Modular AND Gate-Controlled Delivery Platform for Tumor Microenvironment Specific Activation of Protein Activity

Protein therapeutics have inspired intensive research interest in a variety of realms. It is still urgently required to avoid premature or unexpected activation of therapeutic proteins to achieve great specificity for therapy. Herein, we reported a modular AND gate-controlled delivery platform for tumor microenvironment specific activation of therapeutic protein activity based on biomineralization of molecular glue-adhered protein enzyme. The AND gate integrates the specific microenvironment of tumor tissues (acidic pH and a certain concentration of ATP) as inputs and activates the therapeutic activity of protein only when both inputs are active. More importantly, the activity of therapeutic protein would not be activated either at acidic pH or in the presence of ATP, which could greatly avoid the deleterious effect on normal tissues. Besides, this AND gate can be modular design and suitable for a variety of therapeutic proteins and nucleic acids.     

A Bioorthogonal Click Chemistry Toolbox for Targeted Synthesis of Branched and Well‐Defined Protein–Protein Conjugates

Bioorthogonal chemistry holds great potential to generate difficult‐to‐access protein–protein conjugate architectures. Current applications are hampered by challenging protein expression systems, slow conjugation chemistry, use of undesirable catalysts, or often do not result in quantitative product formation. Here we present a highly efficient technology for protein functionalization with commonly used bioorthogonal motifs for Diels–Alder cycloaddition with inverse electron demand (DA_inv). With the aim of precisely generating branched protein chimeras, we systematically assessed the reactivity, stability and side product formation of various bioorthogonal chemistries directly at the protein level. We demonstrate the efficiency and versatility of our conjugation platform using different functional proteins and the therapeutic antibody trastuzumab. This technology enables fast and routine access to tailored and hitherto inaccessible protein chimeras useful for a variety of scientific disciplines. We expect our work to substantially enhance antibody applications such as immunodetection and protein toxin‐based targeted cancer therapies.     

Microfluidic Synthesis of the Tumor Microenvironment-Responsive Nanosystem for Type-I Photodynamic Therapy

Type I photosensitizers with aggregation-induced emission luminogens (AIE-gens) have the ability to generate high levels of reactive oxygen species (ROS), which have a good application prospect in cancer photodynamic therapy (PDT). However, the encapsulation and delivery of AIE molecules are unsatisfactory and seriously affect the efficiency of a practical therapy. Faced with this issue, we synthesized the metal-organic framework (MOF) in one step using the microfluidic integration technology and encapsulated TBP-2 (an AIE molecule) into the MOF to obtain the composite nanomaterial ZT. Material characterization showed that the prepared ZT had stable physical and chemical properties and controllable size and morphology. After being endocytosed by tumor cells, ZT was degraded in response to the acidic tumor microenvironment (TME), and then TBP-2 molecules were released. After stimulation by low-power white light, a large amount of •OH and H₂O₂ was generated by TBP-2 through type I PDT, thereby achieving a tumor-killing effect. Further in vitro cell experiments showed good biocompatibility of the prepared ZT. To the best of our knowledge, this report is the first on the microfluidic synthesis of multifunctional MOF for type I PDT in response to the TME. Overall, the preparation of ZT by the microfluidic synthesis method provides new insight into cancer therapy.     

肿瘤微环境响应药物递送系统的设计

化学药物治疗(化疗)是目前临床上治疗肿瘤最有效的方法之一,但传统的给药方式导致药物对肿瘤的靶向性差、药物利用率低.在杀伤肿瘤细胞的同时,化疗药物对人体正常细胞也有很大的损伤,因此在化疗过程中通常伴随着严重的副作用,例如恶心、呕吐以及脱发等.随着肿瘤学和纳米材料的迅速发展,多种纳米药物载体被应用于肿瘤的治疗.纳米药物载体...     

A High-Efficiency Bioorthogonal Tumor-Membrane Reactor for In Situ Selective and Sustained Prodrug Activation

The site-specific activation of bioorthogonal prodrugs has provided great opportunities for reducing the severe side effects of chemotherapy. However, the precise control of activation location, sustained drug production at the target site, and high bioorthogonal reaction efficiency in vivo remain great challenges. Here, we propose the construction of tumor cell membrane reactors in vivo to solve the above problems. Specifically, tumor-targeted liposomes with efficient membrane fusion capabilities are generated to install the bioorthogonal trigger, the amphiphilic tetrazine derivative, on the surface of tumor cells. These predecorated tumor cells act as many living reactors, transforming the tumor into a “drug factory” that in situ activates an externally delivered bioorthogonal prodrug, for example intratumorally injected transcyclooctene-caged doxorubicin. In contrast to the rapid elimination of cargo that is encapsulated and delivered by liposomes, these reactors permit stable retention of bioorthogonal triggers in tumor for 96 h after a single dose of liposomes via intravenous injection, allowing sustained generation of doxorubicin. Interestingly, an additional supplement of liposomes will compensate for the trigger consumed by the reaction and significantly improve the efficiency of the local reaction. This strategy provides a solution to the efficacy versus safety dilemma of tumor chemotherapy.     

Transporting and Shielding Photosensitisers by Using Water‐Soluble Organometallic Cages: A New Strategy in Drug Delivery and Photodynamic Therapy

Skin photosensitivity remains one of the main limitations in photodynamic therapy. In this Concept article a strategy to overcome this limitation is described, in which the photosensitizer is hidden inside the hydrophobic cavity of a water‐soluble organometallic cage. The metallacage not only protects the photosensitizer from light, it also facilitates its delivery to cancer cells.     

A Glycosylated Covalent Organic Framework Equipped with BODIPY and CaCO3 for Synergistic Tumor Therapy

Ca²⁺, a ubiquitous but nuanced modulator of cellular physiology, is meticulously controlled intracellularly. However, intracellular Ca²⁺ regulation, such as mitochondrial Ca²⁺ buffering capacity, can be disrupted by ¹O₂. Thus, the intracellular Ca²⁺ overload, which is recognized as one of the important cell pro‐death factors, can be logically achieved by the synergism of ¹O₂ with exogenous Ca²⁺ delivery. Reported herein is a nanoscale covalent organic framework (NCOF)‐based nanoagent, namely CaCO₃@COF‐BODIPY‐2I@GAG ( 4 ), which is embedded with CaCO₃ nanoparticle (NP) and surface‐decorated with BODIPY‐2I as photosensitizer (PS) and glycosaminoglycan (GAG) targeting agent for CD44 receptors on digestive tract tumor cells. Under illumination, the light‐triggered ¹O₂ not only kills the tumor cells directly, but also leads to their mitochondrial dysfunction and Ca²⁺ overload. An enhanced antitumor efficiency is achieved via photodynamic therapy (PDT) and Ca²⁺ overload synergistic therapy.     

Molecular,Macromolecular, and Supramolecular Glucuronide Prodrugs: Lead Identified for Anticancer Prodrug Monotherapy

In this work, a tumor growth intervention by localized drug synthesis within the tumor volume, using the enzymatic repertoire of the tumor itself, is presented. Towards the overall success, molecular, macromolecular, and supramolecular glucuronide prodrugs were designed for a highly potent toxin, monomethyl auristatin E (MMAE). The lead candidate exhibited a fold difference in toxicity between the prodrug and the drug of 175, had an engineered mechanism to enhance the deliverable payload to tumours, and contained a highly potent toxin such that bioconversion of only a few prodrug molecules created a concentration of MMAE sufficient enough for efficient suppression of tumor growth. Each of these points is highly significant and together afford a safe, selective anticancer measure, making tumor‐targeted glucuronides attractive for translational medicine.     

Bioorthogonal chemistry:a covalent strategy for the study of biological systems

The development of genetically encoded,wavelength-tunable fluorescent proteins has provided a powerful imaging tool to the study of protein dynamics and functions in cellular and organismal biology.However,many biological functions are not directly encoded in the protein primary sequence,e.g.,dynamic regulation afforded by protein posttranslational modifications such as phosphorylation.To meet this challenge,an emerging field of bioorthogonal chemistry has promised to offer a versatile strategy to selective...     

An Optimized Protocol for the Synthesis of Peptides Containing trans-Cyclooctene and Bicyclononyne Dienophiles as Useful Multifunctional Bioorthogonal Probes

Despite the great advances in solid-phase peptide synthesis (SPPS), the incorporation of certain functional groups into peptide sequences is restricted by the compatibility of the building blocks with conditions used during SPPS. In particular, the introduction of highly reactive groups used in modern bioorthogonal reactions into peptides remains elusive. Here, we present an optimized synthetic protocol enabling installation of two strained dienophiles, trans-cyclooctene (TCO) and bicyclononyne (BCN), into different peptide sequences. The two groups enable fast and modular post-synthetic functionalization of peptides, as we demonstrate in preparation of peptide-peptide and peptide-drug conjugates. Due to the excellent biocompatibility, the click-functionalization of the peptides can be performed directly in live cells. We further show that the introduction of both clickable groups into peptides enables construction of smart, multifunctional probes that can streamline complex chemical biology experiments such as visualization and pull-down of metabolically labeled glycoconjugates. The presented strategy will find utility in construction of peptides for diverse applications, where high reactivity, efficiency and biocompatibility of the modification step is critical.     

A New Porphyrin for the Preparation of Functionalized Water-Soluble Gold Nanoparticles with Low Intrinsic Toxicity

A potential new photosensitizer based on a dissymmetric porphyrin derivative bearing a thiol group was synthesized. 5-[4-(11-Mercaptoundecyloxy)-phenyl-10,15,20-triphenylporphyrin (PR-SH) was used to functionalize gold nanoparticles in order to obtain a potential drug delivery system. Water-soluble multifunctional gold nanoparticles GNP-PR/PEG were prepared using the Brust–Schiffrin methodology, by immobilization of both a thiolated polyethylene glycol (PEG) and the porphyrin thiol compound (PR-SH). The nanoparticles were fully characterized by transmission electron microscopy and ¹H nuclear magnetic resonance spectroscopy, UV/Vis absorption spectroscopy, and X-ray photoelectron spectroscopy. Furthermore, the ability of GNP-PR/PEGs to induce singlet oxygen production was analyzed to demonstrate the activity of the photosensitizer. Cytotoxicity experiments showed the nanoparticles are nontoxic. Finally, cellular uptake experiments demonstrated that the functionalized gold nanoparticles are internalized. Therefore, this colloid can be considered to be a novel nanosystem that could potentially be suitable as an intracellular drug delivery system of photosensitizers for photodynamic therapy.     

A Phototheranostic Strategy to Continuously Deliver Singlet Oxygen in the Dark and Hypoxic Tumor Microenvironment

Continuous irradiation during photodynamic therapy (PDT) inevitably induces tumor hypoxia, thereby weakening the PDT effect. In PDT‐induced hypoxia, providing singlet oxygen from stored chemical energy may enhance the cell‐killing effect and boost the therapeutic effect. Herein, we present a phototheranostic (DPPTPE@PEG‐Py NPs) prepared by using a 2‐pyridone‐based diblock polymer (PEG‐Py) to encapsulate a semiconducting, heavy‐atom‐free pyrrolopyrrolidone‐tetraphenylethylene (DPPTPE) with high singlet‐oxygen‐generation ability both in dichloromethane and water. The PEG‐Py can trap the ¹O₂ generated from DPPTPE under laser irradiation and form a stable intermediate of endoperoxide, which can then release ¹O₂ in the dark, hypoxic tumor microenvironment. Furthermore, fluorescence‐imaging‐guided phototherapy demonstrates that this phototheranostic could completely inhibit tumor growth with the help of laser irradiation.     

A Bioorthogonal Approach for the Preparation of a Titanium‐Binding Insulin‐like Growth‐Factor‐1 Derivative by Using Tyrosinase

The generation of metal surfaces with biological properties, such as cell‐growth‐enhancing and differentiation‐inducing abilities, could be potentially exciting for the development of functional materials for use in humans, including artificial dental implants and joint replacements. However, currently the immobilization of proteins on the surfaces of the metals are limited. In this study, we have used a mussel‐inspired bioorthogonal approach to design a 3,4‐hydroxyphenalyalanine‐containing recombinant insulin‐like growth‐factor‐1 using a combination of recombinant DNA technology and tyrosinase treatment for the surface modification of titanium. The modified growth factor prepared in this study exhibited strong binding affinity to titanium, and significantly enhanced the growth of NIH3T3 cells on the surface of titanium.     

Bioorthogonal Probes for the Study of MDM2‐p53 Inhibitors in Cells and Development of High‐Content Screening Assays for Drug Discovery

To study the behavior of MDM2‐p53 inhibitors in a disease‐relevant cellular model, we have developed and validated a set of bioorthogonal probes that can be fluorescently labeled in cells and used in high‐content screening assays. By using automated image analysis with single‐cell resolution, we could visualize the intracellular target binding of compounds by co‐localization and quantify target upregulation upon MDM2‐p53 inhibition in an osteosarcoma model. Additionally, we developed a high‐throughput assay to quantify target occupancy of non‐tagged MDM2‐p53 inhibitors by competition and to identify novel chemical matter. This approach could be expanded to other targets for lead discovery applications.