In vivo heat-stimulus-triggered osteogenesis. (February 2015)

• Record Type: Journal Article
• Authors: Ikuta, Kunihiro; Urakawa, Hiroshi; Kozawa, Eiji; Hamada, Shunsuke; Ota, Takehiro; Kato, Ryuji; Honda, Hiroyuki; Kobayashi, Takeshi; Ishiguro, Naoki; Nishida, Yoshihiro
• Is Part Of: International journal of hyperthermia. Volume 31:Number 1(2015)
• Page Start: 58
• Page End: 66
• Publication Date: 2015-02
• Subjects: Thermotherapy -- Periodicals; 615.832
• DOI: 10.3109/02656736.2014.988662
• Languages: English
• ISSNs: 0265-6736

Abstract

<abstract> <title>Abstract</title> <p>Several studies have reported that heat stress stimulates the activity of osteoblastic cells <italic>in vitro</italic>. However, few have addressed the effects of heat stress on osteogenesis <italic>in vivo</italic>, nor have the optimal temperatures for bone formation been determined. The aim of the present study was to investigate the effects of hyperthermia treatment on osteogenesis in a rat tibial defect model. Forty-four Sprague Dawley rats were divided into two groups with or without hyperthermia treatment. A 3-mm circular defect in the proximal tibia filled with magnetite cationic liposomes embedded in alginate beads was subjected to hyperthermia treatment (43–46 °C). Radiological assessment at 2 weeks after the treatment showed that significantly stimulated osteogenesis was observed in the hyperthermia group as compared to the control group (<italic>p</italic> = 0.003). Histomorphometrical analysis at 2 weeks revealed a significant increase of newly formed bone in the hyperthermia group, compared with the control group (<italic>p</italic> < 0.001). Area of newly formed bone in each hyperthermia group was significantly increased as compared with the control group (43 °C; <italic>p</italic> = 0.005, 44 °C; <italic>p</italic> = 0.019, 45 °C; <italic>p</italic> = 0.003, and 46 °C; <italic>p</italic> = 0.003, respectively). Alkaline phosphatase was overexpressed at the surfaces of newly formed bone adjacent to magnetite cationic liposome implantation. Our results demonstrate for the first time that heat stimulus accelerates osteogenesis <italic>in vivo</italic>, and may thus be of interest as a novel and promising tool to induce osteogenesis clinically as well.</p> </abstract>