Papers by Author: Kazuo Takakuda

Abstract: The bone-like self-organized hydroxyapatite/collagen (HAp/Col) nanocomposite sponge was prepared from HAp/Col nanocomposite fibers. We analyzed osteogenic activity of human osteoblastic MG63 cells in the HAp/Col sponge under pressure/perfusion culture. Collagen (Col) sponge was used as a control. The MG63 cells were attached well and showed good proliferation in the HAp/Col sponge. The total DNA content in the HAp/Col sponge was approximately 1.8 times greater than that in the Col sponge at 21 days. The MG63 cells showed good osteogenic gene expression in the HAp/Col sponge by reverse transcription-polymerase chain reaction analysis. These result suggested that HAp/Col sponge can be useful for bone tissue engineering scaffold materials.

Abstract: The purpose of this study is to analyze osteogenic activity of human osteoblastic MG63 cells on the bone-like self-organized hydroxyapatite/collagen (HAp/Col) nanocomposite sponge cultured by a pressure/perfusion technique using collagen sponge as a control. Histological analyses, alkaline phosphatase (AlkP) protein analysis and real-time polymerase chain reaction (PCR) analyses for AlkP and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) to evaluate the osteogenic activity of MG63. The MG63 cells were attached well and showed good proliferation on the HAp/Col sponge as well as in the control. The MG63 cells on HAp/Col sponge demonstrated higher osteogenic activity than those on the control. The results suggested that the HAp/Col sponge is expected to be a good scaffold for bone tissue engineering.

Abstract: In the treatment based on Guided Bone Regeneration method (GBR), membranes are necessary to cover bone defects and prevent the invasion of surrounding soft tissues. In spite of the potential usefulness of GBR method, no appropriate materials for the membrane have been developed and this method is not utilized frequently in common clinical practice. Here we developed materials such as a composite of β-tricalcium phosphate (β-TCP) and copolymer of L-lactide, glycolide and ε-caplolactone (PLGC), and designed the novel GBR membranes with ideal mechanical properties. The materials had good biocompatibility, and the membrane had sufficient strength although their thickness was as thin as 200 μm. The membranes were applied to large bone defects created in canine mandibular bones, and significant enhancement in bone regeneration was demonstrated.

Abstract: Regeneration of dura mater of the brain is one of the most urgent tasks in the fields of regeneration medicine, considering the facts that we have many patients infected with fatal Creutzfeldt-Jakob disease following transplant of dried dura mater in the brain operations. Hence we designed the artificial dura mater made from poly(L-lactic acid-co-glycolic acid-co-ε-caprolactone). The sutured substitutes have the ability to prevent the leakage of cerebral fluid, would be absorbed in several months and the patient might be free from the possible side effects caused by the implanted materials. The leakage-proof tests for the developed substitutes were carried out and it was demonstrated that the sutured substitutes and dura mater support the pressure of saline as large as 400mmAq without leakage. The dural regeneration experiments were carried out with rabbits and successful regenerations of dura mater were observed. No inflammations were observed around the substitutes throughout the experimental period till the complete absorption of the materials.