Carboxylated branched poly(β-amino ester) nanoparticles enable robust cytosolic protein delivery and CRISPR-Cas9 gene editing

Advances in locally administered nucleic acid therapeutics

Nucleic acid drugs represent the latest generation of precision therapeutics, holding significant promise for the treatment of a wide range of intractable diseases. Delivery technology is crucial for the clinical application of nucleic acid drugs. However, extrahepatic delivery of nucleic acid drugs remains a significant challenge. Systemic administration often fails to achieve sufficient drug enrichment in target tissues. Localized administration has emerged as the predominant approach to facilitate extrahepatic delivery. While localized administration can significantly enhance drug accumulation at the injection sites, nucleic acid drugs still face biological barriers in reaching the target lesions. This review focuses on non-viral nucleic acid drug delivery techniques utilized in local administration for the treatment of extrahepatic diseases. First, the classification of nucleic acid drugs is described. Second, the current major non-viral delivery technologies for nucleic acid drugs are discussed. Third, the bio-barriers, administration approaches, and recent research advances in the local delivery of nucleic acid drugs for treating lung, brain, eye, skin, joint, and heart-related diseases are highlighted. Finally, the challenges associated with the localized therapeutic application of nucleic acid drugs are addressed.

Intracellular delivery of proteins for live cell imaging

The majority of cellular functions are regulated by intracellular proteins, and regulating their interactions can unlock fundamental insights in biology and open new avenues for drug discovery. Because the vast majority of intracellular targets remain undruggable, there is significant current interest in developing protein-based agents especially monoclonal antibodies due to their specificity, availability, and established screening/engineering methods. However, efficient delivery of proteins into the cytoplasm has been a major challenge in biological engineering and drug discovery. We previously reported a platform technology based on a Coomassie blue-cholesterol conjugate (CB-tag) capable of delivering small proteins directly into the cytoplasm. Here, we report a new generation of CB-tag that can bring proteins with a wide size range into the cytoplasm, bypassing endosomal sequestration. Remarkably, intracellular targets with distinct structures were visualized. Overall, the new CB-tag demonstrated a robust ability in protein delivery with broad applications ranging from live-cell immunofluorescence to protein-based therapeutic development.

Lipid Nanoparticles for In Vivo Lung Delivery of CRISPR-Cas9 Ribonucleoproteins Allow Gene Editing of Clinical Targets

In the past 10 years, CRISPR-Cas9 has revolutionized the gene-editing field due to its modularity, simplicity, and efficacy. It has been applied for the creation of in vivo models, to further understand human biology, and toward the curing of genetic diseases. However, there remain significant delivery barriers for CRISPR-Cas9 application in the clinic, especially for in vivo and extrahepatic applications. In this work, high-throughput molecular barcoding techniques were used alongside traditional screening methodologies to simultaneously evaluate LNP formulations encapsulating ribonucleoproteins (RNPs) for in vitro gene-editing efficiency and in vivo biodistribution. This resulted in the identification of a lung-tropic LNP formulation, which shows efficient gene editing in endothelial and epithelial cells within the lung, targeting both model reporter and clinically relevant genomic targets. Further, this LNP shows no off-target indel formation in the liver, making it a highly specific extrahepatic delivery system for lung-editing applications.

Precisely Targeted Nanoparticles for CRISPR-Cas9 Delivery in Clinical Applications

Clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR-Cas9), an emerging gene-editing technology, has recently gained rapidly increasing attention. However, the lack of efficient delivery vectors to deliver CRISPR-Cas9 to specific cells or tissues has hindered the translation of this biotechnology into clinical applications. Chemically synthesized nanoparticles (NPs), as attractive non-viral delivery platforms for CRISPR-Cas9, have been extensively investigated because of their unique characteristics, such as controllable size, high stability, multi-functionality, bio-responsive behavior, biocompatibility, and versatility in chemistry. In this review, the key considerations for the precise design of chemically synthesized-based nanoparticles include efficient encapsulation, cellular uptake, the targeting of specific tissues and cells, endosomal escape, and controlled release. We discuss cutting-edge strategies to integrate chemical modifications into non-viral nanoparticles that guide the CRISPR-Cas9 genome-editing machinery to specific edits. We also highlighted the rationale of intelligent nanoparticle design. In particular, we have summarized promising functional groups and molecules that can effectively optimize carrier function. In addition, this review focuses on advances in the widespread application of NPs delivery in the biomedical fields to promote the development of safe, specific, and efficient NPs for delivering CRISPR-Cas9 systems, providing references for accelerating their clinical translational applications.

Prime Editing: A Revolutionary Technology for Precise Treatment of Genetic Disorders

Genetic diseases have long posed significant challenges, with limited breakthroughs in treatment. Recent advances in gene editing technologies offer new possibilities in gene therapy for the treatment of inherited disorders. However, traditional gene editing methods have limitations that hinder their potential for clinical use, such as limited editing capabilities and the production of unintended byproducts. To overcome these limitations, prime editing (PE) has been developed as a powerful tool for precise and efficient genome modification. In this review, we provide an overview of the latest advancements in PE and its potential applications in the treatment of inherited disorders. Furthermore, we examine the current delivery vehicles employed for delivering PE systems in vitro and in vivo, and analyze their respective benefits and limitations. Ultimately, we discuss the challenges that need to be addressed to fully unlock the potential of PE for the remission or cure of genetic diseases.

Advanced delivery systems for gene editing: A comprehensive review from the GenE-HumDi COST Action Working Group

In the past decade, precise targeting through genome editing has emerged as a promising alternative to traditional therapeutic approaches. Genome editing can be performed using various platforms, where programmable DNA nucleases create permanent genetic changes at specific genomic locations due to their ability to recognize precise DNA sequences. Clinical application of this technology requires the delivery of the editing reagents to transplantable cells ex vivo or to tissues and organs for in vivo approaches, often representing a barrier to achieving the desired editing efficiency and safety. In this review, authored by members of the GenE-HumDi European Cooperation in Science and Technology (COST) Action, we described the plethora of delivery systems available for genome-editing components, including viral and non-viral systems, highlighting their advantages, limitations, and potential application in a clinical setting.

Guanidyl-rich highly branched poly(β-amino ester)s for the delivery of dual CRISPR ribonucleoprotein for efficient large DNA fragment deletion

Gene editing technologies, particularly clustered regularly interspersed short palindromic repeats (CRISPR) and CRISPR-associated (Cas) proteins, have revolutionized the ability to modify gene sequences in living cells for therapeutic purposes. Delivery of CRISPR/Cas ribonucleoprotein (RNP) is preferred over its DNA and RNA formats in terms of gene editing effectiveness and low risk of off-target events. However, the intracellular delivery of RNP poses significant challenges and necessitates the development of non-viral vectors. Our previous study has demonstrated that phenyl guanidine (PG) group modified linear poly(β-amino ester)s (PAEs) can facilitate CRISPR/Cas9 RNP mediated gene knockout in HeLa cells. Here, we further investigated the utilization of highly branched PAEs (HPAEs) with PG groups (HPAE-PG) for efficient delivery of cytosolic protein and CRISPR/Cas9 RNP complexes, while also examining the influence of branching units and branching ratios on the delivery process. The efficiency of HPAE-PG/RNP transfection for large DNA fragment deletion was assessed using a dual sgRNA-guided approach to delete exon 80 of the human COL7A1 gene, which harbors mutations associated with dystrophic epidermolysis bullosa (DEB). Our findings demonstrate that HPAE-PG/RNP successfully induced a deletion of 56 base pairs (exon 80) within COL7A1 in both HEK cells and keratinocytes derived from recessive DEB patients. This study highlights the potential of HPAE-PG as a non-viral vector for large DNA fragment deletion, emphasizing the importance of branching factors of HPAEs in optimizing CRISPR RNP delivery for therapeutic applications in genetic disorders.

Targeted Delivery of mRNA with Polymer-Lipid Nanoparticles for In Vivo Base Editing

Messenger RNA (mRNA) encoding base editors, along with single guide RNAs (sgRNAs), have emerged as a promising therapeutic approach for various disorders. However, there is still insufficient exploration in achieving targeted and efficient delivery of mRNA and sgRNA to multiple organs while ensuring high biocompatibility and stability in vivo. To address this challenge, we synthesized a library of 108 poly(β-amino) esters (PBAEs) by incorporating 100% hydrophobic side chains and end-caps with varying amines. These PBAEs were further formulated with other excipients, including helper lipids, cholesterol, and PEGylated lipids, to form polymer-lipid nanoparticles (PLNPs). Structure-function analysis revealed that eLog P of PBAEs could serve as a predictive parameter for determining the liver or lung tropism of PLNPs. The biocompatibility of PBAEs end-capped with monoamines was significantly higher compared to those end-capped with diamines. Leveraging these findings, we expanded the PBAE library and identified a leading PBAE (7C8C8) with mRNA delivery efficiency outperforming current FDA-approved ionizable lipids (ALC-0315, SM-102, and Dlin-MC3-DMA). The LD50 of the empty PLNPs (7C8C8) was determined to be 403.8 ± 49.46 mg/kg, indicating a significantly high safety profile. Additionally, PLNPs (7C8C8) demonstrated sustained transfection activity for at least 2 months when stored at -20 °C after freezing or at 4 °C following lyophilization. Subsequently, in vivo base editing using PLNPs (7C8C8) achieved an impressive editing efficiency of approximately 70% along with a significant reduction in protein levels exceeding 90%. Notably, synergistic effects were observed through simultaneous disruption of proprotein convertase subtilisin/kexin type 9 and angiopoietin-like protein 3 genes, resulting in a sustained low-density lipoprotein cholesterol reduction of over 60% for several months. These compelling findings provide strong support for the further development of PLNPs as promising platforms for mRNA-based therapies.

Modulation of CRISPR-Cas9 Cleavage with an Oligo-Ribonucleoprotein Design

Clustered regularly interspaced short palindromic repeats (CRISPR) associated protein Cas9 system has been widely used for genome editing. However, the editing or cleavage specificity of CRISPR Cas9 remains a major concern due to the off-target effects. The existing approaches to control or modulate CRISPR Cas9 cleavage include engineering Cas9 protein and development of anti-CRISPR proteins. There are also attempts on direct modification of sgRNA, for example, structural modification via truncation or hairpin design, or chemical modification on sgRNA such as partially replacing RNA with DNA. The above-mentioned strategies rely on extensive protein engineering and direct chemical or structural modification of sgRNA. In this study, we proposed an indirect method to modulate CRISPR Cas9 cleavage without modification on Cas9 protein or sgRNA. An oligonucleotide was used to form an RNA-DNA hybrid structure with the sgRNA spacer, creating steric hindrance during the Cas9 mediated DNA cleavage process. We first introduced a simple and robust method to assemble the oligo-ribonucleoprotein (oligo-RNP). Next, the cleavage efficiency of the assembled oligo-RNP was examined using different oligo lengths in vitro. Lastly, we showed that the oligo-RNP directly delivered into cells could also modulate Cas9 activity inside cells using three model gene targets with reduced off-target effects.

Guanidyl-rich α-helical polypeptide enables efficient cytosolic pro-protein delivery and CRISPR-Cas9 genome editing

Intracellular delivery of proteins has attracted significant interest in biological research and cancer treatment, yet it continues to face challenges due to the lack of effective delivery approaches. Herein, we developed an efficient strategy via cationic α-helical polypeptide-mediated anionic proprotein delivery. The protein was reversibly modified with adenosine triphosphate via dynamic covalent chemistry to prepare an anionic proprotein (A-protein) with abundant phosphate groups. A guanidyl-decorated α-helical polypeptide (LPP) was employed not only to encapsulate A-protein through electrostatic attraction and hydrogen bonding, forming stable nanocomplexes, but also to enhance cell membrane penetration due to its rigid α-helical conformation. Consequently, this strategy mediated the effective delivery of various proteins with different isoelectric points and molecular weights, including α-chymotrypsin, bovine serum albumin, ribonuclease A, cytochrome C, saporin, horseradish peroxidase, β-galactosidase, and anti-phospho-Akt, into cancer cells. More importantly, it enabled efficient delivery of CRISPR-Cas9 ribonucleoproteins to elicit robust polo-like kinase 1 genome editing for inhibiting cancer cell growth. This rationally designed protein delivery system may benefit the development of intracellular protein-based cancer therapy.

Advancing CNS Therapeutics: Enhancing Neurological Disorders with Nanoparticle-Based Gene and Enzyme Replacement Therapies

Given the complexity of the central nervous system (CNS) and the diversity of neurological conditions, the increasing prevalence of neurological disorders poses a significant challenge to modern medicine. These disorders, ranging from neurodegenerative diseases to psychiatric conditions, not only impact individuals but also place a substantial burden on healthcare systems and society. A major obstacle in treating these conditions is the blood-brain barrier (BBB), which restricts the passage of therapeutic agents to the brain. Nanotechnology, particularly the use of nanoparticles (NPs), offers a promising solution to this challenge. NPs possess unique properties such as small size, large surface area, and modifiable surface characteristics, enabling them to cross the BBB and deliver drugs directly to the affected brain regions. This review focuses on the application of NPs in gene therapy and enzyme replacement therapy (ERT) for neurological disorders. Gene therapy involves altering or manipulating gene expression and can be enhanced by NPs designed to carry various genetic materials. Similarly, NPs can improve the efficacy of ERT for lysosomal storage disorders (LSDs) by facilitating enzyme delivery to the brain, overcoming issues like immunogenicity and instability. Taken together, this review explores the potential of NPs in revolutionizing treatment options for neurological disorders, highlighting their advantages and the future directions in this rapidly evolving field.

Advanced Polymeric Nanoparticles for Cancer Immunotherapy: Materials Engineering, Immunotherapeutic Mechanism and Clinical Translation

Cancer immunotherapy, which leverages immune system components to treat malignancies, has emerged as a cornerstone of contemporary therapeutic strategies. Yet, critical concerns about the efficacy and safety of cancer immunotherapies remain formidable. Nanotechnology, especially polymeric nanoparticles (PNPs), offers unparalleled flexibility in manipulation-from the chemical composition and physical properties to the precision control of nanoassemblies. PNPs provide an optimal platform to amplify the potency and minimize systematic toxicity in a broad spectrum of immunotherapeutic modalities. In this comprehensive review, the basics of polymer chemistry, and state-of-the-art designs of PNPs from a physicochemical standpoint for cancer immunotherapy, encompassing therapeutic cancer vaccines, in situ vaccination, adoptive T-cell therapies, tumor-infiltrating immune cell-targeted therapies, therapeutic antibodies, and cytokine therapies are delineated. Each immunotherapy necessitates distinctively tailored design strategies in polymeric nanoplatforms. The extensive applications of PNPs, and investigation of their mechanisms of action for enhanced efficacy are particularly focused on. The safety profiles of PNPs and clinical research progress are discussed. Additionally, forthcoming developments and emergent trends of polymeric nano-immunotherapeutics poised to transform cancer treatment paradigms into clinics are explored.

Synthesis and characterization of poly (β-amino ester) polyplex nanocarrier with high encapsulation and uptake efficiency: impact of extracellular conditions

BACKGROUND

Poly (β-amino Ester) nanocarriers show promise for gene therapy, but their effectiveness can be limited by the environment within the body. This study aims to understand how common cell culture media components affect optimized PBAE nanocarrier performance in gene delivery.

METHODS

Optimized PBAE was synthesized based on Michael addition reaction and characterized by different assays, this study employed techniques like DLS and TEM to characterize PBAE nanocarriers, followed by cellular uptake analysis (flow cytometry and confocal imaging) and evaluation of gene expression under different polymer/DNA ratio ratios and media conditions.

RESULTS

The nanocarriers exhibited size under 200 nm and surface positive charge, with high encapsulation efficiency (up to 95%). Cellular uptake, transfection efficiency, and cytotoxicity were evaluated. Flow cytometry analysis revealed high cellular uptake (over 77% at 1 hour and up to 95% after 3 hours) and good viability. Transfection efficiency reached up to 80% with 2 μg DNA, particularly at weight ratios of 60 and 90.

CONCLUSION

The study also identified factors affecting transfection efficiency, including serum concentration and antibiotics in the culture medium, highlighting the importance of optimizing these conditions for future applications.

Suprachoroidal Delivery of Viral and Nonviral Vectors for Treatment of Retinal and Choroidal Vascular Diseases

PURPOSE

Current treatments for retinal and choroidal neovascular diseases suffer from insufficient durability, including anti-vascular endothelial growth factor-A agents. It is, therefore, of interest to explore alternative methods that could allow for robust improvement in visual acuity with fewer injections required.

DESIGN

Literature review.

RESULTS

Among various preclinical and clinical studies in the literature, a promising approach is the use of suprachoroidal injection with viral and nonviral gene delivery vectors. Compared with other ocular injection methods, suprachoroidal injection has demonstrated wide biodistribution of injected agents and safety as an outpatient procedure. In terms of viral vectors, suprachoroidal injection of an adeno-associated virus 8 vector expressing an anti-vascular endothelial growth factor-A antibody fragment has shown an excellent safety profile and evidence of biological activity. In terms of nonviral vectors, lipid nanoparticles and polymeric nanoparticles both demonstrate strong promise for ocular gene therapy in large animal models. In particular, biodegradable poly(β-amino ester) nanoparticles show excellent biodistribution, safety, and efficacy for gene therapy via the suprachoroidal route. Nonviral nanoparticle approaches can have notable advantages over viral vectors in terms of carrying capacity, redosability, and manufacturing costs. An advantage of gene therapy is that once a delivery vector has been optimized, genetic cargos can be readily tailored without changing the safety, efficacy, and pharmacokinetic properties of the delivery vector.

CONCLUSIONS

This review highlights recent progress that has been made and compares viral and nonviral suprachoroidal gene delivery for the treatment of retinal and choroidal vascular diseases. Suprachoroidal gene therapy is an emerging biotechnology that holds substantial potential to make a translational impact in treating these diseases.

Technologies for Targeted RNA Degradation and Induced RNA Decay

The vast majority of the human genome codes for RNA, but RNA-targeting therapeutics account for a small fraction of approved drugs. As such, there is great incentive to improve old and develop new approaches to RNA targeting. For many RNA targeting modalities, just binding is not sufficient to exert a therapeutic effect; thus, targeted RNA degradation and induced decay emerged as powerful approaches with a pronounced biological effect. This review covers the origins and advanced use cases of targeted RNA degrader technologies grouped by the nature of the targeting modality as well as by the mode of degradation. It covers both well-established methods and clinically successful platforms such as RNA interference, as well as emerging approaches such as recruitment of RNA quality control machinery, CRISPR, and direct targeted RNA degradation. We also share our thoughts on the biggest hurdles in this field, as well as possible ways to overcome them.

Unlocking Genome Editing: Advances and Obstacles in CRISPR/Cas Delivery Technologies

CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats associated with protein 9) was first identified as a component of the bacterial adaptive immune system and subsequently engineered into a genome-editing tool. The key breakthrough in this field came with the realization that CRISPR/Cas9 could be used in mammalian cells to enable transformative genetic editing. This technology has since become a vital tool for various genetic manipulations, including gene knockouts, knock-in point mutations, and gene regulation at both transcriptional and post-transcriptional levels. CRISPR/Cas9 holds great potential in human medicine, particularly for curing genetic disorders. However, despite significant innovation and advancement in genome editing, the technology still possesses critical limitations, such as off-target effects, immunogenicity issues, ethical considerations, regulatory hurdles, and the need for efficient delivery methods. To overcome these obstacles, efforts have focused on creating more accurate and reliable Cas9 nucleases and exploring innovative delivery methods. Recently, functional biomaterials and synthetic carriers have shown great potential as effective delivery vehicles for CRISPR/Cas9 components. In this review, we attempt to provide a comprehensive survey of the existing CRISPR-Cas9 delivery strategies, including viral delivery, biomaterials-based delivery, synthetic carriers, and physical delivery techniques. We underscore the urgent need for effective delivery systems to fully unlock the power of CRISPR/Cas9 technology and realize a seamless transition from benchtop research to clinical applications.

Trehalose-based coacervates for local bioactive protein delivery to the central nervous system

Therapeutic outcomes of local biomolecule delivery to the central nervous system (CNS) using bulk biomaterials are limited by inadequate drug loading, neuropil disruption, and severe foreign body responses. Effective CNS delivery requires addressing these issues and developing well-tolerated, highly-loaded carriers that are dispersible within local neural parenchyma. Here, we synthesized biodegradable trehalose-based polyelectrolyte oligomers using facile A2:B3:AR thiol-ene Michael addition reactions that form complex coacervates upon mixing of oppositely charged oligomers. Coacervates permit high concentration loading and controlled release of bioactive growth factors, enzymes, and antibodies, with modular formulation parameters that confer tunable release kinetics. Coacervates are cytocompatible with cultured neural cells in vitro and can be formulated to either direct intracellular protein delivery or sequester media containing proteins and remain extracellular. Coacervates serve as effective vehicles for precisely delivering biomolecules, including bioactive neurotrophins, to the mouse striatum following intraparenchymal injection. These results support the use of trehalose-based coacervates as part of therapeutic protein delivery strategies for CNS disorders.

Iron-Confined CRISPR/Cas9-Ribonucleoprotein Delivery System for Redox-Responsive Gene Editing

Clustered regularly interspaced short palindromic repeat (CRISPR)-associated protein 9 (Cas9) is a promising gene editing tool to treat diseases at the genetic level. Nonetheless, the challenge of the safe and efficient delivery of CRISPR/Cas9 to host cells constrains its clinical applicability. In the current study, a facile, redox-responsive CRISPR/Cas9-Ribonucleoprotein (RNP) delivery system by combining iron-coordinated aggregation with liposomes (Fe-RNP@L) is reported. The Fe-RNP is formed by the coordination of Fe3+ with amino and carboxyl groups of Cas9, which modifies the lipophilicity and surface charge of RNP and alters cellular uptake from primary endocytosis to endocytosis and cholesterol-dependent membrane fusion. RNP can be rapidly and reversibly released from Fe-RNP in response to glutathione without loss of structural integrity and enzymatic activity. In addition, iron coordination also improves the stability of RNP and substantially mitigates cytotoxicity. This construct enabled highly efficient cytoplasmic/nuclear delivery (≈90%) and gene-editing efficiency (≈70%) even at low concentrations. The high payload content, high editing efficiency, good stability, low immunogenicity, and ease of production and storage, highlight its potential for diverse genome editing and clinical applications.

Zwitterionic Strategy to Stabilize Self-Immolative Polymer Nanoarchitecture under Physiological pH for Drug Delivery In Vitro and In Vivo

The major bottleneck in using polymer nanovectors for biomedical application, particularly those based on self-immolative poly(amino ester) (PAE), lies in their uncontrolled autodegradation at physiological pH before they can reach the intended target. Here, an elegant triblock-copolymer strategy is designed to stabilize the unstable PAE chains via zwitterionic interactions under physiological pH (pH 7.4) and precisely program their enzyme-responsive biodegradation specifically within the intracellular compartments, ensuring targeted delivery of the cargoes. To achieve this goal, biodegradable polycaprolactone (PCL) platform is chosen, and structure-engineered several di- and triblock architectures to arrive the precise macromolecular geometry. The hydrophobic-PCL core and hydrophilic anionic-PCL block at the periphery shield PAEs against autodegradation, thereby ensuring stability under physiological pH in PBS, FBS, cell culture medium and bloodstream. The clinical anticancer drug doxorubicin and deep-tissue penetrable near-infrared IR-780 biomarker is encapsulated to study their biological actions by in vitro live cancer cells and in vivo bioimaging in live animals. These zwitterions are biocompatible, nonhemolytic, and real-time in vitro live-cell confocal studies have confirmed their internalization and enzymatic biodegradation in the endo-lysosomal compartments to deliver the payload. In vivo bioimaging establishes their prolonged blood circulation for over 72 h, and the biodistribution analysis reveals the accumulation of nanoparticles predominantly in the excretory organs.

Strategies for enhanced gene delivery to the central nervous system

The delivery of genes to the central nervous system (CNS) has been a persistent challenge due to various biological barriers. The blood-brain barrier (BBB), in particular, hampers the access of systemically injected drugs to parenchymal cells, allowing only a minimal percentage (<1%) to pass through. Recent scientific insights highlight the crucial role of the extracellular space (ECS) in governing drug diffusion. Taking into account advancements in vectors, techniques, and knowledge, the discussion will center on the most notable vectors utilized for gene delivery to the CNS. This review will explore the influence of the ECS - a dynamically regulated barrier-on drug diffusion. Furthermore, we will underscore the significance of employing remote-control technologies to facilitate BBB traversal and modulate the ECS. Given the rapid progress in gene editing, our discussion will also encompass the latest advances focused on delivering therapeutic editing in vivo to the CNS tissue. In the end, a brief summary on the impact of Artificial Intelligence (AI)/Machine Learning (ML), ultrasmall, soft endovascular robots, and high-resolution endovascular cameras on improving the gene delivery to the CNS will be provided.

Ionizable lipid nanoparticles for RAS protease delivery to inhibit cancer cell proliferation

Mutations in RAS, a family of proteins found in all human cells, drive a third of cancers, including many pancreatic, colorectal, and lung cancers. However, there is a lack of clinical therapies that can effectively prevent RAS from causing tumor growth. Recently, a protease was engineered that specifically degrades active RAS, offering a promising new tool for treating these cancers. However, like many other intracellularly acting protein-based therapies, this protease requires a delivery vector to reach its site of action within the cell. In this study, we explored the incorporation of cationic lipids into ionizable lipid nanoparticles (LNPs) to develop a RAS protease delivery platform capable of inhibiting cancer cell proliferation in vitro and in vivo. A library of 13 LNPs encapsulating RAS protease was designed, and each formulation was evaluated for in vitro delivery efficiency and toxicity. A subset of four top-performing LNP formulations was identified and further evaluated for their impact on cancer cell proliferation in human colorectal cancer cells with mutated KRAS in vitro and in vivo, as well as their in vivo biodistribution and toxicity. In vivo, both the concentration of cationic lipid and type of cargo influenced LNP and cargo distribution. All lead candidate LNPs showed RAS protease functionality in vitro, and the top-performing formulation achieved effective intracellular RAS protease delivery in vivo, decreasing cancer cell proliferation in an in vivo xenograft model and significantly reducing tumor growth and size. Overall, this work demonstrates the use of LNPs as an effective delivery platform for RAS proteases, which could potentially be utilized for cancer therapies.

Targeted protein delivery based on stimuli-triggered nanomedicine

Protein-based drugs have shown unique advantages to treat various diseases in recent years. However, most protein therapeutics in clinical use are limited to extracellular targets with low delivery efficiency. To realize targeted protein delivery, a series of stimuli-triggered nanoparticle formulations have been developed to improve delivery efficiency and reduce off-target release. These smart nanoparticles are designed to release cargo proteins in response to either internal or external stimuli at pathological tissues. In this way, varieties of protein-based drugs including antibodies, enzymes, and pro-apoptotic proteins can be effectively delivered to desired sites for the treatment of cancer, inflammation, metabolic diseases, and so on with minimal side effects. In this review, recent advances in the design of stimuli-triggered nanomedicine for targeted protein delivery in different biomedical applications will be discussed. A deeper understanding of these emerging strategies helps develop more efficient protein delivery systems for clinical use in the future.

Dual-responsive nanocarriers for efficient cytosolic protein delivery and CRISPR-Cas9 gene therapy of inflammatory skin disorders

Developing protein drugs that can target intracellular sites remains a challenge due to their inadequate membrane permeability. Efficient carriers for cytosolic protein delivery are required for protein-based drugs, cancer vaccines, and CRISPR-Cas9 gene therapies. Here, we report a screening process to identify highly efficient materials for cytosolic protein delivery from a library of dual-functionalized polymers bearing both boronate and lipoic acid moieties. Both ligands were found to be crucial for protein binding, endosomal escape, and intracellular protein release. Polymers with higher grafting ratios exhibit remarkable efficacies in cytosolic protein delivery including enzymes, monoclonal antibodies, and Cas9 ribonucleoprotein while preserving their activity. Optimal polymer successfully delivered Cas9 ribonucleoprotein targeting NLRP3 to disrupt NLRP3 inflammasomes in vivo and ameliorate inflammation in a mouse model of psoriasis. Our study presents a promising option for the discovery of highly efficient materials tailored for cytosolic delivery of specific proteins and complexes such as Cas9 ribonucleoprotein.

Non-viral systems for intracellular delivery of genome editing tools

A hallmark of the last decades is an extensive development of genome editing systems and technologies propelling genetic engineering to the next level. Specific and efficient delivery of genome editing tools to target cells is one of the key elements of such technologies. Conventional vectors are not always suitable for this purpose due to a limited cargo volume, risks related to cancer and immune reactions, toxicity, a need for high-purity viral material and quality control, as well as a possibility of integration of the virus into the host genome leading to overexpression of the vector components and safety problems. Therefore, the search for novel approaches to delivering proteins and nucleic acids into cells is a relevant priority. This work reviews abiotic vectors and systems for delivering genome editing tools into target cells, including liposomes and solid lipid particles, other membrane-based vesicles, cell-penetrating peptides, micelles, dendrimers, carbon nanotubes, inorganic, polymer, metal and other nanoparticles. It considers advantages, drawbacks and preferred applications of such systems as well as suitability thereof for the delivery of genome editing systems. A particular emphasis is placed on metal-organic frameworks (MOFs) and their potential in the targeted intracellular delivery of proteins and polynucleotides. It has been concluded that further development of MOF-based vectors and technologies, as well as combining MOFs with other carriers can result in safe and efficient delivery systems, which would be able to circulate in the body for a long time while recognizing target cells and ensuring cell-specific delivery and release of intact cargoes and, thereby, improving the genome editing outcome.

Nanocarriers address intracellular barriers for efficient drug delivery, overcoming drug resistance, subcellular targeting and controlled release

The cellular barriers are major bottlenecks for bioactive compounds entering into cells to accomplish their biological functions, which limits their biomedical applications. Nanocarriers have demonstrated high potential and benefits for encapsulating bioactive compounds and efficiently delivering them into target cells by overcoming a cascade of intracellular barriers to achieve desirable therapeutic and diagnostic effects. In this review, we introduce the cellular barriers ahead of drug delivery and nanocarriers, as well as summarize recent advances and strategies of nanocarriers for increasing internalization with cells, promoting intracellular trafficking, overcoming drug resistance, targeting subcellular locations and controlled drug release. Lastly, the future perspectives of nanocarriers for intracellular drug delivery are discussed, which mainly focus on potential challenges and future directions. Our review presents an overview of intracellular drug delivery by nanocarriers, which may encourage the future development of nanocarriers for efficient and precision drug delivery into a wide range of cells and subcellular targets.

Bridging Smart Nanosystems with Clinically Relevant Models and Advanced Imaging for Precision Drug Delivery

Intracellular delivery of nano-drug-carriers (NDC) to specific cells, diseased regions, or solid tumors has entered the era of precision medicine that requires systematic knowledge of nano-biological interactions from multidisciplinary perspectives. To this end, this review first provides an overview of membrane-disruption methods such as electroporation, sonoporation, photoporation, microfluidic delivery, and microinjection with the merits of high-throughput and enhanced efficiency for in vitro NDC delivery. The impact of NDC characteristics including particle size, shape, charge, hydrophobicity, and elasticity on cellular uptake are elaborated and several types of NDC systems aiming for hierarchical targeting and delivery in vivo are reviewed. Emerging in vitro or ex vivo human/animal-derived pathophysiological models are further explored and highly recommended for use in NDC studies since they might mimic in vivo delivery features and fill the translational gaps from animals to humans. The exploration of modern microscopy techniques for precise nanoparticle (NP) tracking at the cellular, organ, and organismal levels informs the tailored development of NDCs for in vivo application and clinical translation. Overall, the review integrates the latest insights into smart nanosystem engineering, physiological models, imaging-based validation tools, all directed towards enhancing the precise and efficient intracellular delivery of NDCs.

Antiangiogenic Therapeutic mRNA Delivery Using Lung-Selective Polymeric Nanomedicine for Lung Cancer Treatment

Therapeutic antibodies that block vascular endothelial growth factor (VEGF) show clinical benefits in treating nonsmall cell lung cancers (NSCLCs) by inhibiting tumor angiogenesis. Nonetheless, the therapeutic effects of systemically administered anti-VEGF antibodies are often hindered in NSCLCs because of their limited distribution in the lungs and their adverse effects on normal tissues. These challenges can be overcome by delivering therapeutic antibodies in their mRNA form to lung endothelial cells, a primary target of VEGF-mediated pulmonary angiogenesis, to suppress the NSCLCs. In this study, we synthesized derivatives of poly(β-amino esters) (PBAEs) and prepared nanoparticles to encapsulate the synthetic mRNA encoding bevacizumab, an anti-VEGF antibody used in the clinic. Optimization of nanoparticle formulations resulted in a selective lung transfection after intravenous administration. Notably, the optimized PBAE nanoparticles were distributed in lung endothelial cells, resulting in the secretion of bevacizumab. We analyzed the protein corona on the lung- and spleen-targeting nanoparticles using proteomics and found distinctive features potentially contributing to their organ-selectivity. Lastly, bevacizumab mRNA delivered by the lung-targeting PBAE nanoparticles more significantly inhibited tumor proliferation and angiogenesis than recombinant bevacizumab protein in orthotopic NSCLC mouse models, supporting the therapeutic potential of bevacizumab mRNA therapy and its selective delivery through lung-targeting nanoparticles. Our proof-of-principle results highlight the clinical benefits of nanoparticle-mediated mRNA therapy in anticancer antibody treatment in preclinical models.

Biomineralization of Human Genomic DNA into ZIF-8, a Zeolite-Like Metal-Organic Framework

The aim of the study was to assess the capabilities of human genomic DNA biomineralization into ZIF-8 metal-organic framework (MOF) preserving DNA sequence integrity after the encapsulation cycle and composite dissolving. The study is an initial stage of the project aimed at developing an abiotic vector to be used when working with native nucleic acids of an arbitrary size based on DNA@ZIF-8 composite.

Materials and Methods

We studied human genomic DNA isolated from lymphocytes of peripheral blood of healthy volunteers using Proba-NK kit (DNA-Technology LLC, Russia). Genomic DNA purity and concentration was estimated spectrophotometrically at 260/280 nm using Tecan Infinity 200 Pro plate reader (Tecan Instruments, Austria). ZIF-8 was synthesized in the physiological conditions (37°C) by mixing zinc salt and 2-methylimidazole aqueous solutions at different molar ratios. Human genomic DNA was encapsulated into ZIF-8 in similar conditions. The obtained MOF and DNA@ZIF-8 composite were studied using X-ray powder diffraction at the Phaser D2 XRPD device (Bruker, USA), and the specific surface area was estimated using Autosorb iQ porosimetry analyzer (Quantachrome, USA). The encapsulated DNA was quantified by dissolving DNA@ZIF-8 composite in the citrate buffer. DNA integrity was assessed by real-time allele-specific PCR (AS-PCR) using the kits for single nucleotide polymorphisms (Lytech, Russia) at the Quantstudio 6 Pro PCR machine (Thermo Scientific, USA). In case of using the kits with electrophoretic detection, the amplification was performed on the thermal cycler T100 (Thermo Scientific, USA).

Results

The polymer ZIF-8 and DNA@ZIF-8 composite were obtained at different molar ratios of zinc ions and 2-methylimidazole. We characterized their structure and specific surface area. Genomic DNA biomineralization efficacy was found to be about 7-8%. PCR indicated the integrity of non-selectively chosen loci within the biomineralized DNA.

Conclusion

The study confirmed the possibility of human genomic DNA encapsulation into ZIF-8 metal-organic framework. After the biomineralization, DNA was found to preserve feasibility to be used in studies to investigate genetic constructs.

Sugar alcohol-modified polyester nanoparticles for gene delivery via selective caveolae-mediated endocytosis

Nucleic acid-based drugs are changing the scope of emerging medicine in preventing and treating diseases. Nanoparticle systems based on lipids and polymers developed to navigate tissue-level and cellular-level barriers are now emerging as vector systems that can be translated to clinical settings. A class of polymers, poly(β-amino esters) (PBAEs) known for their chemical flexibility and biodegradability, has been explored for gene delivery. These polymers are sensitive to changes in the monomer composition affecting transfection efficiency. Hence to add functionality to these polymers, we partially substituted ligands to an identified effective polymer chemistry. We report here a new series of statistical copolymers based on PBAEs where the backbone is modified with sugar alcohols to selectively facilitate the caveolae-mediated endocytosis pathway of cellular transport. These ligands are grafted at the polymer's backbone, thereby establishing a new strategy of modification in PBAEs. We demonstrate that these polymers form nanoparticles with DNA, show effective complexation and cargo release, enter the cell via selective caveolae-mediated endocytosis, exhibit low cytotoxicity, and increase transfection in neuronal cells.

Hydroxyl-rich branched polycations for nucleic acid delivery

Recently, nucleic acid delivery has become an amazing route for the treatment of various malignant diseases, and polycationic vectors are attracting more and more attention among gene vectors. However, conventional polycationic vectors still face many obstacles in nucleic acid delivery, such as significant cytotoxicity, high protein absorption behavior, and unsatisfactory blood compatibility caused by a high positive charge density. To solve these problems, the fabrication of hydroxyl-rich branched polycationic vectors has been proposed. For the synthesis of hydroxyl-rich branched polycations, a one-pot method is considered as the preferred method due to its simple preparation process. In this review, typical one-pot methods for fabricating hydroxyl-rich polycations are presented. In particular, amine-epoxide ring-opening polymerization as a novel approach is mainly introduced. In addition, various therapeutic scenarios of hydroxyl-rich branched polycations via one-pot fabrication are also generalized. We believe that this review will motivate the optimized design of hydroxyl-rich branched polycations for potential nucleic acid delivery and their bio-applications.

Intracellular Protein Delivery: Approaches, Challenges, and Clinical Applications

Protein biologics are powerful therapeutic agents with diverse inhibitory and enzymatic functions. However, their clinical use has been limited to extracellular applications due to their inability to cross plasma membranes. Overcoming this physiological barrier would unlock the potential of protein drugs for the treatment of many intractable diseases. In this review, we highlight progress made toward achieving cytosolic delivery of recombinant proteins. We start by first considering intracellular protein delivery as a drug modality compared to existing Food and Drug Administration-approved drug modalities. Then, we summarize strategies that have been reported to achieve protein internalization. These techniques can be broadly classified into 3 categories: physical methods, direct protein engineering, and nanocarrier-mediated delivery. Finally, we highlight existing challenges for cytosolic protein delivery and offer an outlook for future advances.

mRNA Vaccine Nanoplatforms and Innate Immunity

mRNA-based vaccine technology has been significantly developed and enhanced, particularly highlighted by the authorization of mRNA vaccines for addressing the COVID-19 pandemic. Various biomaterials are developed in nano-scales and applied as mRNA vaccine delivery platforms. However, how these mRNA nanoplatforms influence immune responses has not been thoroughly studied. Hence, we have reviewed the current understanding of various mRNA vaccine platforms. We discussed the possible pathways through which these platforms moderate the host's innate immunity and contribute to the development of adaptive immunity. We shed light on their development in reducing biotoxicity and enhancing antigen delivery efficiency. Beyond the built-in adjuvanticity of mRNA vaccines, we propose that supplementary adjuvants may be required to fine-tune and precisely control innate immunity and subsequent adaptive immune responses.

Cyclodextrin-based tailored polyrotaxanes for highly efficient delivery of the genome-editing molecule

Direct cytosolic delivery of the Cas9 ribonucleoprotein is the most promising method for inducing CRISPR-Cas9 genome editing in mammalian cells. Recently, we focused the movable properties of cyclodextrin-based polyrotaxanes (PRXs), which consist of numerous cyclodextrins threaded onto the axile molecule with bulky endcaps at both ends of the axile molecule, and developed aminated PRXs as multistep transformable carriers for Cas9 ribonucleoprotein, ensuring efficient complexation, cellular internalization, endosomal escape, release, and nuclear localization. This study reports the structural fine-tuning and structure-property relationship of multistep transformable PRXs for more efficient Cas9 ribonucleoprotein delivery. Among various PRXs, PRX derivatives with a longer molecular length (35 kDa polyethylene glycol as the axile molecule) and a low total degree of substitution (1.5 amino groups/α-cyclodextrins), as well as the modified ratio of two modified amines (cystamine and diethylenetriamine) = ≈1:1, exhibited the highest genome-editing efficacy and intracellular dynamics control. These structural properties are important for efficient endosomal escape and Cas9 RNP release. Furthermore, ligand-modified-β-CD, which can endow the ligand through complexation with PRX termini, improved the cellular uptake and genome-editing effects of the optimized PRX/Cas9 RNP in target cells. Thus, structural fine-tuning and the addition of ligand-modified-β-cyclodextrin enabled efficient genome editing by the Cas9 RNP.

Nanoparticle-mediated delivery of non-viral gene editing technology to the brain

Neurological disorders pose a significant burden on individuals and society, affecting millions worldwide. These disorders, including but not limited to Alzheimer's disease, Parkinson's disease, and Huntington's disease, often have limited treatment options and can lead to progressive degeneration and disability. Gene editing technologies, including Zinc Finger Nucleases (ZFN), Transcription Activator-Like Effector Nucleases (TALEN), and Clustered Regularly Interspaced Short Palindromic Repeats-associated Protein 9 (CRISPR-Cas9), offer a promising avenue for potential cures by targeting and correcting the underlying genetic mutations responsible for neurologic disorders. However, efficient delivery methods are crucial for the successful application of gene editing technologies in the context of neurological disorders. The central nervous system presents unique challenges to treatment development due to the blood-brain barrier, which restricts the entry of large molecules. While viral vectors are traditionally used for gene delivery, nonviral delivery methods, such as nanoparticle-mediated delivery, offer safer alternatives that can efficiently transport gene editing components. Herein we aim to introduce the three main gene editing nucleases as nonviral treatments for neurologic disorders, the delivery barriers associated with brain targeting, and the current nonviral techniques used for brain-specific delivery. We highlight the challenges and opportunities for future research in this exciting and growing field that could lead to blood-brain barrier bypassing therapeutic gene editing.

The potential of mRNA vaccines in cancer nanomedicine and immunotherapy

Owing to their outstanding performance against COVID-19, mRNA vaccines have brought great hope for combating various incurable diseases, including cancer. Differences in the encoded proteins result in different molecular and cellular mechanisms of mRNA vaccines. With the rapid development of nanotechnology and molecular medicine, personalized antigen-encoding mRNA vaccines that enhance antigen presentation can trigger effective immune responses and prevent off-target toxicities. Herein, we review new insights into the influence of encoded antigens, cytokines, and other functional proteins on the mechanisms of mRNA vaccines. We also highlight the importance of delivery systems and chemical modifications for mRNA translation efficiency, stability, and targeting, and we discuss the potential problems and application prospects of mRNA vaccines as versatile tools for combating cancer.

Engineering Nucleotidoproteins for Base-Pairing-Assisted Cytosolic Delivery and Genome Editing

Protein therapeutics targeting intracellular machineries hold profound potential for disease treatment, and hence robust cytosolic protein delivery technologies are imperatively demanded. Inspired by the super-negatively charged, nucleotide-enriched structure of nucleic acids, adenylated pro-proteins (A-proteins) with dramatically enhanced negative surface charges have been engineered for the first time via facile green synthesis. Then, thymidine-modified polyethyleneimine is developed, which exhibits strong electrostatic attraction, complementary base pairing, and hydrophobic interaction with A-proteins to form salt-resistant nanocomplexes with robust cytosolic delivery efficiencies. The acidic endolysosomal environment enables traceless restoration of the A-proteins and consequently promotes the intracellular release of the native proteins. This strategy shows high efficiency and universality for a variety of proteins with different molecular weights and isoelectric points in mammalian cells. Moreover, it enables highly efficient delivery of CRISPR-Cas9 ribonucleoproteins targeting fusion oncogene EWSR1-FLI1, leading to pronounced anti-tumor efficacy against Ewing sarcoma. This study provides a potent and versatile platform for cytosolic protein delivery and gene editing, and may benefit the development of protein pharmaceuticals.

Drug delivery systems for CRISPR-based genome editors

CRISPR-based drugs can theoretically manipulate any genetic target. In practice, however, these drugs must enter the desired cell without eliciting an unwanted immune response, so a delivery system is often required. Here, we review drug delivery systems for CRISPR-based genome editors, focusing on adeno-associated viruses and lipid nanoparticles. After describing how these systems are engineered and their subsequent characterization in preclinical animal models, we highlight data from recent clinical trials. Preclinical targeting mediated by polymers, proteins, including virus-like particles, and other vehicles that may deliver CRISPR systems in the future is also discussed.

CRISPR/Cas9 systems: Delivery technologies and biomedical applications

The emergence of the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) genome-editing system has brought about a significant revolution in the realm of managing human diseases, establishing animal models, and so on. To fully harness the potential of this potent gene-editing tool, ensuring efficient and secure delivery to the target site is paramount. Consequently, developing effective delivery methods for the CRISPR/Cas9 system has become a critical area of research. In this review, we present a comprehensive outline of delivery strategies and discuss their biomedical applications in the CRISPR/Cas9 system. We also provide an in-depth analysis of physical, viral vector, and non-viral vector delivery strategies, including plasmid-, mRNA- and protein-based approach. In addition, we illustrate the biomedical applications of the CRISPR/Cas9 system. This review highlights the key factors affecting the delivery process and the current challenges facing the CRISPR/Cas9 system, while also delineating future directions and prospects that could inspire innovative delivery strategies. This review aims to provide new insights and ideas for advancing CRISPR/Cas9-based delivery strategies and to facilitate breakthroughs in biomedical research and therapeutic applications.

A Novel Peptide Prevents Enterotoxin- and Inflammation-Induced Intestinal Fluid Secretion by Stimulating Sodium-Hydrogen Exchanger 3 Activity

BACKGROUND & AIMS

Acute diarrheal diseases are the second most common cause of infant mortality in developing countries. This is contributed to by lack of effective drug therapy that shortens the duration or lessens the volume of diarrhea. The epithelial brush border sodium (Na+)/hydrogen (H+) exchanger 3 (NHE3) accounts for a major component of intestinal Na+ absorption and is inhibited in most diarrheas. Because increased intestinal Na+ absorption can rehydrate patients with diarrhea, NHE3 has been suggested as a potential druggable target for drug therapy for diarrhea.

METHODS

A peptide (sodium-hydrogen exchanger 3 stimulatory peptide [N3SP]) was synthesized to mimic the part of the NHE3 C-terminus that forms a multiprotein complex that inhibits NHE3 activity. The effect of N3SP on NHE3 activity was evaluated in NHE3-transfected fibroblasts null for other plasma membrane NHEs, a human colon cancer cell line that models intestinal absorptive enterocytes (Caco-2/BBe), human enteroids, and mouse intestine in vitro and in vivo. N3SP was delivered into cells via a hydrophobic fluorescent maleimide or nanoparticles.

RESULTS

N3SP uptake stimulated NHE3 activity at nmol/L concentrations under basal conditions and partially reversed the reduced NHE3 activity caused by elevated adenosine 3',5'-cyclic monophosphate, guanosine 3',5'-cyclic monophosphate, and Ca2+ in cell lines and in in vitro mouse intestine. N3SP also stimulated intestinal fluid absorption in the mouse small intestine in vivo and prevented cholera toxin-, Escherichia coli heat-stable enterotoxin-, and cluster of differentiation 3 inflammation-induced fluid secretion in a live mouse intestinal loop model.

CONCLUSIONS

These findings suggest pharmacologic stimulation of NHE3 activity as an efficacious approach for the treatment of moderate/severe diarrheal diseases.

Guanidyl-Rich Poly(β Amino Ester)s for Universal Functional Cytosolic Protein Delivery and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) Cas9 Ribonucleoprotein Based Gene Editing

Protein therapeutics are highly promising for complex disease treatment. However, the lack of ideal delivery vectors impedes their clinical use, especially the carriers for in vivo delivery of functional cytosolic protein. In this study, we modified poly(β amino ester)s (PAEs) with a phenyl guanidine (PG) group to enhance their suitability for cytosolic protein delivery. The effects of the PG group on protein binding, cell internalization, protein function protection, and endo/lysosomal escape were systematically evaluated. Compared to the unmodified PAEs (L3), guanidyl rich PAEs (L3PG) presented superior efficiency of protein binding and protein internalization, mainly via clathrin-mediated endocytosis. In addition, both PAEs showed robust capabilities to deliver cytosolic proteins with different molecular weight (ranging from 30 to 464 kDa) and isoelectric points (ranging from 4.3 to 9), which were significantly improved in comparison with the commercial reagents of PULsin and Pierce Protein Transection Reagent. Moreover, L3PG successfully delivered Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) Cas9 ribonucleoprotein (RNP) into HeLa cells expressing green fluorescent protein (GFP) and achieved more than 80% GFP expression knockout. These results demonstrated that guanidyl modification on PAEs can enhance its capabilities for intracellular delivery of cytosolic functional proteins and CRISPR/Cas9 ribonucleoprotein. The guanidyl-rich PAEs are promising nonviral vectors for functional protein delivery and potential use in protein and nuclease-based gene editing therapies.

Genetic Engineered Ultrasound-Triggered Injectable Hydrogels for Promoting Bone Reconstruction

Genetic engineering technology can achieve specific gene therapy for a variety of diseases, but the current strategy still has some flaws, such as a complex system, single treatment, and large implantation trauma. Herein, the genetic engineering injectable hydrogels were constructed by ultrasonic technology for the first time to realize in vivo ultrasound-triggered in situ cross-linking and cell gene transfection, and finally complete in situ gene therapy to promote bone reconstruction. First, ultrasound-triggered calcium release was used to activate transglutaminase and catalyze the transamidation between fibrinogen. Simultaneously, liposome loaded with Zinc-finger E-box-binding homeobox 1 (ZEB1) gene plasmid (Lip-ZEB1) was combined to construct an ultrasound-triggered in situ cross-linked hydrogels that can deliver Lip-ZEB1. Second, ultrasound-triggered injectable hydrogel introduced ZEB1 gene plasmid into endothelial cell genome through Lip-ZEB1 sustained release, and then acted on the ZEB1/Notch signal pathway of cells, promoting angiogenesis and local bone reconstruction of osteoporosis through genetic engineering. Overall, this strategy provides an advanced gene delivery system through genetic engineered ultrasound-triggered injectable hydrogels.

Design and fabrication of intracellular therapeutic cargo delivery systems based on nanomaterials: current status and future perspectives

Intracellular cargo delivery, the introduction of small molecules, proteins, and nucleic acids into a specific targeted site in a biological system, is an important strategy for deciphering cell function, directing cell fate, and reprogramming cell behavior. With the advancement of nanotechnology, many researchers use nanoparticles (NPs) to break through biological barriers to achieving efficient targeted delivery in biological systems, bringing a new way to realize efficient targeted drug delivery in biological systems. With a similar size to many biomolecules, NPs possess excellent physical and chemical properties and a certain targeting ability after functional modification on the surface of NPs. Currently, intracellular cargo delivery based on NPs has emerged as an important strategy for genome editing regimens and cell therapy. Although researchers can successfully deliver NPs into biological systems, many of them are delivered very inefficiently and are not specifically targeted. Hence, the development of efficient, target-capable, and safe nanoscale drug delivery systems to deliver therapeutic substances to cells or organs is a major challenge today. In this review, on the basis of describing the research overview and classification of NPs, we focused on the current research status of intracellular cargo delivery based on NPs in biological systems, and discuss the current problems and challenges in the delivery process of NPs in biological systems.

Emerging non-viral vectors for gene delivery

Gene therapy holds great promise for treating a multitude of inherited and acquired diseases by delivering functional genes, comprising DNA or RNA, into targeted cells or tissues to elicit manipulation of gene expression. However, the clinical implementation of gene therapy remains substantially impeded by the lack of safe and efficient gene delivery vehicles. This review comprehensively outlines the novel fastest-growing and efficient non-viral gene delivery vectors, which include liposomes and lipid nanoparticles (LNPs), highly branched poly(β-amino ester) (HPAE), single-chain cyclic polymer (SCKP), poly(amidoamine) (PAMAM) dendrimers, and polyethyleneimine (PEI). Particularly, we discuss the research progress, potential development directions, and remaining challenges. Additionally, we provide a comprehensive overview of the currently approved non-viral gene therapeutics, as well as ongoing clinical trials. With advances in biomedicine, molecular biology, materials science, non-viral gene vectors play an ever-expanding and noteworthy role in clinical gene therapy.

Synthetic nanoparticles for the delivery of CRISPR/Cas9 gene editing system: classification and biomedical applications

Gene editing has great potential in biomedical research including disease diagnosis and treatment. Clustered regularly interspaced short palindromic repeats (CRISPR) is the most straightforward and cost-effective method. The efficient and precise delivery of CRISPR can impact the specificity and efficacy of gene editing. In recent years, synthetic nanoparticles have been discovered as effective CRISPR/Cas9 delivery vehicles. We categorized synthetic nanoparticles for CRISPR/Cas9 delivery and discribed their advantages and disadvantages. Further, the building blocks of different kinds of nanoparticles and their applications in cells/tissues, cancer and other diseases were described in detail. Finally, the challenges encountered in the clinical application of CRISPR/Cas9 delivery materials were discussed, and potential solutions were provided regarding efficiency and biosafety issues.

Direct Cytosolic Delivery of Proteins and CRISPR-Cas9 Genome Editing by Gemini Amphiphiles via Non-Endocytic Translocation Pathways

Intracellular delivery of therapeutic biomacromolecules is often challenged by the poor transmembrane and limited endosomal escape. Here, we establish a combinatorial library composed of 150 molecular weight-defined gemini amphiphiles (GAs) to identify the vehicles that facilitate robust cytosolic delivery of proteins in vitro and in vivo. These GAs display similar skeletal structures but differential amphiphilicity by adjusting the length of alkyl tails, type of ionizable cationic heads, and hydrophobicity or hydrophilicity of a spacer. The top candidate is highly efficient in translocating a broad spectrum of proteins with various molecular weights and isoelectric points into the cytosol. Particularly, we notice that the entry mechanism is predominantly mediated via the lipid raft-dependent membrane fusion, bypassing the classical endocytic pathway that limits the cytosolic delivery efficiency of many presently available carriers. Remarkably, the top GA candidate is capable of delivering hard-to-deliver Cas9 ribonucleoprotein in vivo, disrupting KRAS mutation in the tumor-bearing mice to inhibit tumor growth and extend their survival. Our study reveals a GA-based small-molecule carrier platform for the direct cytosolic delivery of various types of proteins for therapeutic purposes.

Airborne fine particles drive H1N1 viruses deep into the lower respiratory tract and distant organs

Mounting data suggest that environmental pollution due to airborne fine particles (AFPs) increases the occurrence and severity of respiratory virus infection in humans. However, it is unclear whether and how interactions with AFPs alter viral infection and distribution. We report synergetic effects between various AFPs and the H1N1 virus, regulated by physicochemical properties of the AFPs. Unlike infection caused by virus alone, AFPs facilitated the internalization of virus through a receptor-independent pathway. Moreover, AFPs promoted the budding and dispersal of progeny virions, likely mediated by lipid rafts in the host plasma membrane. Infected animal models demonstrated that AFPs favored penetration of the H1N1 virus into the distal lung, and its translocation into extrapulmonary organs including the liver, spleen, and kidney, thus causing severe local and systemic disorders. Our findings revealed a key role of AFPs in driving viral infection throughout the respiratory tract and beyond. These insights entail stronger air quality management and air pollution reduction policies.

Biomaterial-based gene therapy

Gene therapy, a medical approach that involves the correction or replacement of defective and abnormal genes, plays an essential role in the treatment of complex and refractory diseases, such as hereditary diseases, cancer, and rheumatic immune diseases. Nucleic acids alone do not easily enter the target cells due to their easy degradation in vivo and the structure of the target cell membranes. The introduction of genes into biological cells is often dependent on gene delivery vectors, such as adenoviral vectors, which are commonly used in gene therapy. However, traditional viral vectors have strong immunogenicity while also presenting a potential infection risk. Recently, biomaterials have attracted attention for use as efficient gene delivery vehicles, because they can avoid the drawbacks associated with viral vectors. Biomaterials can improve the biological stability of nucleic acids and the efficiency of intracellular gene delivery. This review is focused on biomaterial-based delivery systems in gene therapy and disease treatment. Herein, we review the recent developments and modalities of gene therapy. Additionally, we discuss nucleic acid delivery strategies, with a focus on biomaterial-based gene delivery systems. Furthermore, the current applications of biomaterial-based gene therapy are summarized.

Intracellular delivery of therapeutic proteins. New advancements and future directions

Achieving the full potential of therapeutic proteins to access and target intracellular receptors will have enormous benefits in advancing human health and fighting disease. Existing strategies for intracellular protein delivery, such as chemical modification and nanocarrier-based protein delivery approaches, have shown promise but with limited efficiency and safety concerns. The development of more effective and versatile delivery tools is crucial for the safe and effective use of protein drugs. Nanosystems that can trigger endocytosis and endosomal disruption, or directly deliver proteins into the cytosol, are essential for successful therapeutic effects. This article aims to provide a brief overview of the current methods for intracellular protein delivery to mammalian cells, highlighting current challenges, new developments, and future research opportunities.

Phosphocholine-Functionalized Zwitterionic Highly Branched Poly(β-amino ester)s for Cytoplasmic Protein Delivery

Proteins have tremendous potential for vaccine development and disease treatment, but multiple extracellular and intracellular biological barriers must be overcome before they can exert specific biological functions in the target tissue. The use of polymers as carriers would greatly improve their bioavailability and therapeutic efficiency. Nevertheless, effective protein packaging and cell membrane penetration without causing cytotoxicity is particularly challenging, due largely to the simultaneous distribution of positive and negative charges on protein surface. Here, phosphocholine-functionalized zwitterionic poly(β-amino ester)s, HPAE-D-(±), are developed for cytoplasmic protein delivery. The zwitterionic phosphocholine is capable of binding to both proteins and the cell membrane to facilitate protein packaging and nanoparticle cellular uptake. Compared to amine-functionalized HPAE-E-(+) and carboxylic acid-functionalized HPAE-C-(-), HPAE-D-(±) exhibits much higher cytoplasmic protein delivery efficiency and lower cytotoxicity. In addition, HPAE-D-(±) are readily degraded in aqueous solution. This strategy may be extended to other zwitterions and polymers, thus having profound implications for the development of safe and efficient protein delivery systems.