Lipid Nanoparticles (LNPs) for Protein Delivery: Breaking Through Therapeutic Barriers and Empowered by Absin Recombinant IL-10

1. Introduction: The Critical Challenge of Protein Intracellular Delivery in Cancer Immunotherapy
Protein-based therapeutic agents, characterized by high bioactivity and specificity, have emerged as core candidates for the treatment of major diseases such as cancer and autoimmune disorders. However, their clinical potential is severely hampered by inherent limitations in intracellular delivery, including low encapsulation efficiency, poor endosomal escape, and inadequate serum stability. These bottlenecks have long restricted the translation of promising protein drugs into effective clinical therapies. In recent years, lipid nanoparticles (LNPs) have gained widespread attention as versatile delivery vectors, particularly in nucleic acid delivery (e.g., mRNA vaccines). Yet, adapting LNPs for protein delivery remains a significant challenge due to the distinct charge heterogeneity and structural complexity of proteins compared to nucleic acids.

A groundbreaking study published in Advanced Science (DOI: 10.1002/advs.202500844) has successfully addressed these obstacles by developing a novel five-component LNP system, enabling efficient intracellular delivery of various protein therapeutics and revolutionizing cancer immunotherapy. A key enabler of this research was the use of Absin's Recombinant Mouse IL-10 Protein, which served as a critical experimental tool to validate the delivery efficacy and therapeutic potential of the optimized LNPs. This article systematically explores the technical breakthroughs of LNP-mediated protein delivery, highlights the core research findings, and emphasizes the indispensable role of high-quality recombinant proteins in advancing such cutting-edge therapeutic strategies.

2. Technical Breakthroughs: The Innovative Design of Five-Component LNPs
To overcome the triple core barriers of protein delivery (poor binding, inefficient endosomal escape, and serum instability), the research team proposed a synergistic design strategy of "cationic lipid + ionizable lipid", constructing a five-component LNP system. This innovative design achieves a balance between delivery efficiency and therapeutic safety, laying a solid foundation for clinical translation.

2.1 Rational Optimization of LNP Composition
The optimized LNPs consist of five key components, each playing a distinct and complementary role:
1) Cationic Lipids (DOTMA/DOTAP): Responsible for electrostatic interaction with proteins, enhancing encapsulation efficiency by forming stable complexes with negatively or positively charged protein molecules.
2) Ionizable Lipids (MC3/ALC0315/SM102): Facilitate endosomal escape—a critical step in intracellular delivery. Under the acidic environment of endosomes, ionizable lipids undergo protonation, disrupting the endosomal membrane and releasing the encapsulated protein cargo into the cytoplasm.
3) Helper Lipid (DOPE): Improves membrane fluidity, assisting in the fusion and disruption of endosomal membranes, thereby enhancing the endosomal escape efficiency of LNPs.
4) Cholesterol: Stabilizes the LNP membrane structure, reducing leakage of encapsulated proteins and improving the serum stability of the vector.
5) PEG-Lipid: Reduces non-specific adsorption of serum proteins, minimizing clearance by the reticuloendothelial system (RES) and prolonging the in vivo circulation half-life of LNPs.
Through systematic optimization of the molar ratio of each component, the research team identified the optimal formulation (DOTMA/MC3/DOPE molar ratio 20:20:20), which achieves superior protein binding capacity and endosomal escape efficiency simultaneously.

2.2 Serum-Enhanced Delivery Mechanism: A Game-Changer for In Vivo Application
A major innovation of this study is the discovery of a serum-enhanced delivery mechanism. The surface of the optimized LNPs can adsorb serum albumin, enabling entry into cells through the caveolin-dependent endocytosis pathway mediated by albumin receptors. This mechanism offers two critical advantages:
1) Enhanced Serum Stability: Unlike traditional delivery vectors that suffer from reduced efficiency in serum-containing environments, the albumin-adsorbed LNPs exhibit improved delivery efficiency in the presence of serum, addressing the long-standing issue of serum instability in protein delivery.
2) Tumor-Targeted Enrichment: Tumor cells typically overexpress albumin receptors. The albumin-mediated endocytosis pathway allows LNPs to specifically target and accumulate in tumor tissues, reducing off-target effects and enhancing the therapeutic index of protein drugs.

3. Core Research Results: From Efficient Delivery to Efficacy in Cancer Immunotherapy
The optimized five-component LNP system demonstrated remarkable performance across in vitro cell models, 3D tumor spheroids, and in vivo animal models, achieving full-chain breakthroughs from efficient protein delivery to effective cancer treatment.
3.1 Efficient Intracellular Delivery of Diverse Proteins with High Activity Retention
The LNPs exhibited robust delivery capabilities for proteins of varying molecular weights and isoelectric points, including antibodies (IgG), enzymes (SOD, CAT), toxins (saporin), and Cas9 ribonucleoproteins (RNPs). Key results include:
1) High Cellular Positivity Rate: The cellular positivity rate for GFP protein delivered via LNPs exceeded 80%, significantly outperforming the commercial reagent Pulsin.
2) Preservation of Natural Bioactivity: The delivered proteins maintained their native biological functions. For example, SOD (superoxide dismutase) efficiently scavenged intracellular reactive oxygen species (ROS), and Cas9 RNP successfully achieved genome editing with detectable indel formation.

3.2 Effective Penetration of 3D Tumor Spheroids
In 3D tumor spheroid models, Cy5.5-labeled saporin-LNPs efficiently penetrated deep into the tumor tissue, while free saporin showed almost no penetration. This deep tumor penetration capability is critical for overcoming the heterogeneous tumor microenvironment and achieving effective treatment of solid tumors.

3.3 Enhanced Cancer Immunotherapy Efficacy via IL-10 Delivery
In a melanoma mouse model, the research team validated the immunotherapeutic potential of IL-10-LNPs. IL-10, a key immunomodulatory cytokine, alleviates T cell exhaustion, promotes T cell proliferation, and enhances cytotoxicity. The delivery of IL-10 via LNPs achieved two critical therapeutic benefits:
1) Improved Pharmacokinetic Profile: LNPs significantly prolonged the in vivo half-life of IL-10 and increased its concentration in tumor tissues, addressing the rapid clearance issue of free IL-10.
2) Synergistic Tumor Suppression: When combined with adoptive OT-1 CD8+ T cell therapy, IL-10-LNPs substantially inhibited tumor growth, with a significantly higher tumor growth inhibition rate compared to free IL-10 or LNP controls. Flow cytometry analysis confirmed that the treatment significantly increased the number of tumor-infiltrating CD3+ T cells and OT-1 CD8+ T cells, and elevated IFN-γ secretion levels, indicating effective activation of the anti-tumor immune response.

4. The Indispensable Role of Absin Recombinant Mouse IL-10 Protein in the Research
Absin's Recombinant Mouse IL-10 Protein was a critical experimental material throughout the key stages of validating the LNP delivery system, playing an irreplaceable role in verifying the efficacy and therapeutic potential of the technology.

4.1 Key Application Scenarios
1) In Vitro Experiments: Used to validate the encapsulation efficiency of LNPs for cytokines and their ability to maintain protein activity. The high purity and bioactivity of the recombinant IL-10 ensured reliable evaluation of LNP performance in vitro.
2) In Vivo Experiments: Formulated into IL-10-LNP preparations and delivered via intravenous injection to evaluate their efficacy in enhancing adoptive T cell therapy in a melanoma model. The consistent biological activity of the recombinant IL-10 was essential for generating reproducible in vivo therapeutic results.

4.2 Core Contributions to the Research
1) Functional Readout Indicator: As a well-characterized immunomodulatory molecule, Absin's Recombinant Mouse IL-10 provided a direct functional readout for evaluating LNP in vivo delivery efficiency and targeting. By detecting IL-10 concentration in tumor tissues, T cell proliferation, and cytokine secretion levels, the research team clearly validated the superiority of the LNP delivery system.
2) Guarantee of Experimental Reliability: The high purity (≥95%) and high biological activity of Absin's recombinant IL-10 ensured the reliability and reproducibility of experimental results, providing solid support for the core conclusion that "LNPs prolong cytokine half-life and enhance immunotherapeutic efficacy".

5. ANT BIO PTE. LTD. (Absin) High-Quality Recombinant Protein Products for Advanced Therapeutic Research
To support researchers in advancing cutting-edge studies such as LNP-mediated protein delivery and cancer immunotherapy, ANT BIO PTE. LTD. (Absin brand) offers a comprehensive portfolio of high-quality recombinant proteins, including the Recombinant Mouse IL-10 Protein used in this landmark study. Our recombinant proteins are produced using advanced prokaryotic or eukaryotic expression systems, with strict quality control processes to ensure high purity, consistent bioactivity, and excellent batch-to-batch reproducibility. Detailed product information for key related products is shown in Table 1:

Table 1 Absin Recombinant Proteins for Immunotherapy and Delivery Research

Catalog Number	Product Name	Specification
abs04067	Recombinant Mouse IL-10 Protein	10ug
abs00977	Recombinant Mouse IL-10 Protein	10ug
abs04053	Recombinant Mouse IL-22 Protein (E.coli)	10ug
abs05717	Recombinant Mouse IL10RB Protein (His Tag)	100ug
abs05568	Recombinant Mouse IL-19 Protein	10ug

Core Advantages of Absin Recombinant Proteins
1) High Purity and Bioactivity: All recombinant proteins undergo rigorous purification processes, with purity ≥95% as verified by SDS-PAGE and HPLC. The bioactivity is validated through relevant in vitro bioassays (e.g., cell proliferation, cytokine secretion), ensuring consistency with natural proteins.
2) Excellent Batch-to-Batch Consistency: Strict quality control standards are implemented throughout the production process, minimizing batch-to-batch variation in protein concentration, purity, and bioactivity. This ensures the reproducibility of experimental results, a critical requirement for advanced therapeutic research.
3) Comprehensive Product Portfolio: In addition to immunomodulatory cytokines (IL-10, IL-22, IL-19), Absin offers a wide range of recombinant proteins, including growth factors, receptors, and signaling molecules, covering diverse research needs in cancer immunotherapy, gene editing, and drug delivery.

6. Future Perspectives: Expanding the Horizons of LNP-Mediated Protein Therapy
The successful development of the five-component LNP system represents a significant advancement in protein delivery technology, expanding the application boundaries of LNPs from nucleic acids to proteins. Future research directions will focus on three key areas:
1) Precision Targeting Optimization: Further engineering LNP surfaces to incorporate tumor-specific ligands (e.g., antibodies, peptides) to enhance targeted delivery to specific tumor subtypes, reducing off-target effects and improving therapeutic specificity.
2) Combination Therapy Strategies: Exploring combinations of LNP-delivered proteins (e.g., cytokines, checkpoint inhibitors) with other therapeutic modalities (e.g., chemotherapy, radiotherapy, mRNA vaccines) to achieve synergistic anti-tumor effects.
3) Clinical Translation Progress: Accelerating preclinical studies of LNP-protein formulations, including toxicity evaluations, pharmacokinetic studies, and dose optimization, to advance the translation of this technology into clinical applications for cancer and other diseases.

7. Brand Mission
ANT BIO PTE. LTD. is committed to advancing life science research and therapeutic development through high-quality, reliable reagents and comprehensive solutions. We deeply recognize the critical role of high-performance recombinant proteins in cutting-edge research fields such as LNP-mediated delivery and cancer immunotherapy. Therefore, we adhere to strict quality control standards in every stage of product development and production, ensuring that our products meet the highest standards of quality and performance.

With our specialized sub-brands (Absin, Starter, UA), we cover a full spectrum of research needs from general reagents and kits to antibodies and recombinant proteins. Our professional technical team is dedicated to providing personalized guidance for researchers in product selection, experimental design, and result analysis. We strive to be a trusted partner for researchers worldwide, providing powerful tool support for unlocking scientific mysteries and advancing the development of life-saving therapies.

8. Disclaimer
This article is compiled and interpreted with AI assistance. All intellectual property (e.g., product data, technical information, research findings) related to the original study shall belong to Advanced Science and the research team. Product-related intellectual property shall belong to ANT BIO PTE. LTD. For any infringement, please contact us promptly and we will take immediate action.

9. Brand Promotion Copy
ANT BIO PTE. LTD. – Empowering Scientific Breakthroughs in Therapeutic Research
At ANTBIO, we are committed to advancing life science research and therapeutic development through high-quality, reliable reagents and comprehensive solutions. Our Absin brand recombinant proteins, including the Recombinant Mouse IL-10 Protein that empowered landmark LNP delivery research, are designed to meet the rigorous demands of cutting-edge therapeutic studies. With a focus on innovation, quality, and customer-centricity, we strive to be your trusted partner in unlocking the potential of protein therapies and driving medical progress. Explore our comprehensive recombinant protein portfolio today and accelerate your journey towards scientific breakthroughs.