Nanoassemblies with Effective Serum Tolerance Capability Achieving Robust Gene Silencing Efficacy for Breast Cancer Gene Therapy

Mitochondrial endogenous substance transport-inspired nanomaterials for mitochondria-targeted gene delivery

Mitochondrial genome (mtDNA) independent of nuclear gene is a set of double-stranded circular DNA that encodes 13 proteins, 2 ribosomal RNAs and 22 mitochondrial transfer RNAs, all of which play vital roles in functions as well as behaviors of mitochondria. Mutations in mtDNA result in various mitochondrial disorders without available cures. However, the manipulation of mtDNA via the mitochondria-targeted gene delivery faces formidable barriers, particularly owing to the mitochondrial double membrane. Given the fact that there are various transport channels on the mitochondrial membrane used to transfer a variety of endogenous substances to maintain the normal functions of mitochondria, mitochondrial endogenous substance transport-inspired nanomaterials have been proposed for mitochondria-targeted gene delivery. In this review, we summarize mitochondria-targeted gene delivery systems based on different mitochondrial endogenous substance transport pathways. These are categorized into mitochondrial steroid hormones import pathways-inspired nanomaterials, protein import pathways-inspired nanomaterials and other mitochondria-targeted gene delivery nanomaterials. We also review the applications and challenges involved in current mitochondrial gene editing systems. This review delves into the approaches of mitochondria-targeted gene delivery, providing details on the design of mitochondria-targeted delivery systems and the limitations regarding the various technologies. Despite the progress in this field is currently slow, the ongoing exploration of mitochondrial endogenous substance transport and mitochondrial biological phenomena may act as a crucial breakthrough in the targeted delivery of gene into mitochondria and even the manipulation of mtDNA.

Personalized Cancer Nanomedicine: Overcoming Biological Barriers for Intracellular Delivery of Biopharmaceuticals

The success of personalized medicine in oncology relies on using highly effective and precise therapeutic modalities such as small interfering RNA (siRNA) and monoclonal antibodies (mAbs). Unfortunately, the clinical exploitation of these biological drugs has encountered obstacles in overcoming intricate biological barriers. Drug delivery technologies represent a plausible strategy to overcome such barriers, ultimately facilitating the access to intracellular domains. Here, an overview of the current landscape on how nanotechnology has dealt with protein corona phenomena as a first and determinant biological barrier is presented. This continues with the analysis of strategies facilitating access to the tumor, along with conceivable methods for enhanced tumor penetration. As a final step, the cellular barriers that nanocarriers must confront in order for their biological cargo to reach their target are deeply analyzed. This review concludes with a critical analysis and future perspectives of the translational advances in personalized oncological nanomedicine.

Self-Assembled Oligopeptoplex-Loaded Dissolving Microneedles for Adipocyte-Targeted Anti-Obesity Gene Therapy

Advancements in gene delivery systems are pivotal for gene-based therapeutics in oncological, inflammatory, and infectious diseases. This study delineates the design of a self-assembled oligopeptoplex (SA-OP) optimized for shRNA delivery to adipocytes, targeting obesity and associated metabolic syndromes. Conventional systems face challenges, including instability due to electrostatic interactions between genetic materials and cationic oligopeptides. Additionally, repeated injections induce discomfort and compromise patient well-being. To circumvent these issues, a dissolvable hyaluronic acid-based, self-locking microneedle (LMN) patch is developed, with improved micro-dose efficiency, for precise SA-OP delivery. This platform offers pain-free administration and improved SA-OP storage stability. In vitro studies in 3T3-L1 cells demonstrated improvements in SA-OP preservation and gene silencing efficacy. In vivo evaluation in a mice model of diet-induced type 2 diabetes yielded significant gene silencing in adipose tissue and a 21.92 ± 2.51% reduction in body weight with minimum relapse risk at 6-weeks post-treatment, representing a superior therapeutic efficacy in a truncated timeframe relative to the GLP-1 analogues currently available on the market. Additionally, SA-OP (LMN) mitigated insulin resistance, inflammation, and hepatic steatosis. These findings establish SA-OP (LMN) as a robust, minimally invasive transdermal gene delivery platform with prolonged storage stability for treating obesity and its metabolic comorbidities.

Novel aromatic moieties-modified poly(glycidyl amine)s with potent siRNA delivery and cancer treatment effect

The development of safe and effective delivery systems is critical for the clinical applications of siRNA-based therapeutics. Polymer-based vectors have garnered significant attention owing to their structural flexibility and functional tunability. Polyethyleneimine (PEI) has been extensively studied for nucleic acid delivery; nevertheless, its high cytotoxicity has posed challenges for clinical applications. In this study, we have reported poly(glycidyl amine) (PGAm), a linear PEI analogue, demonstrating remarkable siRNA delivery efficacy and improved biocompatibility. By introducing three aromatic moieties (tyrosine, p-hydroxybenzenepropanoic acid, and phenylalanine) at varying ratios to further modify PGAms, we successfully constructed a library comprising 36 PGAm-based carriers. In vitro evaluations revealed that PGAm-based carriers exhibited significantly enhanced biocompatibility and reduced non-specific protein absorption in comparison to PEI25k. Among them, 10 modified PGAms achieved a knockdown of target gene expressions exceeding 80%, and 26 modified PGAms maintained over 70% cell viability when utilized for the in vitro delivery of siRNA to HeLa cells. Explorations into the structure-activity relationship of PGAm-based polyplex nanoparticles (NPs) indicated that the siRNA delivery efficacy of NPs depended on factors such as the molecular weight of PGAm precursors, the type of modifying moieties, and the modification ratio. Furthermore, it was demonstrated that two top-performing NPs, namely 2T100/siLuc and 2A50/siLuc, exhibited potent silencing of target genes in tumors following i.v. injection into mice bearing HeLa-Luc xenografts. The in vivo efficacy of the selected NPs was further validated by a remarkable anti-cancer effect when employed for the delivery of siRNA targeting polo-like kinase 1 (siPLK1) to mice with PC-3 xenograft tumors. The intravenous administration of NPs resulted in a substantial inhibition of tumor growth without significant toxicity. These findings demonstrate the feasibility of employing PGAm in siRNA delivery and provide valuable insights for the development of efficient siRNA carriers based on PGAm.

Recent advances in multifunctional dendrimer-based complexes for cancer treatment

The application of nanotechnology in biological and medical fields have resulted in the creation of new devices, supramolecular systems, structures, complexes, and composites. Dendrimers are relatively new nanotechnological polymers with unique features; they are globular in shape, with a topological structure formed by monomeric subunit branches diverging to the sides from the central nucleus. This review analyzes the main features of dendrimers and their applications in biology and medicine regarding cancer treatment. Dendrimers have applications that include drug and gene carriers, antioxidant agents, imaging agents, and adjuvants, but importantly, dendrimers can create complex nanosized constructions that combine features such as drug/gene carriers and imaging agents. Dendrimer-based nanosystems include different metals that enhance oxidative stress, polyethylene glycol to provide biosafety, an imaging agent (a fluorescent, radioactive, magnetic resonance imaging probe), a drug or/and nucleic acid that provides a single or dual action on cells or tissues. One of major benefit of dendrimers is their easy release from the body (in contrast to metal nanoparticles, fullerenes, and carbon nanotubes), allowing the creation of biosafe constructions. Some dendrimers are already clinically approved and are being used as drugs, but many nanocomplexes are currently being studied for clinical practice. In summary, dendrimers are very useful tool in the creation of complex nanoconstructions for personalized nanomedicine. This article is categorized under: Diagnostic Tools > Diagnostic Nanodevices Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

CES1-Triggered Liver-Specific Cargo Release of CRISPR/Cas9 Elements by Cationic Triadic Copolymeric Nanoparticles Targeting Gene Editing of PCSK9 for Hyperlipidemia Amelioration

The broad application of clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 genome editing tools is hindered by challenges in the efficient delivery of its two components into specific cells and intracytoplasmic release. Herein, a novel copolymer for delivery of Cas9-mRNA/ single-guide RNA (Cas9-mRNA/sgRNA) in vitro and vivo, using carboxylesterase-responsive cationic triadic copolymeric nanoparticles targeted proprotein convertase subtilisin/kexin type 9 (PCSK9) for hyperlipidemia amelioration is reported. A dimethyl biguanide derivative is designed and synthesized to form cationic block, and copolymerization onto prepolymer with propyl methacrylate, to fabricate a triadic copolymer mPEG-b-P(Met/n-PMA). The copolymer can self-assemble with Cas9-mRNA/sgRNA, indicating the excellent potential of nanoparticles to form a delivery carrier. This vehicle can efficiently release RNA in response to the hepatocytes carboxylesterase for genome editing. It was demonstrated that the mPEG-b-P(Met/n-PMA)/Cas9 mRNA/sgRNA nanoparticles effectively accumulated in hepatocytes, lead to the inhibition of PCSK9, and lowered the levels of Low-density lipoprotein cholesterol and total cholesterol in mouse serum down 20% of nontreatment. Interestingly, the nanoparticles even enable multiple functions in the regulation of blood glucose and weight. This study establishes a novel method to achieve complex CRISPR components stable loading, safe delivery, and fixed-point release, which expand the application of CRISPR delivery systems.

High-Performance Multi-Dynamic Bond Cross-Linked Hydrogel with Spatiotemporal siRNA Delivery for Gene-Cell Combination Therapy of Intervertebral Disc Degeneration

Chronic inflammatory diseases, such as intervertebral disc degeneration (IVDD), which affect the lives of hundreds of millions of people, still lack effective and precise treatments. In this study, a novel hydrogel system with many extraordinary properties is developed for gene-cell combination therapy of IVDD. Phenylboronic acid-modified G5 PAMAM (G5-PBA) is first synthesized, and therapeutic siRNA silencing the expression of P65 mixed with G5-PBA (siRNA@G5-PBA) is then embedded into the hydrogel (siRNA@G5-PBA@Gel) based on multi-dynamic bonds including acyl hydrazone bonds, imine linkage, π-π stacking, and hydrogen bonding interactions. Local and acidic inflammatory microenvironment-responsive gene-drug release can achieve spatiotemporal regulation of gene expression. In addition, gene-drug release from the hydrogel can be sustained for more than 28 days in vitro and in vivo, greatly inhibiting the secretion of inflammatory factors and the subsequent degeneration of nucleus pulposus (NP) cells induced by lipopolysaccharide (LPS). Through prolonged inhibition of the P65/NLRP3 signaling pathway, the siRNA@G5-PBA@Gel is verified to relieve inflammatory storms, which can significantly enhance the regeneration of IVD when combined with cell therapy. Overall, this study proposes an innovative system for gene-cell combination therapy and a precise and minimally invasive treatment method for IVD regeneration.

Functionalized PAMAM constructed nanosystems for biomacromolecule delivery

Polyamidoamines (PAMAMs) are a class of dendrimer with monodispersity and controlled topology, which can deliver biologically active macromolecules (e.g., genes and proteins) to specific regions with high efficiency and minimum side effects. In detail, PAMAMs can be functionalized easily by core modification or surface amendment to encapsulate a wide range of biomacromolecules. Besides, self-assembled, cross-linked and hybrid PAMAMs with customized therapeutic purposes are developed as delivery vehicles, which makes PAMAMs promising for biomacromolecule therapy. In this review, we comprehensively summarize the application of PAMAMs in biomacromolecule delivery from the synthesis of functionalized PAMAM carriers to the development of PAMAM-based drug delivery systems. The underlying strategies for PAMAM functionalization and assembly are first systematically discussed, and then the current applications of PAMAMs for biomacromolecule delivery are reviewed. Finally, a brief perspective on the further applications of PAMAMs concludes, aiming to provide insights into developing PAMAM-based biomacromolecule delivery systems.

Carbon Dots with Guanidinium and Amino Acid Functional Groups for Targeted Small Interfering RNA Delivery toward Tumor Gene Therapy

Small interfering RNA (siRNA)-based gene therapy represents a promising strategy for tumor treatment. Novel gene vectors that can achieve targeted delivery of siRNA to the tumor cells without causing any side effects are urgently needed. To this end, the large amino acid mimicking carbon dots with guanidinium functionalization (LAAM GUA-CDs) are designed and synthesized by choosing arginine and dopamine hydrochloride as precursors. LAAM GUA-CDs can load siRNA through the multiple hydrogen bonds between their guanidinium groups and phosphate groups in siRNA. Meanwhile, the amino acid groups at the edges of LAAM GUA-CDs endow them the capacity to target tumors. After loading siBcl-2 as a therapeutic agent, LAAM GUA-CDs/siBcl-2 has a high tumor inhibition rate of up to 68%, which is twice more than that of commercial Lipofectamine 2000. Furthermore, LAAM GUA-CDs do not cause side effect during antitumor treatment owing to their high tumor-targeting ability, thus providing a versatile strategy for tumor-targeted siRNA delivery and cancer therapy.

A hypoxia-dissociable siRNA nanoplatform for synergistically enhanced chemo-radiotherapy of glioblastoma

Glioblastoma (GBM), as the most aggressive adult brain tumor, seriously threatened people's lives with a low survival time. Standard postoperative treatment, chemotherapy combined with radiotherapy (RT), was the major therapeutic strategy for GBM. However, this therapeutic efficacy was hindered by chemoradiotherapy resistance of GBM. Herein, to sensitize temozolomide (TMZ)-based chemotherapy and RT, a hypoxia-radiosensitive nanoparticle for co-delivering TMZ and siMGMT (RDPP(Met)/TMZ/siMGMT) was synthesized in this study. Our nanoparticle could effectively release the encapsulated alkylating agent (TMZ) and small interfering O6-methylguanine-DNA-methyltransferase RNA (siMGMT) in the hypoxic GBM. DNA-damage repair was effectively inhibited by down-regulating MGMT expression and activating cell apoptosis, which obviously enhanced the sensitivity of TMZ as well as RT. In vitro and in vivo experiments showed that RDPP(Met)/TMZ/siMGMT could efficiently penetrate the blood-brain barrier (BBB), accurately target GBM cells and effectively inhibit GBM proliferation. Compared with traditional TMZ combined with RT, RDPP(Met)/TMZ/siMGMT remarkably improved the survival time of orthotopic GBM-bearing mice, which demonstrated that our nanoplatform was an efficient combinatorial GBM therapy.

Combination of polythyleneimine regulating autophagy prodrug and Mdr1 siRNA for tumor multidrug resistance

Multidrug resistance (MDR) has been restricting the efficacy of chemotherapy, which mainly include pump resistance and non-pump resistance. In order to fight overall MDR, a novel targeted gene/drug co-deliver nano system is developed, which can suppress the drug efflux pumps and modulate autophagy to overcoming both pump and non-pump resistance. Here, small interfere RNA (siRNA) is incorporated into polymer-drug conjugates (PEI-PTX, PP) which are composed of polyethyleneimine (PEI) and paclitaxel (PTX) via covalent bonds, and hyaluronic acid (HA) is coated on the surface of PP/siRNA to achieve long blood cycle and CD44-targeted delivery. The RNA interference to mdr1 gene is combined with autophagy inhibition by PP, which efficiently facilitate apoptosis of Taxol-resistant lung cancer cells (A549/T). Further study indicates that PEI in PP may play a significant role to block the autophagosome–lysosome fusion process by means of alkalizing lysosomes. Both in vitro and in vivo studies confirm that the nanoassemblies can successfully deliver PTX and siRNA into tumor cells and significantly inhibited A549/T tumor growth. In summary, the polymeric nanoassemblies provide a potential strategy for combating both pump and non-pump resistance via the synergism of RNAi and autophagy modulation.

Polymeric Dendrimers as Nanocarrier Vectors for Neurotheranostics

Dendrimers are polymers with well-defined 3D branched structures that are vastly utilized in various neurotheranostics and biomedical applications, particularly as nanocarrier vectors. Imaging agents can be loaded into dendrimers to improve the accuracy of diagnostic imaging processes. Likewise, combining pharmaceutical agents and anticancer drugs with dendrimers can enhance their solubility, biocompatibility, and efficiency. Practically, by modifying ligands on the surface of dendrimers, effective therapeutic and diagnostic platforms can be constructed and implemented for targeted delivery. Dendrimer-based nanocarriers also show great potential in gene delivery. Since enzymes can degrade genetic materials during their blood circulation, dendrimers exhibit promising packaging and delivery alternatives, particularly for central nervous system (CNS) treatments. The DNA and RNA encapsulated in dendrimers represented by polyamidoamine that are used for targeted brain delivery, via chemical-structural adjustments and appropriate generation, significantly improve the correlation between transfection efficiency and cytotoxicity. This article reports a comprehensive review of dendrimers' structures, synthesis processes, and biological applications. Recent progress in diagnostic imaging processes and therapeutic applications for cancers and other CNS diseases are presented. Potential challenges and future directions in the development of dendrimers, which provide the theoretical basis for their broader applications in healthcare, are also discussed.

Self-Healing Hydrogel Embodied with Macrophage-Regulation and Responsive-Gene-Silencing Properties for Synergistic Prevention of Peritendinous Adhesion

Antiadhesion barriers such as films and hydrogels used to wrap repaired tendons are important for preventing the formation of adhesion tissue after tendon surgery. However, sliding of the tendon can compress the adjacent hydrogel barrier and cause it to rupture, which may then lead to unexpected inflammation. Here, a self-healing and deformable hyaluronic acid (HA) hydrogel is constructed as a peritendinous antiadhesion barrier. Matrix metalloproteinase-2 (MMP-2)-degradable gelatin-methacryloyl (GelMA) microspheres (MSs) encapsulated with Smad3-siRNA nanoparticles are entrapped within the HA hydrogel to inhibit fibroblast proliferation and prevent peritendinous adhesion. GelMA MSs are responsively degraded by upregulation of MMP-2, achieving on-demand release of siRNA nanoparticles. Silencing effect of Smad3-siRNA nanoparticles is around 75% toward targeted gene. Furthermore, the self-healing hydrogel shows relatively attenuated inflammation compared to non-healing hydrogel. The mean adhesion scores of composite barrier group are 1.67 ± 0.51 and 2.17 ± 0.75 by macroscopic and histological evaluation, respectively. The proposed self-healing hydrogel antiadhesion barrier with MMP-2-responsive drug release behavior is highly effective for decreasing inflammation and inhibiting tendon adhesion. Therefore, this research provides a new strategy for the development of safe and effective antiadhesion barriers.

Nature-inspired dynamic gene-loaded nanoassemblies for the treatment of brain diseases

Gene therapy has great potential to treat brain diseases. However, genetic drugs need to overcome a cascade of barriers for their full potential. The conventional delivery systems often struggle to meet expectations. Natural biological particles that are highly optimized for specific functions in body, can inspire optimization of dynamic gene-loaded nanoassemblies (DGN). The DGN refer to gene loaded nanoassemblies whose functions and structures are changeable in response to the biological microenvironments or can dynamically interact with tissues or cells. The nature-inspired DGN can meet the needs in brain diseases treatment, including i) Non-elimination in blood (N), ii) Across the blood-brain barrier (A), iii) Targeting cells (T), iv) Efficient uptake (U), v) Controllable release (R), vi) Eyeable (E)-abbreviated as the "NATURE". In this Review, from nature to "NATURE", we mainly summarize the specific application of nature-inspired DGN in the "NATURE" cascade process. Furthermore, the Review provides an outlook for this field.

Facile fabrication of a biodegradable multi-hollow iron phosphate nanoplatform for tumor-specific nanocatalytic therapy and chemotherapy

Doxorubicin-loaded iron phosphate could be disintegrated in a low pH environment, releasing both ferric and ferrous ions as well as doxorubicin, and achieve combination tumor therapy.

Injectable self-healing hydrogel with siRNA delivery property for sustained STING silencing and enhanced therapy of intervertebral disc degeneration

Inflammatory responses of nucleus pulposus (NP) can induce imbalanced anabolism and catabolism of extracellular matrix, and the cytosolic dsDNA accumulation and STING–NF–κB pathway activation found in NP inflammation are considered as fairly important cause of intervertebral disc (IVD) degeneration. Herein, we constructed a siSTING delivery hydrogel of aldehyde hyaluronic acid (HA-CHO) and poly(amidoamine) PAMAM/siRNA complex to intervene the abnormal STING signal for IVD degeneration treatment, where the formation of dynamic Schiff base bonds in the system (siSTING@HP^gel) was able to overcome the shortcomings such as low cellular uptake, short half-life, and rapid degradation of siRNA-based strategy. PAMAM not only formed complexes with siRNA to promote siRNA transfection, but also served as dynamic crosslinker to construct hydrogel, and the injectable and self-healing hydrogel efficiently and steadily silenced STING expression in NP cells. Finally, the siSTING@HP^gel significantly eased IVD inflammation and slowed IVD degeneration by prolonging STING knockdown in puncture-induced IVD degeneration rat model, revealing that STING pathway was a therapeutic target for IVD degeneration and such novel hydrogel had great potential for being applied to many other diseases for gene delivery.

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STING-NF-κB pathway activation was identified an important cause of intervertebral disc degeneration.

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PAMAM was employed as both linker and gene vector for siRNA delivery.

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The injectable self-healing hydrogel could significantly ease the IVD inflammation and degeneration by prolonging STING knockdown.

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This novel hydrogel system opened new ways of thinking and had great potential for gene delivery.

Bioreducible, arginine-rich polydisulfide-based siRNA nanocomplexes with excellent tumor penetration for efficient gene silencing

RNA interference (RNAi) technology has great potential in cancer therapy, e.g., small interfering RNA (siRNA) can be exploited to silence specific oncogenes related to tumor growth and progression. However, it is critical to achieve high transfection efficiency while reducing cytotoxicity. In this paper, we report an siRNA delivery strategy targeting the oncogene KRAS based on arginine-modified poly(disulfide amine)/siRNA nanocomplexes. The poly(disulfide amine) is synthesized via aza-Michael polyaddition followed by the introduction of arginine groups onto its backbone to afford poly((N,N'-bis(acryloyl)cystamine-co-ethylenediamine)-g-Nω-p-tosyl-l-arginine) (PBR) polycations. Thus multiple interactions including electrostatic interaction, hydrogen bonding and a hydrophobic effect are introduced simultaneously between PBR and siRNA or cell membranes to improve transfection efficiency. By optimizing the grafting density of arginine groups, PBR/siRNA nanocomplexes achieve high cellular uptake efficiency, successful endosomal/lysosomal escape, and rapid biodegradation in the presence of high GSH concentration in the cytoplasm, and finally release siRNA to activate the RNAi mechanism. Additionally, compared to commercially available PEI 25K, PBR/siRNA nanocomplexes possess a significantly increased gene silencing effect on human pancreatic cancer cells (PANC-1) with decreased cytotoxicity and enhanced tumor penetration ability in PANC-1 multicellular spheroids in vitro. Overall, with both GSH-responsiveness and excellent tumor penetration, this safe and efficient poly(disulfide amine)-based siRNA delivery system is expected to provide a new strategy for gene therapy of pancreatic cancer and other stromal-rich tumors.

Recent Advances in Preclinical Research Using PAMAM Dendrimers for Cancer Gene Therapy

Carriers of genetic material are divided into vectors of viral and non-viral origin. Viral carriers are already successfully used in experimental gene therapies, but despite advantages such as their high transfection efficiency and the wide knowledge of their practical potential, the remaining disadvantages, namely, their low capacity and complex manufacturing process, based on biological systems, are major limitations prior to their broad implementation in the clinical setting. The application of non-viral carriers in gene therapy is one of the available approaches. Poly(amidoamine) (PAMAM) dendrimers are repetitively branched, three-dimensional molecules, made of amide and amine subunits, possessing unique physiochemical properties. Surface and internal modifications improve their physicochemical properties, enabling the increase in cellular specificity and transfection efficiency and a reduction in cytotoxicity toward healthy cells. During the last 10 years of research on PAMAM dendrimers, three modification strategies have commonly been used: (1) surface modification with functional groups; (2) hybrid vector formation; (3) creation of supramolecular self-assemblies. This review describes and summarizes recent studies exploring the development of PAMAM dendrimers in anticancer gene therapies, evaluating the advantages and disadvantages of the modification approaches and the nanomedicine regulatory issues preventing their translation into the clinical setting, and highlighting important areas for further development and possible steps that seem promising in terms of development of PAMAM as a carrier of genetic material.