Biocompatibility of nanostructural biomaterials based on active calcium silicate systems and hydroxyapatite

Abstract

Development of new materials, that could be used as biological bone "replacement", is today one of the most important and the most active research areas of biomaterials. Bioactivity and biocompatibility of these materials provides the interaction with biological systems, and thereby enables restoring the function of damaged tissues and/or organs in the human body. In recent years, a large number of materials for endodontic applications have been developed. Besides biocompatibility, these materials have an additional role as bio- inducers in health preservation of the periodontal and pulpal tissue, as well as stimulation of damaged tissues regeneration. The aim of this study was to examine the biocompatibility and bioactivity of new nanostructured materials based on calcium silicate systems (CS) and hydroxyapatites (CS-HA). The first step in this research was to analyze the composition, particle sizing, and to determine the setting time and the strength of the newly synthesized material. The structure of calcium silicates is mainly composed of agglomerates with few micrometers in size, which are made of smaller particles with sizes between 117 and 477nm. These particles are generally spherical or ellipsoidal shape, more or less elongated in one direction. HA particles were irregular in shape, mostly rounded, with dimensions of 60 nm to 470nm. EDS analysis showed that the chemical composition of calcium silicate (Ca 22.21 , 8.22 Si , O 69.7 in atomic % ) corresponded to the Ca/Si ratio in about 2.7 (in atomic %). The setting time of the CS began 3 minutes after addition of deionized water, and the bonding was completed within 10 minutes after. For HA-CS these values were 5 and 15 minutes, respectively. To test the biocompatibility of these materials pre-clinical in vitro and in vivo assays were used...

Usavršavanje materijala koji bi mogli da se koriste kao biološke «zamene» kosti,danas je jedna od najznačajnijih i najaktivnijih oblasti istraživanja biomaterijala. Biokompatibilnost i bioaktivnost ovih materijala obezbeđuje interakciju sa biološkim sistemima, a time i obnavljanje funkcije oštećenih tkiva i/ili organa u ljudskom organizmu... Poslednjih godina razvijen je veliki broj materijala za endodontsku primenu, koji osim biokompatibilnosti imaju ulogu i bio-induktora u očuvanju zdravlja pulpe i periodontalnog tkiva, ali i stimulišu regeneraciju oštećenih tkiva. Cilj ovog istraživanja je bio da se proveri biokompatibilnost i biofunkcionalnost novih nanostrukturnih materijala na bazi kalcijum silikatnih sistema (CS) i hidroksiapatita (CS-HA). Prvi korak u ovom istraživanju je bilo analiziranje sastava, određivanje veličine čestica, merenje vremena vezivanja i određivanje čvrstoće novosintetisanih materijala. Strukturu kalcijum silikata čine uglavnom aglomerati veličine nekoliko mikrometara koji su izgrađeni od manjih partikula (čestica) sa dimenzijama između 117 i 477nm. Ove partikule su uglavnom sferičnog ili elipsoidnog oblika, manje ili više izdužene u jednom pravcu. Partikule HA su bile nepravilnog oblika, većinom okruglaste, sa dimenzijama od 60 nm do 470nm. EDS analiza je pokazala da je hemijski sastav kalcijum silikata (Ca 22.21, Si 8.22, O 69.7 u atomskim%) odgovarao odnosu Ca/Si od približno 2.7 (atomski%). Vreme vezivanja za CS je započinjalo 3 minuta nakon dodavanja dejonizovane vode, a kompletno vezivanje se završava nakon 10 minuta. Za CSHA ove vrednosti su bile 5 i 15 minuta, respektivno. Za proveru biokompatibilnosti ovih materijala korišćeni su predklinički in vitro i in vivo testovi.