Nanoparticle-mediated gene delivery represents a major advancement in modern biotechnology, offering an innovative approach for the efficient and precise transport of genetic materials such as siRNA and mRNA. The continuous evolution of nanotechnology has significantly enhanced the efficiency, stability, and targeting capability of gene delivery systems. Compared with conventional delivery approaches, nanoparticle-based carriers provide a versatile and tunable platform that overcomes many biological barriers associated with nucleic acid transport. This technology is redefining the landscape of genetic medicine research and is driving the development of next-generation therapeutic modalities.
The fundamental objective of a gene delivery system is to introduce exogenous genetic material into target cells efficiently and safely. Depending on the carrier type, gene delivery systems are generally divided into viral and non-viral vectors.
Viral vectors, such as adenoviral and retroviral systems, have been extensively utilized due to their naturally high transfection efficiency. However, issues such as immunogenicity, limited loading capacity, and complex manufacturing processes restrict their broader use.
Non-viral vectors, particularly nanoparticle-based systems, offer greater flexibility, scalability, and safety. These synthetic carriers leverage physicochemical interactions, such as electrostatic attraction, hydrophobic association, or receptor-specific binding, to encapsulate and transport nucleic acids into target cells.
Once internalized, nanoparticles typically undergo a multi-step delivery process involving cellular uptake, endosomal escape, and cytoplasmic release of the genetic payload. For instance, cationic polymers exhibiting a "proton sponge effect" can buffer the acidic endosomal environment, leading to osmotic swelling and membrane disruption that facilitate the release of nucleic acids into the cytoplasm.
The direct administration of naked nucleic acids faces substantial biological and physicochemical barriers that severely limit delivery efficiency. Due to their large molecular size and strong negative charge, nucleic acids cannot easily penetrate the lipid bilayer of cell membranes. Once introduced into the body, they are quickly degraded by nucleases, resulting in extremely short circulation half-lives. Moreover, naked nucleic acids exhibit poor biodistribution, dispersing non-specifically across tissues without accumulating at the intended sites of action. Rapid clearance through renal filtration and uptake by the reticuloendothelial system further reduces their bioavailability. These limitations underscore the critical need for engineered nanocarrier systems capable of protecting nucleic acids, enhancing their stability, and achieving targeted intracellular delivery.
Nanoparticle-based carriers offer multiple intrinsic advantages that address the shortcomings of naked nucleic acid delivery:
Enhanced protection and stability
Cationic lipids or polymers form stable complexes with negatively charged nucleic acids, shielding them from nuclease degradation. For example, polyethylenimine (PEI)-siRNA complexes demonstrate significantly prolonged stability during systemic circulation.
Improved cellular uptake
The physicochemical parameters of nanoparticles, such as size, surface charge, and shape, can be precisely tuned to enhance membrane interaction and internalization. Nanoparticles around 100 nm in diameter often achieve optimal uptake efficiency through endocytosis.
Targeted delivery potential
By conjugating targeting ligands (e.g., antibodies, peptides, or sugars) onto the nanoparticle surface, carriers can selectively bind to specific cell receptors. This active targeting approach enables higher local concentrations at desired sites and reduces off-target distribution.
Controlled release capability
Stimuli-responsive materials that react to pH, redox potential, or enzymatic activity can enable environment-specific release of siRNA or mRNA within the cell, ensuring efficient gene expression modulation.
Fig.1 Therapeutic mRNA delivery via engineered lipid nanoparticles1,2.
Effective loading and protection of nucleic acids are central to the success of nanoparticle-based delivery systems. Modern nanocarriers employ a variety of molecular interactions and structural designs to encapsulate genetic materials securely and enable controlled release. Electrostatic complexation between cationic polymers and negatively charged nucleic acids forms stable complexes that prevent enzymatic degradation. Lipid nanoparticles encapsulate nucleic acids within lipid cores to provide additional protection and biostability. More advanced approaches involve covalent conjugation using cleavable linkers or self-assembling DNA nanostructures that allow for programmable encapsulation and release. Collectively, these strategies ensure that nucleic acids remain intact during circulation while enabling efficient intracellular release when they reach target cells.
The physicochemical characteristics of nanoparticles, particularly surface charge and particle size, play decisive roles in determining their interaction with cells and in vivo distribution. Moderately positive surface charge enhances electrostatic attraction to negatively charged cell membranes, improving internalization efficiency, while excessive charge can trigger non-specific binding or toxicity. Likewise, nanoparticles within the 100-150 nm size range generally exhibit an optimal balance between extended circulation, cellular uptake, and tissue penetration, whereas larger particles tend to be cleared more rapidly. Surface modification with polyethylene glycol (PEG), known as PEGylation, further refines these properties by reducing protein adsorption and phagocytic recognition, leading to prolonged stability and consistent biodistribution.
Achieving controlled intracellular release of nucleic acids is one of the key challenges in nanocarrier design. Stimuli-responsive nanoparticles that respond to specific intracellular cues, such as pH, enzymatic activity, or redox gradients, enable precise release of their genetic payloads within the cytoplasm. Equally important is the ability of the carrier to facilitate endosomal escape after cellular uptake. Mechanisms such as the proton sponge effect in buffering polymers, pH-activated ionizable lipids, and membrane-disruptive peptides promote the disruption of endosomal membranes and efficient cytosolic delivery of nucleic acids. The integration of these mechanisms into carrier design substantially improves gene transfer efficiency while minimizing degradation during the delivery process.
Functional modification of nanocarriers with targeting ligands greatly enhances delivery specificity and cellular uptake efficiency. Ligands such as antibodies, aptamers, peptides, and small molecules can be engineered to recognize receptors expressed on specific cell types, enabling selective gene delivery. The effectiveness of such targeting depends on optimizing ligand density and spatial orientation to ensure strong receptor interaction without compromising nanoparticle stability. In addition, environment-responsive designs allow ligands to remain shielded during systemic circulation and become exposed only within specific microenvironments, such as enzyme-rich or acidic tissues. Combining multiple functional elements, such as PEGylation for extended circulation and targeting ligands for cell selectivity, enables a balanced and versatile delivery platform. As targeting technologies advance, nanoparticle systems are evolving toward increasing precision, from organ-level selectivity to cell-type and even subcellular targeting, thereby broadening the potential of genetic nanomedicine.
BOC Sciences provides versatile nanoparticles with diverse compositions and functional modifications, customized solutions for your delivery needs.
Nanoparticles typically enter cells through endocytosis, with the specific route influenced by particle size, surface charge, and ligand decoration. Clathrin-mediated uptake dominates for particles smaller than 200 nm, whereas caveolae-mediated and macropinocytic pathways accommodate larger or aggregated structures. Following entry, particles traffic through endosomal compartments, where successful systems must achieve timely escape before lysosomal degradation. Surface charge and PEGylation significantly affect intracellular routing. Positively charged surfaces enhance binding but may increase endosomal entrapment, while PEGylation prolongs circulation but can reduce uptake, requiring a balanced design strategy.
Once internalized, efficient cytoplasmic release of nucleic acids determines the overall delivery outcome. Mechanisms include carrier degradation, charge neutralization, or molecular exchange. Properly timed release ensures that the nucleic acid remains intact long enough for translation or gene silencing. mRNA translation depends on maintaining the integrity of the 5′ cap and 3′ poly(A) tail, which must be protected by the carrier during intracellular trafficking. Well-engineered nanoparticles sustain mRNA stability for several hours, sufficient for productive protein synthesis.
RNA molecules are inherently unstable and prone to degradation or immune recognition. Nanoparticle encapsulation isolates RNA from extracellular and intracellular nucleases and prevents activation of pattern recognition receptors. Chemical modifications of carrier components, such as optimized ionizable lipids and PEG-lipids, further reduce immune recognition. Similarly, modified nucleotides such as pseudouridine minimize innate immune sensing, enabling enhanced translation with reduced inflammatory signaling.
Transfection efficiency depends on multiple physicochemical and biological parameters. Nanoparticles of 100–200 nm generally achieve the best balance between cellular uptake and systemic distribution. Moderately positive surface charge promotes membrane interaction without inducing toxicity, while particle shape, flexibility, and degradation kinetics influence tissue penetration and persistence. The transfection outcome also varies by cell type; primary cells often require specialized carriers compared with immortalized lines. Successful nanocarrier systems must harmonize protection, uptake, endosomal escape, and release to achieve high efficiency with minimal side effects.
Lipid nanoparticles are currently the most advanced platform for mRNA delivery, built around a core composition of ionizable lipids, helper lipids, cholesterol and PEG-lipids. The ionizable lipids become positively charged under acidic conditions, enabling efficient complexation with the negatively charged mRNA and facilitating endosomal escape in the intracellular acidic environment. Helper lipids such as DSPC contribute to bilayer stability, cholesterol modulates membrane fluidity, and PEG-lipids reduce aggregation and non-specific interactions.
The fabrication of LNPs typically employs microfluidic mixing techniques, allowing precise control of flow rates and mixing parameters to yield monodisperse particles with high encapsulation efficiency. Optimized particles generally fall within the 80-100 nm size range, which is favourable for cellular endocytosis. In applications delivering mRNA cargos, such particles have demonstrated successful transport of mRNA into the cytosol, where it is translated into the target protein, thereby eliciting the desired downstream response. The success of LNP-based platforms has been exemplified by mRNA vaccines, which deliver an mRNA encoding a viral spike protein into cells and achieve high-efficiency translation, underlining the advantages of high encapsulation efficiency, biocompatibility and scalable manufacturing.
Polymeric nanocarriers deliver siRNA through electrostatic complexation between cationic polymers and negatively charged siRNA. Common polymers include polyethyleneimine (PEI), poly(amidoamine) (PAMAM) dendrimers, chitosan derivatives, and poly(β-amino esters) (PBAEs). These polymers are rich in amino groups that become protonated in physiological environments, protecting siRNA from nuclease degradation and supporting endosomal escape.
The structural flexibility of polymers enables fine-tuning of molecular weight, degradability, and surface functionality to achieve the desired balance between efficiency and cytocompatibility. Incorporating degradable linkages, such as disulfide bonds in PEI derivatives, allows intracellular cleavage under reducing conditions, thereby minimizing long-term toxicity. Functionalization with targeting ligands or stimuli-responsive groups can further enhance specificity and delivery precision.
Table 1. Comparative characteristics of representative polymeric nanocarriers for siRNA delivery.
| Polymer Type | Molecular Weight Range | Transfection Efficiency | Cytotoxicity | Primary Application |
| Polyethyleneimine (PEI) | 10–25 kDa | High | Moderate | siRNA and plasmid DNA delivery |
| PAMAM Dendrimers | G5–G7 | High | Moderate | Gene silencing and editing |
| Chitosan Derivatives | 50–200 kDa | Moderate | Low | Oral siRNA delivery |
| Poly(β-amino ester) (PBAE) | 10–30 kDa | High | Low | Tissue-specific gene delivery |
Inorganic nanoparticles such as gold nanoparticles, mesoporous silica nanoparticles and quantum dots bring unique physical-chemical features to nucleic acid delivery. Gold nanoparticles can be functionalized through thiol chemistry to covalently attach nucleic acid cargos, and their surface plasmon resonance properties support intracellular tracking. Mesoporous silica nanoparticles feature regular pore channels that enable high loading of nucleic acids and can be surface‐functionalized to permit controlled release. Hybrid nanoparticles, which integrate organic and inorganic components (for example lipid–polymer hybrids or metal–organic frameworks (MOFs)), combine the biocompatibility and self‐assembly advantages of organic systems with the structural stability and tunable architecture of inorganic materials. These hybrid constructs can support high‐capacity nucleic acid loading and multi-modal functionality, including imaging or responsive release. Their responsiveness to external stimuli (e.g., light, heat, magnetic fields) further enables spatiotemporal control of delivery that is difficult to achieve with purely organic carriers.
Table 2. Representative inorganic nanoparticles used in gene delivery.
| Nanoparticle Type | Size Range (nm) | Loading Mechanism | Release Characteristic | Imaging Capability |
| Gold Nanoparticles | 5–50 | Covalent conjugation | Photothermally triggered | Surface-enhanced Raman scattering |
| Magnetic Nanoparticles | 10–30 | Surface adsorption | Magnetothermal release | Magnetic resonance imaging |
| Mesoporous Silica Nanoparticles | 50–200 | Pore adsorption | pH-responsive release | Fluorescence imaging |
| Carbon Nanoparticles | 20–100 | π–π stacking | Near-infrared responsive | Photoacoustic imaging |
Nanocarriers modified via peptides or proteins represent another advanced class of delivery platforms. Cell-penetrating peptides (CPPs) such as TAT or Penetratin facilitate transmembrane transport of the carrier, while nuclear localization signal (NLS) peptides guide transport into the nucleus when required. These peptide ligands are either chemically conjugated to nanoparticle surfaces or co‐assembled with nucleic acids to form defined nanostructures. Protein modifications leverage the intrinsic biological recognition capabilities of proteins; for example, transferrin-modified particles target cells overexpressing transferrin receptors, and antibody‐modified carriers can achieve cell‐subtype specific delivery. Emerging strategies such as the protein corona engineering of nanocarriers allow pre‐coating with specific proteins to modulate biodistribution and cellular interactions. Self-assembling peptide–nucleic acid conjugates also provide a well‐defined architecture, enabling batch reproducibility and scalable manufacturing. These designs enhance uptake, specificity and intracellular routing, advancing the precision of nucleic acid delivery systems.
The physicochemical properties of nanoparticles directly determine their biological interactions and gene delivery performance. Dynamic Light Scattering (DLS) is the most widely used technique to measure hydrodynamic diameter, providing rapid evaluation of particle size distribution and dispersion stability. Laser Doppler Electrophoresis enables determination of zeta potential, reflecting the surface charge characteristics that influence cellular uptake, aggregation tendency, and in vivo distribution behavior.
Electron microscopy provides detailed morphological information. Transmission Electron Microscopy (TEM) visualizes particle architecture, core–shell structure, and dispersion state, while Cryogenic Electron Microscopy (cryo-EM) preserves the native hydrated morphology, particularly valuable for soft materials such as lipid nanoparticles. Atomic Force Microscopy (AFM) complements these methods by providing three-dimensional topographic and surface roughness data at the nanoscale.
Characterization under biologically relevant conditions is essential, as nanoparticles often exhibit altered physicochemical behavior in complex media compared with aqueous buffers. The adsorption of serum proteins may alter surface charge and aggregation, forming a dynamic "protein corona." Therefore, supplementary measurements in culture medium or simulated physiological fluids provide more biologically relevant insights into nanoparticle stability and functionality.
Encapsulation efficiency (EE) represents the percentage of nucleic acid successfully entrapped within the nanocarrier relative to the total input amount and serves as a key indicator of formulation performance. Common analytical methods include fluorescent dye displacement assays and nuclease protection tests. The former utilizes intercalating dyes such as RiboGreen, which fluoresce only upon binding to free nucleic acids, allowing the quantification of encapsulated versus unencapsulated fractions. The latter relies on enzymatic digestion, where protected nucleic acids within nanoparticles remain intact and are subsequently quantified.
Loading capacity (LC) denotes the amount of nucleic acid carried per unit mass or volume of nanocarrier, directly influencing the achievable dose and material safety profile. High loading capacity minimizes excipient burden and improves overall formulation efficiency. Strategies such as core condensation, electrostatic layer-by-layer assembly, and solvent-controlled encapsulation have been developed to enhance both EE and LC simultaneously.
Integrity analysis of the encapsulated nucleic acids provides an important complementary assessment. Gel electrophoresis and high-performance liquid chromatography (HPLC) are commonly employed to evaluate structural degradation or modification, ensuring that the nanoparticle microenvironment maintains nucleic acid integrity during formulation and storage.
Advanced imaging and analytical techniques elucidate the intracellular trafficking and fate of nanocarriers. Confocal fluorescence microscopy, combined with labeled nanoparticles and organelle-specific probes (e.g., LysoTracker for endosomes, MitoTracker for mitochondria), enables three-dimensional mapping of subcellular localization. Super-resolution microscopy further surpasses diffraction limits, providing nanoscale visualization of intracellular transport pathways.
Electron microscopy, particularly immunogold labeling, allows direct observation of nanoparticle positioning at nanometer resolution. Complementary quantitative approaches such as flow cytometry and imaging flow cytometry provide population-level statistical data while preserving spatial context. Individual cell analyses reveal cellular heterogeneity in uptake and transfection performance, crucial for understanding variability in gene delivery outcomes.
At the organismal level, bioluminescence and fluorescence imaging enable noninvasive monitoring of nanoparticle biodistribution, supporting correlation between physicochemical parameters and delivery efficiency.
Table 3. Services for Nanoparticle Gene Delivery Development at BOC Sciences.
| Service Type | Technical Strengths | Research Application | Inquiry |
| Nanoparticle Formulation Customization | Precision flow control for uniform particles with tunable EE | Optimization of mRNA/siRNA nanocarrier systems | Inquiry |
| Nucleic Acid Loading and Stability Evaluation | Multi-dye and nuclease protection analysis for performance validation | Lipid or polymer system assessment | Inquiry |
| Surface Functionalization and Ligand Conjugation | Controlled ligand coupling with quantitative binding validation | Targeted nanoparticle design and screening | Inquiry |
| Physicochemical Characterization | Comprehensive data reporting on particle size, charge, and morphology | Quality control and formulation optimization | Inquiry |
| Cellular Uptake and Transfection Testing | High-throughput assays with imaging and quantitative outputs | Evaluation of delivery efficiency and biocompatibility | Inquiry |
| Nanoparticle Stability and Protein Corona Profiling | Simulated biological environment to assess aggregation and surface changes | Stability assessment under physiological conditions | Inquiry |
| Functional Genomics Screening | RNAi-based high-content screening with validated delivery platforms | Functional genomics and pathway discovery | Inquiry |
| Imaging and Quantitative Tracking Analysis | 3D confocal imaging combined with quantitative cell-level analysis | Intracellular trafficking and release mechanism studies | Inquiry |
Functional evaluation of nanocarriers is primarily conducted in vitro. Transfection efficiency is typically quantified using reporter genes such as GFP or luciferase. Flow cytometry provides statistical analysis of transfection-positive cell populations, while fluorescence microscopy visualizes spatial distribution at the individual cell level.
For siRNA-based systems, gene silencing efficiency is evaluated through quantitative PCR for mRNA reduction and Western blot for corresponding protein expression levels. Proper negative controls, such as scrambled siRNA sequences, are essential to verify sequence-specific effects. Time-course studies further determine the onset, duration, and decay of gene silencing activity.
Parallel cytotoxicity and cell viability assays are performed to distinguish true gene silencing effects from non-specific cytotoxic responses. Extended culture assessments also examine potential long-term effects of nanoparticles on cell proliferation and metabolic activity, ensuring functional specificity and biocompatibility.
Nanoparticle-mediated siRNA delivery has revolutionized functional genomics research by enabling systematic gene knockdown in diverse cellular systems. High-throughput RNA interference (RNAi) platforms allow large-scale screening to identify genes and signaling pathways associated with disease progression, drug resistance, and cellular homeostasis. For instance, genome-wide siRNA screening using lipid-based nanoparticles has uncovered multiple genes linked to stress response and proliferation control.
Conditionally responsive nanocarriers, such as pH- or enzyme-sensitive systems, enable spatially and temporally regulated gene silencing, facilitating studies of developmental or regenerative processes. Co-delivery of multiple siRNAs targeting complementary pathways enhances pathway-level suppression and provides valuable models for studying network redundancy and compensatory mechanisms.
Messenger RNA (mRNA) delivery platforms enable transient and programmable protein expression. Nanoparticles protect mRNA molecules and promote cytoplasmic release, transforming target cells into temporary "bioreactors" for protein synthesis. Applications include transcription factor delivery for cellular reprogramming, where somatic cells are converted into pluripotent or lineage-specific phenotypes.
A critical design parameter involves controlling the kinetics of protein expression. Certain research applications demand short-term high-level translation, whereas others benefit from sustained low-level production. Tailoring mRNA sequence elements and nanoparticle composition enables tunable expression profiles suited to distinct experimental objectives.
Localized mRNA delivery for protein production has emerged as a promising research direction, providing flexible approaches for tissue regeneration and metabolic modulation without the need for recombinant protein manufacturing.
mRNA-loaded nanoparticles have become a versatile platform for immunological studies and vaccine development. Their modular design and rapid production cycles support agile antigen design and comparative analysis of immune mechanisms. Nanocarriers delivering antigen-encoding mRNA alongside immunostimulatory components can be used to study adaptive immune activation, T-cell dynamics, and memory formation.
Beyond activation, tolerance-inducing mRNA delivery systems are being investigated for immune modulation research, where self-antigen expression supports regulatory T-cell induction and homeostatic balance within immune microenvironments. These models advance understanding of immune regulation and cross-talk between innate and adaptive pathways.
Nanoparticle-based gene delivery provides a controllable interface for constructing synthetic genetic networks inside living cells. Sequential delivery of multiple genetic elements enables the assembly of artificial regulatory circuits, facilitating programmable cellular behaviors such as logic-based sensing and signal processing.
In biosensing research, delivery of gene modules encoding input sensors and reporter systems allows the design of living diagnostic platforms capable of detecting disease-related biomarkers and generating quantifiable outputs.
At the population level, nanoparticle-mediated gene delivery supports the engineering of multicellular communication systems and coordinated group behaviors, offering tools for studying self-organization and emergent biological functions.
As advances in nanocarrier design and synthetic biology converge, gene delivery systems are evolving from passive carriers to active components of programmable biological platforms, enabling next-generation research in precision molecular engineering and functional genomics.
Table 4. Products for Nanoparticle-Based Gene Delivery Research at BOC Sciences.
| Product Category | Key Technical Features | Typical Application | Inquiry |
| Lipid Nanoparticles | Preformulated ionizable lipid system with >90% encapsulation efficiency | mRNA delivery development, transfection efficiency testing | Inquiry |
| Cationic Polymeric Carriers | Adjustable molecular weight and branching; "proton sponge" buffering effect | siRNA or plasmid DNA delivery studies | Inquiry |
| Peptide-Functionalized Nanoparticles | Surface modification with TAT or Penetratin for enhanced membrane penetration | Cell-specific or hard-to-transfect models | Inquiry |
| Hybrid Organic–Inorganic Nanoparticles | Dual-layer architecture combining polymer core and lipid shell | Co-delivery of siRNA and mRNA payloads | Inquiry |
| Inorganic and Mesoporous Nanoparticles | Tunable particle size, functionalizable surface chemistry | Tracking, imaging-assisted delivery experiments | Inquiry |
Nanoparticle-based gene delivery offers unprecedented solutions for the efficient, stable, and targeted transport of siRNA and mRNA through diverse carrier designs, precise surface functionalization, and controlled nucleic acid release mechanisms. Compared with conventional naked nucleic acid delivery, nanoparticles significantly enhance cellular uptake, systemic stability, and targeted delivery while enabling environment-responsive release. Advances in lipid, polymeric, inorganic, and hybrid nanocarriers, combined with ligand, peptide, and protein modifications, are driving innovation in functional genomics, protein expression, immune modulation, and synthetic biology. BOC Sciences provides comprehensive services and products, from nanoparticle formulation, nucleic acid loading and stability evaluation, surface functionalization, to cellular uptake and transfection testing, offering researchers robust tools and solutions to accelerate gene delivery and nanobiotechnology research.
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