CRISPR/Cas9 Delivery Mediated with Hydroxyl-Rich Nanosystems for Gene Editing in Aorta

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.

Precision in Action: The Role of Clustered Regularly Interspaced Short Palindromic Repeats/Cas in Gene Therapies

Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)-associated enzyme-CAS holds great promise for treating many uncured human diseases and illnesses by precisely correcting harmful point mutations and disrupting disease-causing genes. The recent Food and Drug Association (FDA) approval of the first CRISPR-based gene therapy for sickle cell anemia marks the beginning of a new era in gene editing. However, delivering CRISPR specifically into diseased cells in vivo is a significant challenge and an area of intense research. The identification of new CRISPR/Cas variants, particularly ultra-compact CAS systems with robust gene editing activities, paves the way for the low-capacity delivery vectors to be used in gene therapies. CRISPR/Cas technology has evolved beyond editing DNA to cover a wide spectrum of functionalities, including RNA targeting, disease diagnosis, transcriptional/epigenetic regulation, chromatin imaging, high-throughput screening, and new disease modeling. CRISPR/Cas can be used to engineer B-cells to produce potent antibodies for more effective vaccines and enhance CAR T-cells for the more precise and efficient targeting of tumor cells. However, CRISPR/Cas technology has challenges, including off-target effects, toxicity, immune responses, and inadequate tissue-specific delivery. Overcoming these challenges necessitates the development of a more effective and specific CRISPR/Cas delivery system. This entails strategically utilizing specific gRNAs in conjunction with robust CRISPR/Cas variants to mitigate off-target effects. This review seeks to delve into the intricacies of the CRISPR/Cas mechanism, explore progress in gene therapies, evaluate gene delivery systems, highlight limitations, outline necessary precautions, and scrutinize the ethical considerations associated with its application.

Advances and challenges in regenerative therapies for abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is a significant source of mortality worldwide and carries a mortality of greater than 80% after rupture. Despite extensive efforts to develop pharmacological treatments, there is currently no effective agent to prevent aneurysm growth and rupture. Current treatment paradigms only rely on the identification and surveillance of small aneurysms, prior to ultimate open surgical or endovascular repair. Recently, regenerative therapies have emerged as promising avenues to address the degenerative changes observed in AAA. This review briefly outlines current clinical management principles, characteristics, and pharmaceutical targets of AAA. Subsequently, a thorough discussion of regenerative approaches is provided. These include cellular approaches (vascular smooth muscle cells, endothelial cells, and mesenchymal stem cells) as well as the delivery of therapeutic molecules, gene therapies, and regenerative biomaterials. Lastly, additional barriers and considerations for clinical translation are provided. In conclusion, regenerative approaches hold significant promise for in situ reversal of tissue damages in AAA, necessitating sustained research and innovation to achieve successful and translatable therapies in a new era in AAA management.

Spleen-Targeted mRNA Delivery by Amphiphilic Carbon Dots for Tumor Immunotherapy

In recent years, the application of mRNA vaccine-based tumor immunotherapy invigorated anti-tumor therapy. However, the low efficiency of mRNA delivery and the lack of targeting ability in vivo are the major obstacles to achieving highly efficient immunotherapy. In this work, we report a chemical library of amphiphilic carbon dots (ACDs) and the synthesized ACDs were applied to mRNA delivery, bio-imaging, and tumor immunotherapy. The ACDs can smoothly bind with mRNA to form ACDs@mRNA nanocomplexes, and the fluorescent properties of the ACDs afforded the nanoparticles with bio-imaging ability. By screening of the ACDs, O₁₂-Tta-CDs were found to have optimal mRNA transfection efficiency and the ability of spleen-targeted delivery. In addition, O₁₂-Tta-CDs can well transfect the immune cells and promote the maturation and antigen presentation of bone marrow-derived dendritic cells (BMDCs). Furthermore, O₁₂-Tta-CDs@OVA-mRNA was successfully applied to inhibit tumor growth, and more specific T-cell infiltration was observed in spleen and tumors of mice after treatment in the E.G7-OVA tumor model. Besides, O₁₂-Tta-CDs@OVA-mRNA also achieved a good therapeutic effect in tumor recurrence inhibition and tumor prophylactic experiments. This study provided a new direction for the design of mRNA vectors, which is promising in tumor immunotherapy.

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.

Pre-clinical non-viral vectors exploited for in vivo CRISPR/Cas9 gene editing: an overview

Clustered regulatory interspaced short palindromic repeats or CRISPR/Cas9 has emerged as a potent and versatile tool for efficient genome editing. This technology has been exploited for several applications including disease modelling, cell therapy, diagnosis, and treatment of many diseases including cancer. The in vivo application of CRISPR/Cas9 is hindered by poor stability, pharmacokinetic profile, and the limited ability of the CRISPR payloads to cross biological barriers. Although viral vectors have been implemented as delivery tools for efficient in vivo gene editing, their application is associated with high immunogenicity and toxicity, limiting their clinical translation. Hence, there is a need to explore new delivery methods that can guarantee safe and efficient delivery of the CRISPR/Cas9 components to target cells. In this review, we first provide a brief history and principles of nuclease-mediated gene editing, we then focus on the different CRISPR/Cas9 formats outlining their potentials and limitations. Finally, we discuss the alternative non-viral delivery strategies currently adopted for in vivo CRISPR/Cas9 gene editing.

Nanoparticles-mediated CRISPR/Cas gene editing delivery system

The CRISPR/Cas gene editing system utilizes CRISPR RNA to guide the endonuclease in specifically breaking target gene, and then repairs genomic DNA by the means of homology directed repair (HDR) and non-homologous end joining (NHEJ). The gene editing system can only play its role in gene editing when it enters the nucleus. This crucial step in the process of gene editing is the major hurdle to gene therapy as it is still a huge challenge to efficiently deliver the CRISPR/Cas system to target tissues and cells. The low delivery efficiency hinders the clinical transformation of this technology. At present, delivery systems mainly include physical methods, viral vectors, and non-viral vectors. Due to the advantages of nanomaterial, it is currently being used rapidly in developing non-viral delivery systems. This review focuses on the mechanism of CRISPR/Cas and the delivery of gene editing system, following the research progress of nanoparticle-mediated gene editing.

Non-viral delivery of the CRISPR/Cas system: DNA versus RNA versus RNP

Since its discovery, the CRISPR/Cas technology has rapidly become an essential tool in modern biomedical research. The opportunities to specifically modify and correct genomic DNA has also raised big hope...

The Important Role of Endothelium and Extracellular Vesicles in the Cellular Mechanism of Aortic Aneurysm Formation

Homeostasis is a fundamental property of biological systems consisting of the ability to maintain a dynamic balance of the environment of biochemical processes. The action of endogenous and exogenous factors can lead to internal balance disorder, which results in the activation of the immune system and the development of inflammatory response. Inflammation determines the disturbances in the structure of the vessel wall, connected with the change in their diameter. These disorders consist of accumulation in the space between the endothelium and the muscle cells of low-density lipoproteins (LDL), resulting in the formation of fatty streaks narrowing the lumen and restricting the blood flow in the area behind the structure. The effect of inflammation may also be pathological dilatation of the vessel wall associated with the development of aneurysms. Described disease entities strongly correlate with the increased migration of immune cells. Recent scientific research indicates the secretion of specific vesicular structures during migration activated by the inflammation. The review focuses on the link between endothelial dysfunction and the inflammatory response and the impact of these processes on the development of disease entities potentially related to the secretion of extracellular vesicles (EVs).

Gene Therapy for Cardiovascular Disease: Basic Research and Clinical Prospects

In recent years, the vital role of genetic factors in human diseases have been widely recognized by scholars with the deepening of life science research, accompanied by the rapid development of gene-editing technology. In early years, scientists used homologous recombination technology to establish gene knock-out and gene knock-in animal models, and then appeared the second-generation gene-editing technology zinc-finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs) that relied on nucleic acid binding proteins and endonucleases and the third-generation gene-editing technology that functioned through protein-nucleic acids complexes-CRISPR/Cas9 system. This holds another promise for refractory diseases and genetic diseases. Cardiovascular disease (CVD) has always been the focus of clinical and basic research because of its high incidence and high disability rate, which seriously affects the long-term survival and quality of life of patients. Because some inherited cardiovascular diseases do not respond well to drug and surgical treatment, researchers are trying to use rapidly developing genetic techniques to develop initial attempts. However, significant obstacles to clinical application of gene therapy still exists, such as insufficient understanding of the nature of cardiovascular disease, limitations of genetic technology, or ethical concerns. This review mainly introduces the types and mechanisms of gene-editing techniques, ethical concerns of gene therapy, the application of gene therapy in atherosclerosis and inheritable cardiovascular diseases, in-stent restenosis, and delivering systems.

Rational designs of in vivo CRISPR-Cas delivery systems

The CRISPR-Cas system initiated a revolution in genome editing when it was, for the first time, demonstrated success in the mammalian cells. Today, scientists are able to readily edit genomes, regulate gene transcription, engineer posttranscriptional events, and image nucleic acids using CRISPR-Cas-based tools. However, to efficiently transport CRISPR-Cas into target tissues/cells remains challenging due to many extra- and intra-cellular barriers, therefore largely limiting the applications of CRISPR-based therapeutics in vivo. In this review, we summarize the features of plasmid-, RNA- and ribonucleoprotein (RNP)-based CRISPR-Cas therapeutics. Then, we survey the current in vivo delivery systems. We specify the requirements for efficient in vivo delivery in clinical settings, and highlight both efficiency and safety for different CRISPR-Cas tools.

Coassembly of nucleus-targeting gold nanoclusters with CRISPR/Cas9 for simultaneous bioimaging and therapeutic genome editing

The clustered regularly interspaced short palindromic repeats (CRISPR)/associated protein 9 (CRISPR/Cas9) technology enables genome editing with high precision and versatility and has been widely utilized to combat viruses, bacteria, cancers, and genetic diseases. Nonviral nanocarriers can overcome several limitations of viral vehicles, including immunogenicity, inflammation, carcinogenicity, and low versatility, and thus represent promising platforms for CRISPR/Cas9 delivery. Herein, we for the first time develop the application of protamine-capped gold nanoclusters (protamine-AuNCs) as an effective nanocarrier for Cas9-sgRNA plasmid transport and release to achieve efficient genome editing. The protamine-AuNCs integrate the merits of AuNCs and protamine: AuNCs are able to promptly assemble with Cas9-sgRNA plasmids to allow efficient cellular delivery, while the cationic protamine facilitates the effective release of Cas9-sgRNA plasmids into the cellular nucleus. The AuNCs/Cas9-gRNA plasmid nanocomplexes can not only achieve successful gene editing in cells but also knock out the oncogenic gene for cancer therapy. Moreover, the AuNCs with excellent photoluminescence characteristics endow our nanoplatform with the functionality of bioimaging. Overall, our study provides strong evidence that demonstrates protamine-AuNCs as an effective CRISPR/Cas9 delivery tool for gene therapy.

Advances of Nanoparticles for Leukemia Treatment

Leukemia is a liquid tumor caused by a hematopoietic stem cell malignant clone, which seriously affects the normal function of the hematopoietic system. Conventional drugs have poor therapeutic effects due to their poor specificity and stability. With the development of nanotechnology, nonviral nanoparticles bring hope for the efficient treatment of leukemia. Nanoparticles are easily modified. They can be designed to target lesion sites and control drug release. Thereby, nanoparticles can improve the effects of drugs and reduce side effects. This review mainly focuses on and summarizes the current research progress of nanoparticles to deliver different leukemia therapeutic drugs, as to demonstrate the potential of nanoparticles in leukemia treatment.

Recent progress on nanoparticles for targeted aneurysm treatment and imaging

An abdominal aortic aneurysm (AAA) is a localized dilatation of the aorta that plagues millions. Its rupture incurs high mortality rates (~80-90%), pressing an urgent need for therapeutic methods to prevent this deadly outcome. Judiciously designed nanoparticles (NPs) have displayed a unique potential to fulfill this need. Aneurysms feature excessive inflammation and extracellular matrix (ECM) degradation. As such, typically inflammatory cells and exposed ECM proteins have been targeted with NPs for therapeutic, diagnostic, or theranostic purposes in experimental models. NPs have been used not only for encapsulation and delivery of drugs and biomolecules in preclinical tests, but also for enhanced imaging to monitor aneurysm progression in patients. Moreover, they can be readily modified with various molecules to improve lesion targeting, detectability, biocompatibility, and circulation time. This review updates on the progress, limitations, and prospects of NP applications in the context of AAA.

A Lactose-Derived CRISPR/Cas9 Delivery System for Efficient Genome Editing In Vivo to Treat Orthotopic Hepatocellular Carcinoma

Gene editing is a crucial and effective strategy to treat genetic diseases. Safe and effective delivery vectors are specially required for efficient gene editing in vivo of CRISPR/Cas9 system. Interestingly, lactose, a natural saccharide, can specifically bind to asialoglycoprotein receptors, highly expressed on the surface of hepatocellular carcinoma (HCC) cells. Herein, a lactose-derived branched cationic biopolymer (LBP) with plentiful reducible disulfide linkages and hydroxyl groups is proposed as a potential delivery vector of CRISPR/Cas9 system for efficient genome editing in vivo to treat orthotopic HCC. LBP is synthesized via a facile one-pot ring-opening reaction. LBP possesses excellent compacting ability, degradability, biocompatibility, gene transfection performances, and HCC-targeting ability. LBP-mediated delivery of classical pCas9-survivin, which can target and knockout survivin oncogene, produces efficient gene editing performances, and superb anti-cancer activities in orthotopic HCC mouse models. This study provides an attractive and safe strategy for the rational design of CRISPR/Cas9 delivery system.

Hydrophobically modified carbon dots as a multifunctional platform for serum-resistant gene delivery and cell imaging

The development of novel multifunctional gene delivery systems with high efficiency is significant. Herein, due to the unique physical and optical properties of carbon dots (CDs), CDs prepared from polyethyleneimine (PEI) were modified with various hydrophobic chains and different degrees of substitution via an epoxide ring-opening reaction. The modification and substitution degree were confirmed using several analytical methods including ¹H NMR spectroscopy, FT-IR spectroscopy, TEM, and XPS. These CDs were utilized as multifunctional, safe and efficient non-viral gene vectors. The results showed that these materials possessed capability for dual-channel imaging, which enabled the intracellular tracking of the delivered DNA. Both the type and substitution degree of the hydrophobic chain have a large influence on their transfection efficiency. Among the prepared CDs, Ole1.5-CD gave the highest transfection efficiency, which was up to 200 times higher than that of PEI 25 kDa in the presence of serum in A549 cells. Meanwhile, these CD materials showed much less cytotoxicity and better serum tolerance than the traditional cationic polymeric gene vector. The cellular uptake assay further confirmed the good serum tolerance and structure-activity relationship of the CD materials. Thus, these CDs with good biocompatibility, self-imaging and high gene transfection efficiency may serve as a promising platform for both gene delivery and bio-imaging.

Self-responsive co-delivery system for remodeling tumor intracellular microenvironment to promote PTEN-mediated anti-tumor therapy

Delivering the pten gene into tumor cells to reacquire PTEN functionality is considered to be an attractive method for cancer treatment. However, the inhibition effect of the tumor intracellular microenvironment (TIME), especially at the high reactive oxygen species (ROS) level, on pten expression and PTEN protein functionality was nearly overlooked. Herein, the development of a potential strategy is described, which enhances PTEN-mediated anti-tumor capability by exhausting the intracellular ROS in TIME. To achieve this, poly(ethyleneimine) (PEI)-modified DSPE was introduced to protect the pten plasmid, and form liposomes for encapsulating the "scavenger" of oxidation homeostasis, epigallocatechin-3-gallate (EGCG). Notably, this was a simple system with improved safety compared which when compared with the use of PEI could accomplish efficient pten transfection and simultaneous disintegration to cause transient release of EGCG responding to the endosome environment through the "proton sponge effect". In the cytoplasm, EGCG depleted ROS and promoted the expression of the pten gene as well as restoring protein functionality, thus negatively regulating the PI3K-AKT signaling pathway. In vitro and in vivo results revealed that this system significantly inhibited tumor growth via remodeling of the TIME, and provided a promising way to control malignant tumors.

CRISPR-Cas12a delivery by DNA-mediated bioresponsive editing for cholesterol regulation

CRISPR-Cas12a represents an efficient tool for genome editing in addition to the extensively investigated CRISPR-Cas9. However, development of efficient nonviral delivery system for CRISPR-Cas12a remains challenging. Here, we demonstrate a DNA nanoclew (NC)-based carrier for delivery of Cas12a/CRISPR RNA (crRNA) ribonucleoprotein (RNP) toward regulating serum cholesterol levels. The DNA NC could efficiently load the Cas12a/crRNA RNP through complementation between the DNA NC and the crRNA. Addition of a cationic polymer layer condensed the DNA-templated core and allowed further coating of a charge reversal polymer layer, which makes the assembly negatively charged under a physiological pH but reverts to positive charge under an acidic environment. When Pcsk9 was selected as the target gene because of its important role in regulating the level of serum cholesterol, efficient Pcsk9 disruption was observed in vivo (~48%), significantly reducing the expression of PCSK9 and gaining the therapeutic benefit of cholesterol control (~45% of cholesterol reduction).

Controlled Cellular Delivery of Amphiphilic Cargo by Redox-Responsive Nanocontainers

The specific transport of amphiphilic compounds such as fluorescently labeled phospholipids into cells is a prerequisite for the analysis of highly dynamic cellular processes involving these molecules, e.g., the intracellular distribution and metabolism of phospholipids. However, cellular delivery remains a challenge as it should not affect the physiological integrity and morphology of the cell membrane. To address this, polymer nanocontainers based on redox-responsive cyclodextrin (CD) amphiphiles are prepared, and their potential to deliver fluorescently labeled phospholipids to intracellular membrane compartments is analyzed. It is shown that mixtures of reductively degradable cyclodextrin amphiphiles and different phospholipids form liposome-like vesicles (CD-lipid vesicles, CSSLV) with a homogeneous distribution of each lipid. Host-guest-mediated self-assembly of a cystamine-crosslinked polymer shell on these CSSLV produces polymer-shelled liposomal vesicles (PSSCSSLV) with the unique feature of a redox-sensitive CSSLV core and reductively degradable polymer shell. PSSCSSLV show high stability and a redox-sensitive release of the amphiphilic cargo. Live cell experiments reveal that the novel PSSCSSLV are readily internalized by primary human endothelial cells and that the reductive microenvironment of the cells' endosomes triggers the release of the amphiphilic cargo into the cytosol. Thus, PSSCSSLV represent a highly efficient system to transport lipid-like amphiphilic cargo into the intracellular environment.