A peptide-AIEgen nanocomposite mediated whole cancer immunity cycle-cascade amplification for improved immunotherapy of tumor

Spatiotemporally Controllable Covalent Bonding of RNA for Multi-Protein Interference

Many diseases are associated with genetic mutation and expression of mutated proteins, such as cancers. Therapeutic approaches that selectively target the synthesis process of multiple proteins show greater potential compared to single-protein approaches in oncological diseases. However, conventional agents to regulate the synthesis of multiple protein still suffer from poor spatiotemporal selectivity and stability. Here, a new method using a dye-peptide conjugate, PRFK, for multi-protein interference with spatiotemporal selectivity and reliable stability, is reported. By using the peptide sequence that targets tumor cells, PRFK can be efficiently taken up, followed by specific binding to the KDELR (KDEL receptor) protein located in the endoplasmic reticulum (ER). The dye generates 1O2 under light irradiation, enabling photodynamic therapy. This process converts the furan group into a cytidine-reactive intermediate, which covalently binds to mRNA, thereby blocking protein synthesis. Upon treating 4T1 cells, the proteomics data show alterations in apoptosis, ferroptosis, proliferation, migration, invasion, and immune infiltration, suggesting that multi-protein interference leads to the disruption of cellular physiological activities, ultimately achieving tumor treatment. This study presents a multi-protein interference probe with the potential for protein interference within various subcellular organelles in the future.

Supramolecular Peptide Amphiphile Nanospheres Reprogram Tumor-associated Macrophage to Reshape the Immune Microenvironment for Enhanced Breast Cancer Immunotherapy

Tumor immunotherapy has become a research hotspot in cancer treatment, with macrophages playing a crucial role in tumor development. However, the tumor microenvironment restricts macrophage functionality, limiting their therapeutic potential. Therefore, modulating macrophage function and polarization is essential for enhancing tumor immunotherapy outcomes. Here, a supramolecular peptide amphiphile drug-delivery system (SPADS) is utilized to reprogram macrophages and reshape the tumor immune microenvironment (TIM) for immune-based therapies. The approach involved designing highly specific SPADS that selectively targets surface receptors of M2-type macrophages (M2-Mφ). These targeted peptides induced M2-Mφ repolarization into M1-type macrophages by dual inhibition of endoplasmic reticulum and oxidative stresses, resulting in improved macrophagic antitumor activity and immunoregulatory function. Additionally, TIM reshaping disrupted the immune evasion mechanisms employed by tumor cells, leading to increased infiltration, and activation of immune cells. Furthermore, the synergistic effect of macrophage reshaping and anti-PD-1 antibody (aPD-1) therapy significantly improved the immune system's ability to recognize and eliminate tumor cells, thereby enhancing tumor immunotherapy efficacy. SPADS utilization also induced lung metastasis suppression. Overall, this study demonstrates the potential of SPADS to drive macrophage reprogramming and reshape TIM, providing new insights, and directions for developing more effective immunotherapeutic approaches in cancer treatment.

Recent Advances in Reprogramming Strategy of Tumor Microenvironment for Rejuvenating Photosensitizers-Mediated Photodynamic Therapy

Photodynamic therapy (PDT) has recently been considered a potential tumor therapy due to its time-space specificity and non-invasive advantages. PDT can not only directly kill tumor cells by using cytotoxic reactive oxygen species but also induce an anti-tumor immune response by causing immunogenic cell death of tumor cells. Although it exhibits a promising prospect in treating tumors, there are still many problems to be solved in its practical application. Tumor hypoxia and immunosuppressive microenvironment seriously affect the efficacy of PDT. The hypoxic and immunosuppressive microenvironment is mainly due to the abnormal vascular matrix around the tumor, its abnormal metabolism, and the influence of various immunosuppressive-related cells and their expressed molecules. Thus, reprogramming the tumor microenvironment (TME) is of great significance for rejuvenating PDT. This article reviews the latest strategies for rejuvenating PDT, from regulating tumor vascular matrix, interfering with tumor cell metabolism, and reprogramming immunosuppressive related cells and factors to reverse tumor hypoxia and immunosuppressive microenvironment. These strategies provide valuable information for a better understanding of the significance of TME in PDT and also guide the development of the next-generation multifunctional nanoplatforms for PDT.

Luminescent polypeptides

Polypeptides, as biomacromolecules, hold immense potential in various biological applications such as tissue engineering, immunomodulating agents, and target binding. Among these applications, the attention towards luminescent polypeptides has grown significantly, due to their ability to visualize biological processes effectively. In this perspective, we have compiled information on three distinct types of luminescent polypeptides: natural fluorescent proteins, luminophores-bioconjugated polypeptides, and synthesized polypeptides with clusteroluminescence. Last, we shed light on the significance and prospects of clusteroluminescent polypeptides, which are expected to emerge as crucial new-generation bioluminophores, offering high emission efficiency and tunable emission wavelengths.

Nanoplatform-enhanced photodynamic therapy for the induction of immunogenic cell death

As an efficient, non-invasive, low-side-effect, and highly selective cancer therapy, photodynamic therapy (PDT) is used to treat various malignant tumors. However, the inefficiency of dealing with deep tumors and metastatic lesions highly limits the use of PDT. Immunogenic cell death (ICD) is a particular form of tumor cell death that could elicit a tumor-special immune response, leading to a systemic anti-tumor effect and providing therapeutic benefits for metastatic lesions. In this regard, it is crucial to enhance the ability of PDT to induce ICD. Luckily, advanced nanotechnology created many promising ways to improve the immunogenicity of PDT and achieve photoimmunotherapy. This review summarizes the emerging strategies for triggering immunogenic cell death via nanoplatform-enhanced PDT, with particular emphasis on their advantages in photoimmunotherapy. We highlight the nanoplatforms classified according to the basic principles of photodynamic therapy and immunogenic cell death, which provides a valuable reference for the design of nanoplatform for photoimmunotherapy. In addition, we also discuss the current situation and prospect of nano-based photoimmunotherapy in clinical studies.

Tumor Microenvironment Sequential Drug/Gene Delivery Nanosystem for Realizing Multistage Boosting of Cancer-Immunity Cycle on Cancer Immunotherapy

The antitumor immune response of cancer immunotherapy is a cascade of cancer-immunity cycles (CIC). The immunosuppression of the tumor microenvironment and low immunogenicity of tumor cells, insufficient T lymphocyte activation, trafficking, and infiltration caused the failure to initiate and run the continuous multistage CIC, leading to unsatisfactory cancer immunotherapy outcomes. A doxorubicin/interleukin-12 plasmid DNA/celecoxib (DOX/pIL-12/CXB) combination strategy was designed by targeting the cascade CIC. Then, an intratumoral CXB-detachable nanosystem, or DOX/PAC/pIL-12 micelleplexes, was developed for sequential drug/gene delivery to facilitate the multistage boosting of CIC on synergistic cancer immunotherapy. The DOX/PAC/pIL-12 micelleplexes could program intratumorally sequential release of CXB to remodulate the tumor microenvironment immunosuppression by suppressing the cyclooxygenase-2/prostaglandin E2 (COX-2/PGE2) pathway. The smaller sizes and surface charge-switched micelleplexes facilitated the codelivery and corelease of DOX and pIL-12 inside 4T1 tumor cells. These micelleplexes exerted a synergistic antitumor immune response using CIC cascade activation and amplification, providing therapeutic antitumor and antimetastasis efficacy. The drug/gene sequential delivery nanosystem provides a complete CIC-boosted combinatory strategy for developing immunotherapy against cancer.

Aggregation-Induced Emission (AIE), Life and Health

Light has profoundly impacted modern medicine and healthcare, with numerous luminescent agents and imaging techniques currently being used to assess health and treat diseases. As an emerging concept in luminescence, aggregation-induced emission (AIE) has shown great potential in biological applications due to its advantages in terms of brightness, biocompatibility, photostability, and positive correlation with concentration. This review provides a comprehensive summary of AIE luminogens applied in imaging of biological structure and dynamic physiological processes, disease diagnosis and treatment, and detection and monitoring of specific analytes, followed by representative works. Discussions on critical issues and perspectives on future directions are also included. This review aims to stimulate the interest of researchers from different fields, including chemistry, biology, materials science, medicine, etc., thus promoting the development of AIE in the fields of life and health.

Microneedle Device Delivering Aggregation-Induced Emission Photosensitizers for Enhanced Metronomic Photodynamic Therapy of Cancer

Metronomic photodynamic therapy (mPDT), which induces cancer cell death by prolonged intermittent continuous irradiation at lower light power, has profoundly promising applications. However, the photobleaching sensitivity of the photosensitizer (PS) and the difficulty of delivery pose barriers to the clinical application of mPDT. Here, we constructed a microneedle-based device (Microneedles@AIE PSs) that combined with aggregation-induced emission (AIE) PSs to achieve enhanced mPDT for cancer. Due to the strong anti-photobleaching property of the AIE PS, it can maintain superior photosensitivity even after long-time light exposure. The delivery of the AIE PS to the tumor through a microneedle device allows for greater uniformity and depth. This Microneedles@AIE PSs-based mPDT (M-mPDT) offers better treatment outcomes and easier access, and combining M-mPDT with surgery or immunotherapy can also significantly improve the effectiveness of these clinical therapies. In conclusion, M-mPDT offers a promising strategy for the clinical application of PDT due to its better efficacy and convenience.

Platelet membrane camouflaged AIEgen-mediated photodynamic therapy improves the effectiveness of anti-PD-L1 immunotherapy in large-burden tumors

Although immunotherapy has achieved recent clinical success in antitumor therapy, it is less effective for solid tumors with large burdens. To overcome this challenge, herein, we report a new strategy based on platelet membrane-camouflaged aggregation-induced emission (AIE) luminogen (Plt-M@P) combined with the anti-programmed death ligand 1 (anti-PD-L1) for tumoral photodynamic-immunotherapy. Plt-M@P is prepared by using poly lactic-co-glycolic acid (PLGA)/PF3-PPh₃ complex as a nanocore, and then by co-extrusion with platelet membranes. PF3-PPh₃ is an AIE-active conjugated polyelectrolyte with photosensitizing capability for photodynamic therapy (PDT). Plt-M@P exhibits superior tumor targeting capacity in vivo. When applied in small tumor-bearing (~40 mm³) mice, Plt-M@P-mediated PDT significantly inhibits tumor growth. In tumor models with large burdens (~200 mm³), using Plt-M@P-mediated PDT or anti-PD-L1 alone is less effective, but the combination of both is effective in inhibiting tumor growth. Importantly, this combination therapy has good biocompatibility, as demonstrated by the absence of damage to the major organs, especially the reproductive system. In conclusion, we show that Plt-M@P-mediated PDT can improve anti-PD-L1 immunotherapy by enhancing antitumor effects, providing a promising strategy for the treatment of tumors with large burdens.

Modular Peptide Probe for Protein Analysis

The analysis and regulation of proteins are of great significance for the development of disease diagnosis and treatment. However, complicated analytical environment and complex protein structure severely limit the accuracy of their analysis results. Nowadays, ascribing to the editability and bioactivity of peptides, peptide-based probes could meet the requirements of good selectivity and high affinity to overcome the challenges. In this review, we summarize the advances in the use of modular peptide probes for proteins analysis. It focuses on how to design and optimize the structure of probes, as well as their performance. Then, the strategies and application to improve the analysis result of modular peptide probes are introduced. Finally, we also discuss current challenge and provide some ideas for the future direction for modular peptide probes, hoping to accelerate their clinical transformation.

Erythrocyte Membrane-Camouflaged Aggregation-Induced Emission Nanoparticles for Fetal Intestinal Maturation Assessment

Assessment of fetal maturity is essential for timely termination of pregnancy, especially in pregnant women with pregnancy complications. However, there is a lack of methods to assess the maturity of fetal intestinal function. Here, we constructed erythrocyte membrane-camouflaged aggregation-induced emission (AIE) nanoparticles. Nanocore is formed using a hollow mesoporous silicon nanobox (HMSN) of different particle sizes loaded with AIE luminogens -PyTPA (P), which are then co-extruded with erythrocyte membranes (M) to construct M@HMSN@P. The 100 nm M@HMSN@P has a more effective cellular uptake efficiency in vitro and in vivo. Swallowing and intestinal function in fetal mice mature with the increase in gestational age. After intrauterine injection of M@HMSN@P, they were swallowed and absorbed by fetal mice, and their swallowed and absorbed amount was positively correlated with the gestational age with a correlation coefficient of 0.9625. Using the M@HMSN@P (fluorescence intensity) in fetal mice, the gestational age can be imputed, and the difference between this imputed gestational age and the actual gestational age is less than 1 day. Importantly, M@HMSN@P has no side effect on the health status of pregnant and fetal mice, showing good biocompatibility. In conclusion, we constructed M@HMSN@P nanoparticles with different particle sizes and confirmed that the smaller size M@HMSN@P has more efficient absorption efficiency and it can assess fetal intestinal maturity by the intensity of the fluorescence signal.

Combining PD-L1 blockade with immunogenic cell death induced by AIE photosensitizer to improve antitumor immunity

Immunogenic cell death (ICD) is considered an effective death mode to trigger immune response. However, the currently available efficient ICD inducers are quite limited. Endoplasmic reticulum (ER) stress is known as the precursor of ICD, which can be directly triggered by reactive oxygen species in situ. Herein, a novel photosensitizer (α-Th-TPA-PIO) based on phosphindole oxide, featuring aggregation-induced emission (AIE) is designed and prepared, which possesses good ability of hydroxyl radicals (HO^•) generation. Besides, α-Th-TPA-PIO can selectively accumulate in ER and trigger ER stress under white light irradiation, further leading to effective ICD. Combining with anti-programmed death-ligand 1 (anti-PD-L1), the synergistic effect of photodynamic therapy (PDT) and immune checkpoint blockade can achieve a significantly enhanced inhibition effect on the growth of tumors and simultaneously provoke a systemic antitumor immune response. Notably, by adopting this therapeutic strategy to bilateral and metastatic tumor models, the growth of both primary and distant subcutaneous tumors can be successfully suppressed, and metastatic tumor can also be inhibited to some degree. Taken together, this work not only provides a novel ICD photoinducer based on PDT, but also brings about a useful immunomodulatory strategy to realize superior antitumor effect.

Programmable design and self assembly of peptide conjugated AIEgens for biomedical applications

Aggregation-induced emission luminogens (AIEgens) possess enhanced fluorescence in highly aggregated states, thus enabling AIEgens as a promising module for highly emissive fluorescence biomaterials. So far, AIEgens-based nanomaterials and their hybrids have been reported for biomedical applications. Benefiting from the intrinsic biocompatibility and biofunction-editing properties of peptides, peptide-AIEgens hybrid biomaterials reveal unlimited possibilities including target capacity, specificity, stimuli-responsiveness, self-assembly, controllable structural transformation, etc.. In the last two decades, peptide-AIEgens hybrid nanomaterials with a unique design concept in aggregated states have achieved various biomedical applications such as biosensing, bioimaging, imaging-guided surgery, drug delivery and therapy. More recently, programmable design of peptide-AIEgens for in situ self-assembly provides a unique strategy for constructing intelligent entities with defined biological functions. In this review, we summarize the basic design principle of programmable peptide-AIEgens, structure-effect relationship and their unusual biomedical effects. Finally, an outlook and perspective toward future challenges and developments of peptide-AIEgens nanomaterials are concluded.

Aggregation-induced emission photosensitizer-based photodynamic therapy in cancer: from chemical to clinical

Cancer remains a serious threat to human health owing to the lack of effective treatments. Photodynamic therapy (PDT) has emerged as a promising non-invasive cancer treatment that consists of three main elements: photosensitizers (PSs), light and oxygen. However, some traditional PSs are prone to aggregation-caused quenching (ACQ), leading to reduced reactive oxygen species (ROS) generation capacity. Aggregation-induced emission (AIE)-PSs, due to their distorted structure, suppress the strong molecular interactions, making them more photosensitive in the aggregated state instead. Activated by light, they can efficiently produce ROS and induce cell death. PS is one of the core factors of efficient PDT, so proceeding from the design and preparation of AIE-PSs, including how to manipulate the electron donor (D) and receptor (A) in the PSs configuration, introduce heavy atoms or metal complexes, design of Type I AIE-PSs, polymerization-enhanced photosensitization and nano-engineering approaches. Then, the preclinical experiments of AIE-PSs in treating different types of tumors, such as ovarian cancer, cervical cancer, lung cancer, breast cancer, and its great potential clinical applications are discussed. In addition, some perspectives on the further development of AIE-PSs are presented. This review hopes to stimulate the interest of researchers in different fields such as chemistry, materials science, biology, and medicine, and promote the clinical translation of AIE-PSs.