Histological evaluation of tissue reactions to newly synthetized calcium silicate- and hydroxyapatite-based bioactive materials: in vivo study

Abstract

Introduction/Objective Development of materials which could be used as biological bone substitutes is one of the most valuable and active fields of biomaterial research. The goal of the study was to research the reaction of tissue on calcium silicate-(CS) and hydroxyapatitebased (CS-HA) newly synthesized nanomaterials, after being implanted into the subcutaneous tissue of a rats and direct pulp capping of rabbit teeth. Methods The tested materials were implanted in 40 Wistar male rats, sacrificed after seven, 15, 30, and 60 days. The direct pulp capping was performed on the teeth of rabbits. Cavities were prepared on the vestibular surface of the incisors. The animals were sacrificed after 10 and 15 days. The control material was mineral trioxide aggregate (MTA). Histological analysis covered the tracking of inflammatory reaction cellular components, presence of gigantic cells, and necrosis of the tissue. Results Seven days after the implantation, the strongest inflammatory response was given by the MTA (3.3 ± 0.48), while CS and CS-HA scored 3 ± 0.71. After 60 days, the rate of inflammatory reactions dropped, which was the least visible with CS-HA (0.2 ± 0.45). The least visible inflammatory reaction of the rabbits' pulp tissue was spotted with the CS (1.83 ± 0.75), than with the MTA and CS-HA (2.67 ± 1.53, 3 ± 0.63). Conclusion The newly synthesized materials caused a slight reaction of the subcutaneous tissue. CS-HA showed the best tissue tolerance. Nanostructural biomaterials caused a slight to moderate inflammatory reaction of the rabbits' pulp tissue only in the immediate vicinity of the implanted material.

Biocompatibility nanostructured biomaterials based on calcium aluminate

“…Although a wide range of different types of tubes are in use today -dentine [20], silicone [21], Teflon [3], polyethylene [22], polypropylene [23] -our choice were polyethylene tubes, considering their inert nature and wide application. They do not cause a tissue reaction and in controlled and effective way expose tested material to the living tissue.…”

Physico-chemical and biological properties of dental calcium silicate cements - literature review

“…Subcutaneous implantation of new CS formulations containing CS and nanoHAP in rats has shown good tolerance of the surrounding tissue even 60 days after implantation [80]. Also, an experimental CS-HAP cement implanted subcutaneously in rats has induced a low inflammatory reaction of the tissue over the same period of time, which was lower than that of ProRoot MTA [81]. In addition, a nanostructured CS mixture did not show any negative effect on liver in rats after thirty days of oral administration [82].…”

“…In addition, nanostructured calcium silicate cements show increased osteoblast adhesion, proliferation and differentiation, since bone itself is nanostructured, and the crystal size and geometry can modify response of the surrounding tissue. Therefore, it is to assume that CS with the addition of nanostructured HAP presents numerous advantages in comparison to MTA Angelus and may be considered for further clinical trials [81].…”

Stem cells in tissue engineering – dynamic cultivation requirement

“…However, problems such as variability and the potential of xenogenic media components to cause disease limit their use [15,16]. Synthetic polymers (polyethylene glycol, poly-l-lysine, poly-lactic acid, polyglycolic acid, and poly-dl-lactic acid-co-glycolic acid) are the group of artificially made scaffolds with different mechanical properties (pore size, elasticity, adhesion, tensile strength) [17][18][19][20][21][22]. Biodegradable, porous scaffolds represent the most promising in vitro imitation of SC niche that provides physical support, enables cell growth, regeneration and neovascularization, while they were replaced in time with new bone [23, 24,25].…”

“…Međutim, problem kao što je raznolikost i mogućnost prenosa određenih bolesti preko materijala životinjskog porekla ograničavaju njihovu primenu [15,16]. Sintetski polimeri (polietilen glikol, polilizin, polilaktična kiselina, poliglikolna kiselina, polilaktid-koglikolna kiselina) predstavljaju grupu veštački napravljenih nosača različitih mehaničkih svojstava (veličina pora, elastičnost, adhezija, zatezna čvrstoća) [17][18][19][20][21][22]. Biorazgradivi, porozni nosači ćelija predstavljaju ključne činioce u imitaciji ćelijske niše koji obezbeđuju mehaničku potporu, omogućuju rast ćelija, regeneraciju i razvoj novih krvnih sudova, dok vremenom bivaju razgrađeni i zamenjeni novostvorenim tkivom [23, 24,25].…”