Department of Ophthalmology, Peking University First Hospital, Beijing, 100034, People's Republic of China.
Department of Nuclear Medicine, Peking University First Hospital, Beijing, 100034, People's Republic of China.
J Nanobiotechnology. 2024 Mar 28;22(1):134. doi: 10.1186/s12951-024-02317-7.
Corneal neovascularization (CoNV) threatens vision by disrupting corneal avascularity, however, current treatments, including pharmacotherapy and surgery, are hindered by limitations in efficacy and adverse effects. Minocycline, known for its anti-inflammatory properties, could suppress CoNV but faces challenges in effective delivery due to the cornea's unique structure. Therefore, in this study a novel drug delivery system using minocycline-loaded nano-hydroxyapatite/poly (lactic-co-glycolic acid) (nHAP/PLGA) nanoparticles was developed to improve treatment outcomes for CoNV.
Ultra-small nHAP was synthesized using high gravity technology, then encapsulated in PLGA by a double emulsion method to form nHAP/PLGA microspheres, attenuating the acidic by-products of PLGA degradation. The MINO@PLGA nanocomplex, featuring sustained release and permeation properties, demonstrated an efficient delivery system for minocycline that significantly inhibited the CoNV area in an alkali-burn model without exhibiting apparent cytotoxicity. On day 14, the in vivo microscope examination and ex vivo CD31 staining corroborated the inhibition of neovascularization, with the significantly smaller CoNV area (29.40% ± 6.55%) in the MINO@PLGA Tid group (three times daily) than that of the control group (86.81% ± 15.71%), the MINO group (72.42% ± 30.15%), and the PLGA group (86.87% ± 14.94%) (p < 0.05). Fluorescein sodium staining show MINO@PLGA treatments, administered once daily (Qd) and three times daily (Tid) demonstrated rapid corneal epithelial healing while the Alkali injury group and the DEX group showed longer healing times (p < 0.05). Additionally, compared to the control group, treatments with dexamethasone, MINO, and MINO@PLGA were associated with an increased expression of TGF-β as evidenced by immunofluorescence, while the levels of pro-inflammatory cytokines IL-1β and TNF-α demonstrated a significant decrease following alkali burn. Safety evaluations, including assessments of renal and hepatic biomarkers, along with H&E staining of major organs, revealed no significant cytotoxicity of the MINO@PLGA nanocomplex in vivo.
The novel MINO@PLGA nanocomplex, comprising minocycline-loaded nHAP/PLGA microspheres, has shown a substantial capacity for preventing CoNV. This study confirms the complex's ability to downregulate inflammatory pathways, significantly reducing CoNV with minimal cytotoxicity and high biosafety in vivo. Given these findings, MINO@PLGA stands as a highly promising candidate for ocular conditions characterized by CoNV.
角膜新生血管（CoNV）通过破坏角膜无血管性来威胁视力，然而，目前的治疗方法，包括药物治疗和手术，都受到疗效和不良反应的限制。米诺环素具有抗炎特性，可抑制 CoNV，但由于角膜的独特结构，其有效传递面临挑战。因此，在这项研究中，开发了一种使用米诺环素负载纳米羟基磷灰石/聚（乳酸-共-羟基乙酸）（nHAP/PLGA）纳米粒子的新型药物递送系统，以改善 CoNV 的治疗效果。
使用高重力技术合成了超小 nHAP，然后通过双乳液法将其包封在 PLGA 中形成 nHAP/PLGA 微球，从而减轻了 PLGA 降解产生的酸性副产物。MINO@PLGA 纳米复合物具有缓释和渗透特性，是米诺环素的有效递送系统，可显著抑制碱烧伤模型中的 CoNV 面积，而无明显细胞毒性。在第 14 天，体内显微镜检查和体外 CD31 染色证实了新生血管的抑制作用，MINO@PLGA Tid 组（每日三次）的 CoNV 面积（29.40%±6.55%）明显小于对照组（86.81%±15.71%）、MINO 组（72.42%±30.15%）和 PLGA 组（86.87%±14.94%）（p<0.05）。荧光素钠染色显示，MINO@PLGA 治疗组，每日一次（Qd）和每日三次（Tid），角膜上皮愈合迅速，而碱烧伤组和 DEX 组的愈合时间较长（p<0.05）。此外，与对照组相比，用地塞米松、米诺环素和 MINO@PLGA 治疗后，转化生长因子-β（TGF-β）的表达增加，这一点通过免疫荧光得到证实，而促炎细胞因子 IL-1β和 TNF-α的水平在碱烧伤后明显下降。体内安全性评估，包括肾和肝生物标志物的评估以及主要器官的 H&E 染色，显示 MINO@PLGA 纳米复合物没有明显的细胞毒性。
新型 MINO@PLGA 纳米复合物由负载米诺环素的 nHAP/PLGA 微球组成，具有显著的预防 CoNV 能力。本研究证实了该复合物能够下调炎症途径，在体内具有显著的抗 CoNV 作用，同时具有最小的细胞毒性和高生物安全性。鉴于这些发现，MINO@PLGA 有望成为 CoNV 为特征的眼部疾病的一种有前途的候选药物。
