Evaluation of biocompatibility of the AC8 peptide and its potential use as a drug carrier.

Peptide-based nanoparticles have emerged as promising drug delivery systems for targeted cancer therapy. Yet, the biocompatibility of these nanoparticles has not been elucidated. Here, the in vitro biocompatibility and toxicity and in vivo immunocompatibility and bioactivity of the self/coassembling peptide AC8 in its nanoparticle form are evaluated. AC8 showed minimal hemolytic activity (5%) and did not cause aggregation of red blood cells. The in vitro assay revealed that AC8 did not activate the complement system via the classical or alternative pathway but did activate the lectin pathway to a small extent. However, AC8 showed no C3a and C5a anaphylotoxin activation suggesting that complement activation did not proceed to the later, inflammatory, stages. The in vivo immune response assay showed that administration of AC8 to BALB/c mice had no effect on the weight of immune organs or body weight of mice at doses less than 0.1 mg/kg. This peptide also did not have any effect on the expression of CD3+ T-cells and natural killer (NK) cells, the ratio of CD4+/CD8+ T-cell, and the proliferation of B-cells. These results suggest that AC8 can be a potential carrier candidate for drug delivery.