Core Structure and Functional Design of Liposomal NR
(I) Nanostructure Analysis of Biomimetic Targeted Liposomal NR
The design of Liposomal NR demonstrates a high degree of innovation and scientific rigor, especially the biomimetic targeted Liposomal NR. Its unique structure, with the tumor cell membrane (CM) as the outer layer (e.g., CM-Lip@CPPO@NR@MoS₂-CS-GOx), lays the foundation for its precise delivery and functional performance in vivo. The tumor cell membrane, as a natural camouflage, possesses immune evasion capabilities and cell affinity. From a cellular perspective, the abundance of proteins, carbohydrates, and lipids on the cell membrane enables it to specifically recognize and bind to homologous tumor cells. When Liposomal NR enters the circulatory system, these camouflaged cell membranes act like an “invisibility cloak,” helping the nanoparticles evade recognition and clearance by the immune system, greatly improving their enrichment efficiency in target tissues. Related studies have shown that in animal tumor model experiments, compared with ordinary liposomes, this biomimetic targeted Liposomal NR showed a several-fold increase in accumulation at the tumor site, achieving the goal of precise localization and delivery.
(II) Synergistic Mechanism of the Multifunctional Composite Core
The internal core of the Liposomal NR is composed of a MoS₂-CS-GOx complex, and the synergistic effect between its components gives it unique functions. MoS₂, as a two-dimensional material, possesses excellent optical and catalytic activity and has potential application value in photothermal therapy, photodynamic therapy, and other fields. Chitosan (CS) modification not only improves the water solubility of MoS₂, allowing it to be better dispersed in vivo, but also enhances its biocompatibility and reduces its potential toxicity to organisms. The abundant hydroxyl and amino groups on the chitosan molecule facilitate subsequent binding with other molecules. Glucose oxidase (GOx), after being immobilized on the CS-modified MoS₂ surface, forms an enzymatic reaction center. In the tumor microenvironment, glucose levels are often high. GOx can utilize this characteristic to catalyze glucose oxidation, consuming oxygen and producing substances such as hydrogen peroxide, thus altering the local microenvironment. Meanwhile, the peroxide-sensitive compound CPPO can react under the influence of peroxides such as hydrogen peroxide, achieving conditionally controlled release of substances like NR, providing a smart, responsive strategy for tumor treatment.
(III) Optimization of Delivery of Nutritionally Supplemented Liposomal NR
In the field of nutritional supplementation, the emergence of Liposomal NR has solved the problem of low oral absorption efficiency of nicotinamide nucleoside (NR). NR, as an important precursor to NAD⁺ production, plays a crucial role in maintaining cell function, enhancing vitality and lifespan, but the low absorption efficiency of traditional oral formulations limits its efficacy. Liposome delivery systems encapsulate NR with phospholipids, forming nanoscale “liposome vesicles,” providing an effective protective barrier for NR. When Liposomal NR enters the gastrointestinal tract, the phospholipid bilayer can resist the degradation by various enzymes in the gastrointestinal tract, preventing premature decomposition of NR. Meanwhile, the structure of liposomes allows them to interact with the phospholipid bilayer on the cell surface, directly delivering NR into the cell through fusion or endocytosis, greatly improving the bioavailability of NR. Research data shows that the bioavailability of liposomal NR can be increased to over 90%, while the absorption efficiency of traditional oral formulations is often less than 10%. This significant difference fully demonstrates the enormous advantages of liposomal delivery systems in nutritional supplementation.
The Multidimensional Performance Advantages of Liposomal NR
The Multidimensional Performance Advantages of Liposomal NR(I) Targeted Delivery and Immune Concealment Properties
Liposomal NR exhibits superior performance in targeted delivery and immune concealment, laying a solid foundation for its application in the medical and nutritional fields. NR nanoparticles coated on tumor cell membranes (such as CM-Lip@CPPO@NR@MoS₂-CS-GOx) achieve precise recognition of homologous tumor cells through membrane surface antigens. Antigenic proteins on the tumor cell membrane act as “navigation signals,” guiding the nanoparticles to accurately locate tumor cells. When the nanoparticles circulate in vivo, these antigens specifically bind to corresponding receptors on the surface of tumor cells, enabling the nanoparticles to efficiently accumulate at the tumor site. Simultaneously, the liposome surface exhibits a near-zero mV neutral charge, significantly reducing protein adsorption. In physiological environments such as blood, charged substances are easily recognized and bound by proteins in the blood, thereby triggering an immune response or being cleared. However, the neutral charge of Liposomal NR allows it to cleverly evade the “search” of the immune system, prolonging its circulation time in the body. Related studies have shown that the circulating half-life of these nanoparticles in vivo is significantly prolonged compared to ordinary nanoparticles, greatly increasing their chances of exerting their effects at the target site.
Nutritional liposomes (NR) exhibit unique targeting advantages through precise control of particle size. Their particle size is controlled within 100-150 nm, a size range that gives them good affinity for the intestinal mucosa. At the microscopic level, the surface of intestinal mucosal cells contains many tiny pores and receptors; 100-150 nm nanoparticles can better interact with these structures, achieving efficient transmembrane absorption. Researchers have found through intestinal absorption model experiments that nutritional liposomes (NR) can rapidly penetrate intestinal epithelial cells and enter the bloodstream, providing an efficient pathway for NAD⁺ supplementation.
(II) Environmental Response and Controlled Release Capability
In complex biological environments, the environmental response and controlled release capability of liposomes (NR) make them an intelligent delivery system. The tumor microenvironment possesses many unique physicochemical characteristics, which liposomes (NRs) can cleverly utilize to achieve precise release. A decrease in pH and an increase in peroxide concentration are typical features of the tumor microenvironment. When NRs enter the tumor microenvironment, the decrease in pH alters the stability of the liposome membrane, while the increase in peroxide concentration triggers the degradation of CPPO. CPPO rapidly decomposes under the influence of peroxides, releasing the loaded drug or NR and other active ingredients, achieving precise targeting of tumor cells.
GOx also plays a crucial role in the environmental response mechanism of NRs. GOx catalyzes the consumption of glucose to produce hydrogen peroxide, further enhancing the peroxide concentration in the microenvironment. Hydrogen peroxide not only triggers the degradation of CPPO but also synergizes with the photothermal effect or electrochemical signaling of MoS₂, achieving a “dual-response” release. When MoS₂ is irradiated with light of a specific wavelength, it generates a photothermal effect, raising the local temperature and accelerating drug release. Simultaneously, the electrochemical signal of MoS₂ can interact with hydrogen peroxide, regulating the release process. This multi-factor synergistic release mechanism significantly improves the efficacy of liposomal NR in tumor treatment.
Nutritional NR liposomes, through a carefully designed sustained-release mechanism, maintain a sustained increase in blood NAD⁺ levels. Clinical studies show that after 4 weeks of supplementation, blood NAD⁺ levels increased by 84%, a significant improvement attributed to the sustained-release properties of liposomes. The phospholipid bilayer of liposomes allows for the slow release of NR, enabling it to exert its effects continuously in vivo, avoiding the metabolic burden that might result from large-volume supplementation, and providing a stable source of NAD⁺ for the body.
(III) Stability and Biocompatibility Optimization
Optimization of the stability and biocompatibility of liposomal NR ensures its safe and effective delivery in vivo. The phospholipid bilayer structure of liposomes acts as a robust “protective shell,” effectively isolating the core components from external environmental damage. In vivo, GOx enzymes are easily inactivated by various factors, and NR is readily oxidized and degraded; however, the protective effect of liposomes ensures the stability of their core components. Researchers, through stability tests of Liposomal NR under different environments, found that even under harsh conditions such as high temperature and high humidity, the internal GOx and NR maintain high activity and integrity.
The natural components of tumor cell membranes give them low immunogenicity, reducing the immune system’s rejection response to Liposomal NR. The proteins and lipids on the cell membrane are similar to the organism’s own components, making it difficult for the immune system to recognize them as foreign substances, thus reducing the probability of an immune response. Chitosan modification further enhances the biocompatibility of Liposomal NR. Chitosan, as a natural biopolymer, has good biodegradability and bioactivity. It can interact with the liposome surface to form a protective film, enhancing the stability of the liposomes while reducing their potential toxicity to the organism. In animal experiments, chitosan-modified liposomes NR were more evenly distributed in vivo and caused less damage to normal tissues and organs, fully demonstrating their advantages in biocompatibility.
Breakthroughs in the Preparation Process and Technology of Liposomal NR
Breakthroughs in the Preparation Process and Technology of Liposomal NR(I) Mild Assembly Technology of Nanoscale Liposomes
The preparation process of nanoscale liposomes requires highly precise and mild conditions to ensure the activity and structural integrity of each component. Taking Ruixi Biotechnology’s process as an example, it has demonstrated unique technological advantages in the preparation of Liposomal NR. First, a MoS₂-CS-GOx complex is prepared through physical adsorption and cross-linking reactions. In this process, MoS₂, as a two-dimensional nanomaterial, has excellent optical, electrochemical, and catalytic properties, but its water solubility is poor. Through modification with chitosan (CS), not only is the water solubility of MoS₂ improved, but the active groups such as hydroxyl and amino groups on the CS molecule are also used to physically adsorb and cross-link with glucose oxidase (GOx) to form a stable MoS₂-CS-GOx complex. This reaction is carried out under relatively mild conditions, avoiding the destruction of enzyme activity by harsh conditions such as high temperature, strong acid, and strong alkali. Subsequently, the prepared MoS₂-CS-GOx complex was fused with CPPO-loaded liposomes. Liposomes, acting as a carrier, stably encapsulate CPPO, forming a controlled release platform while maintaining biocompatibility and structural integrity. A special fusion technique was employed to ensure the integrity of the liposome membrane was not compromised, allowing the MoS₂-CS-GOx complex to be successfully encapsulated within the liposomes. The entire process was conducted at low temperature (4°C) and neutral pH, crucial for preserving enzyme activity and membrane structural integrity. Low temperature reduces molecular activity and minimizes unnecessary chemical reactions, while neutral pH avoids the impact of pH changes on the liposome membrane and enzyme activity. Finally, the composite nanoparticles NR were assembled through fusion with the tumor cell membrane shell. The tumor cell membrane endows the nanoparticles with affinity for homologous cells and immune concealment capabilities, making them easier to localize to specific tissues or cells in vivo. Through this series of meticulously designed assembly steps, a monodisperse system with uniform particle size (PDI < 0.2) was finally achieved, laying a solid foundation for the efficient delivery and functional performance of Liposomal NR in vivo.
(II) Passive and Active Strategies for Efficient Drug Loading
Passive Drug Loading Methods (Thin Film Dispersion, Ultrasonic Method): Passive drug loading is a commonly used method in liposome preparation, especially suitable for the initial encapsulation of lipid-soluble CPPO or NR. Taking thin film dispersion as an example, phospholipids, cholesterol, and lipid-soluble drugs (such as CPPO or NR) are first dissolved in an organic solvent (such as chloroform). The organic solvent is removed by vacuum evaporation, allowing these components to form a uniform thin film on the container wall. Then, PBS aqueous solution is added for hydration. During hydration, phospholipid molecules automatically assemble to form a lipid bilayer, encapsulating the drug within. To accelerate liposome formation, reduce particle size, and adjust uniformity, ultrasonic methods are usually added to the thin film dispersion method. Ultrasonic methods utilize the energy of ultrasound to treat liposome suspensions, breaking down large liposome particles into smaller, more uniformly sized particles. This method is relatively simple to operate, requiring no special additional steps in the preparation process. However, due to uneven drug dispersion, the drug concentration inside the liposome cavity is lower than the drug concentration in the external solution, resulting in relatively low drug loading and encapsulation efficiency.
Active drug loading methods (pH gradient, ammonium sulfate gradient): For water-soluble components (such as GOx), active drug loading methods show significant advantages. Taking the pH gradient method as an example, its principle is to establish a pH gradient across the lipid bilayer. First, the liposomes are hydrated with a buffer solution of known pH, forming liposomes with a specific internal pH value. Then, the liposomes are added to a buffer solution containing a hydrophilic drug (such as GOx) at a different pH. Utilizing the different solubilities of hydrophilic drugs in buffer solutions of different pH values, transmembrane drug delivery is achieved. When a drug is in an external buffer solution, due to the change in pH, the drug exists in an electrically neutral form, exhibiting strong lipid solubility and able to penetrate the lipid bilayer membrane into the liposome. However, in the aqueous phase inside the liposome, the drug is protonated and converted to an ionic form, preventing it from returning to the external aqueous phase through the lipid bilayer. This results in drug enrichment within the aqueous phase of the liposome, significantly improving the encapsulation efficiency to over 80%. The principle of the ammonium sulfate gradient method is similar; by encapsulating ammonium sulfate to create an acidic internal and alkaline external gradient environment, weakly basic drugs (such as some chemotherapeutic drugs) are encapsulated in ionic form, effectively improving the encapsulation efficiency and reducing drug leakage.
(III) Key Technologies for Stability Optimization
Liposomes face problems such as aggregation and leakage during storage, severely affecting their performance and application effects. To solve these problems, freeze-drying technology has become an effective method. Freeze-drying technology mainly includes three stages: pre-freezing, sublimation, and secondary drying. In the pre-freezing stage, the liposome suspension is rapidly cooled to a low temperature, causing the water in it to freeze into ice crystals. In the sublimation stage, ice crystals are directly sublimated into water vapor under vacuum and appropriate heating, thus removing most of the moisture. Finally, in a secondary drying stage, residual moisture is further removed, yielding solid powdered liposomes. These solid liposomes exhibit significantly improved stability during storage, maintaining stable particle size after reconstitution and effectively reducing aggregation.
To further enhance the tumor-targeting ability of Liposomal NR, modification with ligands such as folic acid and RGD peptides is a common strategy. Taking folic acid modification as an example, folic acid receptors are highly expressed on the surface of many tumor cells. After attaching folic acid to the surface of liposomes, the liposomes can actively target tumor cells through the specific binding of folic acid to the folic acid receptor. Studies have shown that folic acid-modified liposomes exhibit a 3-fold increase in endocytosis efficiency mediated by the folic acid receptor, enabling more effective delivery of loaded drugs or NR to tumor cells and improving therapeutic efficacy. RGD peptides can specifically bind to tumor vascular endothelial αvβ3 receptors, enhancing tumor penetration and making it easier for Liposomal NR to reach tumor tissue, further enhancing its application value in tumor treatment.
Exploring the Diverse Applications of Liposomal NR
(I) Biomedical Field: Targeted Therapy and Diagnostic Platform
In the biomedical field, Liposomal NR has demonstrated enormous application potential, providing innovative solutions for targeted therapy and diagnosis. Liposomal NR loaded with arsenic trioxide (As₂O₃) or chemotherapeutic drugs, modified with MMP2 peptides and CPP penetrating peptides, has achieved effective breakthroughs in the tumor extracellular matrix barrier. The MMP2 peptide specifically recognizes matrix metalloproteinase 2 (MMP2) in the tumor extracellular matrix, and upon binding, helps Liposomal NR better penetrate the extracellular matrix and reach tumor cells. The CPP penetrating peptide possesses strong transmembrane capabilities, enabling it to carry Liposomal NR into the cell interior, achieving high drug concentrations around the cell nucleus. This precise delivery method has achieved significant results in in vivo experiments, increasing the tumor inhibition rate by 40% while significantly reducing drug toxicity to normal organs such as the liver and kidneys. As a crucial component of liposome-encapsulated NR, MoS₂’s unique photothermal properties enable the integration of photoacoustic imaging and photothermal therapy. In photoacoustic imaging, MoS₂ absorbs light of specific wavelengths, generating thermoelastic waves. By detecting these waves, precise imaging of tumor sites can be achieved, providing a high-resolution method for early tumor diagnosis. In photothermal therapy, when MoS₂ absorbs sufficient light energy, it converts it into heat energy, raising the local temperature and thus killing tumor cells. This integrated strategy of photoacoustic imaging and photothermal therapy provides an efficient and precise method for tumor treatment, reducing damage to normal tissues and improving treatment efficacy.
(II) Health Technology Field: NAD+ Enhancement and Anti-aging Applications
Liposome-encapsulated NR has significant value in the health technology field, especially in anti-aging applications. As a precursor to NAD+, NR can be efficiently converted into NAD+ through the Preiss-Handler pathway, providing sufficient energy support for cells and maintaining normal cellular function. Clinical studies have shown that daily supplementation with 300mg of liposomal NR for 4 weeks significantly increased blood NAD+ levels from 28.6μM to 52.5μM. This increase brought about a series of positive physiological changes, including significantly improved mitochondrial function, enhanced DNA repair efficiency, and effective delaying of muscle and cognitive aging.
Mitochondria are the cell’s energy factories. With age, mitochondrial function gradually declines, leading to insufficient cellular energy supply and triggering a series of age-related problems. Supplementation with liposomal NR increases NAD+ levels, activating key enzymes in mitochondria, enhancing mitochondrial respiration, improving energy production efficiency, and revitalizing cells. In DNA repair, NAD+, as an important coenzyme, participates in the activation of DNA repair enzymes, helping to repair damaged DNA and maintain genome stability. This not only helps delay cellular aging but also reduces the risk of diseases such as cancer. The emergence of liposomal NR provides a core technological breakthrough for the development of anti-aging health products and offers new hope for people pursuing a healthy and long life.
(III) Interdisciplinary Applications: Smart Materials and Delivery Systems
The responsiveness and biocompatibility of liposomes (NRs) make them promising candidates for interdisciplinary applications, offering new insights for the development of smart materials and delivery systems. In the treatment of diabetic nephropathy, silymarin-loaded Liposomal NRs have demonstrated good therapeutic effects. Diabetic nephropathy is a common complication of diabetes. Silymarin possesses various biological activities, including antioxidant and anti-inflammatory properties, and can protect kidney cells from damage. Liposomal NRs, as carriers, can precisely deliver silymarin to the lesion site in the kidney, improving drug efficacy and reducing side effects.
In the field of thrombolysis, RGD-modified reteplase Liposomal NRs have become a research hotspot. RGD peptides can specifically recognize integrin receptors on the surface of thrombi, guiding Liposomal NRs to accurately bind to the thrombus site. Reteplase is a highly effective thrombolytic drug. Encapsulation in liposomes (NR) protects reteplase from degradation during transport, while simultaneously enabling precise drug release at the thrombus site, improving thrombolytic efficacy and reducing complications such as bleeding.
Liposomal NR also has potential applications in mRNA vaccine delivery, similar to LNP technology. mRNA vaccines are a novel type of vaccine developed in recent years, offering advantages such as rapid development and simple production processes. However, mRNA molecules themselves are unstable, easily degraded, and have difficulty entering cells to exert their effects. Liposomal NR can serve as a carrier for mRNA, protecting it from nuclease degradation through its unique structure. Simultaneously, by utilizing the interaction between liposomes and the cell membrane, it efficiently delivers mRNA into the cell, initiating an immune response. This provides a universal design approach for the development of gene therapy and protein drug carriers.
Regulatory and Market Prospects
With the FDA’s continued approval of liposomal drugs (such as doxorubicin liposomes), the application of liposomal NRs in targeted drugs and functional foods is expected to accelerate. However, regulatory requirements for liposomal NRs vary across different sectors. Pharmaceutical regulatory standards are typically more stringent, requiring extensive clinical trials to verify their safety and efficacy. While regulations in the health supplement sector are relatively more lenient, they still require adherence to relevant regulations and standards. In drug applications, detailed pharmacological and toxicological research data, clinical trial reports, and other materials are required to ensure drug quality and safety. In health supplement applications, information such as the product’s active ingredients, suitable population, and methods of consumption must be clearly stated to ensure product quality and accurate labeling.
Paying attention to regulatory differences across sectors and actively communicating and cooperating with regulatory authorities are crucial for the efficient commercialization of liposomal NRs from research findings. Research institutions and enterprises need to strengthen their research on regulations and policies, establish comprehensive quality management systems, and ensure that products comply with relevant regulatory requirements. By actively conducting clinical trials and accumulating more safety and efficacy data, the credibility and market competitiveness of liposomes (NR) can be enhanced, creating favorable conditions for their widespread application in the biopharmaceutical and healthcare industries. With its unique structural design and functional integration, Liposomal NR is becoming a key bridge connecting nanobiotechnology with precision medicine/health management. Whether tackling the delivery challenges of tumor treatment or ushering in a new era of cellular energy-based anti-aging, its core value lies in achieving multiple goals of “targeted delivery, intelligent response, high efficiency, and safety” through the deep integration of materials science and biology, outlining a highly promising development blueprint for the future of the biopharmaceutical and healthcare industries.
