The chemical and biological mechanisms of life processes mostly consist of multistep and programmed processes at nanoscale levels. Interestingly enough, cell, the basic functional unit and platform that maintains life processes, is composed of various organelles fulfilling sophisticated functions through the precise control on the biomolecules (e.g., proteins, phospholipid, nucleic acid and ions) in a spatial dimension of nanoscale sizes. Thus, understanding of the activities of manufactured nanoscale materials including their interaction with biological sys- tems is of great significance in chemistry, materials sci- ence, life science, medicine, environmental science and toxicology. In this brief review, we summarized the recent advances in nanotoxicological chemistry through the dis- section of pivotal factors (primarily focusing on dose and nanosurface chemistry) in determining nanomaterial- induced biological/toxic responses with particular empha- sis on the nanomaterial bioaccumulation (and interaction organs or target organs) at intact animal level. Due to the volume of manufacture and material application, we deliberately discussed carbon nanotubes, metal/metal oxide nanomaterials and quantum dots, severing as representativematerial types to illustrate the impact of dose and nanosurface chemistry in these toxicological scenarios. Finally, we have also delineated the grand challenges in this field in a conceptual framework of nanotoxicological chemistry. It is noted that this review is a part of our persistent endeavor of building the systematic knowledge framework for toxicological properties of engineered nanomaterials.
Biocompatible and biodegradable ε-poly-L- lysine (EPL)/poly (ε-caprolactone) (PCL) copolymer was designed and synthesized. The amphiphilic EPL-PCL copolymer could easily self-assembled into monodispersed nanoparticles (NPs), which showed a broad-spectrum antibacterial activity against Escherichia coli, Staphylococcus aureus and Bacillus subtilis. Interestingly, the antibacterial efficacy of the novel NPs is more potent than the cationic peptide EPL. To explore the underlying mechanism of the biodegradable cationic NPs, various possible antibacterial pathways have been validated. The NPs have been found that they can disrupt bacterial walls/ membranes and induce the increasing in reactive oxygen species and alkaline phosphatase levels. More importantly, the self-assembled NPs induced the changes in bacterial osmotic pressure, resulting in cell invagination to form holes and cause the leakage of cytoplasm. Taken together, our results suggest that the EPL-PCL NPs can be further developed to be a promising antimicrobial agent to treat infectious diseases as surfactants and emulsifiers to enhance drug encapsulation efficiency and antimicrobial activity.