Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium.
Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium; Laboratory for Molecular and Cellular Therapy, Department of Biomedical Sciences, Medical School of the Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1050 Jette, Belgium; Cancer Research Institute Ghent (CRIG), Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium.
Eur J Pharm Biopharm. 2019 Aug;141:161-171. doi: 10.1016/j.ejpb.2019.05.023. Epub 2019 May 28.
Considerable research over the last few years has revealed dysregulation of growth factors in various retinal diseases, such as glaucoma, diabetic retinopathy and photoreceptor degenerations. The use of messengerRNA (mRNA) to transiently overexpress a specific factor could compensate for this imbalance. However, a critical challenge of this approach lies in the ability to efficiently deliver mRNA molecules to the retinal target cells. In this study we found that intravitreal (IVT) injection is an attractive approach to deliver mRNA to the retina, providing two critical barriers can be overcome: the vitreous and the inner limiting membrane (ILM). We demonstrated that the vitreous is indeed a major hurdle in the delivery of the cationic mRNA-complexes to retinal cells, both in terms of vitreal mobility and cellular uptake. To improve their intravitreal mobility and avoid unwanted extracellular interactions, we evaluated the use of hyaluronic acid (HA) as an electrostatic coating strategy. This HA-coating provided the complexes with a negative surface charge, markedly enhancing their mobility in the vitreous humor, without reducing their cellular internalization and transfection efficiency. However, although this coating strategy allows the mRNA-complexes to successfully overcome the vitreal barrier, the majority of the particles accumulated at the ILM. This study therefore underscores the crucial barrier function of the ILM toward non-viral retinal gene delivery and the need to smartly design mRNA-carriers able to surmount the vitreous as well as the ILM.
在过去的几年中，大量研究表明，生长因子在各种视网膜疾病中失调，如青光眼、糖尿病性视网膜病变和光感受器变性。使用信使 RNA（mRNA）短暂过表达特定因子可以弥补这种失衡。然而，这种方法的一个关键挑战在于能够将 mRNA 分子有效地递送到视网膜靶细胞。在这项研究中，我们发现玻璃体内（IVT）注射是将 mRNA 递送到视网膜的一种有吸引力的方法，可以克服两个关键障碍：玻璃体液和内界膜（ILM）。我们证明，玻璃体液确实是阳离子 mRNA 复合物递送到视网膜细胞的主要障碍，无论是在玻璃体液的流动性还是细胞摄取方面。为了提高它们在玻璃体内的迁移能力并避免不必要的细胞外相互作用，我们评估了使用透明质酸（HA）作为静电涂层策略的用途。这种 HA 涂层使复合物带有负表面电荷，显着提高了它们在玻璃体液中的迁移能力，而不会降低细胞内化和转染效率。然而，尽管这种涂层策略允许 mRNA 复合物成功克服玻璃体液障碍，但大多数颗粒积聚在内界膜。因此，这项研究强调了内界膜对非病毒视网膜基因传递的关键屏障功能，以及需要设计能够克服玻璃体液和内界膜的智能 mRNA 载体。
