Charcoal suspension for tumor labelling modifies macrophage activity in mice.

We have previously developed a charcoal suspension for injection into human breast cancers in order to facilitate their location during surgery. We observed that charcoal particles were ingested by intra and peritumoral macrophages, some of which carried the particles at some distance from the injection site. We studied the influence of the formulation parameters of the charcoal suspension for intratumoral injection on in vitro and in vivo activation and in vivo mobilization of mouse peritoneal macrophages after intra-peritoneal injection of 2 mL of each preparation. The influence of the charcoal origin (peat vs wood), granulometry, suspension vehicle (water for parenteral injection, vs saline), concentration and excipients were studied. Micronized peat charcoal in water for injection at the highest studied concentration reduced macrophage activation in vitro and in vivo. However, macrophage mobilization was weaker than after thioglycolate injection and did not seem to be charcoal dose-dependent. The additives incorporated in the charcoal suspension led in vivo to increased peritoneal macrophage activation and mobilization (mannitol, and glucose), only increased activation (polysorbate 80 and pluronic F68) or mobilization (dextran 40, egg lecithin, and cabosil), or inhibited both activation and mobilization (cremophor EL).

Effects of tail alkyl chain length (n), head group structure and junction (Z) on amphiphilic properties of 1-Z-R-D,L-xylitol compounds (R = CnH2n+1).

In the family of 1-Z-R-D,L-xylitol, we have determined the main amphiphilic properties of esters (Z = OCO) as a function of alkyl chain length (R = CnH2n+1, n = 4-17). A classical decrease of critical micelle concentration with the increase in the alkyl chain has been found. With water, esters displayed lamellar phases at temperatures of 25 degrees C or higher. The extent of hydrophilic/lipophilic balance range obtained by emulsification method can be proven to be of interest for pharmaceutical applications. The results were compared with those obtained in previous investigations, i.e. for alkyl-substituted xylitol, with thioether (Z=S) and ether (Z=O) linking groups in order to discuss the role of the junction nature. Likewise, they were compiled with the results related to their D-glucose homologues, in order to put forward the effects of the head group configuration, cyclic or acyclic.