Light responsive nucleic acid for biomedical application

Robust Photocleavable Linkers for DNA Synthesis: Enabling Visible Light-Triggered Antisense Oligonucleotide Release in 3D DNA Nanocages

We synthesized new para-dialkylaminonitrobiphenyl (ANBP) derivatives, s-ANBP and t-ANBP, functionalized with dimethyltrityl and phosphoramidite groups for incorporation into DNA backbones as photocleavable linkers via solid-phase synthesis. Both derivatives exhibited excellent chemical stability under diverse conditions, including acidic, alkaline, and high-salt environments and elevated temperatures. Their incorporation into DNA influenced duplex stability and antisense oligonucleotide (ASO) dissociation efficiency, depending on the number of ANBP units and adjacent nucleotide deletions. The s-/t-ANBP-conjugated DNA showed efficient one-photon photolysis at 415 nm and enhanced two-photon absorption for extended π-system in t-ANBP, with δuΦu values of 1.6 GM (740 nm) and 2.7 GM (800 nm). ANBP-conjugated DNA was used to construct a 3D DNA nanocage capable of light-triggered ASO 4625 release, validated by an in vitro RNA digestion assay, confirming antisense functionality. This platform demonstrates precise, light-mediated therapeutic delivery and offers potential for broader applications in drug delivery and clinical use.

Enhancing photodynamic and radionuclide therapy by small interfering RNA (siRNA)-RAD51 transfection via self-emulsifying delivery systems (SNEDDS)

BACKGROUND AIMS

Gene-silencing by small interfering RNA (siRNA) is an attractive therapy to regulate cancer death, tumor recurrence or metastasis. Because siRNAs are easily degraded, it is necessary to develop transport and delivery systems to achieve efficient tumor targeting. Self-nanoemulsifying systems (SNEDDS) have been successfully used for pDNA transport and delivery, so they may be useful for siRNA. The aim of this work is to introduce siRNA-RAD51 into a SNEDDS prepared with Phospholipon-90G, Labrafil-M1944-CS and Cremophor-RH40 and evaluate its efficacy in preventing homologous recombination of DNA double-strand breaks caused by photodynamic therapy (PDT) and ionizing radiation (IR).

METHODS

The siRNA-RAD51 was loaded into SNEDDS using chitosan. Transfection capacity was estimated by comparison with Lipofectamine-2000.

RESULTS

SNEDDS(siRNA-RAD51) induced gene silencing effect on the therapies evaluated by cell viability and clonogenic assays using T47D breast cancer cells.

CONCLUSIONS

SNEDDS(siRNA-RAD51) shown to be an effective siRNA-delivery system to decrease cellular resistance in PDT or IR.

Molecular Programming Design of Glyconucleic Acid Aptamer with High Stability

Functional nucleic acids (FNAs), possessing specific biological functions beyond their informational roles, have gained widespread attention in disease therapeutics. However, their clinical application is severely limited by their low serum stability in complex physiological environments. In this work, a precise molecular programming strategy is explored to prepare glyconucleic acid aptamers (GNAAs) with high serum stability. Four glyconucleic acid modules compatible with commercial solid-phase synthesis are designed and synthesized. Through precise molecular design, the accurate modification of four different carbohydrate ligands at specific sites of DNA aptamers is achieved. It is demonstrated that glycosylation modification can significantly increase DNA aptamers' serum stability while maintaining their structures and high affinity. The stabilization effect is superior to that of currently commonly used commercial chemical modifications. Moreover, it is confirmed that this approach displays insignificant effects on the DNA aptamers' tumor-targeting ability and metabolism in vivo. This method offers a simple, economical, and efficient strategy for precise glycosylation modification of nucleic acids. This allows to prepare glycosyl functional nucleic acids with high serum stability, which can expand the application scope of functional nucleic acids and promote the practical transformation of functional nucleic acids.

Prevent and Reverse Metabolic Dysfunction-Associated Steatohepatitis and Hepatic Fibrosis via mRNA-Mediated Liver-Specific Antibody Therapy

Chronic exposure of the liver to multiple insults culminates in the development of metabolic dysfunction-associated steatohepatitis (MASH), a complicated metabolic syndrome characterized by hepatic steatosis and inflammation, typically accompanied by progressive fibrosis. Despite extensive clinical evaluation, there remain challenges in MASH drug development, which are primarily due to unsatisfactory efficacy and limited specificity. Strategies to address the unmet medical need for MASH with fibrosis before it reaches the irreversible stage of decompensated cirrhosis are critically needed. Herein, we developed an mRNA-mediated liver-specific antibody therapy for MASH and hepatic fibrosis using a targeted lipid nanoparticle (LNP) delivery system. When encapsulated with IL-11 single-chain variable fragment (scFv)-encoded mRNA, the targeted AA3G LNP (termed mIL11-scFv@AA3G) specifically accumulated in the liver and secreted IL-11 scFv to neutralize overexpressed IL-11 in hepatic environments, thus inhibiting the IL-11 signaling pathway in hepatocytes and hepatic stellate cells. As a preventative regimen, systemic administration of mIL11-scFv@AA3G reversed MASH and prevented the progression to fibrosis in a murine model of early MASH. Notably, mIL11-scFv@AA3G exhibited superior efficacy compared to systemic administration of IL-11 scFv alone, attributed to the sustained antibody expression in the liver, which lasted 18-fold longer than that of IL-11 scFv. When tested in the MASH model with fibrosis, mIL11-scFv@AA3G effectively ameliorated steatosis and resolved fibrosis and inflammation. These findings present a versatile LNP platform targeting liver cell subtypes for the sustained expression of therapeutic antibodies to treat MASH and fibrosis. The developed mRNA-mediated liver-specific antibody therapy offers a promising approach for addressing MASH and holds the potential for expansion to various other diseases.

AI-empowered visualization of nucleic acid testing

AIMS

The visualization of nucleic acid testing (NAT) results plays a critical role in diagnosing and monitoring infectious and genetic diseases. The review aims to review the current status of AI-based NAT result visualization. It systematically introduces commonly used AI-based methods and techniques for NAT, emphasizing the importance of result visualization for accessible, clear, and rapid interpretation. This highlights the importance of developing a NAT visualization platform that is user-friendly and efficient, setting a clear direction for future advancements in making nucleic acid testing more accessible and effective for everyday applications.

METHOD

This review explores both the commonly used NAT methods and AI-based techniques for NAT result visualization. The focus then shifts to AI-based methodologies, such as color detection and result interpretation through AI algorithms. The article presents the advantages and disadvantages of these techniques, while also comparing the performance of various NAT platforms in different experimental contexts. Furthermore, it explores the role of AI in enhancing the accuracy, speed, and user accessibility of NAT results, highlighting visualization technologies adapted from other fields of experimentation.

SIGNIFICANCE

This review offers valuable insights for researchers and everyday users, aiming to develop effective visualization platforms for NAT, ultimately enhancing disease diagnosis and monitoring.

Sulfur-tetrazine as highly efficient visible-light activatable photo-trigger for designing photoactivatable fluorescence biomolecules

Light-activated fluorescence represents a potent tool for investigating subcellular structures and dynamics, offering enhanced control over the temporal and spatial aspects of the fluorescence signal. While alkyl-substituted tetrazine has previously been reported as a photo-trigger for various fluorophore scaffolds, its limited photochemical efficiency and high activation energy have constrained its widespread application at the biomolecular level. In this study, we demonstrate that a single sulfur atom substitution of tetrazine greatly enhances the photochemical properties of tetrazine conjugates and significantly improves their photocleavage efficiency. Notably, the resulting sulfur-tetrazine can be activated using a lower-energy light source, thus transforming it into a valuable visible-light photo-trigger. To introduce this photo-trigger into biological systems, we have developed a series of visible-light activatable small molecular dyes, along with a photoactivatable noncanonical amino acid containing sulfur-tetrazine. Using the Genetic Code Expansion technology, this novel amino acid is genetically incorporated into fluorescent protein molecules, serving as a phototrigger to create an innovative photoactivatable protein. These advancements in tetrazine-scaffold photo-trigger design open up new avenues for generating photoactivatable biomolecules, promising to greatly facilitate the exploration of biological functions and structures.

Deformable nanocarriers for enhanced drug delivery and cancer therapy

Recently, the field of nanomedicine has witnessed substantial advancements in the development of nanocarriers for targeted drug delivery, emerges as promising platforms to enhance therapeutic efficacy and minimize adverse effects associated with conventional chemotherapy. Notably, deformable nanocarriers have garnered considerable attention due to their unique capabilities of size changeable, tumor-specific aggregation, stimuli-triggered disintegration, and morphological transformations. These deformable nanocarriers present significant opportunities for revolutionizing drug delivery strategies, by responding to specific stimuli or environmental cues, enabling achieved various functions at the tumor site, including size-shrinkage nanocarriers enhance drug penetration, aggregative nanocarriers enhance retention effect, disintegrating nanocarriers enable controlled drug release, and shape-changing nanocarriers improve cellular uptake, allowing for personalized treatment approaches and combination therapies. This review provides an overview of recent developments and applications of deformable nanocarriers for enhancing tumor therapy, underscores the diverse design strategies employed to create deformable nanocarriers and elucidates their remarkable potential in targeted tumor therapy.

Nano revolution of DNA nanostructures redefining cancer therapeutics-A comprehensive review

DNA nanostructures are a promising tool in cancer treatment, offering an innovative way to improve the effectiveness of therapies. These nanostructures can be made solely from DNA or combined with other materials to overcome the limitations of traditional single-drug treatments. There is growing interest in developing nanosystems capable of delivering multiple drugs simultaneously, addressing challenges such as drug resistance. Engineered DNA nanostructures are designed to precisely deliver different drugs to specific locations, enhancing therapeutic effects. By attaching targeting molecules, these nanostructures can recognize and bind to cancer cells, increasing treatment precision. This approach offers tailored solutions for targeted drug delivery, enabling the delivery of multiple drugs in a coordinated manner. This review explores the advancements and applications of DNA nanostructures in cancer treatment, with a focus on targeted drug delivery and multi-drug therapy. It discusses the benefits and current limitations of nanoscale formulations in cancer therapy, categorizing DNA nanostructures into pure forms and hybrid versions optimized for drug delivery. Furthermore, the review examines ongoing research efforts and translational possibilities, along with challenges in clinical integration. By highlighting the advancements in DNA nanostructures, this review aims to underscore their potential in improving cancer treatment outcomes.

Microfluidic-based cardiovascular systems for advanced study of atherosclerosis

Atherosclerosis (AS) is a significant global health concern due to its high morbidity and mortality rates. Extensive efforts have been made to replicate the cardiovascular system and explore the pathogenesis, diagnosis, and treatment of AS. Microfluidics has emerged as a valuable technology for modeling the cardiovascular system and studying AS. Here a brief review of the advances of microfluidic-based cardiovascular systems for AS research is presented. The critical pathogenetic mechanisms of AS investigated by microfluidic-based cardiovascular systems are categorized and reviewed, with a detailed summary of accurate diagnostic methods for detecting biomarkers using microfluidics represented. Furthermore, the review covers the evaluation and screening of AS drugs assisted by microfluidic systems, along with the fabrication of novel drug delivery carriers. Finally, the challenges and future prospects for advancing microfluidic-based cardiovascular systems in AS research are discussed and proposed, particularly regarding new opportunities in multi-disciplinary fundamental research and therapeutic applications for a broader range of disease treatments.

Spatiotemporal-Controlled NIR-II Immune Agonist Sensitizes Cancer Immunotherapy

The integration of nanomedicine and immunotherapy has presented a promising opportunity for the treatment of cancer and diverse diseases. However, achieving spatiotemporal controllable immunotherapy with excellent efficacy and safety performances remains a significant challenge. This study develops a biodegradable near-infrared II (NIR-II) photothermal response polymer nanoparticle (PTEQ) system. This platform exhibits intrinsic immunostimulatory properties while concurrently delivering siRNA for Programmed Death-Ligand 1 (siPD-L1), leveraging enhanced immune responses and immune checkpoint blockade for safe and effective cancer therapy. In the CT26 tumor-bearing mouse model, PTEQ, as an immune stimulant, significantly boosts the infiltration of CD4+ and CD8+ T cells within the tumor microenvironment (TME). The PTEQ/siPD-L1+laser group not only initiates NIR-II photothermal therapy but also promotes the activation and infiltration of T cells, M1 macrophage polarization, and maturation of dendritic cells in the TME, resulting in the complete elimination of tumors in 7/10 cases, achieving a 100% survival rate. In another in vivo vaccine experiment, all tumors on the right side are completely eliminated in the PTEQ/siPD-L1+laser group, reaching a 100% tumor eradication rate. These findings underscore the potential of this strategy to overcome the current immunotherapeutic limitations and achieve immune therapy normalization.

Light Responsive DNA Nanomaterials and Their Biomedical Applications

DNA nanomaterials have been widely employed for various biomedical applications. With rapid development of chemical modification of nucleic acid, serials of stimuli-responsive elements are included in the multifunctional DNA nanomaterials. In this review, we summarize the recent advances in light responsive DNA nanomaterials based on photocleavage/photodecage, photoisomerization, and photocrosslinking for efficient bioimaging (including imaging of small molecule, microRNA, and protein) and drug delivery (including delivery of small molecule, nucleic acid, and gene editing system). We also discuss the remaining challenges and future perspectives of the light responsive DNA nanomaterials in biomedical applications.

Photochromic Nucleosides and Oligonucleotides

Photochromism is a reversible phenomenon wherein a material undergoes a change in color upon exposure to light. In organic photochromes, this effect often results from light-induced isomerization reactions, leading to alterations in either the spatial orientation or electronic properties of the photochrome. The incorporation of photochromic moieties into biomolecules, such as proteins or nucleic acids, has become a prevalent approach to render these biomolecules responsive to light stimuli. Utilizing light as a trigger for the manipulation of biomolecular structure and function offers numerous advantages compared to other stimuli, such as chemical or electrical treatments, due to its non-invasive nature. Consequently, light proves particularly advantageous in cellular and tissue applications. In this review, we emphasize recent advancements in the field of photochromic nucleosides and oligonucleotides. We provide an overview of the design principles of different classes of photochromes, synthetic strategies, critical analytical challenges, as well as structure-property relationships. The applications of photochromic nucleic acid derivatives encompass diverse domains, ranging from the precise photoregulation of gene expression to the controlled modulation of the three-dimensional structures of oligonucleotides and the development of DNA-based fluorescence modulators. Moreover, we present a future perspective on potential modifications and applications.

Structural DNA nanotechnology at the nexus of next-generation bio-applications: challenges and perspectives

DNA nanotechnology has significantly progressed in the last four decades, creating nucleic acid structures widely used in various biological applications. The structural flexibility, programmability, and multiform customization of DNA-based nanostructures make them ideal for creating structures of all sizes and shapes and multivalent drug delivery systems. Since then, DNA nanotechnology has advanced significantly, and numerous DNA nanostructures have been used in biology and other scientific disciplines. Despite the progress made in DNA nanotechnology, challenges still need to be addressed before DNA nanostructures can be widely used in biological interfaces. We can open the door for upcoming uses of DNA nanoparticles by tackling these issues and looking into new avenues. The historical development of various DNA nanomaterials has been thoroughly examined in this review, along with the underlying theoretical underpinnings, a summary of their applications in various fields, and an examination of the current roadblocks and potential future directions.

Nano-bio interactions in mRNA nanomedicine: Challenges and opportunities for targeted mRNA delivery

Upon entering the biological milieu, nanomedicines swiftly interact with the surrounding tissue fluid, subsequently being enveloped by a dynamic interplay of biomacromolecules, such as carbohydrates, nucleic acids, and cellular metabolites, but with predominant serum proteins within the biological corona. A notable consequence of the protein corona phenomenon is the unintentional loss of targeting ligands initially designed to direct nanomedicines toward particular cells or organs within the in vivo environment. mRNA nanomedicine displays high demand for specific cell and tissue-targeted delivery to effectively transport mRNA molecules into target cells, where they can exert their therapeutic effects with utmost efficacy. In this review, focusing on the delivery systems and tissue-specific applications, we aim to update the nanomedicine population with the prevailing and still enigmatic paradigm of nano-bio interactions, a formidable hurdle in the pursuit of targeted mRNA delivery. We also elucidate the current impediments faced in mRNA therapeutics and, by contemplating prospective avenues-either to modulate the corona or to adopt an 'ally from adversary' approach-aim to chart a course for advancing mRNA nanomedicine.

A Mitochondrial Nanoguard Modulates Redox Homeostasis and Bioenergy Metabolism in Diabetic Peripheral Neuropathy

As a major late complication of diabetes, diabetic peripheral neuropathy (DPN) is the primary reason for amputation. Nevertheless, there are no wonder drugs available. Regulating dysfunctional mitochondria is a key therapeutic target for DPN. Resveratrol (RSV) is widely proven to guard mitochondria, yet the unsatisfactory bioavailability restricts its clinical application. Tetrahedral framework nucleic acids (tFNAs) are promising carriers due to their excellent cell entrance efficiency, biological safety, and structure editability. Here, RSV was intercalated into tFNAs to form the tFNAs-RSV complexes. tFNAs-RSV achieved enhanced stability, bioavailability, and biocompatibility compared with tFNAs and RSV alone. With its treatment, reactive oxygen species (ROS) production was minimized and reductases were activated in an in vitro model of DPN. Besides, respiratory function and adenosine triphosphate (ATP) production were enhanced. tFNAs-RSV also exhibited favorable therapeutic effects on sensory dysfunction, neurovascular deterioration, demyelination, and neuroapoptosis in DPN mice. Metabolomics analysis revealed that redox regulation and energy metabolism were two principal mechanisms that were impacted during the process. Comprehensive inspections indicated that tFNAs-RSV inhibited nitrosation and oxidation and activated reductase and respiratory chain. In sum, tFNAs-RSV served as a mitochondrial nanoguard (mito-guard), representing a viable drilling target for clinical drug development of DPN.

Up-to-date molecular medicine strategies for management of ocular surface neovascularization

Ocular surface neovascularization and its resulting pathological changes significantly alter corneal refraction and obstruct the light path to the retina, and hence is a major cause of vision loss. Various factors such as infection, irritation, trauma, dry eye, and ocular surface surgery trigger neovascularization via angiogenesis and lymphangiogenesis dependent on VEGF-related and alternative mechanisms. Recent advances in antiangiogenic drugs, nanotechnology, gene therapy, surgical equipment and techniques, animal models, and drug delivery strategies have provided a range of novel therapeutic options for the treatment of ocular surface neovascularization. In this review article, we comprehensively discuss the etiology and mechanisms of corneal neovascularization and other types of ocular surface neovascularization, as well as emerging animal models and drug delivery strategies that facilitate its management.

Three Compartment Liposome Fusion: Functional Protocells for Biocatalytic Cascades and Operation of Dynamic DNA Machineries

Nucleic acid‐functionalized liposomes modified at their boundaries with o‐nitrobenzyl phosphate‐caged hairpin units and pH‐responsive C‐G·C+ triplex forming strands are used for the concomitant light and pH‐triggered fusion of three types of loaded liposomes. The fusion processes are followed by light‐scattering size enlargement measurements, optical methods, and biocatalytic cascades activated upon the mixing of the liposomes loaded with enzymes and their substrates and their fusion into the cell‐like containments. The fused liposomes act as functional protocells for the integration of biocatalytic machineries. This is exemplified by the operation of an autonomous polymerization/nickase machinery synthesizing a Mg2+‐ion‐dependent DNAzyme and of a transcription machinery yielding the Malachite Green‐RNA aptamer product.

Photocleavable Ortho-Nitrobenzyl-Protected DNA Architectures and Their Applications

This review article introduces mechanistic aspects and applications of photochemically deprotected ortho-nitrobenzyl (ONB)-functionalized nucleic acids and their impact on diverse research fields including DNA nanotechnology and materials chemistry, biological chemistry, and systems chemistry. Specific topics addressed include the synthesis of the ONB-modified nucleic acids, the mechanisms involved in the photochemical deprotection of the ONB units, and the photophysical and chemical means to tune the irradiation wavelength required for the photodeprotection process. Principles to activate ONB-caged nanostructures, ONB-protected DNAzymes and aptamer frameworks are introduced. Specifically, the use of ONB-protected nucleic acids for the phototriggered spatiotemporal amplified sensing and imaging of intracellular mRNAs at the single-cell level are addressed, and control over transcription machineries, protein translation and spatiotemporal silencing of gene expression by ONB-deprotected nucleic acids are demonstrated. In addition, photodeprotection of ONB-modified nucleic acids finds important applications in controlling material properties and functions. These are introduced by the phototriggered fusion of ONB nucleic acid functionalized liposomes as models for cell-cell fusion, the light-stimulated fusion of ONB nucleic acid functionalized drug-loaded liposomes with cells for therapeutic applications, and the photolithographic patterning of ONB nucleic acid-modified interfaces. Particularly, the photolithographic control of the stiffness of membrane-like interfaces for the guided patterned growth of cells is realized. Moreover, ONB-functionalized microcapsules act as light-responsive carriers for the controlled release of drugs, and ONB-modified DNA origami frameworks act as mechanical devices or stimuli-responsive containments for the operation of DNA machineries such as the CRISPR-Cas9 system. The future challenges and potential applications of photoprotected DNA structures are discussed.

CRISPR/Cas9 and Chlorophyll Coordination Micelles for Cancer Treatment by Genome Editing and Photodynamic Therapy

CRISPR/Cas9-based gene therapy and photodynamic therapy both show promise for cancer treatment but still have their drawbacks limited by tumor microenvironment and long treatment duration. Herein, CRISPR/Cas9 genome editing and photodynamic strategy for a synergistic anti-tumor therapeutic modality is merged. Chlorophyll (Chl) extracted from natural green vegetables is encapsulated in Pluronic F127 (F127) micelles and Histidine-tagged Cas9 can be effectively chelated onto micelles via metal coordination by simple incubation, affording Cas9-Chl@F127 micelles. Mg²⁺ acts as an enzyme cofactor to correlatively enhance Cas9 gene-editing activity. Upon laser irradiation, Chl as an effective photosensitizer generates reactive oxygen species (ROS) to kill tumor cells. Meanwhile, CRISPR/Cas9, mediated by dual deliberately designed gRNAs of APE1 and NRF2, can reprogram the tumor microenvironment by increasing the intracellular oxygen accumulation and impairing the oxidative defense system of tumor cells. Cas9-Chl@F127 micelles can responsively release Cas9 in the presence of abundant ATP or low pH in tumor cells. In a murine tumor model, Cas9-Chl@F127 complexed with dual gRNAs including APE1 and NRF2 significantly inhibits the tumor growth. Taken together, Cas9-Chl@F127 micelles, representing the first Chl-based green biomaterial for the delivery of Cas9, show great promise for the synergistic anti-tumor treatment by PDT and gene editing.

Nucleic acid drug vectors for diagnosis and treatment of brain diseases

Nucleic acid drugs have the advantages of rich target selection, simple in design, good and enduring effect. They have been demonstrated to have irreplaceable superiority in brain disease treatment, while vectors are a decisive factor in therapeutic efficacy. Strict physiological barriers, such as degradation and clearance in circulation, blood-brain barrier, cellular uptake, endosome/lysosome barriers, release, obstruct the delivery of nucleic acid drugs to the brain by the vectors. Nucleic acid drugs against a single target are inefficient in treating brain diseases of complex pathogenesis. Differences between individual patients lead to severe uncertainties in brain disease treatment with nucleic acid drugs. In this Review, we briefly summarize the classification of nucleic acid drugs. Next, we discuss physiological barriers during drug delivery and universal coping strategies and introduce the application methods of these universal strategies to nucleic acid drug vectors. Subsequently, we explore nucleic acid drug-based multidrug regimens for the combination treatment of brain diseases and the construction of the corresponding vectors. In the following, we address the feasibility of patient stratification and personalized therapy through diagnostic information from medical imaging and the manner of introducing contrast agents into vectors. Finally, we take a perspective on the future feasibility and remaining challenges of vector-based integrated diagnosis and gene therapy for brain diseases.

Recent Advances in Light-Controlled Activation of Pt(IV) Prodrugs

Pt(IV) prodrugs remain one of the most promising alternatives to conventional Pt(II) therapy due to their versatility in axial ligand choice and delayed mode of action. Selective activation from an external source is especially attractive due to the opportunity to control the activity of an antitumor drug in space and time and avoid damage to normal tissues. In this review, we discuss recent advances in photoabsorber-mediated photocontrollable activation of Pt(IV) prodrugs. Two main approaches developed are the focus of the review. The first one is the photocatalytic strategy based on the flavin derivatives that are not covalently bound to the Pt(IV) substrate. The second one is the conjugation of photoactive molecules with the Pt(II) drug via axial position, yielding dual-action Pt(IV) molecules capable of the controllable release of Pt(II) cytotoxic agents. Thus, Pt(IV) prodrugs with a light-controlled mode of activation are non-toxic in the absence of light, but show high antiproliferative activity when irradiated. The susceptibility of Pt(IV) prodrugs to photoreduction, photoactivation mechanisms, and biological activity is considered in this review.

Photocontrolled Spatiotemporal Delivery of DNA Immunomodulators for Enhancing Membrane-Targeted Tumor Photodynamic Immunotherapy

Immunotherapy is emerging as a paradigm-shifting modality for treatment cancer. However, systemic administration of immunomodulators is usually accompanied by extra-tumor toxicity and adverse immune effects. Precise delivery of immunomodulators with a highly controllable system may provide a solution for this issue. Here, we developed a photocontrolled DNA nanomedicine for localized delivery of DNA immunomodulators to enhance membrane-targeted photodynamic immunotherapy. Specifically, the DNA nanomedicine is composed of long tandemly repeated functional DNA sequences (PDL1 aptamers and CpG) with a photosensitizer (TMPyP₄) inserted into the DNA structure, providing high drug-loading capacity. By blocking the surface PDL1 aptamer with a pHLIP-modified cDNA, the DNA nanomedicine does not induce any obvious immune response and can be specifically delivered and anchored to the tumor membrane. Under localized irradiation, photodynamically generated reactive oxygen species (ROS) causes breakage of DNA sequences, which triggers the collapse of the nanostructure and release of internal DNA immunomodulators. Under localized illumination, photodynamically generated ROS can cause DNA sequence breaks, triggering the collapse of nanostructures and the release of internal DNA immunomodulators thus enhancing membrane-targeted photodynamic immunotherapy. We have demonstrated that the developed DNA nanomedicine can drive efficient immune responses in tumor tissue without perceptibly interfering off-tumor immunity, resulting in efficient antitumor treatment while mitigating systemic toxicity.

Nucleus-specific RNAi nanoplatform for targeted regulation of nuclear lncRNA function and effective cancer therapy

In the context of cancer therapy, a recently identified therapeutic target is represented by the essential subtype of RNA transcripts - the long noncoding RNAs (lncRNA). While this is the case, it is especially difficult to successfully regulate the expression of this subtype in vivo, particularly due to the protection granted by the nuclear envelope of nuclear lncRNAs. This study documents the development of a nucleus-specific RNA interference (RNAi) nanoparticle (NP) platform for the targeted regulation of the nuclear lncRNA function, in order to effectuate successful cancer therapy. An NTPA (nucleus-targeting peptide amphiphile) and an endosomal pH-responsive polymer make up the novel RNAi nanoplatform in development, which is capable of complexing siRNA. The nanoplatform is capable of accumulating greatly in the tumor tissues and being internalized by tumor cells, following intravenous administration. The exposed complexes of the NTPA/siRNA may conveniently escape from the endosome with the pH-triggered NP disassociation, following which it can target the nucleus by specifically interacting with the importin α/β heterodimer. In orthotopic and subcutaneous xenograft tumor models, this would result in a notable suppression of the expression of nuclear lncNEAT2 as well as greatly impede the growth of tumors in liver cancer.

Conscription of Immune Cells by Light-Activatable Silencing NK-Derived Exosome (LASNEO) for Synergetic Tumor Eradication

Exosomes derived from natural killer (NK) cells (NEO) constitute promising antineoplastic nano-biologics because of their versatile functions in immune regulation. However, a significant augment of their immunomodulatory capability is an essential need to achieve clinically meaningful treatment outcomes. Light-activatable silencing NK-derived exosomes (LASNEO) are orchestrated by engineering the NEO with hydrophilic small interfering RNA (siRNA) and hydrophobic photosensitizer Ce6. Profiling of genes involved in apoptosis pathway with Western blot and RNA-seq in cells receiving NEO treatment reveals that NEO elicits effective NK cell-like cytotoxicity toward tumor cells. Meanwhile, reactive oxygen species (ROS) generation upon laser irradiation not only triggers substantial photodynamic therapy effect but also boosts M1 tumor-associated macrophages polarization and DC maturation in the tumor microenvironment (TME). In addition, ROS also accelerates the cellular entry and endosomal escape of siRNA in TME. Finally, siRNAs targeting PLK1 or PD-L1 induce robust gene silencing in cancer cells, and downregulation of PD-L1 restores the immunological surveillance of T cells in TME. Therefore, the proposed LASNEO exhibit excellent antitumor effects by conscripting multiple types of immune cells. Considering that its manufacture is quite simple and controllable, LASNEO show compelling potential for clinical translational application.