International Journal of Chemistry and Material Science Vol. 1(6), pp. 105-174, June 2013 ISSN 2327-5553 ©2013 Academe Research Journals

Review

Nanodimensional and nanocrystalline calcium orthophosphates

Sergey V. Dorozhkin

Kudrinskaja sq. 1-155, Moscow 123242, Russia. E-mail: sedorozhkin@yandex.ru.

Accepted 2 March, 2013

Abstract

Nano-sized particles and crystals play an important role in the formation of calcified tissues of various organisms. For example, nano-sized and nanocrystalline calcium orthophosphates in the form of apatites of a biological origin represent the basic inorganic building blocks of skeletal bones and teeth of mammals. Namely, according to the recent developments in biomineralization, tens to hundreds nanodimensional crystals of a biological apatite are self-assembled into these complex structures. This process occurs under a strict control by bioorganic matrixes. Furthermore, both a greater viability and a better proliferation of various types of cells have been detected on smaller crystals of calcium orthophosphates. All these effects are due to the higher surface-to-volume ratio, reactivity and biomimetic morphologies of the nanodimensional particles. Thus, the nano-sized and nanocrystalline forms of calcium orthophosphates have a great potential to revolutionize the hard tissue-engineering field, starting from bone repair and augmentation to controlled drug delivery systems. Therefore, preparation and application of nanodimensional calcium orthophosphates are the important topics in modern material science and such formulations have already been tested clinically for various purposes. Currently, more efforts are focused on the possibility of combining nanodimensional calcium orthophosphates with cells, drugs and other biologically active substances for multipurpose applications. This review describes current state of the art and recent developments on the subject, starting from synthesis and characterization to biomedical and clinical applications. In addition, future perspectives are also discussed.

Key words: Calcium orthophosphates, hydroxyapatite, nanodimensional, nano-sized, nanocrystalline, biomedical applications, bone grafts, tissue engineering.