Department of Ophthalmology, Stanford University, School of Medicine, Stanford, California, United States.
Department of Ophthalmology, Stanford University, School of Medicine, Stanford, California, United States.
J Control Release. 2020 Dec 10;328:263-275. doi: 10.1016/j.jconrel.2020.08.034. Epub 2020 Aug 25.
Intravitreal delivery of antibody-based therapeutics has revolutionized the treatment of intraocular vascular diseases involving the retina and choroid. Unfortunately, limited durability requires frequent retreatment placing an enormous burden on patients. We sought to solve this problem with a novel approach that uses an anchoring molecule characterized by two key molecular properties: (1) non-covalent binding to an antibody-based therapeutic, and (2) retention in the vitreous cavity. As an initial proof-of-principle, we chose an anchoring molecule composed of agarose microbeads functionalized with an Fc-binding domain. Bevacizumab was chosen as the antibody-based therapeutic. In vitro experiments demonstrated that bevacizumab was maximally bound to this anchoring molecule within 1 h, and was competitively released upon exposure to either polyclonal human (p < 0.0001) or rat (p = 0.0017) immunoglobulins. In silico modeling predicted prolonged intravitreal retention of an antibody-based therapeutic in the presence of this anchoring molecule, which was confirmed by in vivo experiments with this initial anchoring molecule in rats. This anchoring molecule increased the intraocular half-life of bevacizumab from 5.8 days to over 18 days and maintained therapeutic concentrations for over 80 days. Despite showing no evidence of direct cellular toxicity, this anchoring molecule collected in the anterior vitreous, partially obscuring retinal visualization and eliciting a mild chronic microglial/macrophage inflammatory response. These studies provide a plausible approach to the development of novel non-covalent methods of binding, retention, and release of antibody-based therapeutics in the vitreous.
眼内递药技术的发展使治疗涉及视网膜和脉络膜的眼内血管疾病发生了革命性变化。不幸的是，这种方法的疗效有限，需要频繁的再治疗，这给患者带来了巨大的负担。我们试图通过一种新方法来解决这个问题，该方法使用一种具有两个关键分子特性的锚定分子：（1）与抗体药物的非共价结合，以及（2）在玻璃体内的保留。作为初步的原理验证，我们选择了一种由琼脂糖微球组成的锚定分子，该分子具有 Fc 结合域。贝伐单抗被选为抗体药物。体外实验表明，贝伐单抗在 1 小时内最大程度地与这种锚定分子结合，并在暴露于多克隆人（p < 0.0001）或大鼠（p = 0.0017）免疫球蛋白时可竞争释放。计算机建模预测，在存在这种锚定分子的情况下，抗体药物在眼内的保留时间会延长，这一预测在大鼠体内的初步锚定分子实验中得到了证实。这种锚定分子使贝伐单抗的眼内半衰期从 5.8 天延长到超过 18 天，并保持了超过 80 天的治疗浓度。尽管没有证据表明这种锚定分子有直接的细胞毒性，但它在前玻璃体内聚集，部分遮挡了视网膜的可视化，并引起了轻微的慢性小胶质细胞/巨噬细胞炎症反应。这些研究为开发新型非共价结合、保留和释放玻璃体内抗体药物的方法提供了一种可行的方法。
