Independent effect of polymeric nanoparticle zeta potential/surface charge, on their cytotoxicity and affinity to cells.

OBJECTIVES: Up to now, little research has been focussed on discovering how zeta potential independently affects polymeric nanoparticle (NP) cytotoxicity. METHODS: Polymeric nanoparticles of gradient zeta potential ranging from -30 mv to +40 mv were fabricated using the same poly-3-hydroxybutyrate-co-3-hydroxyhexanoate (PHBHHx) biopolymer. Interaction forces between nanoparticles and cells were measured by atomic force microscopy (AFM). Cytotoxicity of the nanoparticles to cells was investigated by using MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide) assay. RESULTS: Four kinds of nanoparticle with similar sizes and gradient zeta potentials, were fabricated. Those with positive surface charges were found to be more toxic than those with negative surface charges. Positively charged nanoparticles or nanoparticles with higher 'like' charges, offered higher interaction force with cells. CONCLUSION: This work proposes a novel approach for investigating interaction between NPs and cells, and discloses the importance of controlling zeta potential in developing NPs-based formulations in the future.

Nanocomplex based on biocompatible phospholipids and albumin for long-circulation applications.

Achieving long circulating delivery of nanoparticles (NPs) is important for efficient drug therapy, but it is difficult due largely to proteins adsorption (opsonization) or/and nonsufficient stability of NPs. In this present work, we aimed to address the above issues by constructing a phospholipid and BSA-based nanocomplex system, namely BSA-phospholipid NPs (BSA-PL-NPs). Combining sodium dodecyl sulfate-polyacrylamide gel electrophoresis, X-ray photoelectron spectroscopy and proteins adsorption property, we confirmed that some BSA molecules were fixed on the inner surface of BSA-PL-NPs via hydrophobic interactions and the others were located in the core area. This special configuration allowed BSA-PL-NPs to not only maintain the antiadsorption and low phagocytosis properties but also have the slow zero-order drug release and the enhanced nanostructure stability. Interestingly, we found that BSA-PL-NPs had no cytotoxicity to mouse L929 fibroblasts but could stimulate the cells' growth instead. In conclusion, BSA-PL-NPs have a great potential to be developed as a long-circulation drug delivery system, and the ready availability, biocompatibility and nontoxicity of phospholipids and albumin give this system great promise for practical use.