Bioactive Surface Structure and Bio-Absorption of Human Dentin Granules Designed by the Supersonic Demineralization and Biomimetic Coating Technique
Bioactive Surface Structure and Bio-Absorption of Human Dentin Granules Designed by the Supersonic Demineralization and Biomimetic Coating Technique
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DOI：
10.2485/jhtb.21.351
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发表时间：
2012-10-01
影响因子：
0.4
通讯作者：
Kimura, Isao
中科院分区：
文献类型：
--
作者：
Akazawa, Toshiyuki;Murata, Masaru;Kimura, Isao
以拔除的人牙为原料，采用冷却粉碎和超声脱矿技术，设计出具有良好生物相容性的脱矿牙本质基质（DDM）颗粒。将拔出的牙齿与盐水冰一起在 ZrO2 容器中以 12,000 rpm 的 ZrO2 刀片粉碎 30 秒。将粒度为0.5-2.0mm的粉碎颗粒通过在120W和38kHz或600W和28-100kHz下的超声处理在2.0％HNO 3 溶液中溶解以获得部分或完全DDM颗粒。粉碎颗粒的溶解效率随着超声速时间的增加而增加。在 600 W 时，28 kHz 处理的 DDM 的溶解效率高于其他频率下的溶解效率。颗粒的Ca/P摩尔比为1.60-1.66，表明部分DDM颗粒是缺Ca2+羟基磷灰石(HAp)和胶原的复合材料。在120W时，随着超声时间的增加，由于矿物成分的洗脱，颗粒表面的凹凸变得明显。 45分钟时，DDM颗粒完全脱矿质，重量减少至约五分之一。观察到表面坚硬的凹凸和微裂纹。将DDM颗粒部分或全部植入大鼠背部皮下组织。 4 周时，完全 DDM 颗粒比部分 DDM 颗粒稍小且形状更不规则。未识别出 DDM 颗粒的感染和排除，但通过酶消化引起的 DDM 生物吸收，观察到炎症细胞侵袭。为了提高 DDM 的表面活性，将 DDM 颗粒在 309.5 K、pH 7.40 的条件下浸泡在模拟体液中。 48小时时，HAp纳米晶体几乎均匀地涂覆在完全DDM颗粒的表面，而144小时时，发现了多孔骨状磷灰石。 DDM颗粒的HAp纳米晶体涂层将形成具有特定孔结构和化学性质的生物活性表面。
Demineralized dentin matrix (DDM) granules with excellent biocompatibility were designed using extracted human teeth by the cooling-pulverizing and supersonic demineralizing technique. Extracted teeth were pulverized together with saline ice at 12,000 rpm of a ZrO2 blade for 30 s in a ZrO2 vessel. The pulverized granules having 0.5-2.0 mm in granular size were dissolved by the supersonic treatment at 120 W and 38 kHz or 600 W and 28-100 kHz in 2.0 % HNO3 solutions to obtain partially or completely DDM granules. Dissolution efficiencies of the pulverized granules increased with increasing the supersonic time. At 600 W, dissolution efficiencies for DDM treated at 28 kHz were higher than those at other frequencies. The Ca/P molar ratios of the granules were 1.60-1.66, suggesting that partial DDM granules were composites of Ca2+-deficient hydroxyapatite (HAp) and collagen. At 120 W, as supersonic time increased, asperity on the surfaces of granules became outstanding due to elution of mineral components. At 45 min, DDM granules were completely demineralized and the weight decreased to about one-fifth. Hard asperity on surfaces and micro-crack were observed. Partially or completely DDM granules were implanted into the subcutaneous tissues of the back region of rats. At 4 weeks, completely DDM granules had a little smaller and more irregular shape than partially DDM ones. Infection and exclusion of DDM granules were not recognized, but inflammatory cell invasion was seen through bio-absorption of DDM due to the enzyme-digestion. To improve surface activity of DDM, DDM granules were soaked at 309.5 K and pH 7.40 in a simulated body fluid. At 48 h, HAp nano-crystals were almost homogeneously coated on the surfaces of completely DDM granules, while at 144 h, porous bone-like apatites were found. The HAp nano-crystals coating for DDM granules would form bioactive surface with specific pore structure and chemical nature.