Chitosan-Based Nanoparticles for Nucleic Acid Delivery: Technological Aspects, Applications, and Future Perspectives

Revolutionizing mRNA Vaccines Through Innovative Formulation and Delivery Strategies

Modernization of existing methods for the delivery of mRNA is vital in advanced therapeutics. Traditionally, mRNA has faced obstacles of poor stability due to enzymatic degradation. This work examines cutting-edge formulation and emerging techniques for safer delivery of mRNA vaccines. Inspired by the success of lipid nanoparticles (LNP) in delivering mRNA vaccines for COVID-19, a variety of other formulations have been developed to deliver mRNA vaccines for diverse infections. The meritorious features of nanoparticle-based mRNA delivery strategies, including LNP, polymeric, dendrimers, polysaccharide-based, peptide-derived, carbon and metal-based, DNA nanostructures, hybrid, and extracellular vesicles, have been examined. The impact of these delivery platforms on mRNA vaccine delivery efficacy, protection from enzymatic degradation, cellular uptake, controlled release, and immunogenicity has been discussed in detail. Even with significant developments, there are certain limitations to overcome, including toxicity concerns, limited information about immune pathways, the need to maintain a cold chain, and the necessity of optimizing administration methods. Continuous innovation is essential for improving delivery systems for mRNA vaccines. Future research directions have been proposed to address the existing challenges in mRNA delivery and to expand their potential prophylactic and therapeutic application.

Enhancing non-viral DNA delivery systems: Recent advances in improving efficiency and target specificity

DNA-based therapies are often limited by challenges such as stability, long-term integration, low transfection efficiency, and insufficient targeted DNA delivery. This review focuses on recent progress in the design of non-viral delivery systems for enhancing targeted DNA delivery and modulation of therapeutic efficiency. Cellular uptake and intracellular trafficking mechanisms play a crucial role in optimizing gene delivery efficiency. There are two main strategies employed to improve the efficiency of gene delivery vectors: (i) explore different administration routes (e.g., mucosal, intravenous, intramuscular, subcutaneous, intradermal, intratumoural, and intraocular) that best facilitates optimal uptake into the targeted cells and organs and (ii) modify the delivery vectors with cell-specific ligands (e.g., natural ligands, antibodies, peptides, carbohydrates, or aptamers) that enable targeted uptake to specific cells with higher specificity and improved biodistribution. We describe how recent progress in employing these DNA delivery strategies is advancing the field and increasing the clinical translation and ultimate clinical application of DNA therapies.

Topical delivery of siRNA to psoriatic skin model using high molecular weight chitosan derivatives: In vitro and in vivo studies

Psoriasis is a chronic inflammatory skin disease that, like other immune-mediated conditions, may benefit from small interfering RNA (siRNA)-based therapies, which are emerging as a promising alternative by addressing several limitations of current treatments. In this study, topical formulations of chitosan-based vectors were developed to deliver siRNA targeting tumor necrosis factor alpha (TNFα) to inflamed skin. Grafting diisopropylethylamine (DIPEA) and polyethylene glycol (PEG) onto the chitosan backbone enhanced siRNA delivery efficiency under physiological conditions, forming robust polymeric vectors with high structural and colloidal stability. These vectors provided siRNA protection against RNAse degradation and oxidative damage. Additionally, the chitosan derivatives displayed lysozyme-mediated biodegradability comparable to native chitosan, while PEG was released in response to reductive environments, supporting controlled vector disassembly. The PEGylated DIPEA-chitosan/siRNA polyplexes demonstrated positive zeta potentials (up to + 11 mV), particle sizes of 100-200 nm, and very low cytotoxicity in keratinocyte and fibroblast cell lines. In vitro, the polyplexes achieved TNFα knockdown levels (65%) in RAW macrophages, comparable to those obtained with Lipofectamine™. Topical formulations showed enhanced interaction of vectors with skin models (Strat-M® and porcine ear skin) compared to naked siRNA. Furthermore, in vivo studies indicated that hair follicles were a key route for polyplexes to penetrate deeper skin layers. A rodent model of psoriasis induced by imiquimod was treated topically with these vectors, resulting in approximately a 50% reduction in TNFα levels at inflammation sites, decreased immune cell infiltration, and preservation of epidermal structure. These findings collectively underscore the potential of DIPEA-chitosan-based vectors for topical siRNA-based therapies.

Tricine-modified chitosan as a strategy for enhancing hydrophilicity and gene delivery

In this study, we investigated the effect of chitosan modification with tricine on transfection efficiency by preserving its ability to form complexes with plasmid DNA (pDNA) and increasing its hydrophilicity. The inherent limitations of chitosan, such as poor solubility at physiological pH, insufficient cellular uptake, and strong ionic interactions with pDNA, typically result in low transfection efficiency. To overcome these challenges, Tricine, a hydrophilic molecule containing a secondary amine group, was conjugated to chitosan. Chitosan of three different molecular weights (low, medium, and high) was modified with tricine. Structural characterization of the modified chitosan was conducted using Fourier Transformed Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR) analyses. The effects of tricine modification were assessed in terms of hydrophilicity/hydrophobicity, proton buffering capacity, particle size, PDI and zeta potential. Tricine modified low molecular weight chitosan nanoparticles (nLMWChiTri), which exhibit suitable properties for gene transfer studies, were evaluated regarding pDNA complexation ability, cytotoxicity and in vitro transfection efficiency. The results demonstrated that tricine modification enhanced the gene transfer potential of chitosan, making it competitive with the commercial transfection agent Lipofectamine™ 2000 and offering a promising strategy for non-viral gene therapy applications. Furthermore, the biocompatibility and biodegradability of chitosan, combined with the improved hydrophilicity provided by tricine, makes nLMWChiTri a safer and more sustainable option for repeated use in gene delivery, overcoming the major limitations associated with other synthetic vectors such as Lipofectamine™ 2000.

Coassembly of a Hybrid Synthetic-Biological Chitosan-g-Poly(N-isopropylacrylamide) Copolymer with DNAs of Different Lengths

Natural polysaccharides can serve as carriers of genes owing to their intrinsic biocompatibility, biodegradability, and low toxicity. Additionally, they can be easily chemically modified, e.g., through grafting, leading to hybrid synthetic-biological copolymers with additional functionalities. In this work we report on the electrostatic interaction between a chitosan-g-poly(N-isopropylacrylamide) (Chit-g-PNIPAM) copolymer and DNA macromolecules of different lengths (i.e., 50 and 2000 bp), towards the construction of polyplexes that can serve as potential gene delivery systems. At the basic science level, the work aims to elucidate the effects of DNA length on the structural and physicochemical properties of the thermoresponsive hybrid macromolecular assemblies. The protonated amino groups on the chitosan backbone enable electrostatic binding with the anionic phosphate groups of the DNA molecules, while the PNIPAM side chains are expected to impart thermoresponsive properties to the formed polyplexes. Different amino to phosphate group (N/P) mixing ratios were examined, aiming to produce stable dispersions. The physicochemical properties of the resulting polyplexes were investigated by dynamic and electrophoretic light scattering (DLS and ELS), while their morphology was studied by scanning-transmission electron microscopy (STEM). Moreover, their response to changes in temperature and ionic strength, as well as their stability against biological media, was also examined. Finally, the binding affinity of the copolymer towards DNA was evaluated through fluorescence spectroscopy, using ethidium bromide quenching assays, while infrared spectroscopy was used to investigate the structure of the incorporated DNA chains.

Deciphering the multifaceted role of microRNAs in hepatocellular carcinoma: Integrating literature review and bioinformatics analysis for therapeutic insights

Hepatocellular carcinoma (HCC) poses a significant global health challenge, necessitating innovative therapeutic strategies. MicroRNAs (miRNAs) have emerged as pivotal regulators of HCC pathogenesis, influencing key processes such as self-renewal, angiogenesis, glycolysis, autophagy, and metastasis. This article integrates findings from a comprehensive literature review and bioinformatics analysis to elucidate the role of miRNAs in HCC. We discuss how dysregulation of miRNAs can drive HCC initiation, progression, and metastasis by modulating various signaling pathways and target genes. Moreover, leveraging high-throughput technology and bioinformatics tools, we identify key miRNAs involved in multiple cancer hallmarks, offering insights into potential combinatorial therapeutic strategies. Through our analysis considering p-values and signaling pathways associated with key features, we unveil miRNAs with simultaneous roles across critical cancer characteristics, providing a basis for the development of high-performance biomarkers. The microRNAs, miR-34a-5p, miR-373-3p, miR-21-5p, miR-214-5p, miR-195-5p, miR-139-5p were identified to be shared microRNAs in stemness, angiogenesis, glycolysis, autophagy, EMT, and metastasis of HCC. However, challenges such as miRNA stability and delivery hinder the translation of miRNA-based therapeutics into clinical practice. This review underscores the importance of further research to overcome existing barriers and realize the full potential of miRNA-based interventions for HCC management.

Drug Loading in Chitosan-Based Nanoparticles

Chitosan nanoparticles (CSNPs) are promising vehicles for targeted and controlled drug release. Recognized for their biodegradability, biocompatibility, low toxicity, and ease of production, CSNPs represent an effective approach to drug delivery. Encapsulating drugs within nanoparticles (NPs) provides numerous benefits compared to free drugs, such as increased bioavailability, minimized toxic side effects, improved delivery, and the incorporation of additional features like controlled release, imaging agents, targeted delivery, and combination therapies with multiple drugs. Keys parameters in nanomedicines are drug loading content and drug loading efficiency. Most current NP systems struggle with low drug loading, presenting a significant challenge to the field. This review summarizes recent research on developing CSNPs with high drug loading capacity, focusing on various synthesis strategies. It examines CSNP systems using different materials and drugs, providing details on their synthesis methods, drug loadings, encapsulation efficiencies, release profiles, stability, and applications in drug delivery. Additionally, the review discusses factors affecting drug loading, providing valuable guidelines for future CSNPs' development.

Nucleic acid-based nanotherapeutics for treating sepsis and associated organ injuries

In recent years, gene therapy has been made possible with the success of nucleic acid drugs against sepsis and its related organ dysfunction. Therapeutics based on nucleic acids such as small interfering RNAs (siRNAs), microRNAs (miRNAs), messenger RNAs (mRNAs), and plasmid DNAs (pDNAs) guarantee to treat previously undruggable diseases. The advantage of nucleic acid-based therapy against sepsis lies in the development of nanocarriers, achieving targeted and controlled gene delivery for improved efficacy with minimal adverse effects. Entrapment into nanocarriers also ameliorates the poor cellular uptake of naked nucleic acids. In this study, we discuss the current state of the art in nanoparticles for nucleic acid delivery to treat hyperinflammation and apoptosis associated with sepsis. The optimized design of the nanoparticles through physicochemical property modification and ligand conjugation can target specific organs-such as lung, heart, kidney, and liver-to mitigate multiple sepsis-associated organ injuries. This review highlights the nanomaterials designed for fabricating the anti-sepsis nanosystems, their physicochemical characterization, the mechanisms of nucleic acid-based therapy in working against sepsis, and the potential for promoting the therapeutic efficiency of the nucleic acids. The current investigations associated with nanoparticulate nucleic acid application in sepsis management are summarized in this paper. Noteworthily, the potential application of nanotherapeutic nucleic acids allows for a novel strategy to treat sepsis. Further clinical studies are required to confirm the findings in cell- and animal-based experiments. The capability of large-scale production and reproducibility of nanoparticle products are also critical for commercialization. It is expected that numerous anti-sepsis possibilities will be investigated for nucleic acid-based nanotherapeutics in the future.

Advances in chitosan-based blends as potential drug delivery systems: A review

During the last decades, the ever-increasing incidence of diseases has led to high rates of mortality throughout the world. On the other hand, the inability and deficiencies of conventional approaches (such as chemotherapy) in the suppression of diseases remain challenging issues. As a result, there is a fundamental requirement to develop novel, biocompatible, bioavailable, and practical nanomaterials to prevent the incidence and mortality of diseases. Chitosan (CS) derivatives and their blends are outstandingly employed as promising drug delivery systems for disease therapy. These biopolymers are indicated more efficient performance against diseases compared with conventional modalities. The CS blends possess improved physicochemical properties, ease of preparation, high affordability, etc. characteristics compared with other biopolymers and even pure CS which result in efficient thermal, mechanical, biochemical, and biomedical features. Also, these blends can be administrated through different routes without a long-term treatment period. Due to the mentioned properties, numerous formulations of CS blends are developed for pharmaceutical sciences to treat diseases. This review article highlights the progressions in the development of CS-based blends as potential drug delivery systems against diseases.

Synthesis of Thermoresponsive Chitosan-graft-Poly(N-isopropylacrylamide) Hybrid Copolymer and Its Complexation with DNA

A hybrid synthetic-natural, thermoresponsive graft copolymer composed of poly(N-isopropyl acrylamide) (PNIPAM) side chains, prepared via RAFT polymerization, and a chitosan (Chit) polysaccharide backbone, was synthesized via radical addition-fragmentation reactions using the "grafting to" technique, in aqueous solution. ATR-FTIR, TGA, polyelectrolyte titrations and 1H NMR spectroscopy were employed in order to validate the Chit-g-PNIPAM copolymer chemical structure. Additionally, 1H NMR spectra and back conductometric titration were utilized to quantify the content of grafted PNIPAM side chains. The resulting graft copolymer contains dual functionality, namely both pH responsive free amino groups, with electrostatic complexation/coordination properties, and thermoresponsive PNIPAM side chains. Particle size measurements via dynamic light scattering (DLS) were used to study the thermoresponsive behavior of the Chit-g-PNIPAM copolymer. Thermal properties examined by TGA showed that, by the grafting modification with PNIPAM, the Chit structure became more thermally stable. The lower critical solution temperature (LCST) of the copolymer solution was determined by DLS measurements at 25-45 °C. Furthermore, dynamic and electrophoretic light scattering measurements demonstrated that the Chit-g-PNIPAM thermoresponsive copolymer is suitable of binding DNA molecules and forms nanosized polyplexes at different amino to phosphate groups ratios, with potential application as gene delivery systems.

Smart co-delivery of plasmid DNA and doxorubicin using MCM-chitosan-PEG polymerization functionalized with MUC-1 aptamer against breast cancer

This study introduces an innovative co-delivery approach using the MCM-co-polymerized nanosystem, integrating chitosan and polyethylene glycol, and targeted by the MUC-1 aptamer (MCM@CS@PEG-APT). This system enables simultaneous delivery of the GFP plasmid and doxorubicin (DOX). The synthesis of the nanosystem was thoroughly characterized at each step, including FTIR, XRD, BET, DLS, FE-SEM, and HRTEM analyses. The impact of individual polymers (chitosan and PEG) on payload retardation was compared to the co-polymerized MCM@CS@PEG conjugation. Furthermore, the DOX release mechanism was investigated using various kinetic models. The nanosystem's potential for delivering GFP plasmid and DOX separately and simultaneously was assessed through fluorescence microscopy and flow cytometry. The co-polymerized nanosystem exhibited superior payload entrapment (1:100 ratio of Plasmid:NPs) compared to separately polymer-coated counterparts (1:640 ratio of Plasmid:NPs). Besides, the presence of pH-sensitive chitosan creates a smart nanosystem for efficient DOX and GFP plasmid delivery into tumor cells, along with a Higuchi model pattern for drug release. Toxicity assessments against breast tumor cells also indicated reduced off-target effects compared to pure DOX, introducing it as a promising candidate for targeted cancer therapy. Cellular uptake findings demonstrated the nanosystem's ability to deliver GFP plasmid and DOX separately into MCF-7 cells, with rates of 32% and 98%, respectively. Flow cytometry results confirmed efficient co-delivery, with 42.7% of cells showing the presence of both GFP-plasmid and DOX, while 52.2% exclusively contained DOX. Overall, our study explores the co-delivery potential of the MCM@CS@PEG-APT nanosystem in breast cancer therapy. This system's ability to co-deliver multiple agents preciselyopens new avenues for targeted therapeutic strategies.

Preparation, characterization and in vitro evaluation of 5-fluorouracil loaded into chitosan-acacia gum nanoparticles

Aim: In this study, we prepared, characterized and in vitro evaluated a 5-fluorouracil (5-FU)-loaded chitosan-acacia gum nanoparticles. Methods: Nanoparticles were characterized for their size, charge, morphology and encapsulation efficiency (EE%) followed by cellular investigations against HT-29 colon cancer cell line. Results: The nanoparticles exhibited a spherical morphological size with 94.42% EE%. Free 5-FU showed a fast and fully cumulative release after 6 h while 5-FU loaded into CS-AG NPs showed good entrapment and slow, prolonged 5-FU release even after 24 h. Enhanced IC50 for the 5-FU loaded NPs compared with free 5-FU against HT-29 colon cancer cell line was reported with high selectivity compared with normal fibroblast cells. Conclusion: 5-FU loaded NPs is promising nano-therapy against colon cancer.

Nanovehicles for melatonin: a new journey for agriculture

The important role of melatonin in plant growth and metabolism together with recent advances in the potential use of nanomaterials have opened up interesting applications in agriculture. Various nanovehicles have been explored as melatonin carriers in animals, and it is now important to explore their application in plants. Recent findings have substantiated the use of silicon and chitosan nanoparticles (NPs) in targeting melatonin to plant tissues. Although melatonin is an amphipathic molecule, nanocarriers can accelerate its uptake and transport to various plant organs, thereby relieving stress and improving plant shelf-life in the post-harvest stages. We review the scope and biosafety concerns of various nanomaterials to devise novel methods for melatonin application in crops and post-harvest products.

Chitosan-functionalized bioplatforms and hydrogels in breast cancer: immunotherapy, phototherapy and clinical perspectives

Breast cancer is the most common and malignant tumor among women. Chitosan (CS)-based nanoparticles have been introduced into breast cancer therapy as a way to increase the targeted delivery of drugs and genes to the tumor site. CS nanostructures suppress tumorigenesis by enhancing both the targeted delivery of cargo (drug and gene) and its accumulation in tumor cells. The tumor cells internalize CS-based nanoparticles through endocytosis. Moreover, chitosan nanocarriers can also induce phototherapy-mediated tumor ablation. Smart and multifunctional types of CS nanoparticles, including pH-, light- and redox-responsive nanoparticles, can be used to improve the potential for breast cancer removal. In addition, the acceleration of immunotherapy by CS nanoparticles has also been achieved, and there is potential to develop CS-nanoparticle hydrogels that can be used to suppress tumorigenesis.