Framework Nucleic Acids as Blood-Retinal-Barrier-Penetrable Nanocarrier for Periocular Administration.

Designing an ocular drugs delivery system that can permeate the outer blood-retinal barrier (oBRB) is crucial for the microinvasive or noninvasive treatment of ocular fundus diseases. However, due to the lack of a nanocarrier that can maintain structure and composition at the oBRB, only intravitreal injection at the eyeball can deliver therapeutics directly to the ocular fundus via paracellular and intercellular routes, despite the intraocular operations risks. Here, we demonstrated tetrahedral framework nucleic acids (tFNAs) can penetrate the oBRB and deliver therapeutic nucleic acids to the retina of the rat eye in vivo following subconjunctival injection. We also discovered that tFNAs were transported via a paracellular route across the intercellular tight junctions at the oBRB. The histology analysis for ocular layers indicated that individual and aptamer/doxorubicin-loaded tFNAs penetrated all layers of the posterior segment of the eyeball to reach the innermost retina and persisted for over 3 days with minimal systemic biodistribution. We expect that the programmability and penetrability of tFNAs will provide a promising method for drug delivery across oBRB and long-term sustenance at the target site via periocular administration to various tissues.

Use of Anthropometric Measures of Obesity to Predict Diabetic Retinopathy in Patients with Type 2 Diabetes in China.

PURPOSE: Obesity is an established risk factor for type 2 diabetes (T2D). Diabetic retinopathy (DR) is a major microvascular complication of T2D. In this cross-sectional study, we investigated the association between various anthropometric indices of obesity and DR. PATIENTS AND METHODS: A representative sample of 1952 patients with T2D participated in this cross-sectional study conducted in Shanghai, China. Anthropometric measures of obesity including weight, height, waist circumference, hip circumference, body mass index (BMI), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR) were evaluated. The association between WHtR, WHR, and BMI and the presence of DR was examined with logistic regression models. RESULTS: The prevalence of DR was higher in T2D patients with high WHtR compared to those with normal WHtR (p<0.05). A higher BMI was associated with elevated risk of DR (model 1, p=0.034; model 2, p=0.036). WHR was unrelated to the occurrence of DR (p>0.05). CONCLUSION: WHtR and BMI but not WHR are risk factors for DR in obese patients with T2D. Patients with high WHtR and BMI should be closely monitored to prevent the development of DR.