteogenic differentiation of seeded marrow mesenchymal stem cells. In vitro X-ray photoelectron spectroscopy (XPS) revealed that this plasma treatment increases levels of oxygen, rather than nitrogen, on the plasma-treated IP-CHA surface. These findings suggest that plasma treatment, an easy and simple processing, can significantly improve the osteoconductive potential of commonly used artificial bones such as IP-CHA. Further optimization of plasma treatment and longer-term follow-up of in vivo application are required toward its clinical application.