Cell-Penetrating, Peptide-Based RAFT Agent for Constructing Penetration Enhancers

Peptide-polymer conjugates represent a promising class of compounds that can be used to overcome some of the limitations associated with peptides intended for therapeutic and diagnostic applications. The efficient generation of well-defined peptide/protein-polymer conjugates can promote the development of the design and synthesis of functional drugs and gene delivery platforms. In this research, a sequence defined cell penetrating peptide (i.e., Transportan 10 (TP 10))-based chain transfer agent (TP-CTA) was designed and synthesized in an automated peptide synthesizer. Thereafter, amphiphilic block copolymers poly[oligo(ethylene glycol) methyl ether acrylate]-b-poly(n-butyl acrylate) (TP-POEGA-b-PBA) were synthesized using the TP-CTA via reversible addition-fragmentation chain transfer (RAFT) polymerization. Circular dichroism (CD) spectroscopy confirmed the preservation of α-helix structure of TP 10, which is crucial for its bioactivity. Transmission electron microscopy (TEM) revealed the formation of self-assembled rod-like and vesicle nanostructures in an aqueous environment. Finally, the obtained peptide-conjugated block copolymers were demonstrated to be effective compounds for cell penetration. This method opens up a way for accessing peptide-polymer conjugates with cell-penetrating abilities.

Black phosphorus quantum dot based novel siRNA delivery systems in human pluripotent teratoma PA-1 cells

As a novel semiconducting materials, BP-QDs possess superior transfection efficiency, excellent biocompatibility and low cytotoxicity, which shows promising potential for siRNA delivery and photothermal effects in cancer therapy.

A fluorescent probe for detection of an intracellular prognostic indicator in early-stage cancer

Cyclin A2 is a promising cancer prognostic indicator, but its intracellular in situ imaging is still a challenging task. This work designs an "off-on" fluorescent probe, which can fluorescently detect intracellular cyclin A2 and distinguish cancer cells. In addition, this work sheds light on the development of future protein biosensors.

Co-Eradication of Breast Cancer Cells and Cancer Stem Cells by Cross-Linked Multilamellar Liposomes Enhances Tumor Treatment

The therapeutic limitations of conventional chemotherapeutic drugs have emerged as a challenge for breast cancer therapy; these shortcomings are likely due, at least in part, to the presence of the cancer stem cells (CSCs). Salinomycin, a polyether antibiotic isolated from Streptomyces albus, has been shown to selectively inhibit cancer stem cells; however, its clinical application has been hindered by the drug's hydrophobility, which limits the available administration routes. In this paper, a novel drug delivery system, cross-linked multilamellar liposomal vesicles (cMLVs), was optimized to allow for the codelivery of salinomycin (Sal) and doxorubicin (Dox), targeting both CSCs and breast cancer cells. The results show that the cMLV particles encapsulating different drugs have similar sizes with high encapsulation efficiencies (>80%) for both Dox and Sal. Dox and Sal were released from the particles in a sustained manner, indicating the stability of the cMLVs. Moreover, the inhibition of cMLV(Dox+Sal) against breast cancer cells was stronger than either single-drug treatment. The efficient targeting of cMLV(Dox+Sal) to CSCs was validated through in vitro experiments using breast cancer stem cell markers. In accordance with the in vitro combination treatment, in vivo breast tumor suppression by cMLV(Dox+Sal) was 2-fold more effective than single-drug cMLV treatment or treatment with the combination of cMLV(Dox) and cMLV(Sal). Thus, this study demonstrates that cMLVs represent a novel drug delivery system that can serve as a potential platform for combination therapy, allowing codelivery of an anticancer agent and a CSC inhibitor for the elimination of both breast cancer cells and cancer stem cells.

Tunable synthesis of self-assembled cyclic peptide nanotubes and nanoparticles

While tremendous efforts have been made in investigating scalable approaches for fabricating nanoparticles, less progress has been made in scalable synthesis of cyclic peptide nanoparticles and nanotubes, despite their great potential for broader biomedical applications. In this paper, tunable synthesis of self-assembled cyclic peptide nanotubes and nanoparticles using three different methods, phase equilibrium, pH-driven, and pH-sensitive methods, were proposed and investigated. The goal is scalable nanomanufacturing of cyclic peptide nanoparticles and nanotubes with different sizes in large quality by controlling multiple process parameters. Cyclo-(L-Gln-D-Ala-L-Glu-D-Ala-)2 was applied to illustrate the proposed ideas. In the study, mass spectrometry and high performance liquid chromatography were employed to verify the chemical structures and purity of the cyclic peptides. Morphology and size of the synthesized nanomaterials were characterized using atomic force microscopy and dynamic light scattering. The dimensions of the self-assembled nanostructures were found to be strongly influenced by the cyclic peptide concentration, side chain modification, pH values, reaction time, stirring intensity, and sonication time. This paper proposed an overall strategy to integrate all the parameters to achieve optimal synthesis outputs. Mechanisms of the self-assembly of the cyclic peptide nanotubes and nanoparticles under variable conditions and tunable parameters were discussed. This study contributes to scalable nanomanufacturing of cyclic peptide based self-assembled nanoparticles and nanotubes for broader biomedical applications.

Reversible PEGylation and Schiff-base linked imidazole modification of polylysine for high-performance gene delivery

In the designed polylysine based catiomer the reversible PEGylation was introduced forin vivocirculation and to augment the cellular internalization, while the Schiff-base linked imidazole to accelerate the endosomal escape and facilitate intracellular DNA unpacking and release.