Impact of Sequence Specificity of Spherical Nucleic Acids on Macrophage Activation in Vitro and in Vivo

Gold nanoparticles modulate macrophage polarization to promote skeletal muscle regeneration

Skeletal muscle regeneration is a complex process that depends on the interplay between immune responses and muscle stem cell (MuSC) activity. Macrophages play a crucial role in this process, exhibiting distinct polarization states-M1 (pro-inflammatory) and M2 (anti-inflammatory)-that significantly affect tissue repair outcomes. Recent advancements in nanomedicine have positioned gold nanoparticles (Au NPs) as promising tools for modulating macrophage polarization and enhancing muscle regeneration. This review examines the role of Au NPs in influencing macrophage behavior, focusing on their physicochemical properties, biocompatibility, and mechanisms of action. We discuss how Au NPs can promote M2 polarization, facilitating tissue repair through modulation of cytokine production, interaction with cell surface receptors, and activation of intracellular signaling pathways. Additionally, we highlight the benefits of Au NPs on MuSC function, angiogenesis, and extracellular matrix remodeling. Despite the potential of Au NPs in skeletal muscle regeneration, challenges remain in optimizing nanoparticle design, developing targeted delivery systems, and understanding long-term effects. Future directions should focus on personalized medicine approaches and combination therapies to enhance therapeutic efficacy. Ultimately, this review emphasizes the transformative potential of Au NPs in regenerative medicine, offering hope for improved treatments for muscle injuries and diseases.

Poly-T-Modified Gold Nanorods Suppress Macrophage-Mediated Inflammation for Periodontitis Therapy

Traditional treatments for periodontitis are limited by their inability to adequately modulate the immune response and control inflammation. Recently, nucleic acid-modified nanomaterials have attracted significant attention for their potential in regulating inflammation. Among these, most nanomaterials, such as spherical nucleic acids, tend to exhibit pro-inflammatory effects. In this study, we identified for the first time that poly-T sequence-modified gold nanorods (PTM AuNRs) possess significant anti-inflammatory properties. The PTM AuNRs demonstrated excellent biocompatibility and efficacy in treating ligation-induced periodontitis. PTM AuNRs modulate immune responses by inhibiting the differentiation of pro-inflammatory M1 macrophages and reducing pro-inflammatory cytokine levels through promoting AMPK activation. When administered via local injection, PTM AuNRs effectively suppress inflammatory response and inflammatory cell infiltration, downregulate inflammatory cytokine levels, and mitigate collagen fiber degradation and alveolar bone loss. Together, these findings highlight PTM AuNRs as a promising and innovative therapeutic strategy for periodontitis management.

Nucleic Acid-Functionalized Gold Nanorods Modulate Inflammation and Dysregulated Intestinal Barriers for Treatment of Ulcerative Colitis

Traditional oral treatments for ulcerative colitis (UC) face marked limitations including their single therapeutic effect, potential off-target interactions, and toxic side effects. In this study, we present nucleic acid-functionalized gold nanorods (NAF AuNRs), a biocompatible nanomaterial designed for the oral treatment of dextran sulfate sodium (DSS)-induced colitis. The NAF AuNRs alleviate immune responses by inhibiting pro-inflammatory macrophages and enhancing the expression of barrier proteins in intestinal epithelial cells. Due to the negatively charged nucleic acid shell, NAF AuNRs preferentially target anionic, inflamed colon tissues upon oral administration, reducing pro-inflammatory cytokine levels and promoting the recovery of intestinal barrier in DSS-induced colitis mice. Collectively, these findings suggest that NAF AuNRs represent an innovative and promising therapeutic approach for UC management, offering novel insights into the application of nucleic acid-functionalized nanomaterials.

Recent advances in gene delivery nanoplatforms based on spherical nucleic acids

Gene therapy is a therapeutic option for mitigating diseases that do not respond well to pharmacological therapy. This type of therapy allows for correcting altered and defective genes by transferring nucleic acids to target cells. Notably, achieving a desirable outcome is possible by successfully delivering genetic materials into the cell. In-vivo gene transfer strategies use two major classes of vectors, namely viral and nonviral. Both of these systems have distinct pros and cons, and the choice of a delivery system depends on therapeutic objectives and other considerations. Safe and efficient gene transfer is the main feature of any delivery system. Spherical nucleic acids (SNAs) are nanotechnology-based gene delivery systems (i.e., non-viral vectors). They are three-dimensional structures consisting of a hollow or solid spherical core nanoparticle that is functionalized with a dense and highly organized layer of oligonucleotides. The unique structural features of SNAs confer them a high potency in internalization into various types of tissue and cells, a high stability against nucleases, and efficay in penetrating through various biological barriers (such as the skin, blood-brain barrier, and blood-tumor barrier). SNAs also show negligible toxicity and trigger minimal immune response reactions. During the last two decades, all these favorable physicochemical and biological attributes have made them attractive vehicles for drug and nucleic acid delivery. This article discusses the unique structural properties, types of SNAs, and also optimization mechanisms of SNAs. We also focus on recent advances in the synthesis of gene delivery nanoplatforms based on the SNAs.

Spherical nucleic acids-based nanoplatforms for tumor precision medicine and immunotherapy

Precise diagnosis and treatment of tumors currently still face considerable challenges due to the development of highly degreed heterogeneity in the dynamic evolution of tumors. With the rapid development of genomics, personalized diagnosis and treatment using specific genes may be a robust strategy to break through the bottleneck of traditional tumor treatment. Nevertheless, efficient in vivo gene delivery has been frequently hampered by the inherent defects of vectors and various biological barriers. Encouragingly, spherical nucleic acids (SNAs) with good modularity and programmability are excellent candidates capable of addressing traditional gene transfer-associated issues, which enables SNAs a precision nanoplatform with great potential for diverse biomedical applications. In this regard, there have been detailed reviews of SNA in drug delivery, gene regulation, and dermatology treatment. Still, to the best of our knowledge, there is no published systematic review summarizing the use of SNAs in oncology precision medicine and immunotherapy, which are considered new guidelines for oncology treatment. To this end, we summarized the notable advances in SNAs-based precision therapy and immunotherapy for tumors following a classification standard of different types of precise spatiotemporal control on active species by SNAs. Specifically, we focus on the structural diversity and programmability of SNAs. Finally, the challenges and possible solutions were discussed in the concluding remarks. This review will promote the rational design and development of SNAs for tumor-precise medicine and immunotherapy.

Small interfering RNA-based nanotherapeutics for treating skin-related diseases

INTRODUCTION

RNA interference (RNAi) has demonstrated great potential in treating skin-related diseases, as small interfering RNA (siRNA) can efficiently silence specific genes. The design of skin delivery systems for siRNA is important to protect the nucleic acid while facilitating both skin targeting and cellular ingestion. Entrapment of siRNA into nanocarriers can accomplish these aims, contributing to improved targeting, controlled release, and increased transfection.

AREAS COVERED

The siRNA-based nanotherapeutics for treating skin disorders are summarized. First, the mechanisms of RNAi are presented, followed by the introduction of challenges for skin therapy. Then, the different nanoparticle types used for siRNA skin delivery are described. Subsequently, we introduce the mechanisms of how nanoparticles enhance siRNA skin penetration. Finally, the current investigations associated with nanoparticulate siRNA application in skin disease management are reviewed.

EXPERT OPINION

The potential application of nanotherapeutic RNAi allows for a novel skin application strategy. Further clinical studies are required to confirm the findings in the cell-based or animal experiments. The capability of large-scale production and reproducibility of nanoparticle products are also critical for translation to commercialization. siRNA delivery by nanocarriers should be optimized to attain cutaneous targeting without the risk of toxicity.

Transferrin Aptamers Increase the In Vivo Blood-Brain Barrier Targeting of Protein Spherical Nucleic Acids

The systemic delivery of exogenous proteins to cells within the brain and central nervous system (CNS) is challenging due to the selective impermeability of the blood-brain barrier (BBB). Herein, we hypothesized that protein delivery to the brain could be improved via functionalization with DNA aptamers designed to bind transferrin (TfR) receptors present on the endothelial cells that line the BBB. Using β-galactosidase (β-Gal) as a model protein, we synthesized protein spherical nucleic acids (ProSNAs) comprised of β-Gal decorated with TfR aptamers (Transferrin-ProSNAs). The TfR aptamer motif significantly increases the accumulation of β-Gal in brain tissue in vivo following intravenous injection over both the native protein and ProSNAs containing nontargeting DNA sequences. Furthermore, the widespread distribution of β-Gal throughout the brain is only observed for Transferrin-ProSNAs. Together, this work shows that the SNA architecture can be used to selectively deliver protein cargo to the brain and CNS if the appropriate aptamer sequence is employed as the DNA shell. Moreover, this highlights the importance of DNA sequence design and provides a potential new avenue for designing highly targeted protein delivery systems by combining the power of DNA aptamers together with the SNA platform.

DNA-Liposome Hybrid Carriers for Triggered Cargo Release

The design of simple and versatile synthetic routes to accomplish triggered-release properties in carriers is of particular interest for drug delivery purposes. In this context, the programmability and adaptability of DNA nanoarchitectures in combination with liposomes have great potential to render biocompatible hybrid carriers for triggered cargo release. We present an approach to form a DNA mesh on large unilamellar liposomes incorporating a stimuli-responsive DNA building block. Upon incubation with a single-stranded DNA trigger sequence, a hairpin closes, and the DNA building block is allowed to self-contract. We demonstrate the actuation of this building block by single-molecule Förster resonance energy transfer (FRET), fluorescence recovery after photobleaching, and fluorescence quenching measurements. By triggering this process, we demonstrate the elevated release of the dye calcein from the DNA–liposome hybrid carriers. Interestingly, the incubation of the doxorubicin-laden active hybrid carrier with HEK293T cells suggests increased cytotoxicity relative to a control carrier without the triggered-release mechanism. In the future, the trigger could be provided by peritumoral nucleic acid sequences and lead to site-selective release of encapsulated chemotherapeutics.

Strategies in the delivery of Cas9 ribonucleoprotein for CRISPR/Cas9 genome editing

CRISPR/Cas9 genome editing has gained rapidly increasing attentions in recent years, however, the translation of this biotechnology into therapy has been hindered by efficient delivery of CRISPR/Cas9 materials into target cells. Direct delivery of CRISPR/Cas9 system as a ribonucleoprotein (RNP) complex consisting of Cas9 protein and single guide RNA (sgRNA) has emerged as a powerful and widespread method for genome editing due to its advantages of transient genome editing and reduced off-target effects. In this review, we summarized the current Cas9 RNP delivery systems including physical approaches and synthetic carriers. The mechanisms and beneficial roles of these strategies in intracellular Cas9 RNP delivery were reviewed. Examples in the development of stimuli-responsive and targeted carriers for RNP delivery are highlighted. Finally, the challenges of current Cas9 RNP delivery systems and perspectives in rational design of next generation materials for this promising field will be discussed.

DNA Nanostructures and DNA-Functionalized Nanoparticles for Cancer Theranostics

In the last two decades, DNA has attracted significant attention toward the development of materials at the nanoscale for emerging applications due to the unparalleled versatility and programmability of DNA building blocks. DNA-based artificial nanomaterials can be broadly classified into two categories: DNA nanostructures (DNA-NSs) and DNA-functionalized nanoparticles (DNA-NPs). More importantly, their use in nanotheranostics, a field that combines diagnostics with therapy via drug or gene delivery in an all-in-one platform, has been applied extensively in recent years to provide personalized cancer treatments. Conveniently, the ease of attachment of both imaging and therapeutic moieties to DNA-NSs or DNA-NPs enables high biostability, biocompatibility, and drug loading capabilities, and as a consequence, has markedly catalyzed the rapid growth of this field. This review aims to provide an overview of the recent progress of DNA-NSs and DNA-NPs as theranostic agents, the use of DNA-NSs and DNA-NPs as gene and drug delivery platforms, and a perspective on their clinical translation in the realm of oncology.

Metal-derived nanoparticles in tumor theranostics: Potential and limitations

Initially, metal derived nanoparticles have been used exclusively as contrasting agents in magnetic resonance imaging. Today, green routes of chemical synthesis together with numerous modifications of the core and surface gave rise to a plethora of biomedical applications of metal derived nanoparticles including tumor imaging, diagnostics, and therapy. These materials are an emerging class of tools for tumor theranostics. Nevertheless, the spectrum of clinically approved metal nanoparticles remains narrow, as the safety, specificity and efficiency still have to be improved. In this review we summarize the major directions for development and biomedical applications of metal based nanoparticles and analyze their effects on tumor cells and microenvironment. We discuss the advantages and possible limitations of metal nanoparticle-based tumor theranostics, as well as the potential strategies to improve the in vivo performance of these unique materials.