Synthetic multi-layer nanoparticles for CRISPR-Cas9 genome editing

Polymeric micellar nanoparticles for effective CRISPR/Cas9 genome editing in cancer

The clustered regularly interspaced short palindromic repeat (CRISPR)-associated protein 9 (Cas9) gene editing has attracted extensive attentions in various fields, however, its clinical application is hindered by the lack of effective and safe delivery system. Herein, we reported a cationic micelle nanoparticle composed of cholesterol-modified branched small molecular PEI (PEI-CHO) and biodegradable PEG-b-polycarbonate block copolymer (PEG-PC), denoted as PEG-PC/PEI-CHO/pCas9, for the CRISPR/Cas9 delivery to realize genomic editing in cancer. Specifically, PEI-CHO condensed pCas9 into nanocomplexes, which were further encapsulated into PEG-PC nanoparticles (PEG-PC/PEI-CHO/pCas9). PEG-PC/PEI-CHO/pCas9 had a PEG shell, protecting DNA from degradation by nucleases. Enhanced cellular uptake of PEG-PC/PEI-CHO/pCas9 nanoparticles was observed as compared to that mediated by Lipo2k/pCas9 nanoparticles, thus leading to significantly elevated transfection efficiency after escaping from endosomes via the proton sponge effect of PEI. In addition, the presence of PEG shell greatly improved biocompatibility, and significantly enhanced the in vivo tumor retention of pCas9 compared to PEI-CHO/pCas9. Notably, apparent downregulation of GFP expression could be achieved both in vitro and in vivo by using PEG-PC/PEI-CHO/pCas9-sgGFP nanoparticles. Furthermore, PEG-PC/PEI-CHO/pCas9-sgMcl1 induced effective apoptosis and tumor suppression in a HeLa tumor xenograft mouse model by downregulating Mcl1 expression. This work may provide an alternative paradigm for the efficient and safe genome editing in cancer.

Nanoparticles for efficient drug delivery and drug resistance in glioma: New perspectives

Gliomas are the most common primary tumors of the central nervous system, with glioblastoma multiforme (GBM) having the highest incidence, and their therapeutic efficacy depends primarily on the extent of surgical resection and the efficacy of postoperative chemotherapy. The role of the intracranial blood-brain barrier and the occurrence of the drug-resistant gene O6-methylguanine-DNA methyltransferase have greatly limited the efficacy of chemotherapeutic agents in patients with GBM and made it difficult to achieve the expected clinical response. In recent years, the rapid development of nanotechnology has brought new hope for the treatment of tumors. Nanoparticles (NPs) have shown great potential in tumor therapy due to their unique properties such as light, heat, electromagnetic effects, and passive targeting. Furthermore, NPs can effectively load chemotherapeutic drugs, significantly reduce the side effects of chemotherapeutic drugs, and improve chemotherapeutic efficacy, showing great potential in the chemotherapy of glioma. In this article, we reviewed the mechanisms of glioma drug resistance, the physicochemical properties of NPs, and recent advances in NPs in glioma chemotherapy resistance. We aimed to provide new perspectives on the clinical treatment of glioma.

Biomaterial-Based CRISPR/Cas9 Delivery Systems for Tumor Treatment

CRISPR/Cas9 gene editing technology is characterized by high specificity and efficiency, and has been applied to the treatment of human diseases, especially tumors involving multiple genetic modifications. However, the clinical application of CRISPR/Cas9 still faces some major challenges, the most urgent of which is the development of optimized delivery vectors. Biomaterials are currently the best choice for use in CRISPR/Cas9 delivery vectors owing to their tunability, biocompatibility, and efficiency. As research on biomaterial vectors continues to progress, hope for the application of the CRISPR/Cas9 system for clinical oncology therapy builds. In this review, we first detail the CRISPR/Cas9 system and its potential applications in tumor therapy. Then, we introduce the different delivery forms and compare the physical, viral, and non-viral vectors. In addition, we analyze the characteristics of different types of biomaterial vectors. We further review recent research progress in the use of biomaterials as vectors for CRISPR/Cas9 delivery to treat specific tumors. Finally, we summarize the shortcomings and prospects of biomaterial-based CRISPR/Cas9 delivery systems.

Research Progress on the Correlation between Acetaldehyde Dehydrogenase 2 and Hepatocellular Carcinoma Development

Hepatocellular carcinoma (HCC) is the predominant pathologic type of primary liver cancer. It is a malignant tumor of liver epithelial cells. There are many ways to treat HCC, but the survival rate for HCC patients remains low. Therefore, understanding the underlying mechanisms by which HCC occurs and develops is critical to explore new therapeutic targets. Aldehyde dehydrogenase 2 (ALDH2) is an important player in the redox reaction of ethanol with endogenous aldehyde products released by lipid peroxidation. Increasing evidence suggests that ALDH2 is a crucial regulator of human tumor development, including HCC. Therefore, clarifying the relationship between ALDH2 and HCC is helpful for formulating rational treatment strategies. This review highlights the regulatory roles of ALDH2 in the development of HCC, elucidates the multiple potential mechanisms by which ALDH2 regulates the development of HCC, and summarizes the progress of research on ALDH2 gene polymorphisms and HCC susceptibility. Meanwhile, we envision viable strategies for targeting ALDH2 in the treatment of HCC SIGNIFICANCE STATEMENT: Numerous studies have aimed to explore novel therapeutic targets for HCC, and ALDH2 has been reported to be a critical regulator of HCC progression. This review discusses the functions, molecular mechanisms, and clinical significance of ALDH2 in the development of HCC and examines the prospects of ALDH2-based therapy for HCC.

CRISPR/Cas detection with nanodevices: moving deeper into liquid biopsy

The emerging field of liquid biopsy has garnered significant interest in precision diagnostics, offering a non-invasive and repetitive method for analyzing bodily fluids to procure real-time diagnostic data. The precision and accuracy offered by the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (CRISPR/Cas) technology have advanced and broadened the applications of liquid biopsy. Significantly, when combined with swiftly advancing nanotechnology, CRISPR/Cas-mediated nanodevices show vast potential in precise liquid biopsy applications. However, persistent challenges are still associated with off-target effects, and the current platforms also constrain the performance of the assays. In this review, we highlight the merits of CRISPR/Cas systems in liquid biopsy, tracing the development of CRISPR/Cas systems and their current applications in disease diagnosis particularly in liquid biopsies. We also outline ongoing efforts to design nanoscale devices with improved sensing and readout capabilities, aiming to enhance the performance of CRISPR/Cas detectors in liquid biopsy. Finally, we identify the critical obstacles hindering the widespread adoption of CRISPR/Cas liquid biopsy and explore potential solutions. This feature article presents a comprehensive overview of CRISPR/Cas-mediated liquid biopsies, emphasizing the progress in integrating nanodevices to improve specificity and sensitivity. It also sheds light on future research directions in employing nanodevices for CRISPR/Cas-based liquid biopsies in the realm of precision medicine.

Nitrogen-Doped Carbon Dots Facilitate CRISPR/Cas for Reducing Antibiotic Resistance Genes in the Environment

The continued acquisition and propagation of antibiotic resistance genes (ARGs) in the environment confound efforts to manage the global rise in antibiotic resistance. Here, CRISPR-Cas9/sgRNAs carried by nitrogen-doped carbon dots (NCDs) were developed to precisely target multi-"high-risk" ARGs (tet, cat, and aph(3')-Ia) commonly detected in the environment. NCDs facilitated the delivery of Cas9/sgRNAs to Escherichia coli (E. coli) without cytotoxicity, achieving sustained elimination of target ARGs. The elimination was optimized using different weight ratios of NCDs and Cas9 protein (1:1, 1:20, and 1:40), and Cas9/multi sgRNAs were designed to achieve multi-cleavage of ARGs in either a single strain or mixed populations. Importantly, NCDs successfully facilitated Cas9/multi sgRNAs for resensitization of antibiotic-resistant bacteria in soil (approaching 50%), whereas Cas9/multi sgRNAs alone were inactivated in the complex environment. This work highlights the potential of a fast and precise strategy to minimize the reservoir of antibiotic resistance in agricultural system.

Nanomaterials for intelligent CRISPR-Cas tools: improving environment sustainability

Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) is a desirable gene modification tool covering a wide area in various sectors of medicine, agriculture, and microbial biotechnology. The role of this incredible genetic engineering technology has been extensively investigated; however, it remains formidable with cargo choices, nonspecific delivery, and insertional mutagenesis. Various nanomaterials including lipid, polymeric, and inorganic are being used to deliver the CRISPR-Cas system. Progress in nanomaterials could potentially address these challenges by accelerating precision targeting, cost-effectiveness, and one-step delivery. In this review, we highlighted the advances in nanotechnology and nanomaterials as smart delivery systems for CRISPR-Cas so as to ameliorate applications for environmental remediation including biomedical research and healthcare, strategies for mitigating antimicrobial resistance, and to be used as nanofertilizers for enhancing crop growth, and reducing the environmental impact of traditional fertilizers. The timely co-evolution of nanotechnology and CRISPR technologies has contributed to smart novel nanostructure hybrids for improving the onerous tasks of environmental remediation and biological sustainability.

Exosomes for CRISPR-Cas9 Delivery: The Cutting Edge in Genome Editing

Gene mutation correction was challenging until the discovery of clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein (Cas). CRISPR is a new era for genome modification, and this technology has bypassed the limitations of previous methods such as zinc-finger nuclease and transcription activator-like effector nuclease. Currently, this method is becoming the method of choice for gene-editing purposes, especially therapeutic gene editing in diseases such as cardiovascular, neurological, renal, genetic, optical, and stem cell, as well as blood disorders and muscular degeneration. However, finding the optimum delivery system capable of carrying this large complex persists as the main challenge of this technology. Therefore, it would be ideal if the delivery vehicle could direct the introduction of editing functions to specific cells in a multicellular organism. Exosomes are membrane-bound vesicles with high biocompatibility and low immunogenicity; they offer the best and most reliable way to fill the CRISPR/Cas9 system delivery gap. This review presents the current evidence on the molecular mechanisms and challenges of CRISPR/Cas9-mediated genome modification. Also, the role of CRISPR/Cas9 in the development of treatment and diagnosis of numerous disorders, from malignancies to viral infections, has been discussed. Lastly, the focus is on new advances in exosome-delivery technologies that may play a role in CRISPR/Cas9 delivery for future clinical settings.

A LIGHTFUL nanomedicine overcomes EGFR-mediated drug resistance for enhanced tyrosine-kinase-inhibitor-based hepatocellular carcinoma therapy

Targeting the activated epidermal growth factor receptor (EGFR) via clustered regularly interspaced short palindromic repeat (CRISPR) technology is appealing to overcome the drug resistance of hepatocellular carcinoma (HCC) towards tyrosine kinase inhibitor (TKI) therapy. However, combining these two distinct drugs using traditional liposomes results in a suboptimal synergistic anti-HCC effect due to the limited CRISPR/Cas9 delivery efficiency caused by lysosomal entrapment after endocytosis. Herein, we developed a liver-targeting gene-hybridizing-TKI fusogenic liposome (LIGHTFUL) that can achieve high CRISPR/Cas9 expression to reverse the EGFR-mediated drug resistance for enhanced TKI-based HCC therapy efficiently. Coated with a galactose-modified membrane-fusogenic lipid layer, LIGHTFUL reached the targeting liver site to fuse with HCC tumor cells, directly and efficiently transporting interior CDK5- and PLK1-targeting CRISPR/Cas9 plasmids (pXG333-CPs) into the HCC cell cytoplasm and then the cell nucleus for efficient expression. Such membrane-fusion-mediated pXG333-CP delivery resulted in effective downregulation of both CDK5 and PLK1, sufficiently inactivating EGFR to improve the anti-HCC effects of the co-delivered TKI, lenvatinib. This membrane-fusion-participant codelivery strategy optimized the synergetic effect of CRISPR/Cas9 and TKI combinational therapy as indicated by the 0.35 combination index in vitro and the dramatic reduction of subcutaneous and orthotopic TKI-insensitive HCC tumor growth in mice. Therefore, the established LIGHTFUL provides a unique co-delivery platform to combine gene editing and TKI therapies for enhanced synergetic therapy.

Photodynamic Cationic Ultrasmall Copper Oxide Nanoparticles-Loaded Liposomes for Alleviation of MRSA Biofilms

Introduction

As we enter the post-antibiotic era, the rise of antibiotic-resistant pathogenic bacteria is becoming a serious threat to public health. This problem is further complicated by antibiotic-resistant biofilms, for which current treatment options are limited.

Methods

To tackle this challenge, we propose a novel approach that involves the use of photodynamic cationic pH-sensitive liposomes loaded with ultra-small copper oxide (Ce6@Lipo/UCONs) to effectively eliminate drug-resistant bacteria and eradicate biofilms while minimizing safety concerns and the risk of resistance development.

Results

Our study demonstrates that Ce6@Lipo/UCONs have minimal toxicity to mammalian cells and can significantly enhance the association affinity with methicillin-resistant Staphylococcus aureus (MRSA) as confirmed by fluorescent microscope and flow cytometry, thereby greatly improving the bactericidal effect against planktonic MRSA. The cationic nature of Ce6@Lipo/UCONs also enables them to penetrate MRSA biofilms and respond to the acidic microenvironment within the biofilm, effectively releasing the loaded UCONs. Our results indicate that Ce6@Lipo/UCONs could effectively eliminate biofilms under light irradiation conditions, as evidenced by both biomass analysis and scanning electron microscopy observations. In addition, significant antibacterial effects and abscess healing were observed in MRSA-infected mice treated with Ce6@Lipo/UCONs upon light irradiation, while good biocompatibility was achieved in vivo.

Conclusion

Taken together, our findings suggest that photodynamic cationic ultrasmall copper oxide nanoparticles-loaded liposomes are a highly promising nano platform for combating antibiotic-resistant microbial pathogens and biofilms. The effective biofilm penetration and synergistic effect between photodynamic inactivation and metal sterilization make them a valuable tool for overcoming the challenges posed by antibiotic resistance.

Biomimetic Mineralized CRISPR/Cas RNA Nanoparticles for Efficient Tumor-Specific Multiplex Gene Editing

CRISPR/Cas9 systems have great potential to achieve sophisticated gene therapy and cell engineering by editing multiple genomic loci. However, to achieve efficient multiplex gene editing, the delivery system needs adequate capacity to transfect all CRISPR/Cas9 RNA species at the required stoichiometry into the cytosol of each individual cell. Herein, inspired by biomineralization in nature, we develop an all-in-one biomimetic mineralized CRISPR/Cas9 RNA delivery system. This system allows for precise control over the coencapsulation ratio between Cas9 mRNA and multiple sgRNAs, while also exhibiting a high RNA loading capacity. In addition, it enhances the storage stability of RNA at 4 °C for up to one month, and the surface of the nanoparticles can be easily functionalized for precise targeting of RNA nanoparticles in vivo at nonliver sites. Based on the above characteristics, as a proof-of-concept, our system was able to achieve significant gene-editing at each target gene (Survivin: 31.9%, PLK1: 24.41%, HPV: 23.2%) and promote apoptosis of HeLa cells in the mouse model, inhibiting tumor growth without obvious off-target effects in liver tissue. This system addresses various challenges associated with multicomponent RNA delivery in vivo, providing an innovative strategy for the RNA-based CRISPR/Cas9 gene editing.

X-ray-Guided In Situ Genetic Engineering of Macrophages for Sustained Cancer Immunotherapy

Effective repolarization of macrophages has emerged as a promising approach for anticancer therapy. However, there are very few studies on the effect of reprogramming macrophages from M2 phenotype to M1 phenotype without reconversion while maintaining an activated M1 phenotype. Moreover, these immunomodulatory methods have serious drawbacks due to the activation of normal monocytic cells. Therefore, it remains a challenge to selectively reprogram tumor-associated macrophages (TAMs) without systemic toxicities. Here, X-ray-guided and triggered remote control of a CRISPR/Cas9 genome editing system (X-CC9) that exclusively activates therapeutic agents at tumor sites is established. Under X-ray irradiation, X-CC9 selectively enhances M2-to-M1 repolarization within the tumor microenvironment, and significantly improves antitumor efficacy with robust immune responses in two animal models. This strategy provides an ideal method for improving the safety of macrophage polarization and may constitute a promising immunotherapy strategy.

Remodeling Tumor Immunogenicity with Dual-Activatable Binary CRISPR Nanomedicine for Cancer Immunotherapy

The specific recognition of cancer cells by the body's immune system is an essential step in initiating antitumor immunity. However, the decreased expression of major histocompatibility complex class I (MHC-1) and overexpression of programmed death ligand 1 (PD-L1) causes insufficient tumor-associated antigens presentation and inactivation of T cells, which accounts for poor immunogenicity. To remodel tumor immunogenicity, herein, a dual-activatable binary CRISPR nanomedicine (DBCN) that can efficiently deliver a CRISPR system into tumor tissues and specifically control its activation is reported. This DBCN is made of a thioketal-cross-linked polyplex core and an acid-detachable polymer shell, which can maintain stability during blood circulation, while detaching a polymer shell to facilitate the cellular internalization of the CRISPR system after entering tumor tissues and ultimately activating gene editing under exogenous laser irradiation, thereby maximizing the therapeutic benefits and reducing potential safety concerns. With the collaborative application of multiple CRISPR systems, DBCN efficiently corrects both dysregulation of MHC-1 and PD-L1 expression in tumors, thus initiating robust T cell-dependent antitumor immune responses to inhibit malignant tumor growth, metastasis, and recurrence. Given the increasing abundance of CRISPR toolkits, this research provides an appealing therapeutic strategy and a universal delivery platform to develop more advanced CRISPR-based cancer treatments.

Dual-Responsive Core-Shell Tecto Dendrimers Enable Efficient Gene Editing of Cancer Cells to Boost Immune Checkpoint Blockade Therapy

Immune checkpoint blockade (ICB) therapy has become a promising strategy in treating multiple tumor types, but the therapeutic efficacy is still unsatisfactory due to the temporary and inefficient blocking and the poor immune responsiveness. Herein, we report the development of dual reactive oxygen species (ROS)- and pH-responsive core-shell tecto dendrimers loaded with gold nanoparticles (for short, Au CSTDs) to deliver a plasmid-clustered regularly interspersed short palindromic repeats (CRISPR)/Cas9 system for the permanent disruption of the programmed death ligand 1 (PD-L1) gene in cancer cells to boost cancer immunotherapy. In our work, Au CSTDs were constructed using lactobionic acid (LA)-modified generation 5 poly(amidoamine) dendrimers entrapped with gold nanoparticles as cores and phenylboronic acid (PBA)-conjugated generation 3 dendrimers as shells via the formation of responsive phenylborate ester bonds between PBA and LA. The plasmid-CRISPR/Cas9 system can be efficiently compacted and specifically taken up by cancer cells overexpressing sialic acids due to the PBA-mediated targeting and be responsively released in cancer cells by the responsive dissociation of the Au CSTDs, leading to the successful endosomal escape and the efficient knockout of the PD-L1 gene. Further in vivo delivery in a mouse melanoma model reveals that the developed Au CSTDs/plasmid-CRISPR/Cas9 complexes can be specifically accumulated at the tumor site for enhanced computed tomography (CT) imaging of tumors, owing to the X-ray attenuation effect of Au, and disrupt the PD-L1 expression in tumor cells, thus promoting the ICB-based antitumor immunity. The designed dual-responsive Au CSTDs may be developed as a versatile tool for genetic engineering of other cell types to achieve different therapeutic effects for expanded space of biomedical applications.

Optimization of CRISPR-Cas system for clinical cancer therapy

Cancer is a genetic disease caused by alterations in genome and epigenome and is one of the leading causes for death worldwide. The exploration of disease development and therapeutic strategies at the genetic level have become the key to the treatment of cancer and other genetic diseases. The functional analysis of genes and mutations has been slow and laborious. Therefore, there is an urgent need for alternative approaches to improve the current status of cancer research. Gene editing technologies provide technical support for efficient gene disruption and modification in vivo and in vitro, in particular the use of clustered regularly interspaced short palindromic repeats (CRISPR)-Cas systems. Currently, the applications of CRISPR-Cas systems in cancer rely on different Cas effector proteins and the design of guide RNAs. Furthermore, effective vector delivery must be met for the CRISPR-Cas systems to enter human clinical trials. In this review article, we describe the mechanism of the CRISPR-Cas systems and highlight the applications of class II Cas effector proteins. We also propose a synthetic biology approach to modify the CRISPR-Cas systems, and summarize various delivery approaches facilitating the clinical application of the CRISPR-Cas systems. By modifying the CRISPR-Cas system and optimizing its in vivo delivery, promising and effective treatments for cancers using the CRISPR-Cas system are emerging.

Microfluidics-enabled Serial Assembly of Lipid-siRNA-sorafenib Nanoparticles for Synergetic Hepatocellular Carcinoma Therapy

Multi-component nanoparticles (mNPs) hold great potential for disease prevention and treatment. However, a major barrier is the lack of versatile platforms to accommodate steps of assembly processes of mNPs. Here the microfluidics-enabled serial assembly (MESA) of mNPs is presented. The microfluidic chip, as a mini-conveyor of initial materials, sequentially enables the assembly of sorafenib supramolecule, electrostatic adsorption of siRNA, and surface assembly of protective lipids. The produced lipid-siRNA-sorafenib nanoparticles (LSS NPs) have ultrahigh encapsulation efficiencies for sorafenib (≈100%) and siRNA (≈95%), which benefit from the accommodation of both fast and slow processes on the chip. Although carrying negative charges, LSS NPs enable cytosolic delivery of agents and high gene silencing efficiency within tumor cells. In vivo, the LSS NPs delivering hypoxia-induced factor (HIF1α)-targeted siRNA efficiently regress tumors of Hep3B xenograft and hepatocellular carcinoma patient-derived primary cells xenograft (PDCX) and finally extend the average survival of PDCX mice to 68 days. Thus, this strategy is promising as a sorafenib/siRNA combination therapy, and MESA can be a universal platform for fabricating complex nanosystems.

Triple functional mild photothermal improves gene editing of PD-L1 for enhanced antitumor immunity

Traditional photothermal therapy ablates tumor cells by a high temperature (> 50 °C). Although it has shown good anti-tumor effect in animal models, the potential damages to healthy tissues and the unnecessary inflammatory reactions caused by the high temperature have hindered the clinical transitions of traditional photothermal therapy. In this study, we used polydopamine (PDA) as a mild photothermal material and control the maximum temperature below 45 °C, which not only avoided the side effects caused by a high temperature, but also ablated a fraction of tumor cells and produced tumor antigens. Meanwhile, the near-infrared (NIR) light also served as a "switch" to trigger the release of CRISPR/Cas9 RNP from Fe₃O₄ nanoparticles (Fe₃O₄ NPs) after their accumulation to tumor sites via magnetic targeting. The triple functional mild photothermal therapy achieved significant PD-L1 gene knockout efficiency in the tumor-bearing mice, reversed the condition of immunosuppression in the tumor microenvironment, led to a higher level of anti-tumor immune responses and effectively inhibited the growth of melanoma. We anticipate that this triple functional mild photothermal therapy would provide a potential new approach for the treatment of malignant tumors.

CRISPR/Cas9 therapeutics: progress and prospects

Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) gene-editing technology is the ideal tool of the future for treating diseases by permanently correcting deleterious base mutations or disrupting disease-causing genes with great precision and efficiency. A variety of efficient Cas9 variants and derivatives have been developed to cope with the complex genomic changes that occur during diseases. However, strategies to effectively deliver the CRISPR system to diseased cells in vivo are currently lacking, and nonviral vectors with target recognition functions may be the focus of future research. Pathological and physiological changes resulting from disease onset are expected to serve as identifying factors for targeted delivery or targets for gene editing. Diseases are both varied and complex, and the choice of appropriate gene-editing methods and delivery vectors for different diseases is important. Meanwhile, there are still many potential challenges identified when targeting delivery of CRISPR/Cas9 technology for disease treatment. This paper reviews the current developments in three aspects, namely, gene-editing type, delivery vector, and disease characteristics. Additionally, this paper summarizes successful examples of clinical trials and finally describes possible problems associated with current CRISPR applications.

Recent advances in nanotechnology approaches for non-viral gene therapy

Gene therapy has shown great potential in the treatment of many diseases by downregulating the expression of certain genes. The development of gene vectors as a vehicle for gene therapy has greatly facilitated the widespread clinical application of nucleic acid materials (DNA, mRNA, siRNA, and miRNA). Currently, both viral and non-viral vectors are used as delivery systems of nucleic acid materials for gene therapy. However, viral vector-based gene therapy has several limitations, including immunogenicity and carcinogenesis caused by the exogenous viral vectors. To address these issues, non-viral nanocarrier-based gene therapy has been explored for superior performance with enhanced gene stability, high treatment efficiency, improved tumor-targeting, and better biocompatibility. In this review, we discuss various non-viral vector-mediated gene therapy approaches using multifunctional biodegradable or non-biodegradable nanocarriers, including polymer-based nanoparticles, lipid-based nanoparticles, carbon nanotubes, gold nanoparticles (AuNPs), quantum dots (QDs), silica nanoparticles, metal-based nanoparticles and two-dimensional nanocarriers. Various strategies to construct non-viral nanocarriers based on their delivery efficiency of targeted genes will be introduced. Subsequently, we discuss the cellular uptake pathways of non-viral nanocarriers. In addition, multifunctional gene therapy based on non-viral nanocarriers is summarized, in which the gene therapy can be combined with other treatments, such as photothermal therapy (PTT), photodynamic therapy (PDT), immunotherapy and chemotherapy. We also provide a comprehensive discussion of the biological toxicity and safety of non-viral vector-based gene therapy. Finally, the present limitations and challenges of non-viral nanocarriers for gene therapy in future clinical research are discussed, to promote wider clinical applications of non-viral vector-based gene therapy.

Nanoparticles-mediated CRISPR-Cas9 gene therapy in inherited retinal diseases: applications, challenges, and emerging opportunities

Inherited Retinal Diseases (IRDs) are considered one of the leading causes of blindness worldwide. However, the majority of them still lack a safe and effective treatment due to their complexity and genetic heterogeneity. Recently, gene therapy is gaining importance as an efficient strategy to address IRDs which were previously considered incurable. The development of the clustered regularly-interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) system has strongly empowered the field of gene therapy. However, successful gene modifications rely on the efficient delivery of CRISPR-Cas9 components into the complex three-dimensional (3D) architecture of the human retinal tissue. Intriguing findings in the field of nanoparticles (NPs) meet all the criteria required for CRISPR-Cas9 delivery and have made a great contribution toward its therapeutic applications. In addition, exploiting induced pluripotent stem cell (iPSC) technology and in vitro 3D retinal organoids paved the way for prospective clinical trials of the CRISPR-Cas9 system in treating IRDs. This review highlights important advances in NP-based gene therapy, the CRISPR-Cas9 system, and iPSC-derived retinal organoids with a focus on IRDs. Collectively, these studies establish a multidisciplinary approach by integrating nanomedicine and stem cell technologies and demonstrate the utility of retina organoids in developing effective therapies for IRDs.

Delivering the CRISPR/Cas9 system for engineering gene therapies: Recent cargo and delivery approaches for clinical translation

Clustered Regularly Interspaced Short Palindromic Repeats associated protein 9 (CRISPR/Cas9) has transformed our ability to edit the human genome selectively. This technology has quickly become the most standardized and reproducible gene editing tool available. Catalyzing rapid advances in biomedical research and genetic engineering, the CRISPR/Cas9 system offers great potential to provide diagnostic and therapeutic options for the prevention and treatment of currently incurable single-gene and more complex human diseases. However, significant barriers to the clinical application of CRISPR/Cas9 remain. While in vitro, ex vivo, and in vivo gene editing has been demonstrated extensively in a laboratory setting, the translation to clinical studies is currently limited by shortfalls in the precision, scalability, and efficiency of delivering CRISPR/Cas9-associated reagents to their intended therapeutic targets. To overcome these challenges, recent advancements manipulate both the delivery cargo and vehicles used to transport CRISPR/Cas9 reagents. With the choice of cargo informing the delivery vehicle, both must be optimized for precision and efficiency. This review aims to summarize current bioengineering approaches to applying CRISPR/Cas9 gene editing tools towards the development of emerging cellular therapeutics, focusing on its two main engineerable components: the delivery vehicle and the gene editing cargo it carries. The contemporary barriers to biomedical applications are discussed within the context of key considerations to be made in the optimization of CRISPR/Cas9 for widespread clinical translation.

Deploying Gold Nanomaterials in Combating Multi-Drug-Resistant Bacteria

Antibiotic resistance has become a serious threat to human health due to the overuse of antibiotics. Different antibiotics are being developed to treat resistant bacteria, but the development cycle of antibiotics is hard to keep up with the high incidence of antibiotic resistance. Recent advances in antimicrobial nanomaterials have made nanotechnology a powerful solution to this dilemma. Among these nanomaterials, gold nanomaterials have excellent antibacterial efficacy and biosafety, making them alternatives to antibiotics. This review presents strategies that use gold nanomaterials to combat drug-resistant bacteria. We focus on the influence of physicochemical factors such as surface chemistry, size, and shape of gold nanomaterials on their antimicrobial properties and describe the antimicrobial applications of gold nanomaterials in medical devices. Finally, the existing challenges and future directions are discussed.

Functional Tumor Targeting Nano-Systems for Reprogramming Circulating Tumor Cells with In Situ Evaluation on Therapeutic Efficiency at the Single-Cell Level

Tumor heterogeneity is primarily responsible for treatment resistance and cancer relapses. Being critically important to address this issue, the timely evaluation of the appropriateness of therapeutic actions at the single-cell level is still facing challenges. By using multi-functionalized nano-systems with the delivery vector composed of histone for plasmids loading, hyaluronic acid for tumor targeting, and a fusion peptide for C-X-C motif chemokine receptor 4 (CXCR4） targeting as well as nuclear localization, the reprogramming of circulating tumor cells (CTCs) with in situ detection on biomarkers at the single-cell level is realized. By efficient co-delivery of the genome editing plasmid for CXCR4 knockout and molecular beacons for detection of upregulated mRNA biomarkers into CTCs in unprocessed whole blood, the therapeutic outcomes of genome editing at the single-cell level can be in situ evaluated. The single-cell analysis shows that CXCR4 in CTCs of cancer patients is efficiently downregulated, resulting in upregulated anticancer biomarkers such as p53 and p21. The study provides a facile strategy for in-depth profiling of cancer cell responses to therapeutic actions at single-cell resolution to evaluate the outcomes of treatments timely and conveniently.

CRISPR/Cas9 ribonucleoprotein-mediated genome and epigenome editing in mammalian cells

The clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein (Cas) system has revolutionized the ability to edit the mammalian genome, providing a platform for the correction of pathogenic mutations and further investigation into gene function. CRISPR reagents can be delivered into the cell as DNA, RNA, or pre-formed ribonucleoproteins (RNPs). RNPs offer numerous advantages over other delivery approaches due to their ability to rapidly target genomic sites and quickly degrade thereafter. Here, we review the production steps and delivery methods for Cas9 RNPs. Additionally, we discuss how RNPs enhance genome and epigenome editing efficiencies, reduce off-target editing activity, and minimize cellular toxicity in clinically relevant mammalian cell types. We include details on a broad range of editing approaches, including novel base and prime editing techniques. Finally, we summarize key challenges for the use of RNPs, and propose future perspectives on the field.

Exploring nano-enabled CRISPR-Cas-powered strategies for efficient diagnostics and treatment of infectious diseases

Biomedical researchers have subsequently been inspired the development of new approaches for precisely changing an organism's genomic DNA in order to investigate customized diagnostics and therapeutics utilizing genetic engineering techniques. Clustered Regulatory Interspaced Short Palindromic Repeats (CRISPR) is one such technique that has emerged as a safe, targeted, and effective pharmaceutical treatment against a wide range of disease-causing organisms, including bacteria, fungi, parasites, and viruses, as well as genetic abnormalities. The recent discovery of very flexible engineered nucleic acid binding proteins has changed the scientific area of genome editing in a revolutionary way. Since current genetic engineering technique relies on viral vectors, issues about immunogenicity, insertional oncogenesis, retention, and targeted delivery remain unanswered. The use of nanotechnology has the potential to improve the safety and efficacy of CRISPR/Cas9 component distribution by employing tailored polymeric nanoparticles. The combination of two (CRISPR/Cas9 and nanotechnology) offers the potential to open new therapeutic paths. Considering the benefits, demand, and constraints, the goal of this research is to acquire more about the biology of CRISPR technology, as well as aspects of selective and effective diagnostics and therapies for infectious illnesses and other metabolic disorders. This review advocated combining nanomedicine (nanomedicine) with a CRISPR/Cas enabled sensing system to perform early-stage diagnostics and selective therapy of specific infectious disorders. Such a Nano-CRISPR-powered nanomedicine and sensing system would allow for successful infectious illness control, even on a personal level. This comprehensive study also discusses the current obstacles and potential of the predicted technology.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40097-022-00472-7.

Core-shell microparticles: From rational engineering to diverse applications

Core-shell microparticles, composed of solid, liquid, or gas bubbles surrounded by a protective shell, are gaining considerable attention as intelligent and versatile carriers that show great potential in biomedical fields. In this review, an overview is given of recent developments in design and applications of biodegradable core-shell systems. Several emerging methodologies including self-assembly, gas-shearing, and coaxial electrospray are discussed and microfluidics technology is emphasized in detail. Furthermore, the characteristics of core-shell microparticles in artificial cells, drug release and cell culture applications are discussed and the superiority of these advanced multi-core microparticles for the generation of artificial cells is highlighted. Finally, the respective developing orientations and limitations inherent to these systems are addressed. It is hoped that this review can inspire researchers to propel the development of this field with new ideas.

Genome editing of PD-L1 mediated by nucleobase-modified polyamidoamine for cancer immunotherapy

Immune checkpoint blockade therapy against programmed death protein-1 and its ligand (PD-1/PD-L1) has been accepted as a promising approach to activate the immune system's anti-tumor response. Although small interfering RNA...

Advanced Nanotheranostics of CRISPR/Cas for Viral Hepatitis and Hepatocellular Carcinoma

Liver disease, particularly viral hepatitis and hepatocellular carcinoma (HCC), is a global healthcare burden and leads to more than 2 million deaths per year worldwide. Despite some success in diagnosis and vaccine development, there are still unmet needs to improve diagnostics and therapeutics for viral hepatitis and HCC. The emerging clustered regularly interspaced short palindromic repeat/associated proteins (CRISPR/Cas) technology may open up a unique avenue to tackle these two diseases at the genetic level in a precise manner. Especially, liver is a more accessible organ over others from the delivery point of view, and many advanced strategies applied for nanotheranostics can be adapted in CRISPR-mediated diagnostics or liver gene editing. In this review, the focus is on these two aspects of viral hepatitis and HCC applications. An overview on CRISPR editor development and current progress in clinical trials is first given, followed by highlighting the recent advances integrating the merits of gene editing and nanotheranostics. The promising systems that are used in other applications but may hold potentials in liver gene editing are also discussed. This review concludes with the perspectives on rationally designing the next-generation CRISPR approaches and improving the editing performance.

Hydrophobic Optimization of Functional Poly(TPAE-co-suberoyl chloride) for Extrahepatic mRNA Delivery following Intravenous Administration

Messenger RNA (mRNA) has generated great attention due to its broad potential therapeutic applications, including vaccines, protein replacement therapy, and immunotherapy. Compared to other nucleic acids (e.g., siRNA and pDNA), there are more opportunities to improve the delivery efficacy of mRNA through systematic optimization. In this report, we studied a high-throughput library of 1200 functional polyesters for systemic mRNA delivery. We focused on the chemical investigation of hydrophobic optimization as a method to adjust mRNA polyplex stability, diameter, pKa, and efficacy. Focusing on a region of the library heatmap (PE4K-A17), we further explored the delivery of luciferase mRNA to IGROV1 ovarian cancer cells in vitro and to C57BL/6 mice in vivo following intravenous administration. PE4K-A17-0.2C8 was identified as an efficacious carrier for delivering mRNA to mouse lungs. The delivery selectivity between organs (lungs versus spleen) was found to be tunable through chemical modification of polyesters (both alkyl chain length and molar ratio in the formulation). Cre recombinase mRNA was delivered to the Lox-stop-lox tdTomato mouse model to study potential application in gene editing. Overall, we identified a series of polymer-mRNA polyplexes stabilized with Pluronic F-127 for safe and effective delivery to mouse lungs and spleens. Structure–activity relationships between alkyl side chains and in vivo delivery were elucidated, which may be informative for the continued development of polymer-based mRNA delivery.

Stimulus-Responsive Smart Nanoparticles-Based CRISPR-Cas Delivery for Therapeutic Genome Editing

The innovative research in genome editing domains such as CRISPR-Cas technology has enabled genetic engineers to manipulate the genomes of living organisms effectively in order to develop the next generation of therapeutic tools. This technique has started the new era of "genome surgery". Despite these advances, the barriers of CRISPR-Cas9 techniques in clinical applications include efficient delivery of CRISPR/Cas9 and risk of off-target effects. Various types of viral and non-viral vectors are designed to deliver the CRISPR/Cas9 machinery into the desired cell. These methods still suffer difficulties such as immune response, lack of specificity, and efficiency. The extracellular and intracellular environments of cells and tissues differ in pH, redox species, enzyme activity, and light sensitivity. Recently, smart nanoparticles have been synthesized for CRISPR/Cas9 delivery to cells based on endogenous (pH, enzyme, redox specie, ATP) and exogenous (magnetic, ultrasound, temperature, light) stimulus signals. These methodologies can leverage genome editing through biological signals found within disease cells with less off-target effects. Here, we review the recent advances in stimulus-based smart nanoparticles to deliver the CRISPR/Cas9 machinery into the desired cell. This review article will provide extensive information to cautiously utilize smart nanoparticles for basic biomedical applications and therapeutic genome editing.

Reversing the Chirality of Surface Ligands Can Improve the Biosafety and Pharmacokinetics of Cationic Gold Nanoclusters

Severe toxicity and rapid in vivo clearance of cationic nanomaterials seriously hinder their clinical translation. Present strategies to improve the biosafety and in vivo performance of cationic nanomaterials require neutralization of positive charge, which often compromises their efficacy. Herein, we report that substituting L-glutathione (L-GSH) on cationic gold nanoclusters (GNCs) with its D-counterpart can effectively improve the biosafety and pharmacokinetics. Compared with L-GNCs, D-GNCs do not exhibit cellular cytotoxicity, hemolysis, or acute damage to organs. Cationic D-GNCs show less cell internalization than L-GNCs, and do not induce cellular apoptosis. In vivo, the chirality of surface ligands distinctly affects the pharmacokinetics and tumor targeting abilities of D-/L-GNCs. D-GNCs show higher extended circulation time in blood plasma compared to similarly-sized and poly (ethylene glycol)-modified gold nanoparticles. This work demonstrates that the choice of chirality of surface ligands can determine toxicities and pharmacokinetics of cationic nanomaterials.

Special Focus Issue Part II: Recruitment of solid lipid nanoparticles for the delivery of CRISPR/Cas9: primary evaluation of anticancer gene editing

Aim: The CRISPR/Cas9 system is a promising gene-editing tool for various anticancer therapies; however, development of a biocompatible, nonviral and efficient delivery of CRISPR/Cas9 expression systems remains a challenge. Materials & methods: Solid lipid nanoparticles (SLNs) were produced based on pseudo and 3D ternary plots. Obtained SLNs and their complexes with PX458 plasmid DNA were characterized and evaluated in terms of cytotoxicity and transfection efficiency. Results: SLNs were found to be nanosized, monodispersed, stable and nontoxic. Furthermore, they revealed similar transfection efficiency as the positive control. Conclusion: Overall, we have achieved a good SLN basis for CRISPR/Cas9 delivery and have the potential to produce SLNs with targeted anticancer properties by modifying production parameters and components to facilitate translating CRISPR/Cas9 into preclinical studies.

Epigenetic editing: Dissecting chromatin function in context

How epigenetic mechanisms regulate genome output and response to stimuli is a fundamental question in development and disease. Past decades have made tremendous progress in deciphering the regulatory relationships involved by correlating aggregated (epi)genomics profiles with global perturbations. However, the recent development of epigenetic editing technologies now enables researchers to move beyond inferred conclusions, towards explicit causal reasoning, through 'programing' precise chromatin perturbations in single cells. Here, we first discuss the major unresolved questions in the epigenetics field that can be addressed by programable epigenome editing, including the context-dependent function and memory of chromatin states. We then describe the epigenetic editing toolkit focusing on CRISPR-based technologies, and highlight its achievements, drawbacks and promise. Finally, we consider the potential future application of epigenetic editing to the study and treatment of specific disease conditions.

Key considerations in designing CRISPR/Cas9-carrying nanoparticles for therapeutic genome editing

CRISPR-Cas9, the breakthrough genome-editing technology, has emerged as a promising tool to prevent and cure various diseases. The efficient genome editing technology strongly relies on the specific and effective delivery of CRISPR/Cas9 cargos. However, the lack of a safe, specific, and efficient non-viral delivery system for in vivo genome editing remains a major limit for its clinical translation. In this review, we will first briefly introduce the working mechanism of CRISPR/Cas9 and the patterns of CRISPR/Cas9 delivery. Furthermore, the physiological obstacles for the delivery process in vivo are elaborated. Finally, the key considerations will be deeply discussed in designing non-viral nanovectors for therapeutic CRISPR/Cas9 delivery in vivo, including the effective encapsulation of large-size macromolecules, targeting specific tissues and cells, efficient endosomal escape and safety concerns of the vector systems, in the hope of inviting more comprehensive studies on the development of safe, specific, and efficient non-viral nanovectors for delivering a CRISPR/Cas9 system.