In-vitro investigation and hydrolytic degradation of antibacterial nanocomposites based on PLLA/triclosan/nano-hydroxyapatite

Abstract

In this study, the encapsulated triclosan in the low molecular weight PLLA comprising 30% triclosan (LATC30), mixed with nano hydroxyapatite (nHA) are dispersed in PLLA of larger molecular weight via melt blending. This method results in a completely homogenous nanocomposite where the presence of 5% nHA improves overall properties in comparison with the PLLA/LATC30 composite and neat PLLA. The kinetics of hydrolytic degradation in an accelerated condition was obtained using a novel method and the Beer–Lambert equation. Compared to LATC30, the rate of hydrolytic degradation is increased more with rise in the nHA concentration. Increase in nHA enhances hydrophilicity, antibacterial activity and the drug release of the nanocomposites. However, according to the results of MTT assay, the negative effect of antibacterial activity of LATC30 was reduced, due to the presence of nHA nanoparticles since it allows better cell attachment. The nanocomposites containing 5% LATC30 and 5% nHA showed an appropriate adjustment between the hydrolytic degradation and the release profile. Therefore, their fabricated scaffolds demonstrated a great osteoblast cell attachment and mineralization. The aforementioned nanocomposite is a suitable antibacterial candidate for bone tissue engineering and medical implants or fixations such as the surgical screws as they only contain 1.5% of triclosan. It also shows a maximum antibacterial efficiency with the minimum side effects, due to its controlled release.