Revolutionary PEI-Mediated Gene Delivery for Superior Transfection Efficiency

Unlock the full potential of gene delivery with Yeasen Biotechnology's innovative PEI (Polyethylenimine) derivative. This advanced gene delivery tool overcomes the limitations of traditional PEI by reducing cytotoxicity and boosting transfection efficiency.

Key Benefits:

• High stability: Unique hydrogen bonding and hydrophobic modifications enhance PEI/nucleic acid complex stability, ensuring reliable transfection.
• Reduced toxicity: Lowered cationic density minimizes cell membrane damage, offering safer, more effective delivery.
• Improved transfection: Higher cell viability and efficient AAV production, perfect for therapeutic and research applications.
• Smarter design: Cutting-edge AI molecular dynamics and high-throughput screening optimize performance.
• Great cost reduced

Yeasen’s advanced PEI formulation delivers superior gene transfection results, ensuring reliable and high-yield AAV production, perfect for both in vivo applications and biomedical research.

Upgrade your gene delivery systems—maximize efficiency and biocompatibility today!

Linear polyethylenimine (PEI) has long been recognized as a versatile and effective gene delivery vector. Its linear structure, with its high density of nitrogen atoms, gives it an inherent capability to interact with negatively charged nucleic acids such as DNA and RNA. This high density of cationic charges makes PEI an efficient proton sponge, a term coined to describe its ability to absorb protons within acidic environments, which is central to its function as a gene delivery tool. In the context of nucleic acid delivery, PEI’s electrostatic interactions with the negatively charged phosphate backbone of nucleic acids facilitate the formation of stable PEI/nucleic acid complexes, which protect the nucleic acids from degradation by nucleases in biological systems. These complexes play a pivotal role in ensuring the stability and functionality of the nucleic acids during the transfection process.

Once formed, these PEI/nucleic acid complexes exhibit enhanced ability to interact with cell membranes. The electrostatic attraction between the positively charged PEI complexes and the negatively charged cell surface facilitates their adhesion, while subsequent endocytosis enables cellular internalization. After entering the cell, the low pH inside the endosome triggers the protonation of PEI, leading to an influx of counterions into the endosome to neutralize the charge imbalance. As a result, water molecules are drawn into the endosome, causing an increase in osmotic pressure. This rising osmotic pressure ultimately leads to the rupture of the endosomal membrane, a phenomenon that facilitates the release of the PEI/nucleic acid complex into the cytoplasm. This process, referred to as the “proton sponge effect,” is a critical mechanism by which PEI-mediated transfection achieves high efficiency.

Despite the impressive transfection capabilities of linear PEI, the high cationic charge density that makes it such an effective gene delivery vector can also lead to cytotoxicity. The positive charge of PEI interacts with negatively charged components in the cell membrane and intracellular structures, causing potential damage to the cell. Consequently, one of the challenges in the application of PEI in gene delivery systems lies in its toxicity, which can significantly hinder its therapeutic potential. As a result, optimizing PEI’s molecular weight and concentration is essential to minimize toxicity while ensuring the maintenance of high transfection efficiency.

Figure 2. PEI Modification molecule screening.

To address the toxicity issue and further enhance PEI’s performance, researchers have explored various strategies to modify and improve the molecule. Among the most promising of these approaches is the development of PEI derivatives through chemical modifications, including PEGylation [1], a process that involves the conjugation of polyethylene glycol (PEG) chains to PEI molecules. PEGylation has been shown to improve the biocompatibility and stability of PEI-based vectors by reducing their immunogenicity and enhancing their solubility in biological systems. Additionally, other chemical modifications [2, 3], such as the introduction of hydrophobic groups or the optimization of polymer chain length, have been explored to improve the delivery efficiency and safety profile of PEI.

Recognizing the need for continued innovation, Yeasen Biotechnology has leveraged advanced technology platforms, including artificial intelligence (AI) molecular dynamics simulations and molecular docking techniques, to design a series of novel PEI derivatives. These computational methods allow for the efficient exploration of potential modifications at the molecular level, enabling the identification of promising PEI derivatives that possess improved biological activity, stability, and safety. Through high-throughput screening, these modified PEI candidates were assessed for their transfection potential, and those demonstrating promising activity were subjected to extensive structural optimization and in vitro cell experiments. This rigorous process led to the identification of lead compounds with enhanced performance.

The culmination of this research and development effort resulted in the creation of a new PEI variant, which holds independent intellectual property rights and offers significant improvements over conventional PEI formulations. This innovative PEI derivative addresses several key challenges associated with gene delivery, including cytotoxicity, transfection efficiency, and biocompatibility.

1. Key characteristics of the newly developed PEI derivative include a carefully reduced cationic density, which significantly decreases cytotoxicity while maintaining an effective level of nucleic acid binding and transfection efficiency. This modification enhances the overall safety profile of the transfection reagent, making it more suitable for in vivo applications where cytotoxicity can be a major concern.
2. Additionally, the structural design of this new PEI variant introduces hydrogen bonding between the transfection complex and the nucleic acid, complementing the electrostatic interactions that are typically responsible for complex formation. This modification improves the stability of the PEI/nucleic acid complex, ensuring more reliable transfection outcomes.
3. Furthermore, the modification group of the new PEI derivative incorporates hydrophobic properties that enhance the fusion of the transfection complex with the cell membrane. This structural adjustment promotes the efficient uptake of the transfection complex by cells, thereby improving the overall transfection efficiency. These dual modifications—reduced cationic density and the introduction of hydrogen bonding and hydrophobic properties—combine to create a more stable, biocompatible, and efficient gene delivery vector.

 

Figure 4. The Ultra PEI AAV demonstrates the highest viral vector yields compared to leading competitors.  AAV2, AAV5, AAV8, and AAV9 were produced in suspension 293F cells, with a DNA dosage of 1 µg per million cells. The virus was harvested 72 hours post-transfection, and the viral supernatant was analyzed.     

Figure 5. The Ultra PEI AAV demonstrates efficient viral vector production with low PEI and plasmid input. AAV9 was produced in suspension 293F cells with different input of Ultra-PEI (Left, Plasmids input: 0.5 μg) or Plasmids (Right, Ultra-PEI input 0.6 μL) dosages per million cells. The virus was harvested 72 hours post-transfection.

The performance of this Novel Ultra PEI formulation has shown substantial improvements in transfection efficiency and cell viability compared to traditional PEI variants. The modified PEI is particularly advantageous for applications such as adeno-associated virus (AAV) production, where there is a need for extended transfection complex exposure times and lower plasmid DNA input levels. By enhancing the stability of the transfection complex and improving its cell membrane fusion capabilities, this new PEI formulation can meet the demanding requirements of AAV production, resulting in higher yields and more efficient gene delivery.

In conclusion, while linear PEI has long been a valuable tool for gene delivery, its potential has been limited by its cytotoxicity and suboptimal transfection efficiency in certain applications. Through the use of advanced molecular design and modification strategies, Yeasen Biotechnology has developed a novel PEI derivative with enhanced performance characteristics.

This new formulation not only reduces toxicity and improves biocompatibility but also offers significant improvements in transfection efficiency, making it a promising candidate for both research and therapeutic applications. As gene delivery technologies continue to evolve, this new PEI variant offers an exciting advancement in the quest to develop safer, more effective gene delivery systems for a variety of biomedical applications.

Citation

[1] Holger Petersen, Petra M. Fechner, Dagmar Fischer, and Thomas Kissel. Synthesis, Characterization, and Biocompatibility of Polyethylenimine-graft-poly(ethylene glycol) Block Copolymers. Macromolecules 2002, 35, 6867-6874.

[2] M Hashemi, BH Parhiz, A Hatefi and M Ramezani. Modified polyethyleneimine with histidine–lysine short peptides as gene carrier.Cancer Gene Therapy (2011) 18, 12–19.

[3] N Mohammadi, N Fayazi Hosseini, H Nemati, H Moradi-Sardareh, M Nabi-Afjadi, GA Kardar. Revisiting of Properties and Modified Polyethylenimine-Based Cancer Gene Delivery Systems.Volume 62, pages 18–39, (2024).

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