School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK.
School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons Ireland, 111 St Stephen's Green, Dublin 2, UK.
Int J Pharm. 2021 Mar 1;596:120223. doi: 10.1016/j.ijpharm.2021.120223. Epub 2021 Jan 27.
RALA is a cationic amphipathic peptide which has shown great promise as an efficient, multifunctional delivery system for the delivery of nucleic acids. Rational peptide design was utilised in this study to understand the essential amino acids required for delivery and if any improvements to the RALA peptide could be made. Six amphipathic peptides were synthesised with strategic sequences and amino acid substitutions to reduce peptide sequence, while maintaining the functional characteristics of RALA including amphipathicity, alpha-helicity and pH responsiveness for endosomal escape. Data demonstrated that all six peptides complexed pEGFP-N1 to produce cationic nanoparticles <200 nm in diameter, but not all peptides resulted in successful transfection; indicating the influence of peptide design for cellular uptake and endosomal escape. Pep2, produced nanoparticles with similar characteristics and transfection efficiency to the parent peptide, RALA. However, Pep2 had issues with toxicity and a lack of pH-responsive alpha-helcity. Therefore, RALA remains the superior sequence for non-toxic gene delivery.
RALA 是一种阳离子两亲肽，已被证明是一种高效、多功能的核酸传递系统，具有很大的应用前景。在本研究中，我们利用合理的肽设计来了解传递所需的必需氨基酸，以及是否可以对 RALA 肽进行任何改进。合成了六个具有战略序列和氨基酸取代的两亲肽，以减少肽序列，同时保持 RALA 的功能特性，包括两亲性、α-螺旋性和 pH 响应性以实现内体逃逸。数据表明，所有六种肽都能将 pEGFP-N1 复合成直径小于 200nm 的阳离子纳米颗粒，但并非所有肽都能成功转染；这表明肽设计对细胞摄取和内体逃逸有影响。Pep2 产生的纳米颗粒具有与亲本肽 RALA 相似的特征和转染效率。然而，Pep2 存在毒性问题和缺乏 pH 响应性的α-螺旋性。因此，对于非毒性基因传递，RALA 仍然是优越的序列。
