Direct Cytosolic Delivery of CRISPR/Cas9-Ribonucleoprotein for Efficient Gene Editing

Efficient One-Step Knockout by Electroporation of Ribonucleoproteins Into Zona-Intact Bovine Embryos

Somatic cell nuclear transfer or cytoplasm microinjection have been used to generate genome-edited farm animals; however, these methods have several drawbacks that reduce their efficiency. This study aimed to develop electroporation conditions that allow delivery of CRISPR/Cas9 system to bovine zygotes for efficient gene knock-out. We optimized electroporation conditions to deliver Cas9:sgRNA ribonucleoproteins to bovine zygotes without compromising embryo development. Higher electroporation pulse voltage resulted in increased membrane permeability; however, voltages above 15 V/mm decreased embryo developmental potential. The zona pellucida of bovine embryos was not a barrier to efficient RNP electroporation. Using parameters optimized for maximal membrane permeability while maintaining developmental competence we achieved high rates of gene editing when targeting bovine OCT4, which resulted in absence of OCT4 protein in 100% of the evaluated embryos and the expected arrest of embryonic development at the morula stage. In conclusion, Cas9:sgRNA ribonucleoproteins can be delivered efficiently by electroporation to zona-intact bovine zygotes, resulting in efficient gene knockouts.

Genome and base editing for genetic hearing loss

Genome editing opens up a new frontier in developing personalized therapeutic solutions. With the unprecedented advance in the discovery and engineering of gene editing nucleases, it has now become potentially feasible to therapeutically influence up to 90% of all human genetic mutations. Hearing loss is one of the most well studied fields from the genetics perspective, with more than one hundred identified deafness genes. Novel viral and non-viral vectors have been established as safe and efficient modalities to deliver transgenes into cells of the cochlea and to the vestibular system in animal models. Recent studies demonstrated proof-of-concept for therapeutic genome and base editing in the mammalian inner ear and preclinical development is ongoing. This review summarizes important advances and future challenges for this transformative therapeutic modality for genetic and non-genetic hearing loss.

Cancer Nanomedicines in an Evolving Oncology Landscape

Nanomedicine represents an important class of cancer therapy. Clinical translation of cancer nanomedicine has significantly reduced the toxicity and adverse consequences of standard-of-care chemotherapy. Recent advances in new cancer treatment modalities (e.g., gene and immune therapies) are profoundly changing the oncology landscape, bringing with them new requirements and challenges for next-generation cancer nanomedicines. We present an overview of cancer nanomedicines in four emerging oncology-associated fields: (i) gene therapy, (ii) immunotherapy, (iii) extracellular vesicle (EV) therapy, and (iv) machine learning-assisted therapy. We discuss the incorporation of nanomedicine into these emerging disciplines, present prominent examples, and evaluate their advantages and challenges. Finally, we discuss future opportunities for next-generation cancer nanomedicines.

Delivery of Tissue-Targeted Scalpels: Opportunities and Challenges for In Vivo CRISPR/Cas-Based Genome Editing

CRISPR/Cas9-based genome editing has quickly emerged as a powerful breakthrough technology for use in diverse settings across biomedical research and therapeutic development. Recent efforts toward understanding gene modification methods in vitro have led to substantial improvements in ex vivo genome editing efficiency. Because disease targets for genomic correction are often localized in specific organs, realization of the full potential of genomic medicines will require delivery of CRISPR/Cas9 systems targeting specific tissues and cells directly in vivo. In this Perspective, we focus on progress toward in vivo delivery of CRISPR/Cas components. Viral and nonviral delivery systems are both promising for gene editing in diverse tissues via local injection and systemic injection. We describe the various viral vectors and synthetic nonviral materials used for in vivo gene editing and applications to research and therapeutic models, and summarize opportunities and progress to date for both methods. We also discuss challenges for viral delivery, including overcoming limited packaging capacity, immunogenicity associated with multiple dosing, and the potential for off-target effects, and nonviral delivery, including efforts to increase efficacy and to expand utility of nonviral carriers for use in extrahepatic tissues and cancer. Looking ahead, additional advances in the safety and efficiency of viral and nonviral delivery systems for tissue- and cell-type-specific gene editing will be required to enable broad clinical translation. We provide a summary of current delivery systems used for in vivo genome editing, organized with respect to route of administration, and highlight immediate opportunities for biomedical research and applications. Furthermore, we discuss current challenges for in vivo delivery of CRISPR/Cas9 systems to guide the development of future therapies.

Spatiotemporal Delivery of CRISPR/Cas9 Genome Editing Machinery Using Stimuli-Responsive Vehicles

Recent innovations in genome editing have enabled the precise manipulation of the genetic information of mammalians, and benefitted the development of next-generation gene therapy. Despite these advances, several barriers to the clinical translation of genome editing remain, including the intracellular delivery of genome editing machinery, and the risk of off-target editing effect. Here, we review the recent advance of spatiotemporal delivery of CRISPR/Cas9 genome editing machinery, which is composed of programmable Cas9 nuclease and a single-guide RNA (sgRNA) using stimuli-responsive nanoparticles. We discuss the specific chemistries that have been used for controlled Cas9/sgRNA delivery and intracellular release in the presence of endogenous or external signals. These methodologies can leverage biological signals found locally within disease cells, or exogenous signals administrated with spatiotemporal control, through which an improved genome editing could be achieved. We also discuss the future in exploiting these approaches for fundamental biomedical applications and therapeutic genome editing.

Cationic Lipid-based Intracellular Delivery of Bacterial Effectors for Rewiring Malignant Cell Signaling

The abundance of bacterial effectors have inspired us to explore their potential in rewiring malignant cell signaling. Their incapability for entering cells, however, hinders such application. Herein we developed a cationic lipid-based high throughput library screening platform for effective intracellular delivery of bacterial effectors. As the misregulated MAPK signaling is a hallmark of many types of cancer, we turned to the Shigella effector OspF which irreversibly inactivates ERK, the terminal component of MAPK cascade. We created a function-based screening assay to obtain AMPA-O16B lipid nanoparticles for effective OspF intracellular delivery, which inhibited the malignant MAPK signaling and tumor growth in vitro and in vivo. Furthermore, the optimized lipid nanoparticle formulation can deliver OspF to modulate the immunosuppressive responses in macrophages. Our work is a general strategy to explore the therapeutic potentials of naturally evolved bacterial effectors.

On the Effect of Modified Carbohydrates on the Size and Shape of Gold and Silver Nanostructures

Gold (Au) and silver (Ag) nanostructures have widespread utilization from biomedicine to materials science. Therefore, their synthesis with control of their morphology and surface chemistry have been among the hot topics over the last decades. Here, we introduce a new approach relying on sugar derivatives that work as reducing, stabilizing, and capping agents in the synthesis of Au and Ag nanostructures. These sugar derivatives are utilized alone and as mixture, resulting in spherical, spheroid, trigonal, polygonic, and star-like morphologies. The synthesis approach was further tested in the presence of acetate and dimethylamine as size- and shape-directing agents. With the use of transmission electron microscopy (TEM), selected area electron diffraction (SAED), x-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet-visible (UV-vis) absorption spectroscopy techniques, the particle size, shape, assembly, aggregation, and film formation characteristics were evaluated. NPs’ attributes were shown to be tunable by manipulating the sugar ligand selection and sugar ligand/metal-ion ratio. For instance, with an imine side group and changing the sugar moiety from cellobiose to lactose, the morphology of the Ag nanoparticles (NPs) transformed from well dispersed cubic to rough and aggregated. The introduction of acetate and dimethylamine further extended the growth pattern and morphological properties of these NPs. As examples, L5 AS, G5AS, and S5AS ligands formed spherical or sheet-like structures when used alone, which upon the use of these additives transformed into larger multicore and rough NPs, revealing their significant effect on the NP morphology. Selected samples were tested for their stability against protein corona formation and ionic strength, where a high chemical stability and resistance to protein coating were observed. The findings show a promising, benign approach for the synthesis of shape- and size-directed Au and Ag nanostructures, along with a selection of the chemistry of carbohydrate-derivatives that can open new windows for their applications.

Progress and challenges towards CRISPR/Cas clinical translation

CRISPR/Cas systems (clustered regularly interspaced short palindromic repeats) have emerged as powerful tools to manipulate the genome for both research and therapeutic purposes. However, the clinical use of this system is hindered by multiple challenges, such as the rate of off-target effects, editing efficiency, the efficacy of HDR, immunogenicity, as well as development of efficient and safe delivery vehicles that can carry these compounds. Tremendous efforts are being conducted to overcome these challenges, including the discovery and engineering of more precise and efficacious Cas nucleases. Moreover, in recent years multiple viral and non-viral delivery approaches have been explored for in vivo delivery of CRISPR components. Here, we summarize the available CRISPR/Cas toolbox for genome editing as well as the recently developed in vivo delivery vehicles for CRISPR/Cas system. Furthermore, we discuss the remaining challenges for successful clinical translation of this system and highlight the current clinical applications.

Effective generation of maternal genome point mutated porcine embryos by injection of cytosine base editor into germinal vesicle oocytes

Cytosine and adenine base editors are promising new tools for introducing precise genetic modifications that are required to generate disease models and to improve traits in pigs. Base editors can catalyze the conversion of C→T (C>T) or A→G (A>G) in the target site through a single guide RNA. Injection of base editors into the zygote cytoplasm can result in the production of offspring with precise point mutations, but most F0 are mosaic, and breeding of F1 heterozygous pigs is time-intensive. Here, we developed a method called germinal vesicle oocyte base editing (GVBE) to produce point mutant F0 porcine embryos by editing the maternal alleles during the GV to MII transition. Injection of cytosine base editor 3 (BE3) mRNA and X-linked Dmd-specific guide RNAs into GVoocytes efficiently edited maternal Dmd during in vitro maturation and did not affect the maturation potential of the oocytes. The edited MII oocytes developed into blastocysts after parthenogenetic activation (PA) or in vitro fertilization (IVF). However, BE3 may reduce the developmental potential of IVF blastocysts from 31.5%±0.8% to 20.4% ±2.1%. There 40%-78.3% diploid PA blastocysts had no more than two different alleles, including up to 10% embryos that had only C>T mutation alleles. Genotyping of IVF blastocysts indicated that over 70% of the edited embryos had one allele or two different alleles of Dmd. Since the male embryos had only a copy of Dmd allele, all five (5/19) F0 male embryos are homozygous and three of them were Dmd precise C>T mutation. Nine (9/19) female IVF embryos had two different alleles including a WT and a C>T mutation. DNA sequencing showed that some of them might be heterozygous embryos. In conclusion, the GVBE method is a valuable method for generating F0 embryos with maternal point mutated alleles in a single step.

Medical applications of clustered regularly interspaced short palindromic repeats (CRISPR/Cas) tool: A comprehensive overview

Since the discovery of the double helix and the introduction of genetic engineering, the possibility to develop new strategies to manipulate the genome has fascinated scientists around the world. Currently scientists have the knowledge andabilitytoedit the genomes. Several methodologies of gene editing have been established, all of them working like "scissor", creating double strand breaks at specific spots. The introduction of a new technology, which was adapted from the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas bacterial immune system, has revolutionized the genetic therapy field, as it allows a much more precise editing of gene than the previously described tools and, therefore, to prevent and treat disease in humans. This review aims to revisit the genome editing history that led to the rediscovery of the CRISPR/Cas technology and to explore the technical aspects, applications and perspectives of this fascinating, powerful, precise, simpler and cheaper technology in different fields.

The delivery challenge: fulfilling the promise of therapeutic genome editing

Genome editing has the potential to treat an extensive range of incurable monogenic and complex diseases. In particular, advances in sequence-specific nuclease technologies have dramatically accelerated the development of therapeutic genome editing strategies that are based on either the knockout of disease-causing genes or the repair of endogenous mutated genes. These technologies are progressing into human clinical trials. However, challenges remain before the therapeutic potential of genome editing can be fully realized. Delivery technologies that have serendipitously been developed over the past couple decades in the protein and nucleic acid delivery fields have been crucial to genome editing success to date, including adeno-associated viral and lentiviral vectors for gene therapy and lipid nanoparticle and other non-viral vectors for nucleic acid and protein delivery. However, the efficiency and tissue targeting capabilities of these vehicles must be further improved. In addition, the genome editing enzymes themselves need to be optimized, and challenges regarding their editing efficiency, specificity and immunogenicity must be addressed. Emerging protein engineering and synthetic chemistry approaches can offer solutions and enable the development of safe and efficacious clinical genome editing.

Delivery of drugs, proteins, and nucleic acids using inorganic nanoparticles

Inorganic nanoparticles provide multipurpose platforms for a broad range of delivery applications. Intrinsic nanoscopic properties provide access to unique magnetic and optical properties. Equally importantly, the structural and functional diversity of gold, silica, iron oxide, and lanthanide-based nanocarriers provide unrivalled control of nanostructural properties for effective transport of therapeutic cargos, overcoming biobarriers on the cellular and organismal level. Taken together, inorganic nanoparticles provide a key addition to the arsenal of delivery vectors for fighting disease and improving human health.

Systemic nanoparticle delivery of CRISPR-Cas9 ribonucleoproteins for effective tissue specific genome editing

CRISPR-Cas9 has emerged as a powerful technology that relies on Cas9/sgRNA ribonucleoprotein complexes (RNPs) to target and edit DNA. However, many therapeutic targets cannot currently be accessed due to the lack of carriers that can deliver RNPs systemically. Here, we report a generalizable methodology that allows engineering of modified lipid nanoparticles to efficiently deliver RNPs into cells and edit tissues including muscle, brain, liver, and lungs. Intravenous injection facilitated tissue-specific, multiplexed editing of six genes in mouse lungs. High carrier potency was leveraged to create organ-specific cancer models in livers and lungs of mice though facile knockout of multiple genes. The developed carriers were also able to deliver RNPs to restore dystrophin expression in DMD mice and significantly decrease serum PCSK9 level in C57BL/6 mice. Application of this generalizable strategy will facilitate broad nanoparticle development for a variety of disease targets amenable to protein delivery and precise gene correction approaches.

Therapeutic targets of CRISPR-Cas can often not be accessed due to lack of carriers to deliver RNPs systematically. Here, the authors engineer modified lipid nanoparticles for delivery of gene editing proteins to specific tissues.

Non-coding RNAs in cancer: platforms and strategies for investigating the genomic "dark matter"

The discovery of the role of non-coding RNAs (ncRNAs) in the onset and progression of malignancies is a promising frontier of cancer genetics. It is clear that ncRNAs are candidates for therapeutic intervention, since they may act as biomarkers or key regulators of cancer gene network. Recently, profiling and sequencing of ncRNAs disclosed deep deregulation in human cancers mostly due to aberrant mechanisms of ncRNAs biogenesis, such as amplification, deletion, abnormal epigenetic or transcriptional regulation. Although dysregulated ncRNAs may promote hallmarks of cancer as oncogenes or antagonize them as tumor suppressors, the mechanisms behind these events remain to be clarified. The development of new bioinformatic tools as well as novel molecular technologies is a challenging opportunity to disclose the role of the "dark matter" of the genome. In this review, we focus on currently available platforms, computational analyses and experimental strategies to investigate ncRNAs in cancer. We highlight the differences among experimental approaches aimed to dissect miRNAs and lncRNAs, which are the most studied ncRNAs. These two classes indeed need different investigation taking into account their intrinsic characteristics, such as length, structures and also the interacting molecules. Finally, we discuss the relevance of ncRNAs in clinical practice by considering promises and challenges behind the bench to bedside translation.

Poly(Beta-Amino Ester) Nanoparticles Enable Nonviral Delivery of CRISPR-Cas9 Plasmids for Gene Knockout and Gene Deletion

The CRISPR-Cas9 system is a powerful gene-editing tool with wide-ranging applications, but the safe and efficient intracellular delivery of CRISPR components remains a challenge. In this study, we utilized biodegradable poly(beta-amino ester) nanoparticles to codeliver plasmid DNA encoding Cas9 and short guide RNA (sgRNA), respectively, to enable gene knockout following a CRISPR-mediated cleavage at one genomic site (1-cut edit), as well as gene deletion following DNA cleavage at two sites flanking a region of interest (2-cut edits). We designed a reporter system that allows for easy evaluation of both types of edits: gene knockout can be assessed by a decrease in near-infrared fluorescent protein (iRFP) fluorescence, whereas deletion of an expression stop cassette turns on a red-enhanced nanolantern fluorescence/luminescence dual reporter. Nanoparticles enabled up to 70% gene knockout due to small indels, as well as 45% gain-of-function expression after a 600-bp deletion edit. The efficiency of 2-cut edits is more sensitive than 1-cut edits to Cas9 and the sgRNA expression level. We demonstrate promising biodegradable nanoparticle formulations for gene editing. Our findings also provide new insights into the screening and transfection requirements for different types of gene edits, which are applicable for designing nonviral delivery systems for the CRISPR-Cas9 platform.

Mutation-Directed Therapeutics for Neurofibromatosis Type I

Significant advances in biotechnology have led to the development of a number of different mutation-directed therapies. Some of these techniques have matured to a level that has allowed testing in clinical trials, but few have made it to approval by drug-regulatory bodies for the treatment of specific diseases. While there are still various hurdles to be overcome, recent success stories have proven the potential power of mutation-directed therapies and have fueled the hope of finding therapeutics for other genetic disorders. In this review, we summarize the state-of-the-art of various therapeutic approaches and assess their applicability to the genetic disorder neurofibromatosis type I (NF1). NF1 is caused by the loss of function of neurofibromin, a tumor suppressor and downregulator of the Ras signaling pathway. The condition is characterized by a variety of phenotypes and includes symptoms such as skin spots, nervous system tumors, skeletal dysplasia, and others. Hence, depending on the patient, therapeutics may need to target different tissues and cell types. While we also discuss the delivery of therapeutics, in particular via viral vectors and nanoparticles, our main focus is on therapeutic techniques that reconstitute functional neurofibromin, most notably cDNA replacement, CRISPR-based DNA repair, RNA repair, antisense oligonucleotide therapeutics including exon skipping, and nonsense suppression.

Recent Advances in CRISPR/Cas9 Delivery Strategies

The clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 system has revolutionized the field of gene editing. Continuous efforts in developing this technology have enabled efficient in vitro, ex vivo, and in vivo gene editing through a variety of delivery strategies. Viral vectors are commonly used in in vitro, ex vivo, and in vivo delivery systems, but they can cause insertional mutagenesis, have limited cloning capacity, and/or elicit immunologic responses. Physical delivery methods are largely restricted to in vitro and ex vivo systems, whereas chemical delivery methods require extensive optimization to improve their efficiency for in vivo gene editing. Achieving a safe and efficient in vivo delivery system for CRISPR/Cas9 remains the most challenging aspect of gene editing. Recently, extracellular vesicle-based systems were reported in various studies to deliver Cas9 in vitro and in vivo. In comparison with other methods, extracellular vesicles offer a safe, transient, and cost-effective yet efficient platform for delivery, indicating their potential for Cas9 delivery in clinical trials. In this review, we first discuss the pros and cons of different Cas9 delivery strategies. We then specifically review the development of extracellular vesicle-mediated gene editing and highlight the strengths and weaknesses of this technology.

Acoustofluidic sonoporation for gene delivery to human hematopoietic stem and progenitor cells

Advances in gene editing are leading to new medical interventions where patients' own cells are used for stem cell therapies and immunotherapies. One of the key limitations to translating these treatments to the clinic is the need for scalable technologies for engineering cells efficiently and safely. Toward this goal, microfluidic strategies to induce membrane pores and permeability have emerged as promising techniques to deliver biomolecular cargo into cells. As these technologies continue to mature, there is a need to achieve efficient, safe, nontoxic, fast, and economical processing of clinically relevant cell types. We demonstrate an acoustofluidic sonoporation method to deliver plasmids to immortalized and primary human cell types, based on pore formation and permeabilization of cell membranes with acoustic waves. This acoustofluidic-mediated approach achieves fast and efficient intracellular delivery of an enhanced green fluorescent protein-expressing plasmid to cells at a scalable throughput of 200,000 cells/min in a single channel. Analyses of intracellular delivery and nuclear membrane rupture revealed mechanisms underlying acoustofluidic delivery and successful gene expression. Our studies show that acoustofluidic technologies are promising platforms for gene delivery and a useful tool for investigating membrane repair.

Genome Editing in a Wide Area of the Brain Using Dendrimer-Based Ternary Polyplexes of Cas9 Ribonucleoprotein

A preassembled Cas9/single-guide RNA complex (Cas9 ribonucleoprotein; Cas9 RNP) induces genome editing efficiently, with small off-target effects compared with the conventional techniques, such as plasmid DNA and mRNA systems. However, penetration of Cas9 RNP through the cell membrane is low. In particular, the incorporation of Cas9 RNP into neurons and the brain is challenging. In the present study, we have reported the use of a dendrimer (generation 3; G3)/glucuronylglucosyl-β-cyclodextrin conjugate (GUG-β-CDE (G3)) as a carrier of Cas9 RNP and evaluated genome editing activity in the neuron and the brain. A Cas9 RNP ternary complex with GUG-β-CDE (G3) was prepared by only mixing the components. The resulting complex exhibited higher genome editing activity than the complex with the dendrimer (G3), Lipofectamine 3000 or Lipofectamine CRISPRMAX in SH-SY5Y cells, a human neuroblastoma cell line. In addition, GUG-β-CDE (G3) enhanced the genome editing activity of Cas9 RNP in the whole mouse brain after a single intraventricular administration. Thus, GUG-β-CDE (G3) is a useful Cas9 RNP carrier that can induce genome editing in the neuron and brain.

Nanotechnology Promotes Genetic and Functional Modifications of Therapeutic T Cells Against Cancer

Growing experience with engineered chimeric antigen receptor (CAR)-T cells has revealed some of the challenges associated with developing patient-specific therapy. The promising clinical results obtained with CAR-T therapy nevertheless demonstrate the urgency of advancements to promote and expand its uses. There is indeed a need to devise novel methods to generate potent CARs, and to confer them and track their anti-tumor efficacy in CAR-T therapy. A potentially effective approach to improve the efficacy of CAR-T cell therapy would be to exploit the benefits of nanotechnology. This report highlights the current limitations of CAR-T immunotherapy and pinpoints potential opportunities and tremendous advantages of using nanotechnology to 1) introduce CAR transgene cassettes into primary T cells, 2) stimulate T cell expansion and persistence, 3) improve T cell trafficking, 4) stimulate the intrinsic T cell activity, 5) reprogram the immunosuppressive cellular and vascular microenvironments, and 6) monitor the therapeutic efficacy of CAR-T cell therapy. Therefore, genetic and functional modifications promoted by nanotechnology enable the generation of robust CAR-T cell therapy and offer precision treatments against cancer.

Supercharged Proteins and Polypeptides

Electrostatic interactions play a vital role in nature. Biomacromolecules such as proteins are orchestrated by electrostatics, among other intermolecular forces, to assemble and organize biochemistry. Natural proteins with a high net charge exist in a folded state or are unstructured and can be an inspiration for scientists to artificially supercharge other protein entities. Recent findings show that supercharging proteins allows for control of their properties such as temperature resistance and catalytic activity. One elegant method to transfer the favorable properties of supercharged proteins to other proteins is the fabrication of fusions. Genetically engineered, supercharged unstructured polypeptides (SUPs) are just one promising fusion tool. SUPs can also be complexed with artificial entities to yield thermotropic and lyotropic liquid crystals and liquids. These architectures represent novel bulk materials that are sensitive to external stimuli. Interestingly, SUPs undergo fluid-fluid phase separation to form coacervates. These coacervates can even be directly generated in living cells or can be combined with dissipative fiber assemblies that induce life-like features. Supercharged proteins and SUPs are developed into exciting classes of materials. Their synthesis, structures, and properties are summarized. Moreover, potential applications are highlighted and challenges are discussed.

Gene editing in dermatology: Harnessing CRISPR for the treatment of cutaneous disease

The discovery of the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) system has revolutionized gene editing research. Through the repurposing of programmable RNA-guided CRISPR-associated (Cas) nucleases, CRISPR-based genome editing systems allow for the precise modification of specific sites in the human genome and inspire novel approaches for the study and treatment of inherited and acquired human diseases. Here, we review how CRISPR technologies have stimulated key advances in dermatologic research.  We discuss the role of CRISPR in genome editing for cutaneous disease and highlight studies on the use of CRISPR-Cas technologies for genodermatoses, cutaneous viruses and bacteria, and melanoma. Additionally, we examine key limitations of current CRISPR technologies, including the challenges these limitations pose for the widespread therapeutic application of CRISPR-based therapeutics.

Cytosolic Delivery of Functional Proteins In Vitro through Tunable Gigahertz Acoustics

Intracellular delivery is essential to therapeutic applications such as genome engineering and disease diagnosis. Current methods lack simple, noninvasive strategies and are often hindered by long incubation time or high toxicity. Hydrodynamic approaches offer rapid and controllable delivery of small molecules, but thus far have not been demonstrated for delivering functional proteins. In this work, we developed a robust hydrodynamic approach based on gigahertz (GHz) acoustics to achieve rapid and noninvasive cytosolic delivery of biologically active proteins. With this method, GHz-based acoustic devices trigger oscillations through a liquid medium (acoustic streaming), generating shear stress on the cell membrane and inducing transient nanoporation. This mechanical effect enhances membrane permeability and enables cytosolic access to cationic proteins without disturbing their bioactivity. We evaluated the versatility of this approach through the delivery of cationic fluorescent proteins to a range of cell lines, all of which displayed equally efficient delivery speed (≤20 min). Delivery of multiple enzymatically active proteins with functionality related to apoptosis or genetic recombination further demonstrated the relevance of this method.

Aptamer/Peptide-Functionalized Genome-Editing System for Effective Immune Restoration through Reversal of PD-L1-Mediated Cancer Immunosuppression

Effective reversal of tumor immunosuppression is of critical importance in cancer therapy. A multifunctional delivery vector that can effectively deliver CRISPR-Cas9 plasmid for β-catenin knockout to reverse tumor immunosuppression is constructed. The multi-functionalized delivery vector is decorated with aptamer-conjugated hyaluronic acid and peptide-conjugated hyaluronic acid to combine the tumor cell/nuclear targeting function of AS1411 with the cell penetrating/nuclear translocation function of TAT-NLS. Due to the significantly enhanced plasmid enrichment in malignant cell nuclei, the genome editing system can induce effective β-catenin knockout and suppress Wnt/β-catenin pathway, resulting in notably downregulated proteins involved in tumor progression and immunosuppression. Programmed death-ligand 1 (PD-L1) downregulation in edited tumor cells not only releases the PD-1/PD-L1 brake to improve the cancer killing capability of CD8⁺ T cells, but also enhances antitumor immune responses of immune cells. This provides a facile strategy to reverse tumor immunosuppression and to restore immunosurveillance and activate anti-tumor immunity.

A Genome-Editing Nanomachine Constructed with a Clustered Regularly Interspaced Short Palindromic Repeats System and Activated by Near-Infrared Illumination

The RNA-guided CRISPR/Cas9 system is a powerful genome-editing technology with broad applications. Improving delivery efficiency and controllable activity of the CRISPR/Cas9 system is an area of intense research. We report the design, construction, and application of a CRISPR/Cas9 nanomachine (LACM), activated by a near-infrared (NIR) laser, which enables efficient delivery of single-guide RNA (sgRNA) into living cells and achieves controlled release of the sgRNA for the CRISPR/Cas9 activity. The LACM was constructed using a gold nanorod (AuNR) as a carrier that was decorated with dozens of protector DNAs stably hybridizing with the target binding domain of sgRNA. The DNA assembly on the AuNR protected the sgRNA. Irradiation with a NIR laser generated heat on the AuNR, resulting in controlled release of sgRNA, which guided the CRISPR/Cas9 genome editing. Successful editing of the EGFP and EMX1 genes in A549 and HEK293T cells, as well as knocking down of the PLK1 gene to induce apoptosis of the target cells, highlights the promising potential of the LACM for diverse applications.

Delivery of nucleic acid therapeutics for cancer immunotherapy

Cancer immunotherapy has shown great potential as witnessed by an increasing number of immuno-oncology drug approvals in the past few years. Meanwhile, the field of nucleic acid therapeutics has made significant advancement. Nucleic acid therapeutics, such as plasmids, antisense oligonucleotides (ASO), small interfering RNA (siRNA) and microRNA, messenger RNA (mRNA), immunomodulatory DNA/RNA, and gene-editing guide RNA (gRNA) are attractive due to their versatile abilities to alter the expression of target endogenous genes or even synthetic genes, and modulate the immune responses. These abilities can play vital roles in the development of novel immunotherapy strategies. However, limited by the intrinsic physicochemical properties such as negative charges, hydrophilicity, as well as susceptibility to enzymatic degradation, the delivery of nucleic acid therapeutics faces multiple challenges. It is therefore pivotal to develop drug delivery systems that can carry, protect, and specifically deliver and release nucleic acid therapeutics to target tissues and cells. In this review, we attempted to summarize recent advances in nucleic acid therapeutics and the delivery systems for these therapeutics in cancer immunotherapy.

Delivery of Cas9/sgRNA Ribonucleoprotein Complexes via Hydroxystearyl Oligoamino Amides

The programmable endonuclease activity and simple usage of CRISPR/Cas9 have revolutionized the field of genome editing. The binding of single guide RNA (sgRNA) by the Cas9 protein results in the formation of negatively charged ribonucleoprotein (RNP) complexes. The presence of this functional complex inside cells is imperative for the intended specific genome modifications. The direct intracellular delivery of Cas9/sgRNA RNP complexes is of great advantage. In this work, a compound library of sequence-defined oligo(ethylenamino) amides containing structural motifs for stable nanoparticle formation, cellular uptake, and endosomal release was used for the screening and development of suitable Cas9 RNP delivery vehicles. Lipid-containing oligoaminoamides (lipo-OAAs) were identified as the most efficient carriers for intracellular Cas9/sgRNA delivery and gene disruption. Fluorescence correlation spectroscopy measurements indicated that the lipo-OAAs only interact with sgRNA-loaded Cas9 protein, which suggests exclusive ionic interaction with the negatively charged RNPs. The type of contained fatty acid turned out to have a critical impact on the knock out efficiency: the presence of one hydroxy group in the fatty acid dramatically changes the properties and performance of the resulting Cas9/sgRNA lipo-OAA complexes. The lipo-OAA-containing hydroxy-stearic acid (OHSteA) was superior to the analogues with saturated or unsaturated fatty acids without hydroxylation; it formed smaller and more defined nanoparticles with Cas9/sgRNA and improved the cellular uptake and endosomal release, which altogether resulted in an increased nuclear association and the highest gene knock out levels. The efficient and adaptable delivery platform has high potential for the future development of therapeutics based on precise genome modifications.

Polyethylenimine based magnetic nanoparticles mediated non-viral CRISPR/Cas9 system for genome editing

Clustered regularly interspaced short palindromic repeats-associated protein (CRISPR/Cas9) system has become a revolutionary tool for gene editing. Since viral delivery systems have significant side effects, and naked DNA delivery is not an option, the nontoxic, non-viral delivery of CRISPR/Cas9 components would significantly improve future therapeutic delivery. In this study, we aim at characterizing nanoparticles to deliver plasmid DNA encoding for the CRISPR-Cas system in eukaryotic cells in vitro. CRISPR/Cas9 complexed polyethylenimine (PEI) magnetic nanoparticles (MNPs) were generated. We used a stable HEK293 cell line expressing the traffic light reporter (TLR-3) system to evaluate efficient homology- directed repair (HDR) and non-homologous end joining (NHEJ) events following transfection with NPs. MNPs have been synthesized by co-precipitation with the average particle size around 20 nm in diameter. The dynamic light scattering and zeta potential measurements showed that NPs exhibited narrow size distribution and sufficient colloidal stability. Genome editing events were as efficient as compared to standard lipofectamine transfection. Our approach tested non-viral delivery of CRISPR/Cas9 and DNA template to perform HDR and NHEJ in the same assay. We demonstrated that PEI-MNPs is a promising delivery system for plasmids encoding CRISPR/Cas9 and template DNA and thus can improve safety and utility of gene editing.

Direct Cytosolic Delivery of Proteins through Coengineering of Proteins and Polymeric Delivery Vehicles

Nanocarrier-mediated protein delivery is a promising strategy for fundamental research and therapeutic applications. However, the efficacy of the current platforms for delivery into cells is limited by endosomal entrapment of delivered protein cargo with concomitantly inefficient access to the cytosol and other organelles, including the nucleus. We report here a robust, versatile polymeric-protein nanocomposite (PPNC) platform capable of efficient (≥90%) delivery of proteins to the cytosol. We synthesized a library of guanidinium-functionalized poly(oxanorborneneimide) (PONI) homopolymers with varying molecular weights to stabilize and deliver engineered proteins featuring terminal oligoglutamate "E-tags". The polymers were screened for cytosolic delivery efficiency using imaging flow cytometry with cytosolic delivery validated using confocal microscopy and activity of the delivered proteins demonstrated through functional assays. These studies indicate that the PPNC platform provides highly effective and tunable cytosolic delivery over a wide range of formulations, making them robust agents for therapeutic protein delivery.

Ex vivo cell-based CRISPR/Cas9 genome editing for therapeutic applications

The recently developed CRISPR/Cas9 technology has revolutionized the genome engineering field. Since 2016, increasing number of studies regarding CRISPR therapeutics have entered clinical trials, most of which are focusing on the ex vivo genome editing. In this review, we highlight the ex vivo cell-based CRISPR/Cas9 genome editing for therapeutic applications. In these studies, CRISPR/Cas9 tools were used to edit cells in vitro and the successfully edited cells were considered as therapeutics, which can be introduced into patients to treat diseases. Considering a large number of previous reviews have been focused on the CRISPR/Cas9 delivery methods and materials, this review provides a different perspective, by mainly introducing the targeted conditions and design strategies for ex vivo CRISPR/Cas9 therapeutics. Brief descriptions of the history, functionality, and applications of CRISPR/Cas9 systems will be introduced first, followed by the design strategies and most significant results from previous research that used ex vivo CRISPR/Cas9 genome editing for the treatment of conditions or diseases. The last part of this review includes general information about the status of CRISPR/Cas9 therapeutics in clinical trials. We also discuss some of the challenges as well as the opportunities in this research area.

Nanomaterials innovation as an enabler for effective cancer interventions

Nanomedicines have been developing very rapidly and have started to play a significant role in several cancer therapeutic modalities. Early on, the nanomedicine field focused on optimizing pharmacokinetics, toxicity, and/or biodistribution of an agent through nanoparticle formulation. In other cases, where materials science is employed more decisively, nanomedicine can include the creation of new agents that take advantage of nanoscale materials properties to enhance treatment efficacy through unique mode of action, molecular targeting, or controlled drug release. Both current and future nanomedicines will seek to contribute to the therapeutic and diagnostic landscape through creative leveraging of mechanical, electrical, optical, magnetic, and biological nanomaterial properties. In this work, we discuss how by modulating these material properties, one can design more diverse and more effective cancer interventions. We focus on six areas in cancer management, including in vitro diagnostics, clinical imaging, theranostics, combination therapy, immunotherapy, and gene therapy.

Tooth Regeneration: Insights from Tooth Development and Spatial-Temporal Control of Bioactive Drug Release

Tooth defect and tooth loss are common clinical diseases in stomatology. Compared with the traditional oral restoration treatment, tooth regeneration has unique advantages and is currently the focus of oral biomedical research. It is known that dozens of cytokines/growth factors and other bioactive factors are expressed in a spatial-temporal pattern during tooth development. On the other hand, the technology for spatial-temporal control of drug release has been intensively studied and well developed recently, making control release of these bioactive factors mimicking spatial-temporal pattern more feasible than ever for the purpose of tooth regeneration. This article reviews the research progress on the tooth development and discusses the future of tooth regeneration in the context of spatial-temporal release of developmental factors.

Cell-Type-Specific CRISPR/Cas9 Delivery by Biomimetic Metal Organic Frameworks

Effective and cell-type-specific delivery of CRISPR/Cas9 gene editing elements remains a challenging open problem. Here we report the development of biomimetic cancer cell coated zeolitic imidazolate frameworks (ZIFs) for targeted and cell-specific delivery of this genome editing machinery. Coating ZIF-8 that is encapsulating CRISPR/Cas9 (CC-ZIF) with a cancer cell membrane resulted in the uniformly covered C³-ZIF_{(cell membrane type)}. Incubation of C³-ZIF_MCF with MCF-7, HeLa, HDFn, and aTC cell lines showed the highest uptake by MCF-7 cells and negligible uptake by the healthy cells (i.e., HDFn and aTC). As to genome editing, a 3-fold repression in the EGFP expression was observed when MCF-7 were transfected with C³-ZIF_MCF compared to 1-fold repression in the EGFP expression when MCF-7 were transfected with C³-ZIF_HELA. In vivo testing confirmed the selectivity of C³-ZIF_MCF to accumulate in MCF-7 tumor cells. This supports the ability of this biomimetic approach to match the needs of cell-specific targeting, which is unquestionably the most critical step in the future translation of genome editing technologies.

Surface chemistry of gold nanoparticles for health-related applications

Functionalization of gold nanoparticles is crucial for the effective utilization of these materials in health-related applications. Health-related applications of gold nanoparticles rely on the physical and chemical reactions between molecules and gold nanoparticles. Surface chemistry can precisely control and tailor the surface properties of gold nanoparticles to meet the needs of applications. Gold nanoparticles have unique physical and chemical properties, and have been used in a broad range of applications from prophylaxis to diagnosis and treatment. The surface chemistry of gold nanoparticles plays a crucial role in all of these applications. This minireview summarizes these applications from the perspective of surface chemistry and explores how surface chemistry improves and imparts new properties to gold nanoparticles for these applications.

Therapeutic applications of CRISPR/Cas9 in breast cancer and delivery potential of gold nanomaterials

Globally, approximately 1 in 4 cancers in women are diagnosed as breast cancer (BC). Despite significant advances in the diagnosis and therapy BCs, many patients develop metastases or relapses. Hence, novel therapeutic strategies are required, that can selectively and efficiently kill malignant cells. Direct targeting of the genetic and epigenetic aberrations that occur in BC development is a promising strategy to overcome the limitations of current therapies, which target the tumour phenotype. The clustered regularly interspaced short palindromic repeats (CRISPR)/Cas system, composed of only an easily modifiable single guide RNA (sgRNA) sequence bound to a Cas9 nuclease, has revolutionised genome editing due to its simplicity and efficiency compared to earlier systems. CRISPR/Cas9 and its associated catalytically inactivated dCas9 variants facilitate the knockout of overexpressed genes, correction of mutations in inactivated genes, and reprogramming of the epigenetic landscape to impair BC growth. To achieve efficient genome editing in vivo, a vector is required to deliver the components to target cells. Gold nanomaterials, including gold nanoparticles and nanoclusters, display many advantageous characteristics that have facilitated their widespread use in theranostics, as delivery vehicles, and imaging and photothermal agents. This review highlights the therapeutic applications of CRISPR/Cas9 in treating BCs, and briefly describes gold nanomaterials and their potential in CRISPR/Cas9 delivery.

Delivery of Cas13a/crRNA by self-degradable black phosphorus nanosheets to specifically inhibit Mcl-1 for breast cancer therapy

The constructed Cas13a/crRNA complex is delivered into cytoplasm by PBP via endocytosis, followed by endosomal escape based on biodegradation of the PBP, and efficiently knocked down Mcl-1 at transcriptional level for breast cancer therapy.

Boronic acid-engineered gold nanoparticles for cytosolic protein delivery

Boronic acid-engineered gold nanoparticles for effective cytosolic protein delivery with the help of hypertonicity.

Lipid and polymer mediated CRISPR/Cas9 gene editing

A clustered regularly interspaced short palindromic repeats (CRISPR)/associated protein 9 (CRISPR/Cas9) system is the most widely used tool for gene editing.

[Development of CRISPR technology and its application in bone and cartilage tissue engineering]

The CRISPR/Cas9 system, consisting of Cas9 nuclease and single guide RNA (sgRNA), is an emerging gene editing technology that can perform gene reprogramming operations such as deletion, insertion, and point mutation on DNA sequences targeted by sgRNA. In addition, CRISPR/dCas9 (a mutant that loses Cas9 nuclease activity) still retains the ability of sgRNA to target DNA. The fusion of dCas9 protein with transcriptional activator (CRISPRa) can activate the expression of the target gene, and fusion transcriptional repressors (CRISPRi) can also be used to suppress target gene expression. Efficient delivery of the CRISPR/Cas9 system is one of the main problems limiting its wide clinical application. Viral vectors are widely used to efficiently deliver CRISPR/Cas9 elements, but non-viral vector research is more attractive in terms of safety, simplicity, and flexibility. In this review, we summarize the principles and research advances of CRISPR technology, including CRISPR/ Cas9 delivery vectors, delivery methods, and obstacles to the delivery, and review the progress of CRISPR-based research in bone and cartilage tissue engineering. Finally, the challenges and future applications of CRISPR technology in bone and cartilage tissue engineering are discussed.

Delivering Cas9/sgRNA ribonucleoprotein (RNP) by lentiviral capsid-based bionanoparticles for efficient 'hit-and-run' genome editing

Transient expression of the CRISPR/Cas9 machinery will not only reduce risks of mutagenesis from off-target activities, but also decrease possible immune response to Cas9 protein. Building on our recent developing of a system able to package up to 100 copies of Cas9 mRNA in each lentivirus-like particle (LVLP) via the specific interaction between aptamer and aptamer-binding proteins (ABP), here we develop a lentiviral capsid-based bionanoparticle system, which allows efficient packaging of Cas9/sgRNA ribonucleoprotein (RNP). We show that replacing the Tetraloop of sgRNA scaffold with a com aptamer preserves the functions of the guide RNA, and the com-modified sgRNA can package Cas9/sgRNA RNP into lentivirus-like particles via the specific interactions between ABP and aptamer, and sgRNA and Cas9 protein. These RNP bionanoparticles generated Indels on different targets in different cells with efficiencies similar to or better than our recently described Cas9 mRNA LVLPs. The new system showed fast action and reduced off-target rates, and makes it more convenient and efficient in delivering Cas9 RNPs for transient Cas9 expression and efficient genome editing.

Casting Light on Intracellular Tracking of a New Functional Graphene-Based MicroRNA Delivery System by FLIM and Raman Imaging

The theranostic ability of a new fluorescently labeled cationic cyclodextrin-graphene nanoplatform (GCD@Ada-Rhod) was investigated by studying its intracellular trafficking and its ability to deliver plasmid DNA and microRNA. The nanoplatform was synthesized by both covalent and supramolecular approaches, and its chemical structure, morphology, and colloidal behavior were investigated by TGA, TEM, spectroscopic analysis such as UV-vis, fluorescence emission, DLS, and ζ-potential measurements. The cellular internalization of GCD@Ada-Rhod and its perinuclear localization were assessed by FLIM, Raman imaging, and fluorescence microscopy. Biological experiments with pCMS-EGFP and miRNA-15a evidenced the excellent capability of GCD@Ada-Rhod to deliver both pDNA and microRNA without significant cytotoxicity. The biological results evidenced an unforeseen caveolae-mediated endocytosis internalization pathway (generally expected for particles <200 nm), despite the fact that the GCD@Ada-Rhod size is about 400 nm (by DLS and TEM data). We supposed that the internalization pathway was driven by physical-chemical features of GCD@Ada-Rhod, and the caveolae-mediated uptake enhanced the transfection efficiency, avoiding the lysosomal acid degradation. The cellular effects of internalized miRNA-15a on the oncogene protein BCL-2 were investigated at two different concentrations (N/P = 10 and 5), and a reduction of the BCL-2 level was detected at a low concentration (i.e., N/P = 10). miRNA-15a is considered an ideal cancer therapy molecule due to its activity on multiple transcription factors, and the elucidation of the correlation between the concentration of delivered miRNA-15a and the down-/up-regulation of the BCL-2 level, documented for the first time in this work, could be an important contribution to guide its clinical application.

Strategies for nonviral nanoparticle-based delivery of CRISPR/Cas9 therapeutics

CRISPR-based genome editing technology has become an important potential therapeutic tool for various diseases. A vital challenge is to reach a safe, efficient, and clinically suitable delivery of a CRISPR-associated protein and a single-guide RNA. A possible translational approach to applying CRISPR-based technology is the use of viral vectors such as adeno-associated virus. However, such vectors give long-term exposure in vivo that may increase potential off-target effects as well as the risk of immunogenicity. Therefore, limitations to clinical applications are addressed using nonviral delivery systems such as nanoparticle-based delivery strategies. Today, the nanoparticle-based delivery approach is becoming more and more attractive in gene therapeutics because of its specific targeting, scale-up efficiency, efficacy of customization, minor stimulation of immune response, and minimal exposure to nucleases. In this review, we will present the most recent advances in developing innovations and potential advantages of the nanoparticle delivery system in CRISPR genome editing. We will also propose potential strategies of CRISPR-based technology for therapeutic and industrial applications. Our review will differ in focus from previous reviews and advance the literature on the subject by (a) focusing on the challenges of the CRISPR/Cas9 delivery system; (b) focusing on the application of nanoparticle-based delivery of CRISPR components (Cas9 and sgRNA), such as lipids and polymeric vectors; (c) discussing the potential nanoparticle-based delivery approaches for CRISPR/Cas9 application. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.