Bispecific fibrous glue synergistically boosts vascular normalization and antitumor immunity for advanced renal carcinoma therapy.

Immune checkpoint blockade therapy represented by programmed cell death ligand 1 (PD-L1) inhibitor for advanced renal carcinoma with an objective response rate (ORR) in patients is less than 20%. It is attributed to abundant tumoral vasculature with abnormal structure limiting effector T cell infiltration and drug penetration. We propose a bispecific fibrous glue (BFG) to regulate tumor immune and vascular microenvironments simultaneously. The bispecific precursor glue peptide-1 (pre-GP1) can penetrate tumor tissue deeply and self-assemble into BFG in the presence of neuropilin-1 (NRP-1) and PD-L1. The resultant fibrous glue is capable of normalizing tumoral vasculature as well as restricting immune escape. The pre-GP1 retains a 6-fold higher penetration depth than that of antibody in the multicellular spheroids (MCSs) model. It also shows remarkable tumor growth inhibition (TGI) from 19% to 61% in a murine advanced large tumor model compared to the clinical combination therapy. In addition, in the orthotopic renal tumor preclinical model, the lung metastatic nodules are reduced by 64% compared to the clinically used combination. This pre-GP1 provides a promising strategy to control the progression and metastasis of advanced renal carcinoma.

Nano Proteolysis Targeting Chimeras (PROTACs) with Anti-Hook Effect for Tumor Therapy.

Proteolysis targeting chimera (PROTAC) is an emerging pharmacological modality with innovated post-translational protein degradation capabilities. However, off-target induced unintended tissue effects and intrinsic "hook effect" hinder PROTAC biotechnology to be maturely developed. Herein, an intracellular fabricated nano proteolysis targeting chimeras (Nano-PROTACs) modality with a center-spoke degradation network for achieving efficient dose-dependent protein degradation in tumor is reported. The PROTAC precursors are triggered by higher GSH concentrations inside tumor cells, which subsequently in situ self-assemble into Nano-PROTACs through intermolecular hydrogen bond interactions. The fibrous Nano-PROTACs can form effective polynary complexes and E3 ligases degradation network with multi-binding sites, achieving dose-dependent protein degradation with "anti-hook effect". The generality and efficacy of Nano-PROTACs are validated by degrading variable protein of interest (POI) such as epidermal growth factor receptor (EGFR) and androgen receptor (AR) in a wide-range dose-dependent manner with a 95 % degradation rate and long-lasting potency up to 72 h in vitro. Significantly, Nano-PROTACs achieve in vivo dose-dependent protein degradation up to 79 % and tumor growth inhibition in A549 and LNCap xenograft mice models, respectively. Taking advantages of in situ self-assembly strategy, the Nano-PROTACs provide a generalizable platform to promote precise clinical translational application of PROTAC.

An In Vivo Self-Assembled Bispecific Nanoblocker for Enhancing Tumor Immunotherapy.

Anti-PD-L1 monoclonal antibody has achieved substantial success in tumor immunotherapy by T-cells activation. However, the excessive accumulation of extracellular matrix components induced by unsatisfactory T-cells infiltration and poor tumor penetration of antibodies make it challenging to realize efficient tumor immunotherapy. Herein, a peptide-based bispecific nanoblocker (BNB) strategy is reported for in situ construction of CXCR4/PD-L1 targeted nanoclusters on the surface of tumor cells that are capable of boosting T-cells infiltration through CXCR4 blockage and enhancing T-cells activation by PD-L1 occupancy, ultimately realizing high-performance tumor immunotherapy. Briefly, the BNB strategy selectively recognizes and bonds CXCR4/PD-L1 with deep tumor penetration, which rapidly self-assembles into nanoclusters on the surface of tumor cells. Compared to the traditional bispecific antibody, BNB exhibits an intriguing metabolic behavior, that is, the elimination half-life (t1/2 ) of BNB in the tumor is 69.3 h which is ≈50 times longer than that in the plasma (1.4 h). The higher tumor accumulation and rapid systemic clearance overcome potential systemic side effects. Moreover, the solid tumor stress generated by excessive extracellular matrix components is substantially reduced to 44%, which promotes T-cells infiltration and activation for immunotherapy efficacy. Finally, these findings substantially strengthen and extend clinical applications of PD-1/PD-L1 immunotherapy.

A bispecific glycopeptide spatiotemporally regulates tumor microenvironment for inhibiting bladder cancer recurrence.

Up to 75% of bladder cancer patients suffer from recurrence due to postoperative tumor implantation. However, clinically used Bacillus Calmette-Guerin (BCG) treatment failed to inhibit the recurrence. Here, we report a bispecific glycopeptide (bsGP) that simultaneously targets CD206 on tumor-associated macrophages (TAMs) and CXCR4 on tumor cells. bsGP repolarizes protumoral M2-like TAMs to antitumor M1-like that mediated cytotoxicity and T cell recruitment. Meanwhile, bsGP is cleaved by the MMP-2 enzyme to form nanostructure for the long-term inhibition of CXCR4 downstream signaling, resulting in reduced tumor metastasis and promoted T cell infiltration. In orthotopic bladder tumor models, bsGP reduced the postoperative recurrence rate to 22%. In parallel, the recurrence rates of 89 and 78% were treated by doxycycline and BCG used in clinic, respectively. Mechanistic studies reveal that bsGP reduces the matrix microenvironment barrier, increasing the spatially redirected CD8+ T cells to tumor cells. We envision that bis-targeting CD206 and CXCR4 may pave the way to inhibit tumor metastasis and recurrence.

A Lysosome-Targeting Self-Condensation Prodrug-Nanoplatform System for Addressing Drug Resistance of Cancer.

Lysosome-targeting self-assembling prodrugs had emerged as an attractive approach to overcome the acquisition of resistance to chemotherapeutics by inhibiting lysosomal sequestration. Taking advantage of lysosomal acidification induced intracellular hydrolytic condensation, we developed a lysosomal-targeting self-condensation prodrug-nanoplatform (LTSPN) system for overcoming lysosome-mediated drug resistance. Briefly, the designed hydroxycamptothecine (HCPT)-silane conjugates self-assembled into silane-based nanoparticles, which were taken up into lysosomes by tumor cells. Subsequently, the integrity of the lysosomal membrane was destructed because of the acid-triggered release of alcohol, wherein the nanoparticles self-condensed into silicon particles outside the lysosome through intracellular hydrolytic condensation. Significantly, the LTSPN system reduced the half-maximal inhibitory concentration (IC50) of HCPT by approximately 4 times. Furthermore, the LTSPN system realized improved control of large established tumors and reduced regrowth of residual tumors in several drug-resistant tumor models. Our findings suggested that target destructing the integrity of the lysosomal membrane may improve the therapeutic effects of chemotherapeutics, providing a potent treatment strategy for malignancies.

OGA activated glycopeptide-based nano-activator to activate PKM2 tetramerization for switching catabolic pathways and sensitizing chemotherapy resistance.

Tumor cells intensively engage in metabolic reprogramming for enhancing the availability of glycolytic metabolites and support cell proliferation. As the most important rate-limiting enzyme in aerobic glycolysis, activating the pyruvate kinase muscle isoform 2 (PKM2) from dimers to tetramers has become a key tumor chemotherapy method to control glucose metabolism. Herein, we developed a glycopeptide-based PKM2 nano-activator, which could induce the tetramerization of PKM2 based on serine bonding to Domain C of PKM2. The bound and trapped PKM2 tetramers significantly hindered glycolytic intermediates, prevented the nucleus translocation of dimeric PKM2, and ultimately inhibited the proliferation, chemoresistance and metastasis of tumor. The glycopeptide assembled into nanoparticles under aqueous conditions and in the circulation, which in situ transformed into PKM2 nano-activator with nanofibrillar structure after specifically activated by O-GlcNAcase recognition upregulated in a wide range of human tumors. Moreover, the glycopeptide-based PKM2 nano-activator successfully accumulated at the tumor sites and boosted the chemo-drug sensitivity against prostate and breast cancers. Attributed to these intriguing results, the newly developed glycopeptide-based PKM2 nano-activator can be envisioned a promising candidate for the treatment of tumors by switching catabolic pathways.

An activated excretion-retarded tumor imaging strategy towards metabolic organs.

Intraoperative fluorescence-based tumor imaging plays a crucial role in performing the oncological safe tumor resection with the advantage of differentiating tumor from normal tissues. However, the application of these fluorescence contrast agents in renal cell carcinoma (RCC) and hepatocellular carcinoma (HCC) was dramatically hammered as a result of lacking active targeting and poor retention time in tumor, which limited the Signal to Noise Ratio (SNR) and narrowed the imaging window for complicated surgery. Herein, we reported an activated excretion-retarded tumor imaging (AERTI) strategy, which could be in situ activated with MMP-2 and self-assembled on the surface of tumor cells, thereby resulting in a promoted excretion-retarded effect with an extended tumor retention time and enhanced SNR. Briefly, the AERTI strategy could selectively recognize the Integrin αvß3. Afterwards, the AERTI strategy would be activated and in situ assembled into nanofibrillar structure after specifically cleaved by MMP-2 upregulated in a variety of human tumors. We demonstrated that the AERTI strategy was successfully accumulated at the tumor sites in the 786-O and HepG2 xenograft models. More importantly, the modified modular design strategy obviously enhanced the SNR of AERTI strategy in the imaging of orthotopic RCC and HCC. Taken together, the results presented here undoubtedly confirmed the design and advantage of this AERTI strategy for the imaging of tumors in metabolic organs.

In Situ Constructed Nano-Drug Depots through Intracellular Hydrolytic Condensation for Chemotherapy of Bladder Cancer.

Intravesical administration of first-line drugs has shown failure in the treatment of bladder cancer owing to the poor tumor retention time of chemotherapeutics. Herein, we report an intracellular hydrolytic condensation (IHC) system to construct long-term retentive nano-drug depots in situ, wherein sustained drug release results in highly efficient suppression of bladder cancer. Briefly, the designed doxorubicin (Dox)-silane conjugates self-assemble into silane-based prodrug nanoparticles, which condense into silicon particle-based nano-drug depots inside tumor cells. Significantly, we demonstrate that the IHC system possesses highly potent antitumor efficacy, which leads to the regression and eradication of large established tumors and simultaneously extends the overall survival of air pouch bladder cancer mice compared with that of mice treated with Dox. The concept of intracellular hydrolytic condensation can be extended via conjugating other chemotherapeutic drugs, which may facilitate rational design of novel nanomedicines for augmentation of chemotherapy.

In Situ Self-Assembly of Bispecific Peptide for Cancer Immunotherapy.

Precise and effective manipulation of protein functions still faces tremendous challenges. Herein we report a programmable peptide molecule, consisted of targeting and self-assembly modules, that enables specific and highly efficient assembly governed by targeting receptor proteins. Upon binding to the cell membrane receptor, peptide conformation is somewhat stabilized along with decreased self-assembly activation energy, promoting peptide-protein complex oligomerization. We first design a GNNQQNY-RGD peptide (G7-RGD) to recognize integrin αV ß3 receptor for proof-of-concept study. In the presence of αV ß3 protein, the critical assembly concentration of free G7-RGD decreases from 525 to 33 µM and the resultant G7-RGD cluster drives integrin receptor oligomerization. Finally, a bispecific assembling peptide antiCD3-G7-RGD is rationally designed for cancer immunotherapy, which validates CD3 oligomerization and concomitant T cell activation, leading to T cell-mediated cancer cell cytolysis.

Targeted in situ self-assembly augments peptide drug conjugate cell-entry efficiency.

Peptide drug conjugate (PDC) has emerged as one of the new generations of targeted therapeutics for cancer, which owns the advantages of improved drug targetability and reduced adverse effects compared with traditional chemotherapy. However, the poor permeability of PDC drugs regarding tumor cells is an urgent problem to be solved. Herein, we design a PDC drug molecule, which is composed of three modules: targeting motif (RGD target), assembly motif (GNNNQNY) and cytotoxic payload (CPT molecule). This PDC in situ forms nanoclusters upon binding cellular receptor, resulting in improved PDC cell-entry efficiency and treatment efficacy. In addition, the PDC shows increased therapeutic efficacy and raises the maximum tolerance dose of the drug in breast and bladder xenografted mice models. This strategy leverages the assembly principle to promote penetration of peptide molecules into cells and increase intracellular drug bioavailability, which is of great significance for the development of PDC drugs in the future.

Rationally designed modular drug delivery platform based on intracellular peptide self-assembly.

Modulated molecular design-based intracellular self-assembly strategy has showed great potentiality in drug delivery, due to its assembling nature-resulted optimized drug biodistribution and metabolism. The modular designing concept endows the delivery system multiple functions, such as, selectivity and universality to improve the pharmacokinetics of loaded drugs. However, the accurate controlling of the self-assembling process in desired site to achieve optimal drug delivery is posed great challenges toward rational molecular design. Here, we fabricated a modulated drug-delivery system (MDS) through intracellular peptide self-assembly to realize effective drug delivery. MDS was designed based on modulated molecular designing strategy which contains five functional motifs and effectively transformed into fibrous nanostructures inside target cells by caspase3/7 hydrolysis directed in situ self-assembly. The experimental studies and molecular simulations were carried out to evaluate the successful construction and delivering efficacy of MDS. According to the experimental results and molecular simulation analysis, the percentage of solvent-exposed surface area of assembling modular (KLVFFAE), as well as its non-covalent interaction between four other modules synergeticly decide the solubility of molecules. The weak intramolecular forces of the peptide back bone, such as, hydrogen bond, as well as multivalent interactions of the side chains such as, salt bridge and hydrophobic interaction both contribute to the self-assembly of the molecules. The significant structural difference between delivering molecules optimize the system to adapt hydrophilic and hydrophobic drugs. Finally, the predicted drug delivery molecule specifically recognizes targeted cancer cell lines and self-assembles to form fibers intracellularly, resulting in prolonged drug retention and accumulation. The regular prediction and rational molecular design will benefit the further construction and optimization of modulated drug delivery platform.

Click Reaction-Assisted Peptide Immune Checkpoint Blockade for Solid Tumor Treatment.

One of the major challenges of immune checkpoint blockade (ICB) is the poor penetration of antibody for solid tumor treatment. Herein, peptides with deeper penetration capability are used to develop a click reaction-assisted peptide immune checkpoint blockade (CRICB) strategy that could in situ construct assemblies, enabling enhanced accumulation and prolonged PD-L1 occupancy, ultimately realizing high-performance tumor inhibition. First, the free DBCO-modified targeting peptide (TP) efficiently recognizes and binds PD-L1 in a deep solid tumor. Upon a reagent-free click reaction with a subsequently introduced azide-tethered assembled peptide (AP), the click reaction results in spontaneous self-aggregation in situ with enhanced accumulation and prolonged occupancy. In addition, the penetration of TP-AP (121.2 ± 15.5 µm) is significantly enhanced compared with that of an antibody (19.9 ± 5.6 µm) in a solid tumor tissue. More importantly, significant immunotherapy effects and negligible side effects are observed in 4T1 and CT26 tumor-bearing mice models treated with TP-AP, suggesting the high-performance tumor inhibition attributed to the CRICB strategy. In summary, this CRICB strategy manifest the preferable effects of immune checkpoint blockade, thereby extending the biomedical application of assembling peptides.

A Near-Infrared Peptide Probe with Tumor-Specific Excretion-Retarded Effect for Image-Guided Surgery of Renal Cell Carcinoma.

Image-guided surgery plays a crucial role in realizing complete tumor removal, reducing postoperative recurrence and increasing patient survival. However, imaging of tumor lesion in the typical metabolic organs, e.g., kidney and liver, still has great challenges due to the intrinsic nonspecific accumulation of imaging probes in those organs. Herein, we report an in situ self-assembled near-infrared (NIR) peptide probe with tumor-specific excretion-retarded (TER) effect in tumor lesions, enabling high-performance imaging of human renal cell carcinoma (RCC) and achieving complete tumor removal, ultimately reducing postoperative recurrence. The NIR peptide probe first specifically recognizes αvß3 integrin overexpressed in renal cancer cells, then is cleaved by MMP-2/9, which is up-regulated in the tumor microenvironment. The probe residue spontaneously self-assembles into nanofibers that exhibit an excretion-retarded effect in the kidney, which contributes to a high signal-to-noise (S/N) ratio in orthotopic RCC mice. Intriguingly, the TER effect also enables precisely identifying eye-invisible tiny lesions (<1 mm), which contributes to complete tumor removal and significantly reduces the postoperative recurrence compared with traditional surgery. Finally, the TER strategy is successfully employed in high-performance identification of human RCC in an ex vivo kidney perfusion model. Taken together, this NIR peptide probe based on the TER strategy is a promising method for detecting tumors in metabolic organs in diverse biomedical applications.

A tumour-selective cascade activatable self-detained system for drug delivery and cancer imaging.

Achieving the activation of drugs within cellular systems may provide targeted therapies. Here we construct a tumour-selective cascade activatable self-detained system (TCASS) and incorporate imaging probes and therapeutics. We show in different mouse models that the TCASS system accumulates in solid tumours. The molecules show enhanced accumulation in tumour regions via the effect of recognition induced self-assembly. Analysis of the molecular penetration in tumour tissue shows that in vivo self-assembly increases the penetration capability compared to typical soft or hard nanomaterials. Importantly, the in vivo self-assembled molecules exhibit a comparable clearance pathway to that of small molecules, which are excreted from organs of the reticuloendothelial system (liver and kidney), while are relatively slowly eliminated from tumour tissues. Finally, this system, combined with the NIR probe, shows high specificity and sensitivity for detecting bladder cancer in isolated intact patient bladders.