CYTOTOXICITY OF SOLID LIPID NANOPARTICLES AS A FUNCTION OF THE LIPID MATRIX AND THE SURFACTANT

Purpose. Assessment of the in vitro cytotoxicity of solid lipid nanopa rticles (SLNs) as a function of lipid matrix (Dynasan 114, Compritol A TO 888), and stabilizing surfactant (poloxamers, Tween 80, soya lecith in, and sodium dodecyl sulphate). Comparison with other colloidal carr iers should determine their potential use in the clinic. Methods, SLNs were produced by high pressure homogenisation. Cytotoxicity was asses sed by measuring the viability of HL60 cells and human granulocytes af ter incubation with SLNs. Particle internalisation was quantified by c hemiluminescence measurements. Results. The nature of the lipid had no effect on viability; distinct differences were found for the surfacta nts. Binding to the SLN surface reduced markedly the cytotoxic effect of the surfactants, e.g., up to a factor of 65 for poloxamer 184. The permanent HL60 cell line-differentiated from cells with granulocyte ch aracteristics by retinoic acid treatment-yielded results identical to freshly isolated human granulocytes. In general, the SLNs showed a low er cytotoxicity compared to polyalkylcyanoacrylate and polylactic/glyc olic acid (PLA/GA) nanoparticles. Conclusions. Because the results are identical when using human granulocytes, differentiated HL60 cells ca n be used as an easily accessible in vitro test system for i.v. inject able SLN formulations. The SLNs appear suitable as a drug carrier syst em for potential intravenous use due to their very low cytotoxicity in vitro.