Tandem molecular self-assembly for selective lung cancer therapy with an increase in efficiency by two orders of magnitude.

In situ self-assembly of prodrug molecules into nanomedicine can elevate the therapeutic efficacy of anticancer medications by enhancing the targeting and enrichment of anticancer drugs at tumor sites. However, the disassembly and biodegradation of nanomedicine after enrichment prevents the further improvement of the efficiency, and avoiding such disassembly and biodegradation remains a challenge. Herein, we rationally designed a tandem molecular self-assembling prodrug that could selectively improve the therapeutic efficacy of HCPT against lung cancer by two orders of magnitude. The tandem molecular self-assembly utilized an elevated level of alkaline phosphatase and reductase in lung cancer cells. The prodrug first self-assembled into nanofibers by alkaline phosphatase catalysis and was internalized more efficiently by lung cancer cells than free HCPT. The resulting nanofiber was next catalyzed by intracellular reductase to form a more hydrophobic nanofiber that prevented the disassembly and biodegradation, which further significantly improved the efficacy of HCPT against lung cancer both in vitro and in vivo.

Encapsulation of LXR ligand by D-Nap-GFFY hydrogel enhances anti-tumorigenic actions of LXR and removes LXR-induced lipogenesis.

Background and purpose: Activation of liver X receptor (LXR) by its ligand T0901317 (T317) enhances interferon-γ (IFNγ) production to inhibit tumor growth. However, induction of severe hypertriglyceridemia and fatty liver by T317 limits its application. The naphthylacetic acid modified D-enantiomeric-glycine-phenylalanine-phenylalanine-tyrosine (D-Nap-GFFY) can form a nanofiber hydrogel which is selectively taken up by antigen-presenting cells (APCs). In this study, we determined if D-Nap-GFFY-encapsulated T317 (D-Nap-GFFY-T317) can potently inhibit tumor growth while having no adverse lipogenic effects on the liver. Methods: We prepared D-Nap-GFFY-T317 nanofiber hydrogel and subcutaneously injected it into IFNγ deficient (IFNγ-/-) and wild-type (WT) mice with lung carcinoma, either inoculated LLC1 cells or urethane-induced carcinoma. Mice received oral T317 administration were used for comparison. Effects of treatment on tumor growth, lipogenesis and involved mechanisms were investigated. Results: Compared with T317 oral administration, injection of D-Nap-GFFY-T317 more potently inhibited LLC1 tumor growth in mice. The inhibition was dependent on LXR-activated IFNγ expression in APCs. D-Nap-GFFY-T317 increased M1 while reducing M2 type macrophages in tumors. Associated with activation of IFNγ expression, D-Nap-GFFY-T317 enhanced dendritic cell maturation and infiltration into tumors, increased CD3+/CD8+ cells in tumors, and inhibited tumor angiogenesis. Similarly, D-Nap-GFFY-T317 more potently inhibited growth of urethane-induced lung carcinomas than T317 oral administration. In these two tumor models, T317 oral administration, but not D-Nap-GFFY-T317 injection, activated hepatic lipogenesis and induced fatty liver. Conclusion: Our study demonstrates that D-Nap-GFFY-T317 inhibits lung tumor growth without adverse effects on the liver, indicating the hydrogel-encapsulated LXR ligand might be a novel therapy for tumor treatment.

Nuclear delivery of dual anticancer drug-based nanomedicine constructed by cisplatinum-induced peptide self-assembly.

Nuclear delivery of anticancer drugs, particularly dual complementary anticancer drugs, can significantly improve chemotherapy efficacy. However, successful examples are rare. We reported a novel dual anticancer drug-based nanomedicine with nuclear accumulation properties. The nanomedicine was formed by chelation between a drug peptide amphiphile Rh-GFFYERGD (Rh represents Rhein, 1,8-dihydroxy-3-carboxy anthraquinonea) and cisplatinum (Pt). A single molecule of the drug peptide amphiphile could chelate up to 8 equiv. of cisplatinum in the resulting nanofibers. The nanofibers with a 1 : 4 ratio of Rh-GFFYERGD to cisplatinum demonstrated remarkable cellular uptake, and more significantly, superior nuclear accumulation properties. Additionally, the nanofibers could also bind to the DNA molecule more efficiently than those formed by the drug peptide amphiphile. Thus the nanofibers exhibited excellent anticancer properties both in vitro and in vivo. We envision a significant therapeutic potential of the dual anticancer drug-based nanomedicine with cisplatinum in cancer.

Preorganization Increases the Self-Assembling Ability and Antitumor Efficacy of Peptide Nanomedicine.

Inspired by the biological process of phosphorylation for which different sites of the same protein may have different activities and functions, we utilized phosphatase-based enzyme-instructed self-assembly (EISA) to construct self-assembled nanomedicine from the precursors with different phosphorylated sites. We found that, although the obtained self-assembling molecules after EISA were identical, the changes of EISA catalytic sites could determine the outcome of molecular self-assembly. The precursor with the phosphorylated site in the middle preorganized before EISA, while the ones with other phosphorylated sites could not preorganize before EISA. After EISA, the preorganized precursor then resulted in more stable and ordered assemblies than those of the others, which showed increased cellular uptake and up to 1.7-fold higher efficacy in an antitumor therapeutic compared to those assembled from unorganized precursors.

A strong CD8+ T cell-stimulating supramolecular hydrogel.

The development of molecules with immune stimulatory properties is crucial for cancer immunotherapy. In this work, we combined two peptide-based molecules, tuftsin (TKPR) and Nap-GDFDFDY, to develop a novel self-assembling molecule Nap-GDFDFDYTKPR (Comp.3), which has strong CD8+ T cell stimulatory properties. Comp.3 could self-assemble into nanofibers and hydrogels, which significantly improved the stability of tuftsin against enzyme digestion. The nanofibers of Comp.3 enhanced the phagocytic activity of macrophages, promoted the maturation of DCs, and stimulated the expression of cytokines. In addition, it demonstrated an excellent anti-tumor efficacy in vivo by eliciting a strong CD8+ T immune response. Taken together, our observations revealed a powerful immune stimulating nanomaterial that is a promising compound for cancer immunotherapy.

Enhanced cellular uptake and nuclear accumulation of drug-peptide nanomedicines prepared by enzyme-instructed self-assembly.

Subcellular delivery of nanomedicines has emerged as a promising approach to enhance the therapeutic efficacy of anticancer drugs. Nuclear accumulation of anticancer drugs are essential for its therapeutic efficacy because their targets are generally located within the nucleus. However, strategies for the nuclear accumulation of nanomedicines with anticancer drugs rarely reported. In this study, we reported a promising nanomedicine, comprising a drug-peptide amphiphile, with enhanced cellular uptake and nuclear accumulation capability for cancer therapy. The drug-peptide amphiphile consisted of the peptide ligand PMI (TSFAEYWNLLSP), which was capable of activating the p53 gene by binding with the MDM2 and MDMX located in the cell nucleus. Peptide conformations could be finely tuned by using different strategies including heating-cooling and enzyme-instructed self-assembly (EISA) to trigger molecular self-assembly at different temperatures. Due to the different peptide conformations, the drug-peptide amphiphile self-assembled into nanomedicines with various properties, including stabilities, cellular uptake, and nuclear accumulation. The optimized nanomedicine formed by EISA strategy at a low temperature of 4 °C showed enhanced cellular uptake and nuclear accumulation capability, and thus exhibited superior anticancer ability both in vitro and in vivo. Overall, our study provides a useful strategy for finely tuning the properties and activities of peptide-based supramolecular nanomaterials, which may lead to optimized nanomedicines with enhanced performance.

Tandem Molecular Self-Assembly Selectively Inhibits Lung Cancer Cells by Inducing Endoplasmic Reticulum Stress.

The selective formation of nanomaterials in cancer cells and tumors holds great promise for cancer diagnostics and therapy. Until now, most strategies rely on a single trigger to control the formation of nanomaterials in situ. The combination of two or more triggers may provide for more sophisticated means of manipulation. In this study, we rationally designed a molecule (Comp. 1) capable of responding to two enzymes, alkaline phosphatase (ALP), and reductase. Since the A549 lung cancer cell line showed elevated levels of extracellular ALP and intracellular reductase, we demonstrated that Comp. 1 responded in a stepwise fashion to those two enzymes and displayed a tandem molecular self-assembly behavior. The selective formation of nanofibers in the mitochondria of the lung cancer cells led to the disruption of the mitochondrial membrane, resulting in an increased level of reactive oxygen species (ROS) and the release of cytochrome C (Cyt C). ROS can react with proteins, resulting in endoplasmic reticulum (ER) stress and the unfolded protein response (UPR). This severe ER stress led to disruption of the ER, formation of vacuoles, and ultimately, apoptosis of the A549 cells. Therefore, Comp. 1 could selectively inhibit lung cancer cells in vitro and A549 xenograft tumors in vivo. Our study provides a novel strategy for the selective formation of nanomaterials in lung cancer cells, which is powerful and promising for the diagnosis and treatment of lung cancer.

Supramolecular Nanofibers of Drug-Peptide Amphiphile and Affibody Suppress HER2+ Tumor Growth.

Antibody-based medicines and nanomedicines are very promising for cancer therapy due to the high specificity and efficacy of antibodies. However, antibody-drug conjugates and antibody-modified nanomaterials frequently suffer from low drug loading and loss of functions due to the covalent modification of the antibody. A novel and versatile strategy to prepare supramolecular nanomaterials by the coassembly of an affibody (antiHER2) and drug-peptide amphiphiles is reported here. During the enzyme-instructed self-assembly process, the drug-peptide amphiphile can coassemble with the affibody, resulting in supramolecular nanofibers in hydrogels. The drug loading in the supramolecular nanofibers is high (>30 wt%), and the stability of antiHER2 is significantly improved in the nanofibers at 37 °C (>15 d in vitro). The supramolecular nanofibers exhibit high affinity for HER2+ cancer cells and can be efficiently taken up by these cells. In a mouse tumor model, the supramolecular nanofibers abolish HER2+ NCI-N87 tumor growth due to the good accumulation and retention of nanofibers in tumor. This study provides a novel strategy to prepare nanomedicines with high drug loading and high specificity.

A supramolecular hydrogel for spatial-temporal release of auxin to promote plant root growth.

Short peptide-based hydrogels have attracted extensive research interests in drug delivery because of their responsive properties. So far, most drug molecules have been conjugated with short peptides via an amide bond, restricting the release of the native drug molecules. In this study, we demonstrated the effectiveness of an auxin-based hydrogelator linked by a hydrolysable ester bond. Hydrogel I, formed by the gelator (NAA-G'FFY) linked with an ester bond, was able to release 1-naphthaleneacetic acid (NAA), whereas hydrogel II, formed by the gelator without an ester bond (NAA-GFFY), was not. By mixing NAA-G'FFY with Fmoc-GFFY to form a two-component hydrogel, the spatial and temporal release of NAA was achieved, promoting on-site auxin responses including primary root elongation and lateral root formation in the model plant Arabidopsis thaliana. The strategy of using a hydrolysable ester bond to connect drug molecules and self-assembling peptides could lead to the development of supramolecular hydrogels with more controllable drug release profiles.