Comparison of the effect of topical bevacizumab and sorafenib in experimental corneal neovascularization

URP20 improves corneal injury caused by alkali burns combined with pathogenic bacterial infection in rats

Corneal alkali burns often occur in industrial production and daily life, combined with infection, and may cause severe eye disease. Oxidative stress and neovascularization (NV) are important factors leading to a poor prognosis. URP20 is an antimicrobial peptide that has been proven to treat bacterial keratitis in rats through antibacterial and anti-NV effects. Therefore, in this study, the protective effect and influence mechanism of URP20 were explored in a rat model of alkali burn together with pathogenic bacteria (Staphylococcus aureus and Escherichia coli) infection. In addition, human umbilical vein endothelial cells (HUVECs) and human corneal epithelial cells (HCECs) were selected to verify the effects of URP20 on vascularization and oxidative stress. The results showed that URP20 treatment could protect corneal tissue, reduce corneal turbidity, and reduce the NV pathological score. Furthermore, URP20 significantly inhibited the expression of the vascularization marker proteins VEGFR2 and CD31. URP20 also reduced the migration ability of HUVECs. In terms of oxidative stress, URP20 significantly upregulated SOD and GSH contents in corneal tissue and HCECs (treated with 200 μM H2O2) and promoted the expression of the antioxidant protein Nrf2/HO-1. At the same time, MDA and ROS levels were also inhibited. In conclusion, URP20 could improve corneal injury combined with bacterial infection in rats caused by alkali burns through antibacterial, anti-NV, and antioxidant activities.

Effect of topical motesanib in experimental corneal neovascularization model

PURPOSE

This study aimed to compare the efficacy of topical bevacizumab and motesanib in an experimental corneal neovascularization model, and find the most effective motesanib dose.

MATERIALS AND METHODS

In experiments, 42 Wistar Albino rats were randomly divided into six groups (n = 7). Corneal cauterization was applied to all groups except the group 1. Group 1 did not receive any treatment. Topical dimethylsulfoxide was applied to sham group three times a day(tid). Topical bevacizumab drops (5 mg/ml) were applied to Group 3 tid. Topical motesanib drops with a dose of 2.5, 5, and 7.5 mg/ml were respectively applied in Groups 4, 5, and 6 tid. On the 8th day, corneal photographs of all rats were taken under general anesthesia, and the percentage of corneal neovascular area was calculated. VEGF-A mRNA, VEGFR-2 mRNA, miRNA-21, miRNA-27a, miRNA-31, miRNA-126, miRNA-184, and miRNA-204 were evaluated by the qRT-PCR method in corneas taken after decapitation.

RESULTS

The percentage of corneal neovascularization areas and VEGF-A mRNA expression levels were decreased in all treatment groups compared to group 2 (p < 0.05). VEGFR-2 mRNA levels were found to be statistically significantly decreased in groups 4 and 6 compared to group 2 (p < 0.05). Statistically significant changes were detected in the expression levels of only miRNA-126 among all miRNAs.

CONCLUSION

Motesanib with a dose of 7.5 mg/ml statistically significantly suppressed the VEGFR-2 mRNA level compared with other treatment doses and may be more effective than bevacizumab. Further, miRNA-126 can be used as a proangiogenic marker.

Ultrasound-mediated in vivo biodistribution of coumarin-labeled sorafenib-loaded liposome-based nanotheranostic system

Aim: This study aimed to synthesize folate-conjugated sorafenib-loaded (FCSL) liposomes for theranostic application using ultrasound (US). Materials & methods: US parameter optimization, in vitro release, anticancer effect, in vivo biodistribution, optical imaging and biocompatibility of liposomes were studied. Results: With 84% in vitro release after 4 min of US exposure at 3 MHz (1.2 mechanical index), FCSL liposomes showed lower IC₅₀ (8.70 μM) versus sorafenib (9.34 μM) against HepG2 cells. In vivo biodistribution of FCSL liposomes versus sorafenib after 9 mg/kg injection in the liver (8.63 vs 0.55) > intestine (8.45 vs 1.07) > stomach (5.62 vs 0.57) > kidney (5.46 vs 0.91) showed longer circulation time in plasma and can be tracked in mice. Conclusion: A threefold higher drug concentration in the liver in US-exposed mice makes this a successful nanotheranostic approach.

Sorafenib-loaded nanostructured lipid carriers for topical ocular therapy of corneal neovascularization: development, in-vitro and in vivo study

Sorafenib (SRB), a multikinase inhibitor, is effective in reducing experimental corneal neovascularization (CNV) after oral administration; however, its therapeutic use in ocular surface disorders is restricted due to poor solubility and limited bioavailability. This study aimed to develop and optimize SRB-loaded nanostructured lipid carriers (SRB-NLCs) for topical ocular delivery by a central composite design response surface methodology (CCD-RSM). It was spherical and uniform in morphology with an average particle size of 111.87 ± 0.93 nm and a narrow size distribution. The in vitro drug release from the released SRB-NLC formulation was well fitted to Korsmeyer Peppas release kinetics. The cell counting kit-8 (CCK-8) cell viability assay demonstrated that SRB-NLC was not obviously cytotoxic to human corneal epithelial cells (HCECs). An in vivo ocular irritation test showed that SRB-NLC was well tolerated by rabbit eyes. Ocular pharmacokinetics revealed 6.79-fold and 1.24-fold increase in the area under concentration-time curves (AUC_0-12h) over 12 h in rabbit cornea and conjunctiva, respectively, treated with one dose of SRB-NLC compared with those treated with SRB suspension. Moreover, SRB-NLC (0.05% SRB) and dexamethasone (0.025%) similarly suppressed corneal neovascularization in mice. In conclusion, the optimized SRB-NLC formulation demonstrated excellent physicochemical properties and good tolerance, sustained release, and enhanced ocular bioavailability. It is safe and potentially effective for the treatment of corneal neovascularization.

Tumor vasculature-targeting nanomedicines

Uncontrolled tumor growth and subsequent distant metastasis are highly dependent on an adequate nutrient supply from tumor blood vessels, which have relatively different pathophysiological characteristics from those of normal vasculature. Obviously, strategies targeting tumor vasculature, such as anti-angiogenic drugs and vascular disrupting agents, are attractive methods for cancer therapy. However, the off-target effects and high dose administration of these drug regimens critically restrict their clinical applications. In recent years, nanomedicines focused on tumor vasculature have been shown to be superior to traditional therapeutic methods and do not induce side effects. This review will first highlight the recent development of tumor vasculature-targeting nanomedicines from the following four aspects: 1) angiogenesis-inhibiting nanomedicines (AINs); 2) vasculature-disrupting nanomedicines (VDNs); 3) vasculature infarction nanomedicines (VINs); and 4) vasculature-regulating nanomedicines (VRNs). Furthermore, the design principles, limitations, and future directions are also discussed. STATEMENT OF SIGNIFICANCE: Based on the essential roles of tumor blood vessels, the therapeutic strategies targeting tumor vasculature have exhibited good clinical therapeutic outcomes. However, poor patient adherence to free drug administration limits their clinical usage. Nanomedicines have great potential to overcome the abovementioned obstacle. This review summarizes the tumor-vasculature targeting nanomedicines from four aspects: 1) angiogenesis-inhibiting nanomedicines (AINs); 2) vasculature-disrupting nanomedicines (VDNs); 3) vasculature infarction nanomedicines (VINs); and 4) vasculature regulating nanomedicines (VRNs). In addition, this review provides perspectives on this research field.

The role of bone morphogenetic protein 4 in corneal injury repair

PURPOSE

Corneal injury may cause neovascularization and lymphangiogenesis in cornea which have a detrimental effect to vision and even lead to blindness. Bone morphogenetic protein 4 (BMP4) regulates a variety of biological processes, which is closely relevant to the regulation of corneal epithelium and angiogenesis. Herein, we aimed to evaluate the effect of BMP4 on corneal neovascularization (CNV), corneal lymphangiogenesis (CL), corneal epithelial repair, and the role of BMP4/Smad pathway in these processes.

METHODS

We used MTT assay to determine the optimal concentration of BMP4. The suture method was performed to induce rat CNV and CL. We used ink perfusion and HE staining to visualize the morphological change of CNV, and utilized RT-qPCR and ELISA to investigate the expression of angiogenic factors and lymphangiogenic factors. The effects of BMP4 and anti-VEGF antibody on migration, proliferation and adhesion of corneal epithelium were determined by scratch test, MTT assay and cell adhesion test.

RESULTS

BMP4 significantly inhibited CNV and possibly CL. Topical BMP4 resulted in increased expression of endogenous BMP4, and decreased expression of angiogenic factors and lymphangiogenic factors. Compared with anti-VEGF antibody, BMP4 enhanced corneal epithelium migration, proliferation and adhesion, which facilitated corneal epithelial injury repair. Simultaneously, these processes could be regulated by BMP4/Smad pathway.

CONCLUSIONS

Our results demonstrated unreported effects of BMP4 on CNV, CL, and corneal epithelial repair, suggesting that BMP4 may represent a potential therapeutic target in corneal injury repair.

The role of microRNAs in corneal neovascularization and its relation to VEGF

PURPOSE

This study aimed to investigate the changes in the level of miRNA associated with Vascular Endothelial Growth Factor (VEGF) in corneal neovascularization (CNV), to elucidate the process of CNV formation and, thus, to prepare the ground for further experimental, and clinical studies together with drug treatments.

METHODS

Twelve male Wistar-Albino rats were randomly divided into two groups of six, and two corneas of each rat were used. In all groups, CNV was generated by silver nitrate sticks. At the end of the study, rats were sacrificed by cervical dislocation under ether anaesthesia, and then, their corneas were removed. The expression levels of VEGF and miRNA in corneas were determined by qRT-PCR array and qRT-PCR. Data analysis was performed using web-based software named PCR array data.

RESULTS

When the corneal samples of rats with CNV were compared to those of the control rats, it was found that a statistically significant difference was present regarding the VEGF level (p < 0.05) with the fold-regulation value> 2. According to the under- and over-expression data in miRNA PCR Array findings of both groups, statistically significant differences were found regarding nine genes with Fold-regulation value <-2 and Fold-regulation value> 2 (p < 0.05). When the corneal samples of the rats with CNV were compared to those of the control rats, statistically significant over-expressions (Fold-regulation value> 2) of rno-miR-21_2, rno-miR-126_1 and rno-miR-150_1 genes were found (p = 0.002443, p = 0.030146, p = 0.000348, respectively). In the same comparison, rno-miR-184_1 gene showed statistically significant under-expression with a Fold-regulation value <-2 (p = 0.006428). Also, in the comparison of the two groups, the fold regulation value of the rno-miR-31_1 gene was found to be close to - g and statistically significantly under-expressed (p = 0.005082).

CONCLUSION

The over-expressions of rno-miR-21_2, rno-miR-126_1, and rno-miR-150_1 genes, and the under-expression of rno-miR-184_1 gene were thought to could play roles in the formation process of CNV by regulation of VEGF-A and through modulation of angiogenesis.