scholarly journals Ion-Complex Microcrystal Formulation Provides Sustained Delivery of a Multimodal Kinase Inhibitor from the Subconjunctival Space for Protection of Retinal Ganglion Cells

Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 647
Author(s):  
Henry T. Hsueh ◽  
Yoo-Chun Kim ◽  
Ian Pitha ◽  
Matthew D. Shin ◽  
Cynthia A. Berlinicke ◽  
...  

Glaucoma is the leading cause of irreversible blindness worldwide. Elevated intraocular pressure (IOP) is one of the major risk factors for glaucoma onset and progression, and available pharmaceutical interventions are exclusively targeted at IOP lowering. However, degeneration of retinal ganglion cells (RGCs) may continue to progress despite extensive lowering of IOP. A complementary strategy to IOP reduction is the use of neuroprotective agents that interrupt the process of cell death by mechanisms independent of IOP. Here, we describe an ion complexation approach for formulating microcrystals containing ~50% loading of a protein kinase inhibitor, sunitinib, to enhance survival of RGCs with subconjunctival injection. A single subconjunctival injection of sunitinib-pamoate complex (SPC) microcrystals provided 20 weeks of sustained retina drug levels, leading to neuroprotection in a rat model of optic nerve injury. Furthermore, subconjunctival injection of SPC microcrystals also led to therapeutic effects in a rat model of corneal neovascularization. Importantly, therapeutically relevant retina drug concentrations were achieved with subconjunctival injection of SPC microcrystals in pigs. For a chronic disease such as glaucoma, a formulation that provides sustained therapeutic effects to complement IOP lowering therapies could provide improved disease management and promote patient quality of life.

Neuroscience ◽  
2012 ◽  
Vol 224 ◽  
pp. 282-293 ◽  
Author(s):  
Z.Z. Zhang ◽  
Y.Y. Gong ◽  
Y.H. Shi ◽  
W. Zhang ◽  
X.H. Qin ◽  
...  

2017 ◽  
Vol 96 ◽  
pp. 1363-1370 ◽  
Author(s):  
Qiang Liu ◽  
Haining Li ◽  
Juan Yang ◽  
Xiaoyan Niu ◽  
Chunmei Zhao ◽  
...  

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Shun Gong ◽  
Hai Jin ◽  
Danfeng Zhang ◽  
Wei Zou ◽  
Chunhui Wang ◽  
...  

Background. Existing evidence suggests the potential therapy of transplanting olfactory ensheathing cells (OEC) either alone or in combination with neurotrophic factors or other cell types in optic nerve injury (ONI). However, clinical use of autologous OEC in the acute stages of ONI is not possible. On the other hand, acute application of heterologous transplantation may bring the issue of immune rejection. The olfactory mucosa (OM) with OEC in the lamina propria layer is located in the upper region of the nasal cavity and is easy to dissect under nasal endoscopy, which makes it a candidate as autograft material in acute stages of ONI. To investigate the potential of the OM on the protection of injured neurons and on the promotion of axonal regeneration, we developed a transplantation of syngenic OM in rats with ONI model. Methods. After the right optic nerve was crushed in Lewis rats, pieces of syngenic whole-layer OM were transplanted into the lesion. Rats undergoing phosphate buffered saline (PBS) injection were used as negative controls (NC). The authors evaluated the regeneration of retinal ganglion cells (RGCs) and axons for 3, 7, 14, and 28 days after transplantation. Obtained retinas and optic nerves were analyzed histologically. Results. Transplantations of OM significantly promoted the survival of retinal ganglion cells (RGCs) and axonal growth of RGCs compared with PBS alone. Moreover, OM group was associated with higher expression of GAP-43 in comparison with the PBS group. In addition to the potential effects on RGCs, transplantations of OM significantly decreased the expression of GFAP in the retinas, suggesting inhibiting astrocyte activation. Conclusions. Transplantation of whole-layer OM in rats contributes to the neuronal survival and axon regeneration after ONI.


2020 ◽  
Vol 13 (12) ◽  
pp. 1880-1886
Author(s):  
Le-Meng Ren

AIM: To determine whether Houttuynia cordata Thunb (HCT) can increase the survival of the retinal ganglion cells (RGCs) and inhibit microglia activation following retinal ischemia-reperfusion (RIR) injury. METHODS: Rat model of RIR was induced by transient elevation of the intraocular pressure (IOP). HCT was orally administered for 2d before the performance of retinal RIR model and once a day for the next 14d. After 14d of RIR injury, the rats were sacrificed for further analysis. Survival RGCs were stained with haematoxylin and eosin (H&E). Apoptosis of RGCs was detected by TUNEL staining. Retinal function was examined by flash-electroretinography (F-ERG). Retinal microglia were labeled using Iba-1, one specific marker for microglia. The mRNA expression levels of inducible nitric oxide synthase (iNOS), tumor necrosis factor alpha (TNF-α), and interleukin 1 beta (IL-1β) were assessed by quantitative real time reverse transcription polymerase chain reaction (qRT-PCR). RESULTS: Systemic HCT treatment significantly reduced RGCs death by H&E staining and exhibited an anti-apoptotic effect as assessed by TUNEL staining at day 14 after RIR injury. HCT greatly improved the retinal function as examined by F-ERG. The number of activated microglia significantly increased after RIR injury, which was significantly attenuated by HCT treatment. Besides, RIR injury induced a strong upregulation of pro-inflammatory genes TNFα, iNOS and IL-1β mRNAs at day 14 post injury, which was suppressed by HCT. CONCLUSION: Neuroprotective effects of HCT encourage the survival of RGCs through inhibiting microglia activation due to RIR injury. Together these results support the use of HCT as promising therapy for the ischemic events of the retina diseases.


2004 ◽  
Vol 28 (3) ◽  
pp. 153-157 ◽  
Author(s):  
Kazuyuki Hirooka ◽  
Masaaki Tokuda ◽  
Osamu Miyamoto ◽  
Toshifumi Itano ◽  
Tetsuya Baba ◽  
...  

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