Mucoadhesive Bletilla striata Polysaccharide-Based Artificial Tears to Relieve Symptoms and Inflammation in Rabbit with Dry Eyes Syndrome

Abstract

<jats:p>Dry eye syndrome (DES) is a multifactorial disorder of the ocular surface affecting many people all over the world. However, there have been many therapeutic advancements for the treatment of DES, substantial long-term treatment remains a challenge. Natural plant-based polysaccharides have gained much importance in the field of tissue engineering for their excellent biocompatibility and unique physical properties. In this study, polysaccharides from a Chinese ground orchid, Bletilla striata, were successfully extracted and incorporated into the artificial tears for DES treatment due to its anti-inflammatory and mucoadhesive properties. The examination for physical properties such as refractive index, pH, viscosity and osmolality of the Bletilla striata polysaccharide (BSP) artificial tears fabricated in this study showed that it was in close association with that of the natural human tears. The reactive oxygen species (ROS) level and inflammatory gene expression tested in human corneal epithelium cells (HCECs) indicated that the low BSP concentrations (0.01–0.1% v/v) could effectively reduce inflammatory cytokines (TNF, IL8) and ROS levels in HCECs, respectively. Longer retention of the BSP-formulated artificial tears on the ocular surface is due to the mucoadhesive nature of BSP allowing lasting lubrication. Additionally, a rabbit’s DES model was created to evaluate the effect of BSP for treating dry eye. Schirmer test results exhibited the effectiveness of 0.1% (v/v) BSP-containing artificial tears in enhancing the tear volume in DES rabbits. This work combines the effectiveness of artificial tears and anti-inflammatory herb extract (BSP) to moisturize ocular surface and to relieve the inflammatory condition in DES rabbit, which further shows great potential of BSP in treating ocular surface diseases like DES in clinics in the future.</jats:p>

Crosslinked Hyaluronic Acid with Liposomes and Crocin Confers Cytoprotection in an Experimental Model of Dry Eye

“…The interaction between adhesive compounds and mucin is generally formed by physical entanglements, van der Walls bonds, electrostatic forces, and hydrogen bonds [22]. The enhanced viscosity and muco-adhesive property of cHA-Cr-L would help to develop a protective layer on the ocular surface, improving lubrication and hydration, and reducing friction [23]. Thus, the results of our study provide a rationale for the use of cHA-Cr-L as a potential agent to improve the rheological characteristics of eye drops.…”

Antifibrotic Effect of Bletilla striata Polysaccharide-Resveratrol-Impregnated Dual-Layer Carboxymethyl Cellulose-Based Sponge for The Prevention of Epidural Fibrosis after Laminectomy

“…The extraction of BSP from B. striata has been described in our previous study [ 30 ]. In brief, dried B. striata were ground, dispersed in double-distilled water (ddH 2 O) at 80 °C for 4 h, and subsequently, filtered to remove impurities.…”

Polysaccharide-Based Nanomaterials for Ocular Drug Delivery: A Perspective

“…Carboxymethyl Terminalia catappa polysaccharides show therapeutic effects in the cornea from blue light-emitting diodes. Moreover, Polygonatum sibiricum polysaccharides could attenuate the damage from diabetic retinopathy, while dry eyes can be relieved by mucoadhesive Bletilla striata polysaccharide-based artificial tears ( Chandel et al, 2019 ; Wang et al, 2019c ; Thacker et al, 2020 ). Evidence has also demonstrated that phyto-based polysaccharides can be utilized for drug delivery systems upon graft modification or synergistic interaction via non-covalent stabilization with other commercial polysaccharides such as hyaluronic acid ( Uccello-Barretta et al, 2013 ; Wang et al, 2019b ).…”