Lactoferrin conjugated SiO2 nanoparticles: a preliminary study on safety and efficacy.

Lactoferrin conjugated SIO2 nanoparticles: a preliminary study on safety and efficacy. Recent developments in nanostructured material synthesis have made a huge impact on a number of fields including biology, and medicine. The need of medicine to create novel methods for targeted and localised delivery of drugs in humans led to the development of many new proposals in drug delivery sector such as nanotechnology. Nano delivery of natural molecules has been proposed for some natural substances. With the emerging nanoscience and nanotechnology various nanoceramics and nanoceramic composites for biomedical applications were proposed. Lactoferrin (Lf), an iron binding cationic glycoprotein synthesized by exocrine glands and neutrophils in infection/inflammation sites, plays a pivotal role in iron and inflammation homeostasis. This effect is due to Lf capability to enter into host cells and localize into nucleus thus modulating pro-inflammatory cytokines. Here we describe an inorganic nanoparticle-based delivery system. In order to increase the stability and the efficacy of Lf in preventing host cell inflammation, this glycoprotein has been conjugated with SiO2 to obtain Lf-SiO2. Our nanoceramics tightly bind and protect lactoferrin molecules and deliver them efficiently to mammalian cells in vitro. Here, we report biological and physical results on cytotoxicity of SiO2 and Lf-SiO2 detected in different cell cultures, as well as data on the Lf release capability by SiO2 nanoparticles. First, Lf does not show any side effect at concentrations until 10 mg/ml in host cell monolayers, while Lf-SiO2 exerts a cytotoxic effect already at a concentration corresponding to 50μg/ml similarly to that observed with SiO2 alone. Second, Lf is not released from Lf-SiO2 in either artificial solutions or saliva. Third, the ability of bLf-SiO2 to enter inside host cells and localize into nucleus will be discussed underlining the putative cell damage by these nanoparticles. These preliminary results show how great care should be used in designing nanoparticle drug delivery, in light of the potential side effects on host cells and not only in reference to the effectiveness of the methods.