Relationship between NO-synthase activity and TNF-alpha secretion in mouse macrophage lines stimulated by a muramyl peptide entrapped in nanocapsules

PEGylated and functionalized polylactide-based nanocapsules: An overview

Polymeric nanocapsules (NC) are versatile mixed vesicular nanocarriers, generally containing a lipid core with a polymeric wall. They have been first developed over four decades ago with outstanding applicability in the cosmetic and pharmaceutical fields. Biodegradable polyesters are frequently used in nanocapsule preparation and among them, polylactic acid (PLA) derivatives and copolymers, such as PLGA and amphiphilic block copolymers, are widely used and considered safe for different administration routes. PLA functionalization strategies have been developed to obtain more versatile polymers and to allow the conjugation with bioactive ligands for cell-targeted NC. This review intends to provide steps in the evolution of NC since its first report and the recent literature on PLA-based NC applications. PLA-based polymer synthesis and surface modifications are included, as well as the use of NC as a novel tool for combined treatment, diagnostics, and imaging in one delivery system. Furthermore, the use of NC to carry therapeutic and/or imaging agents for different diseases, mainly cancer, inflammation, and infections is presented and reviewed. Constraints that impair translation to the clinic are discussed to provide safe and reproducible PLA-based nanocapsules on the market. We reviewed the entire period in the literature where the term "nanocapsules" appears for the first time until the present day, selecting original scientific publications and the most relevant patent literature related to PLA-based NC. We presented to readers a historical overview of these Sui generis nanostructures.

Reduction of no synthase expression and tumor necrosis factor alpha production in macrophages by amphotericin B lipid carriers

The present study compared the abilities of different lipid carriers of amphotericin B (AMB) to activate murine peritoneal macrophages, as assessed by their capacities to produce nitric oxide (NO) and tumor necrosis factor alpha (TNF-alpha). Although AMB alone did not induce NO production, synergy was observed with gamma interferon but not with lipopolysaccharide. This synergy could not be explained by the mobilization of the nuclear activation factor NF-kappaB by AMB. On the other hand, AMB induced TNF-alpha production without a costimulator and no synergy was observed. Anti-TNF-alpha antibodies did not influence NO production, and an inhibitor of NO synthase did not affect TNF-alpha production, indicating that the production of one of these effector molecules was independent of that of the other. The incorporation of AMB into lipid carriers reduced NO and TNF-alpha production with all formulations but more so with liposomes than with lipid complexes. NO production was correlated with the induction of NO synthase II, revealed by Western blotting. The extent of association of AMB with macrophages depended on the formulation, especially on the AMB/lipids ratio: the higher the ratio was, the greater the AMB association with macrophages. However, there was no clear correlation between AMB association with macrophages, whether internalized or bound to the membrane, and immunostimulating effects. These results may explain the reduced toxicities of lipid-based formulations of AMB.