Evaluation of cardiovascular toxicity of carbon nanotubes functionalized with sodium hyaluronate in oral regenerative medicine.

J.V Joviano-Santos,M.A Sá,T.C.S Almeida,A.J Ferreira,V Geraldo,S Oliveira,L.O Ladeira,M.L.A De Maria

doi:10.1590/1414-431x20143894

Abstract

It has been demonstrated that carbon nanotubes (CNTs) associated with sodium hyaluronate (HY-CNTs) accelerate bone repair in the tooth sockets of rats. Before clinical application of HY-CNTs, it is important to assess their biocompatibility. Moreover, cardiac toxicity may be caused by the translocation of these particles to the blood stream. The aim of this study was to evaluate possible changes in cardiovascular function in male Wistar rats whose tooth sockets were treated with either CNTs or HY-CNTs (100 μg/mL, 0.1 mL). Blood pressure and heart rate were monitored in conscious rats 7 days after treatment. Cardiac function was evaluated using the Langendorff perfusion technique. The data showed no changes in blood pressure or heart rate in rats treated with either CNTs or HY-CNTs, and no significant changes in cardiac function were found in any of the groups. To confirm these findings, experiments were conducted in rats injected intraperitoneally with a high concentration of either CNTs or HY-CNTs (0.75 mg/kg). The same parameters were analyzed and similar results were observed. The results obtained 7 days following injection indicate that the administration of low concentrations of CNTs or HY-CNTs directly into tooth sockets did not cause any significant change in cardiovascular function in the rats. The present findings support the possibility of using these biocomposites in humans.

Highlights

Sodium hyaluronate (HY) is one of the main components of the mammalian extracellular matrix and plays an important role in tissue repair [1]
transmission electron microscopy (TEM) analysis showed that the carbon nanotubes (CNTs) had few defects in the walls (Figure 1A and B)
The results of thermogravimetric evaluation of as-grown and purified CNTs demonstrated the efficiency of the purification process

Summary

Introduction

Sodium hyaluronate (HY) is one of the main components of the mammalian extracellular matrix and plays an important role in tissue repair [1]. HY retains osteoinductive growth factors within the local environment due to its chemical properties [3], mediates the adhesion of osteoclasts to the bone surface [4], and accelerates both revascularization [5] and bone formation [5]. These features, in addition to its viscoelastic properties and biocompatibility, make HY a suitable candidate for biomedical applications [6]. By accelerating bone matrix deposition, HY-based gels are potentially useful in the repair process of bone tissue [7]. The low degree of stability of HY formulations in aqueous environments has hindered their use in oral regenerative medicine

Objectives

Methods

Results