Glucopeptide Superstructure Hydrogel Promotes Surgical Wound Healing Following Neoadjuvant Radiotherapy by Producing NO and Anticellular Senescence.

Neoadjuvant radiotherapy, a preoperative intervention regimen for reducing the stage of primary tumors and surgical margins, has gained increasing attention in the past decade. However, radiation-induced skin damage during neoadjuvant radiotherapy exacerbates surgical injury, remarkably increasing the risk of refractory wounds and compromising the therapeutic effects. Radiation impedes wound healing by increasing the production of reactive oxygen species and inducing cell apoptosis and senescence. Here, a self-assembling peptide (R-peptide) and hyaluronic-acid (HA)-based and cordycepin-loaded superstructure hydrogel is prepared for surgical incision healing after neoadjuvant radiotherapy. Results show that i) R-peptide coassembles with HA to form biomimetic fiber bundle microstructure, in which R-peptide drives the assembly of single fiber through π-π stacking and other forces and HA, as a single fiber adhesive, facilitates bunching through electrostatic interactions. ii) The biomimetic superstructure contributes to the adhesion and proliferation of cells in the surgical wound. iii) Aldehyde-modified HA provides dynamic covalent binding sites for cordycepin to achieve responsive release, inhibiting radiation-induced cellular senescence. iv) Arginine in the peptides provides antioxidant capacity and a substrate for the endogenous production of nitric oxide to promote wound healing and angiogenesis of surgical wounds after neoadjuvant radiotherapy.

Supramolecular nanofibers co-loaded with dabrafenib and doxorubicin for targeted and synergistic therapy of differentiated thyroid carcinoma.

Rationale: Although surgery, radioiodine therapy, and thyroid hormone therapy are the primary clinical treatments for differentiated thyroid carcinoma (DTC), effective therapy for locally advanced or progressive DTC remains challenging. BRAF V600E, the most common BRAF mutation subtype, is highly related to DTC. Previous studies prove that combination of kinase inhibitors and chemotherapeutic drugs may be a potential approach for DTC treatment. In this study, a supramolecular peptide nanofiber (SPNs) co-loaded with dabrafenib (Da) and doxorubicin (Dox) was constructed for targeted and synergistic therapy with BRAF V600E+ DTC. Methods: A self-assembling peptide nanofiber (Biotin-GDFDFDYGRGD, termed SPNs) bearing biotin at the N-terminus and a cancer-targeting ligand RGD at the C-terminus was used as a carrier for co-loading Da and Dox. D-phenylalanine and D-tyrosine (DFDFDY) are used to improve the stability of peptides in vivo. Under multiple non-covalent interactions, SPNs/Da/Dox assembled into longer and denser nanofibers. RGD ligand endows self-assembled nanofibers with targeting cancer cells and co-delivery, thereby improving cellular uptake of payloads. Results: Both Da and Dox indicated decreased IC50 values upon encapsulation in SPNs. Co-delivery of Da and Dox by SPNs exhibited the strongest therapeutic effect in vitro and in vivo by inhibiting ERK phosphorylation in BRAF V600E mutant thyroid cancer cells. Moreover, SPNs enable efficient drug delivery and lower Dox dosage, thereby significantly reducing its side effects. Conclusion: This study proposes a promising paradigm for the synergistic treatment of DTC with Da and Dox using supramolecular self-assembled peptides as carriers.

Macrophage-Membrane-Camouflaged Nonviral Gene Vectors for the Treatment of Multidrug-Resistant Bacterial Sepsis.

Sepsis is a life-threatening disease caused by systemic bacterial infections, with high morbidity and mortality worldwide. As the standard treatment for sepsis, antibiotic therapy faces the challenge of impaired macrophages and drug-resistant bacteria. In this study, we developed a membrane-camouflaged metal-organic framework (MOF) system for plasmid DNA (pDNA) delivery to combat sepsis. The antimicrobial gene LL37 was efficiently encapsulated in the pH-sensitive MOF, and the nanoparticles were decorated with macrophage membranes in a compatible manner. Macrophage membrane coating allows targeted delivery of LL37 to macrophages and creates macrophage factories for the continuous generation of antimicrobial peptides. Compared to naked nanoparticles, primary bone marrow mesenchymal macrophage membrane-modified nanoparticles greatly improved the survival rate of immunodeficient septic mice through the synergistic effect of efficient gene therapy and inflammatory cytokine sequestration. This study demonstrates an effective membrane biomimetic strategy for efficiently delivering pDNA, offering an excellent option for overcoming sepsis.

Supramolecular Nitric Oxide Depot for Hypoxic Tumor Vessel Normalization and Radiosensitization.

In cancer radiotherapy, the lack of fixed DNA damage by oxygen in hypoxic microenvironment of solid tumors often leads to severe radioresistance. Nitric oxide (NO) is a potent radiosensitizer that acts in two ways. It can directly react with the radical DNA thus fixing the damage. It also normalizes the abnormal tumor vessels, thereby increasing blood perfusion and oxygen supply. To achieve these functions, the dosage and duration of NO treatment need to be carefully controlled, otherwise it will lead to the exact opposite outcomes. However, a delivery method that fulfills both requirements is still lacking. A NO depot is designed for the control of NO releasing both over quantity and duration for hypoxic tumor vessel normalization and radiosensitization. In B16-tumor-bearing mice, the depot can provide low dosage NO continuously and release large amount of NO immediately before irradiation for a short period of time. These two modes of treatment work in synergy to reverse the radioresistance of B16 tumors more efficiently than releasing at single dosage.

Structure of Self-assembled Peptide Determines the Activity of Aggregation-Induced Emission Luminogen-Peptide Conjugate for Detecting Alkaline Phosphatase.

The unique property of turning on their fluorescence after aggregation or assembly makes aggregation-induced emission luminogens (AIEgens) ideal luminescent molecules for the construction of self-assembled peptide-based nanoprobes. However, the characteristic highly twisted or propeller-shaped molecular conformation of AIEgens tends to prevent the assembly of AIEgen-peptides. Here, we show that (i) the distance between tetraphenylethene (TPE) and assembled peptides should not be too far (less than five glycines), otherwise the self-assembly of peptides cannot limit the intramolecular rotation of conjugated TPE and the luminous efficiency of TPE-peptide to alkaline phosphatase (ALP) will decrease; (ii) properly increasing the number of amino acids with self-assembly ability (three phenylalanines) can improve their ALP-responsive self-assembly and luminescence ability; (iii) the strategy of co-assembly with a non-AIEgen-capped self-assembled peptide is a simple and effective way to realize the efficient assembly and luminescence of AIEgen-peptides; and (iv) the hydrophilic and hydrophobic balance of the probe should always be considered in the construction of an efficient AIEgen-peptide probe. In addition, AIEgen-peptide probes show good selectivity and sensitivity for ALP detection both in vitro and in live bacteria. These insights illustrated here are crucial for guiding the design of AIEgen-conjugated supramolecular materials, especially for the construction of AIEgen-peptides, for enzymes detection, biomarker imaging, diseases therapy, and other biomedical fields.

Supramolecular nanofibers increase the efficacy of 10-hydroxycamptothecin by enhancing nuclear accumulation and depleting cellular ATP.

Poor nuclear delivery and accumulation are the main reasons for the reduced drug efficacy of many anticancer drugs that target DNA or enzymes in the nucleus, and it is a major obstacle to successful cancer therapy. To address this problem, developing practical drug delivery systems for nuclear delivery is urgently needed. Here we develop a supramolecular hydrogel by conjugating the anticancer agent 10-hydroxycamptothecine (HCPT) and macrocyclic polyamine cyclen to a self-assembling peptide. The cyclen fragment possesses nuclear localization and ATP hydrolysis properties, which can provide a synergistic therapeutic effect for cancer treatment. The HCPT-FFFK-cyclen nanofibers showed improved nuclear accumulation and inhibition capacity in cancer cells including drug-resistant cancer cells in vitro. The nanofibers also exhibited favorable ATP consuming ability in vitro. Moreover, the obtained nanomedicine showed enhanced anticancer efficiency and favorable biocompatibility in vivo when administered to mice via tail vein injection. This constructed self-delivery drug system significantly improved the delivery efficiency of the small molecule agents into the nucleus and showed favorable ATP consuming ability, offering new strategies for developing nanomedicines for cancer combination therapy.

Selectively enhancing radiosensitivity of cancer cells via in situ enzyme-instructed peptide self-assembly.

The radiotherapy modulators used in clinic have disadvantages of high toxicity and low selectivity. For the first time, we used the in situ enzyme-instructed self-assembly (EISA) of a peptide derivative (Nap-GDFDFpYSV) to selectively enhance the sensitivity of cancer cells with high alkaline phosphatase (ALP) expression to ionizing radiation (IR). Compared with the in vitro pre-assembled control formed by the same molecule, assemblies formed by in situ EISA in cells greatly sensitized the ALP-high-expressing cancer cells to γ-rays, with a remarkable sensitizer enhancement ratio. Our results indicated that the enhancement was a result of fixing DNA damage, arresting cell cycles and inducing cell apoptosis. Interestingly, in vitro pre-formed assemblies mainly localized in the lysosomes after incubating with cells, while the assemblies formed via in situ EISA scattered in the cell cytosol. The accumulation of these molecules in cells could not be inhibited by endocytosis inhibitors. We believed that this molecule entered cancer cells by diffusion and then in situ self-assembled to form nanofibers under the catalysis of endogenous ALP. This study provides a successful example to utilize intracellular in situ EISA of small molecules to develop selective tumor radiosensitizers.

A peptide-drug hydrogel to enhance the anti-cancer activity of chlorambucil.

The clinical applications of nitrogen mustard antitumor drugs are limited by their poor aqueous solubility, poor cellular uptake, lack of targeting, and severe side effects. Cyclen could be protonated under physiological conditions, which may be beneficial for increasing cell membrane affinity and cellular uptake. Herein, a novel self-assembling peptide-drug conjugate was developed by conjugating chlorambucil (CRB) and cyclen to a self-assembling peptide. The resultant supramolecular hydrogel was prepared via a heating-cooling process and displayed improved aqueous solubility. Rheology, CD spectra, and transmission electron microscopy measurements indicated that the hydrogel with a ß-sheet configuration and a nanofiber structure had favorable rheological properties. A cellular uptake experiment demonstrated that cyclen effectively increases the uptake of the resulting hydrogel by tumor cells. MTT results indicated that the hydrogel exhibited favorable inhibitory activities against A549, HeLa, and MCF-7 cancer cell lines and was less toxic towards 3T3 (normal cells). The results of γ-H2AX experiments showed that the obtained nanomedicine could induce significantly more DNA damage compared with free chlorambucil. Hematology analysis experiments revealed that the obtained nanomedicine has good biocompatibility. Our findings indicate that the self-delivery nanodrug system has clinical potential for cancer treatment.