hrvatski

TEM istraživanje utjecaja monomerne i dimerne površinski aktivne tvari na nastajanje amorfnog kalcijevog fosfata

A major problem encountered in the application of bone bioimplant materials is their slower rate of resorption in comparison to the rate of new bone formation. It was shown that the rate of new bone formation coincides more closely with the resorption rate of poorly crystalline or amorphous calcium phosphate (ACP) cements and ceramics [1]. However, these materials still exhibit problems of mechanical strength, injectability, and application techniques. It is known that the highly hydrate spherulites of ACP grow by aggregation of much smaller primary particles and are subsequently joined together by secondary aggregation into chainlike structures [2]. Therefore coating of ACP primary particles with surfactants could be the solution to some of these problems. In recent years, dimeric surfactants, consisting of two monomeric surfactants linked by a spacer at the level of the head groups, have attracted considerable attention due to their superior properties in comparison to conventional surfactants. In this work we have compared the influence of monomeric dodecyltrimethylammonium bromide, DTAB, and corresponding dimeric dimethylene-1, 2-bis(dodecyldimethylammonium bromide), 12-2-12 (Figure 1), on the formation of ACP. Formation of ACP was followed by pH measurements and formed ACP particles were characterized by TEM and DLS. It was shown that wormlike 12-2-12 micelles excert the largest, but opposite, effect on both primary ACP nano particles and ACP secondary micro aggregates (Figure 2.).

TEM; amorfni kalcijev fosfat; površinski aktivne tvari

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