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.

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Vitreoretinal surgeries for ocular diseases such as complicated retinal detachment, diabetic retinopathy, macular holes and ocular trauma has led to the development of various tamponades over the years in search for an ideal vitreous substitute. Current clinically used tamponade agents such as air, perfluorocarbons, silicone oil and expansile gases serve only as a short-term solution and harbors various disadvantages. However, an ideal long-term substitute is yet to be discovered and recent research emphasizes on the potential of polymeric hydrogels as an ideal vitreous substitute. This review highlights the recent progress in the field of vitreous substitution. Suitability and adverse effects of various tamponade agents in present day clinical use and biomaterials in the experimental phase have been outlined and discussed. In addition, we introduced the anatomy and functions of the native vitreous body and the pathological conditions which require vitreous replacement.

Alzheimer's disease (AD) is the most common cause of dementia. Patients are generally to forget taking pills because of memory loss or to skip medication due to side effects; that might stop the medication and affect the results of the treatment. In this study, we combine donepezil with hydroxyapatite (HAP-DPZ) to deliver by intramuscular (IM) injection, which may prevent from patient to skip the daily medication and keep the medicine at a constant level in the blood to achieve a constant release. HAP particles synthesized by using the new oilin-water method, the XRD pattern, and the FTIR spectrum were proved the synthesized of HAP. SEM and DLS showed the particle size of synthesized HAP-DPZ was in the range of 0.9-3 μm, which all in the optimal range for cellular uptake. In the drug release profile, DPZ could be released from HAP-DPZ by endosome/lysosome complex to achieve control releasing. In vitro study, there was no cytotoxicity found in HAP-DPZ. In the animal study, only one injection of HAP-DPZ administration, rats revealed well-focused searching strategies with the longest swimming time and most finding times in the quadrant where the platform was initially after three weeks.