In vivo tracking of bioorthogonally labeled T-cells for predicting therapeutic efficacy of adoptive T-cell therapy

An engineered cellular carrier delivers miR-138-5p to enhance mitophagy and protect hypoxic-injured neurons via the DNMT3A/Rhebl1 axis

Mitophagy influences the progression and prognosis of ischemic stroke (IS). However, whether DNA methylation in the brain is associated with altered mitophagy in hypoxia-injured neurons remains unclear. Here, miR-138-5p was found to be highly expressed in exosomes secreted by astrocytes stimulated with oxygen and glucose deprivation/re-oxygenation (OGD/R), which could influence the recovery of OGD/R-injured neurons through autophagy. Mechanistically, miR-138-5p promotes the stable expression of Ras homolog enriched in brain like 1(Rhebl1) through DNA-methyltransferase-3a (DNMT3A), thereby enhancing ubiquitin-dependent mitophagy to maintain mitochondrial homeostasis. Furthermore, we employed glycosylation engineering and bioorthogonal click reactions to load mirna onto the surface of microglia and deliver them to injured region utilising the inflammatory chemotactic properties of microglia to achieve drug-targeted delivery to the central nervous system (CNS). Our findings demonstrate miR-138-5p improves mitochondrial function in neurons through the miR-138-5p/DNMT3A/Rhebl1 axis. Additionally, our engineered cell vector-targeted delivery system could be promising for treating IS. STATEMENT OF SIGNIFICANCE: In this study, we demonstrated that miR-138-5p in exosomes secreted by astrocytes under hypoxia plays a critical role in the treatment of hypoxia-injured neurons. And we find a new target of miR-138-5p, DNMT3A, which affects neuronal mitophagy and thus exerts a protective effect by regulating the methylation of Rbebl1. Furthermore, we have developed a carrier delivery system by combining miR-138-5p with the cell membrane of microglia and utilized the inflammatory chemotactic properties of microglia to deliver this system to the brain via intravenous injection. This groundbreaking study not only provides a novel therapeutic approach for ischemia-reperfusion treatment but also establishes a solid theoretical foundation for further research on targeted drug delivery for central nervous system diseases with promising clinical applications.

Engineered Leukocyte Biomimetic Colorimetric Sensor Enables High-Efficient Detection of Tumor Cells Based on Bioorthogonal Chemistry

Accurate detection of heterogeneous circulating tumor cells (CTCs) is critical as they can make tumor cells more aggressive, drug-resistant, and metastasizing. Although the leukocyte membrane coating strategy is promising in meeting the challenge of detecting heterogeneous CTCs due to its inherent antiadhesive properties, it is still limited by the reduction or loss of expression of known markers. Bioorthogonal glycol-metabolic engineering is expected to break down this barrier by feeding the cells with sugar derivatives with a unique functional group to establish artificial targets on the surface of tumor cells. Herein, an engineered leukocyte biomimetic colorimetric sensor was accordingly fabricated for high-efficient detection of heterogeneous CTCs. Compared with conventional leukocyte membrane coating, the sensor could covalently bound to the heterogeneous CTCs models fed with Ac4ManNAz in vitro through the synergy of bioorthogonal chemistry and metabolic glycoengineering, ignoring the phenotypic changes of heterogeneous CTCs. Meanwhile, a sandwich structure composed of leukocyte biomimetic layer/CTCs/MoS2 nanosheet was formed for visual detection of HeLa cells as low as 10 cells mL-1. Overall, this approach can overcome the dependence of conventional cell membrane biomimetic technology on specific cell phenotypes and provide a new viewpoint to highly efficiently detect heterogeneous CTCs.

A versatile method for conjugating lipid nanoparticles on T cells through combination of click chemistry and metabolic glycoengineering

Cell-mediated drug delivery by conjugating nanomedicine to the surface of living cells is a promising strategy for enhancing the efficacy of both drug delivery and cell therapy. It exploits the tissue homing properties of the specific cell types to overcome in vivo barriers and forms a drug depot by directly putting the therapeutic payload in target cells. An important concern of developing this system is the method to conjugate nanoparticles on cells. Herein, we developed a bioorthogonal T cell conjugation strategy using SPAAC click chemistry, which allows controllable and highly efficient conjugation without affecting the viability and functions of the cytotoxic T lymphocytes. Azide groups were incorporated on the surface of T cells through metabolic glycoengineering, followed by reacting with dibenzylcyclooctyne (DBCO) modified lipid nanoparticles (LNPs). LNPs can be conjugated to T cells, allowing for the loading of different drug molecules on the cells. The metabolic engineering and click reaction approach provides a simple and versatile strategy to conjugate NPs to living cells and enable the development of sophisticated therapeutic cell products.

Disease-microenvironment modulation by bare- or engineered-exosome for rheumatoid arthritis treatment

BACKGROUND

Exosomes are extracellular vesicles secreted by eukaryotic cells and have been extensively studied for their surface markers and internal cargo with unique functions. A deeper understanding of exosomes has allowed their application in various research areas, particularly in diagnostics and therapy.

MAIN BODY

Exosomes have great potential as biomarkers and delivery vehicles for encapsulating therapeutic cargo. However, the limitations of bare exosomes, such as rapid phagocytic clearance and non-specific biodistribution after injection, pose significant challenges to their application as drug delivery systems. This review focuses on exosome-based drug delivery for treating rheumatoid arthritis, emphasizing pre/post-engineering approaches to overcome these challenges.

CONCLUSION

This review will serve as an essential resource for future studies to develop novel exosome-based therapeutic approaches for rheumatoid arthritis. Overall, the review highlights the potential of exosomes as a promising therapeutic approach for rheumatoid arthritis treatment.

Recent Advances in Bioorthogonal Click Chemistry for Enhanced PET and SPECT Radiochemistry

Due to their high reaction rate and reliable selectivity, bioorthogonal click reactions have been extensively investigated in numerous research fields, such as nanotechnology, drug delivery, molecular imaging, and targeted therapy. Previous reviews on bioorthogonal click chemistry for radiochemistry mainly focus on ¹⁸F-labeling protocols employed to produce radiotracers and radiopharmaceuticals. In fact, besides fluorine-18, other radionuclides such as gallium-68, iodine-125, and technetium-99m are also used in the field of bioorthogonal click chemistry. Herein, to provide a more comprehensive perspective, we provide a summary of recent advances in radiotracers prepared using bioorthogonal click reactions, including small molecules, peptides, proteins, antibodies, and nucleic acids as well as nanoparticles based on these radionuclides. The combination of pretargeting with imaging modalities or nanoparticles, as well as the clinical translations study, are also discussed to illustrate the effects and potential of bioorthogonal click chemistry for radiopharmaceuticals.

In Vivo Applications of Bioorthogonal Reactions: Chemistry and Targeting Mechanisms

Bioorthogonal chemistry involves selective biocompatible reactions between functional groups that are not normally present in biology. It has been used to probe biomolecules in living systems, and has advanced biomedical strategies such as diagnostics and therapeutics. In this review, the challenges and opportunities encountered when translating in vitro bioorthogonal approaches to in vivo settings are presented, with a focus on methods to deliver the bioorthogonal reaction components. These methods include metabolic bioengineering, active targeting, passive targeting, and simultaneously used strategies. The suitability of bioorthogonal ligation reactions and bond cleavage reactions for in vivo applications is critically appraised, and practical considerations such as the optimum scheduling regimen in pretargeting approaches are discussed. Finally, we present our own perspectives for this area and identify what, in our view, are the key challenges that must be overcome to maximise the impact of these approaches.

M, Zarrintaj P, Formela K, Saeb MR, Bencherif SA. Clickable Polysaccharides for Biomedical Applications: A Comprehensive Review

Recent advances in materials science and engineering highlight the importance of designing sophisticated biomaterials with well-defined architectures and tunable properties for emerging biomedical applications. Click chemistry, a powerful method allowing specific and controllable bioorthogonal reactions, has revolutionized our ability to make complex molecular structures with a high level of specificity, selectivity, and yield under mild conditions. These features combined with minimal byproduct formation have enabled the design of a wide range of macromolecular architectures from quick and versatile click reactions. Furthermore, copper-free click chemistry has resulted in a change of paradigm, allowing researchers to perform highly selective chemical reactions in biological environments to further understand the structure and function of cells. In living systems, introducing clickable groups into biomolecules such as polysaccharides (PSA) has been explored as a general approach to conduct medicinal chemistry and potentially help solve healthcare needs. De novo biosynthetic pathways for chemical synthesis have also been exploited and optimized to perform PSA-based bioconjugation inside living cells without interfering with their native processes or functions. This strategy obviates the need for laborious and costly chemical reactions which normally require extensive and time-consuming purification steps. Using these approaches, various PSA-based macromolecules have been manufactured as building blocks for the design of novel biomaterials. Clickable PSA provides a powerful and versatile toolbox for biomaterials scientists and will increasingly play a crucial role in the biomedical field. Specifically, bioclick reactions with PSA have been leveraged for the design of advanced drug delivery systems and minimally invasive injectable hydrogels. In this review article, we have outlined the key aspects and breadth of PSA-derived bioclick reactions as a powerful and versatile toolbox to design advanced polymeric biomaterials for biomedical applications such as molecular imaging, drug delivery, and tissue engineering. Additionally, we have also discussed the past achievements, present developments, and recent trends of clickable PSA-based biomaterials such as 3D printing, as well as their challenges, clinical translatability, and future perspectives.

Emerging Biomaterials Imaging Antitumor Immune Response

Immunotherapy is one of the most promising clinical modalities for the treatment of malignant tumors and has shown excellent therapeutic outcomes in clinical settings. However, it continues to face several challenges, including long treatment cycles, high costs, immune-related adverse events, and low response rates. Thus, it is critical to predict the response rate to immunotherapy by using imaging technology in the preoperative and intraoperative. Here, the latest advances in nanosystem-based biomaterials used for predicting responses to immunotherapy via the imaging of immune cells and signaling molecules in the immune microenvironment are comprehensively summarized. Several imaging methods, such as fluorescence imaging, magnetic resonance imaging, positron emission tomography imaging, ultrasound imaging, and photoacoustic imaging, used in immune predictive imaging, are discussed to show the potential of nanosystems for distinguishing immunotherapy responders from nonresponders. Nanosystem-based biomaterials aided by various imaging technologies are expected to enable the effective prediction and diagnosis in cases of tumors, inflammation, and other public diseases.

Enhancing Adoptive Cell Therapy by T Cell Loading of SHP2 Inhibitor Nanocrystals before Infusion

Whereas adoptive T cell therapy has been extensively studied for cancer treatment, the response is still limited primarily due to immune dysfunction related to poor cell engraftment, tumor infiltration and engagement, and lack of a target. In addition, the modification of therapeutic T cells often suffers from being complex and expensive. Here, we present a strategy to load T cells with SHP099, an allosteric SHP2 inhibitor, to enhance the therapeutic efficacy of the T cells. Remote-loading of SHP099 into lipid nanoparticles decorated with triarginine motifs resulted in nanocrystal formation of SHP099 inside the lipid vesicles and allowed high loading efficiency and prolonged retention of SHP099 nanocrystals within T cells. Cell-loaded SHP099 enabled sustained inhibition of the PD-1/PD-L1 signaling and increased cytolytic activity of the T cells. We show in a mouse model that tumor-homing T cells can circulate with the cargos, improving their tumor accumulation compared to systemically administered lipid nanoparticles. On an established solid tumor model, adoptively transferred SHP099 loaded T cells induced complete tumor eradication and durable immune memory against tumor rechallenging on all treated mice by effectively inhibiting the PD-1/PD-L1 checkpoint signal. We demonstrate that the combination of T cell therapy with SHP2 inhibition is a promising therapeutic strategy, and the lipid nanocrystal platform could be generalized as a promising approach for T cell loading of immunomodulatory drugs.

Copper-Free Click Chemistry: Applications in Drug Delivery, Cell Tracking, and Tissue Engineering

Traditionally, organic chemical reactions require organic solvents, toxic catalysts, heat, or high pressure. However, copper-free click chemistry has been shown to have favorable reaction rates and orthogonality in water, buffer solutions, and physiological conditions without toxic catalysts. Strain-promoted azide-alkyne cycloaddition and inverse electron-demand Diels-Alder reactions are representative of copper-free click chemistry. Artificial chemical reactions via click chemistry can also be used outside of the laboratory in a controllable manner on live cell surfaces, in the cytosol, and in living bodies. Consequently, copper-free click chemistry has many features that are of interest in biomedical research, and various new materials and strategies for its use have been proposed. Herein, recent remarkable trials that have used copper-free click chemistry are described, focusing on their applications in molecular imaging and therapy. The research is categorized as nanoparticles for drug delivery, imaging agents for cell tracking, and hydrogels for tissue engineering, which are rapidly advancing fields based on click chemistry. The content is based primarily on the experience with click chemistry-based biomaterials over the last 10 years.

The Applications of Metabolic Glycoengineering

Mammalian cell membranes are decorated by the glycocalyx, which offer versatile means of generating biochemical signals. By manipulating the set of glycans displayed on cell surface, it is vital for gaining insight into the cellular behavior modulation and medical and biotechnological adhibition. Although genetic engineering is proven to be an effective approach for cell surface modification, the technique is only suitable for natural and genetically encoded molecules. To circumvent these limitations, non-genetic approaches are developed for modifying cell surfaces with unnatural but functional groups. Here, we review latest development of metabolic glycoengineering (MGE), which enriches the chemical functions of the cell surface and is becoming an intriguing new tool for regenerative medicine and tissue engineering. Particular emphasis of this review is placed on discussing current applications and perspectives of MGE.

Recent Advances in Bioorthogonal Click Chemistry for Biomedical Applications

Bioorthogonal click chemistry, first introduced in the early 2000s, has become one of the most widely used approaches for designing advanced biomaterials for applications in tissue engineering and regenerative medicine, due to the selectivity and biocompatibility of the associated reactants and reaction conditions. In this review, we present recent advances in utilizing bioorthogonal click chemistry for the development of three-dimensional, biocompatible scaffolds and cell-encapsulated biomaterials. Additionally, we highlight recent examples using these approaches for biomedical applications including drug delivery, imaging, and cell therapy and discuss their potential as next generation biomaterials.

Characterization of Intrinsically Radiolabeled Poly(lactic-co-glycolic acid) Nanoparticles for ex Vivo Autologous Cell Labeling and in Vivo Tracking

With the advent of novel immunotherapies, interest in ex vivo autologous cell labeling for in vivo cell tracking has revived. However, current clinically available labeling strategies have several drawbacks, such as release of radiolabel over time and cytotoxicity. Poly(lactic-co-glycolic acid) nanoparticles (PLGA NPs) are clinically used biodegradable carriers of contrast agents, with high loading capacity for multimodal imaging agents. Here we show the development of PLGA-based NPs for ex vivo cell labeling and in vivo cell tracking with SPECT. We used primary amine-modified PLGA polymers (PLGA-NH2) to construct NPs similar to unmodified PLGA NPs. PLGA-NH2 NPs were efficiently radiolabeled without chelator and retained the radionuclide for 2 weeks. Monocyte-derived dendritic cells labeled with [111In]In-PLGA-NH2 showed higher specific activity than those labeled with [111In]In-oxine, with no negative effect on cell viability. SPECT/CT imaging showed that radiolabeled THP-1 cells accumulated at the Staphylococcus aureus infection site in mice. In conclusion, PLGA-NH2 NPs are able to retain 111In, independent of chelator presence. Furthermore, [111In]In-PLGA-NH2 allows cell labeling with high specific activity and no loss of activity over prolonged time intervals. Finally, in vivo tracking of ex vivo labeled THP-1 cells was demonstrated in an infection model using SPECT/CT imaging.