The clinical therapy for retinal vascular diseases requires repeated intravitreal injections of drugs owing to their short half-life, which imposes health and economic burdens on patients. Therefore, it is necessary to develop an advanced drug delivery system that can prolong the drug activity and minimize secondary complications. In this study, we developed a core/shell drug-loaded rod (drug rod) to deliver two types of drugs (bevacizumab (BEV) and dexamethasone (DEX)) from a single implant. The coaxial printing technique allowed BEV and DEX to be released with different kinetics at the same site by using a polymeric shell and a hydrogel core, respectively. The suggested printing technique facilitates the production of drug rods with various dimensions and drug concentrations, and the multi-layered design allows to adjust the release profile of dual drug-delivery system. The rod was injected in rat vitreous less invasively using a small-gauge needle. Further, we validated the efficacy of the implanted drug rods in inhibiting inflammatory responses and long-term suppression of neovascularization compared to the conventional intravitreal injection of BEV in animal model, indicating that the drug rods can be an alternative therapeutic approach for the treatment of various types of retinal vascular diseases.

视网膜血管疾病的临床治疗由于半衰期短而需要反复玻璃体内注射药物，这给患者带来了健康和经济负担。因此，有必要开发一种先进的药物输送系统，该系统可以延长药物活性并最大程度地减少继发并发症。在这项研究中，我们开发了一种核/壳载药棒（药物棒），可通过单个植入物递送两种类型的药物（贝伐单抗（BEV）和地塞米松（DEX））。同轴印刷技术分别通过使用聚合物壳和水凝胶芯，以相同的动力学方式释放BEV和DEX。建议的打印技术有助于生产各种尺寸和浓度的药物棒，多层设计可调节双重药物输送系统的释放曲线。使用小号针将杆无创地注射到大鼠玻璃体中。此外，与动物模型中常规的玻璃体内BEV注射相比，我们验证了植入的药物棒在抑制炎症反应和长期抑制新血管形成方面的功效，表明该药物棒可以作为替代疗法来治疗各种视网膜血管疾病的类型。