Bio-Inspired Supramolecular Hybrid Dendrimers Self-Assembled from Low-Generation Peptide Dendrons for Highly Efficient Gene Delivery and Biological Tracking

Currently, supramolecular self-assembly of dendrons and dendrimers emerges as a powerful and challenging strategy for developing sophisticated nanostructures with excellent performances. Here we report a supramolecular hybrid strategy to fabricate a bio-inspired dendritic system as a versatile delivery nanoplatform. With a rational design, dual-functionalized low-generation peptide dendrons (PDs) self-assemble onto inorganic nanoparticles <i>via</i> coordination interactions to generate multifunctional supramolecular hybrid dendrimers (SHDs). These SHDs exhibit well-defined nanostructure, arginine-rich peptide corona, and fluorescent signaling properties. As expected, our bio-inspired supramolecular hybrid strategy largely enhances the gene transfection efficiency of SHDs approximately 50 000-fold as compared to single PDs at the same R/P ratio. Meanwhile the bio-inspired SHDs also (i) provide low cytotoxicity and serum resistance in gene delivery; (ii) provide inherent fluorescence for tracking intracellular pathways including cellular uptake, endosomal escape, and gene release; and (iii) work as an alternative reference for monitoring desired protein expression. More importantly, <i>in vivo</i> animal experiments demonstrate that SHDs offer considerable gene transfection efficiency (in muscular tissue and in HepG2 tumor xenografts) and real-time bioimaging capabilities. These SHDs will likely stimulate studies on bio-inspired supramolecular hybrid dendritic systems for biomedical applications both <i>in vitro</i> and <i>in vivo</i>

Bioreducible Peptide-Dendrimeric Nanogels with Abundant Expanded Voids for Efficient Drug Entrapment and Delivery

Dendrimer-based nanoplatforms have exhibited wide prospects in the field of nanomedicine for drug delivery, without great success due to many predicaments of cytotoxicity, high cost, and low yield. In this work, we report a feasible strategy on dynamic cross-linkings of low-generation peptide dendrimers into bioreducible nanogels for efficient drug controlled release. With a facile fabrication, the disulfide cross-linking of biocompatible peptide dendrimers successfully possess well-defined and stable nanostructures with abundant expanded voids for efficient molecular encapsulation. More importantly, high reducing condition is capable of triggering the cleavage of disulfide bonds, the disintegration of peptide-dendrimeric nanogels, and stimuli-responsive release of guest molecules. The bioreducible nanogels improve antitumor drug internalization, contribute to endosomal escape, and realize intracellular drug controlled release. The doxorubicin-loaded nanogels afford high antitumor efficiency and reduce the side effects to BALB/c mice bearing 4T1 tumor. Therefore, dynamic cross-linkings of low-generation dendrimers into smart nanogels will be an alternative and promising strategy to resolve the dilemmas of current dendrimer-based nanocarriers as well as develop innovative nanoplatforms

Construction of Functional Coatings with Durable and Broad-Spectrum Antibacterial Potential Based on Mussel-Inspired Dendritic Polyglycerol and in Situ-Formed Copper Nanoparticles

A novel surface coating with durable broad-spectrum antibacterial ability was prepared based on mussel-inspired dendritic polyglycerol (MI-dPG) embedded with copper nanoparticles (Cu NPs). The functional surface coating is fabricated via a facile dip-coating process followed by in situ reduction of copper ions with a MI-dPG coating to introduce Cu NPs into the coating matrix. This coating has been demonstrated to possess efficient long-term antibacterial properties against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and kanamycin-resistant E. coli through an “attract–kill–release” strategy. The synergistic antibacterial activity of the coating was shown by the combination of two functions of the contact killing, reactive oxygen species production and Cu ions released from the coating. Furthermore, this coating inhibited biofilm formation and showed good compatibility to eukaryotic cells. Thus, this newly developed Cu NP-incorporated MI-dPG surface coating may find potential application in the design of antimicrobial coating, such as implantable devices