Novel Drug Delivery Methods and Approaches for the Treatment of Retinal Diseases

ROS-Responsive Nanoparticles with Antioxidative Effect for the treatment of Diabetic Retinopathy

Diabetic retinopathy (DR) is a common microvascular complication of diabetes necessitating early intervention to impede progression, despite current clinical treatments focusing on advanced stages. Essential oils from Fructus Alpiniae zerumbet (EOFAZ) have demonstrated efficacy in protecting against high glucose (HG)-induced Müller cell activation and DR development. This study introduced a reactive oxidative species (ROS)-responsive drug delivery system (NPSPHE@EOFAZ) targeting early DR stages and oxidative stress. Our engineered nanoparticles effectively deliver EOFAZ into HG-exposed Müller cells by detecting and responding to elevated oxidative stress levels. The NPSPHE@EOFAZ significantly inhibited abnormal cell growth, reduced oxidative stress, and alleviated inflammation in vitro. In vivo experiments on diabetic mice with DR revealed that NPSPHE@EOFAZ mitigated early pathological changes by reducing oxidative stress and inflammation while also alleviating organ damage in the heart, liver, spleen, lung, and kidney. These findings underscore the potential of NPSPHE@EOFAZ as a promising antioxidant for early intervention in DR pathogenesis.

Melanopsin DNA aptamers can regulate input signals of mammalian circadian rhythms by altering the phase of the molecular clock

DNA aptamers can bind specifically to biomolecules to modify their function, potentially making them ideal oligonucleotide therapeutics. Herein, we screened for DNA aptamer of melanopsin (OPN4), a blue-light photopigment in the retina, which plays a key role using light signals to reset the phase of circadian rhythms in the central clock. Firstly, 15 DNA aptamers of melanopsin (Melapts) were identified following eight rounds of Cell-SELEX using cells expressing melanopsin on the cell membrane. Subsequent functional analysis of each Melapt was performed in a fibroblast cell line stably expressing both Period2:ELuc and melanopsin by determining the degree to which they reset the phase of mammalian circadian rhythms in response to blue-light stimulation. Period2 rhythmic expression over a 24-h period was monitored in Period2:ELuc stable cell line fibroblasts expressing melanopsin. At subjective dawn, four Melapts were observed to advance phase by >1.5 h, while seven Melapts delayed phase by >2 h. Some Melapts caused a phase shift of approximately 2 h, even in the absence of photostimulation, presumably because Melapts can only partially affect input signaling for phase shift. Additionally, some Melaps were able to induce phase shifts in Per1::luc transgenic (Tg) mice, suggesting that these DNA aptamers may have the capacity to affect melanopsin in vivo. In summary, Melapts can successfully regulate the input signal and shifting phase (both phase advance and phase delay) of mammalian circadian rhythms in vitro and in vivo.

Hydrogels in Ophthalmology: Novel Strategies for Overcoming Therapeutic Challenges

The human eye's intricate anatomical and physiological design necessitates tailored approaches for managing ocular diseases. Recent advancements in ophthalmology underscore the potential of hydrogels as a versatile therapeutic tool, owing to their biocompatibility, adaptability, and customizability. This review offers an exploration of hydrogel applications in ophthalmology over the past five years. Emphasis is placed on their role in optimized drug delivery for the posterior segment and advancements in intraocular lens technology. Hydrogels demonstrate the capacity for targeted, controlled, and sustained drug release in the posterior segment of the eye, potentially minimizing invasive interventions and enhancing patient outcomes. Furthermore, in intraocular lens domains, hydrogels showcase potential in post-operative drug delivery, disease sensing, and improved biocompatibility. However, while their promise is immense, most hydrogel-based studies remain preclinical, necessitating rigorous clinical evaluations. Patient-specific factors, potential complications, and the current nascent stage of research should inform their clinical application. In essence, the incorporation of hydrogels into ocular therapeutics represents a seminal convergence of material science and medicine, heralding advancements in patient-centric care within ophthalmology.