JPH0832552B2 - Hydroxyapatite fine single crystal and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a hydroxyapatite fine single crystal and a method for producing the same, more specifically, a stationary phase agent packed in a column for column chromatography, a carrier for cell culture / separation. TECHNICAL FIELD The present invention relates to a hydroxyapatite fine single crystal useful as a bio-related material such as a material and a method for producing the same.

<Prior Art> Conventionally, hydroxyapatite (hereinafter referred to as HAp) crystal particles have an excellent chromatographic separation ability (substance separation development ability) as a stationary phase agent packed in a column for column chromatography.
It is used as an essential material for high-purity separation and purification of substances in the biotechnology field.

The HAp particles and the method for producing the same are described in JP-A-62-20
In 2808 publication, the suspension water of the brushite crystal particles is heated in the range of the boiling point of the suspension water from the dehydration phase transition temperature, and by subjecting the monetite suspension water obtained by the dehydration phase transition to an alkali treatment and boiling treatment, A method has been proposed for synthesizing plate-like HAp crystal particles that retain the shape of the substance, brushite crystal particles. However, the synthetic body obtained by the above-mentioned method only obtains a polycrystalline aggregate of HAp crystal particles, and does not control the morphology of the HAp primary particles constituting it, so that the packed stationary phase in the column is packed. When used as an agent, a carrier material for cell culture / separation, etc., there is a drawback that a highly accurate substance separation and development ability cannot be obtained.

Further, in JP-A-61-242968, an autoclave is used to conduct a hydraulic reaction under pressure to produce a hexagonal columnar shape.
Although a method of synthesizing HAp crystal particles has been proposed, the HAp crystal particles synthesized by the above method have an aspect ratio of 2.5.
~ 3.0 hexagonal columnar primary particles, the HAp crystal particles are
The shape of the HAp precursor obtained by wet synthesis is the same as that of HAp particles obtained by calcination at around 800 ° C. Therefore, the development of HAp crystal particles whose primary particles are more precisely controlled in shape is desired. It is rare.

<Problems to be Solved by the Invention> An object of the present invention is to provide HAp fine single crystal particles having a precisely controlled primary particle shape and having a more accurate material separation and development capability, and a method for producing the same. It is in.

<Means for Solving the Problems> According to the present invention, a calcium phosphate compound slurry adjusted to pH = 10 or more, or a calcium phosphate compound slurry containing an additive consisting of potassium chloride, sodium chloride, potassium sulfate, and sodium sulfate, is a slurry. Provided is a hydroxyapatite fine single crystal having an aspect ratio (c / a) of less than 2.0 obtained by hydrothermal treatment under a saturated vapor pressure at a temperature equal to or higher than the boiling point of a solvent.

Further, according to the present invention, the pH of the calcium phosphate compound slurry, the slurry adjusted to pH = 10 or more, or calcium phosphate compound slurry containing an additive consisting of potassium chloride, sodium chloride, potassium sulfate, sodium sulfate, the boiling point of the slurry solvent Provided is a method for producing a hydroxyapatite fine single crystal having an aspect ratio (c / a) of less than 2.0 obtained by hydrothermal treatment under saturated vapor pressure at the above temperature.

 Hereinafter, the present invention will be described in more detail.

The HAp fine single crystal of the present invention is a fine crystal by a specific method, preferably a plate-like crystal characterized by having a specific aspect ratio.

In the present invention, for example, when used as a stationary phase filling agent in a column, a carrier for cell culture / separation, etc., the aspect ratio (c / a) of the fine single crystal is less than 2.0 in order to enhance the efficiency of cell separation or culture. It is a crystal. Aspect ratio is 2.
When it is 0 or more, when used as a stationary phase agent packed in a column, the adsorption rate characteristic may be deteriorated.

Further, the lengths of the a-axis and the c-axis in the HAp fine single crystal of the present invention facilitate the granulation and prevent the occurrence of clogging or the like in the a-axis direction when used as a stationary phase packing material in a column or the like. Crystal length 10 to 100 nm, crystal length in the c-axis direction 1 to 200 nm
Is preferred.

Next, the HAp fine single crystal of the present invention will be described in more detail by the production method.

To produce the HAp fine single crystal of the present invention, first, pH = 1
A calcium phosphate compound slurry adjusted to 0 or more, preferably pH = 12 or more, or a calcium phosphate compound slurry containing an additive consisting of potassium chloride, sodium chloride, potassium sulfate, and sodium sulfate is prepared. The
To prepare a calcium phosphate compound slurry adjusted to pH = 10 or more, for example, wet synthesizing Ca (OH) ₂ and H ₃ PO ₄ by a known method to obtain a slurry, and then adjusting pH of ammonia water, for example. It can be obtained by adding an agent. At this time, the weight mixing ratio of the calcium phosphate compound and water in the slurry is preferably in the range of 1: 1 to 100. When the pH of the calcium phosphate compound slurry is less than 10, it is not possible to suppress dissolution and precipitation of constituent ions necessary for c-axis growth in the formation and growth process of HAp fine single crystals in the hydrothermal region. Hydroxy ions cannot be adsorbed on the c-plane, and the relative growth rate of the a-axis cannot be increased.

In the present invention, the c-plane of a fine single crystal means that when a hexagonal crystal is represented by unit cell vectors a, b, c,
The surface defined by the axis and the b axis is defined as the c surface.

On the other hand, apart from this, it is also possible to obtain fine crystals having an aspect ratio (c / a) of less than 20 by adding an additive consisting of potassium chloride, sodium chloride, potassium sulfate and sodium sulfate. The calcium phosphate compound slurry containing the additive can be prepared by adding the additive during preparation of the calcium phosphate compound, after preparation, or both during preparation and after preparation. The additive is capable of adsorbing anions on the c-plane of the HAp fine single crystal, dissolving the crystal in the c-axis direction, or capable of accelerating the growth rate of the a-axis, or having these effects. Specifically, for example, potassium chloride, sodium chloride, potassium sulfate, and sodium sulfate. In this case, the additive amount of the calcium phosphate compound slurry 100
It is preferably in the range of 0.1 to 50 parts by weight with respect to parts by weight.

In order to produce HAp fine single crystals, the calcium phosphate compound slurry adjusted to pH = 10 or above or the calcium phosphate compound slurry containing an additive consisting of potassium chloride, sodium chloride, potassium sulfate and sodium sulfate is added to the boiling point of the slurry solvent. It can be obtained by hydrothermal treatment at the above temperature, preferably 100 to 300 ° C., under saturated vapor pressure, preferably 0.1 to 20 MPa. The hydrothermal treatment may be carried out under the conditions described above using a known autoclave, and more preferably the hydrothermal treatment is carried out for 0.1 to 24 hours, whereby a HAp fine single crystal having a desired aspect ratio can be obtained. When the reaction temperature in the hydrothermal treatment is lower than the boiling temperature of the slurry solvent, the reaction does not proceed, and when the pressure is lower than the saturated vapor pressure, the crystallinity is not improved.

The HAp fine single crystal of the present invention can be used after purification treatment if necessary by a known method.

<Effects of the Invention> The HAp fine single crystal of the present invention is produced by a specific method, has an aspect ratio (c / a) of less than 2.0, and has a large amount of calcium sites on the surface.
Since the surface is selectively grown and relatively exposed to a large amount, it is possible to selectively increase the efficiency of separation or culture of biochemical substances having affinity for calcium sites, cells, etc.
Therefore, it is extremely useful as a stationary phase agent packed in a column, a carrier material for cell culture / separation, and the like. Further, according to the production method of the present invention, a HAp fine single crystal can be obtained by simply subjecting it to hydrothermal treatment under specific conditions, which is extremely useful industrially.

<Examples> The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Example 1 Ca (OH) ₂ and 85 wt% H ₃ PO ₄ were wet-synthesized to obtain a 10 wt% slurry of calcium phosphate compound. Ammonia water as a pH adjuster was added and dissolved in 500 ml of the obtained calcium phosphate compound slurry to adjust the pH to 10,12. Then, each of the obtained slurries was charged into an autoclave, and
Hydrothermal treatment was performed under the conditions of 0 ℃, 2MPa and 5 hours. After the treatment was completed, each of the obtained slurries was washed with distilled water 1, filtered, and then dried at 100 ° C. in a drier. The shape of the obtained hydroxyapatite fine crystals was analyzed by X-ray diffraction. When the crystallite size was pH = 10, the crystal length in the a-axis direction was 80 nm, the crystal length in the c-axis direction was 50 nm, and the aspect ratio ( When c / a) = 1.6 and pH = 12, the plate-shaped single crystal had a length in the a-axis direction of 50 nm, a length in the c-axis direction of 50 nm, and an aspect ratio (c / a) of 1.0.

Example 2 The crystallite diameter was the same as in Example 1 except that 5 g of the additive KCl was added and mixed instead of the pH adjuster ammonia water.
The crystal length in the a-axis direction is 45 nm, the crystal length in the c-axis direction is 80 nm,
Plate-like HAp single crystals with an aspect ratio (c / a) of 1.8 were obtained.

Comparative Example 1 The crystallite size was 50 nm in the a-axis direction and the crystal length in the c-axis direction was 14 nm in the same manner as in Example 1 except that the pH adjusting agent or the additive was not added to the calcium phosphate compound slurry.
Hexagonal HAp single crystal with 0 nm and aspect ratio (c / a) of 2.8 was obtained.

Test Example The dried HAp fine crystal product obtained in Example 1 (fine crystals obtained by using a slurry of pH = 12), 2 and Comparative Example 1 was
Each was pulverized and classified to obtain an aggregate powder of 144 nm or less.
As a binder, 5% by weight of the product powder, "Maxellon" (manufactured by Shin-Etsu Chemical Co., Ltd.), was added and mixed as a binder to the obtained powder, and the mixture was pressure-molded with a die, crushed and classified, and the particle size
Granules of 0.3-0.5 mm were obtained. Further, the obtained granules are fired in an electric furnace at 900 ° C. for 3 hours at a temperature rising / falling rate of 5 ° C./minute,
25 g of each cell culture column packing material was obtained. This packing material was packed in a volume of 3 ml in each column, and 1 ml of a cell suspension (about 10 ⁵ to 10 ⁶ cells) of mouse calvaria-derived bone material cells MC3T3-E1 was loaded into the column. Next, the column was closed, and the medium "α-MEM (manufactured by Hazelton)" was used as the developing solvent, and the medium was caused to flow by a pump at an elution rate of 5 ml / min. 10 ml of the medium eluted from the column was added to a small test tube. The adsorption rate was calculated from the number of eluted cells counted by a hemocytometer (Kayagaki Seisakusho), and the results are shown in Table 1.
From the result of 1, the adsorption rate characteristic as a cell culture column packing material is inversely proportional to the aspect ratio (c / a), that is, a
It was found to increase in proportion to the effective area of the plane or b plane.

Front page continuation (72) Inventor Kengo Okamoto 2270 Yokoze, Yokoze-cho, Chichibu-gun, Saitama Sanryo Mining & Cement Co., Ltd. Ceramics Research Laboratory (56) Reference JP-A-53-111000 (JP, A) JP-A-61 -151010 (JP, A)

Claims (4)

[Claims] 1. A hydroxyapatite fine powder having an aspect ratio (c / a) of less than 2.0 obtained by subjecting a calcium phosphate compound slurry adjusted to pH = 10 or more to a hydrothermal treatment at a temperature not lower than the boiling point of a slurry solvent under saturated normal pressure. Single crystal. 2. An aspect ratio (c) obtained by subjecting a calcium phosphate compound slurry containing an additive consisting of potassium chloride, sodium chloride, potassium sulfate and sodium sulfate to a hydrothermal treatment under a saturated vapor pressure at a temperature not lower than the boiling point of the slurry solvent. / a) Hydroxyapatite fine single crystal of less than 2.0. 3. The pH of the calcium phosphate compound slurry,
A hydroxyapatite fine single crystal having an aspect ratio (c / a) of less than 2.0, which is obtained by performing a hydrothermal treatment under a saturated atmospheric pressure at a temperature of not less than 10 and a boiling point of a slurry solvent or higher. 4. An aspect ratio (c) obtained by subjecting a calcium phosphate compound slurry containing an additive consisting of potassium chloride, sodium chloride, potassium sulfate, and sodium sulfate to a hydrothermal treatment under a saturated vapor pressure at a temperature not lower than the boiling point of the slurry solvent. / a) A method for producing a hydroxyapatite fine single crystal of less than 2.0.