| ObjectiveEye disease is a common disease that can occur in everyone’s lifetime.Although the detailed mechanisms underlying some eye diseases are not fully understood,there is increasing evidence that the underlying etiologic mechanisms of many eye diseases are inflammation and oxidative stress.Yet the development of effective anti-oxidative stress and anti-inflammatory agents remains an urgent medical need in ophthalmology.Therefore,there is a need to develop new drugs that can significantly inhibit oxidative stress damage and prevent inflammatory responses.This study will investigate: 1.The feasibility of using the amphiphilic polymer Polyvinylpyrrolidone(VA64)for the first time to construct the ocular drug delivery nanoplatform;2.In order to improve the bioavailability of more insoluble drugs,explore the feasibility of using VA64 as one of the mixed excipients to construct a nano drug delivery system;3.The feasibility of VA64 nanopreparations constructed with Apocynin(APO)in the treatment of ocular inflammation and dry eye and synergistic regulation of High Mobility Group B1(HMGB1)signaling pathway to promote damage repair;4.VA64-D-α tocopherol succinate polyethylene ester(D-α Tocopherol succinate Polyethylene ester,TPGS)and glycol AES,Feasibility of a nanoagent constructed by AES to treat cataract and synergistically regulate HMGB1 signaling pathway to prevent cataract development.Methods1.Polyvinylpyrrolidone VA64-apocynin micelles(APO-VA64)were prepared by the thin film hydration method,and the encapsulation rate and particle size potential were determined to optimize the prescription,evaluate the storage stability,solubility changes and in vitro safety and tolerance,and investigate the antioxidant activity,in vitro release characteristics,in vivo corneal permeability and cellular level safety.2.A dry eye injury model in BALB/c mice was constructed using benzalkonium chloride(BAC),and ocular surface injury and repair were observed by slit lamp after sodium fluorescein and Bengal rose staining;corneal sensitivity and tear volume were measured,neovascularization and perfusion were observed,and histopathology,scanning electron microscopy and inflammatory factor expression of corneal samples were evaluated.3.AES was selected to construct drug-laden polyvinylpyrrolidone VA64-TPGS micelles eye drops(AES-VA64-TPGS),and the prescription was optimized by the ratio of excipients and encapsulation rate,etc.The evaluation examined the storage stability of micelles,solubility changes,in vitro antioxidation,in vitro release,in vitro and in vivo safety,corneal absorption characteristics and cellular tolerance.4.A sodium selenite cataract model was established,and each group was dosed with each drug according to the predetermined experimental protocol,and the development of lens clouding was observed and scored by slit lamp at a predetermined time;the appearance of the isolated lens was observed at the end of treatment;the level of oxidative stress and the level of related inflammatory factors in the lens were measured.The lenses of healthy Wistar rats were incubated in cell culture medium at37°C for 2 hours and then transferred to each group for 24 hours;the appearance was examined and weighed for wet weight,followed by determination of differences in expression of oxidative stress levels in each group.Results1.APO-VA64 eye drops can be prepared by a simple process.The solution is transparent and colorless,and has the advantages of small micelle size(14.12±1.24 nm),narrow micelle size distribution,and high APO encapsulation efficiency.The micellarized APO also exhibited high aqueous solubility,in vitro release and antioxidant activity.APO-VA64 eye drops exhibited good ocular tolerance and improved corneal permeability in mice.The results of in vitro cellular level cytotoxicity,corneal scratch and oxidative stress damage repair assays indicated a good ocular safety.2.Topically administered APO-VA64 eye drops were found to be more effective against BAC-induced ocular injury than APO,VA64,and a physical mixture of APO&VA64.Corneal injury repair,corneal sensitivity,tears,and neovascularization were largely restored to normal,and the conjunctiva was not significantly edematous or congested after treatment with APO-VA64 micellar drops in mice.In addition,the blockage of HMGB1 signaling pathway and its associated pro-inflammatory cytokines were involved in this therapeutic effect,and the levels of inflammatory factors and m RNA in the cornea were decreased(P < 0.05 compared with PBS).3.The prepared AES-VA64-TPGS eye drops were pale yellow and transparent with a micelle size of 13.10±0.16 nm,polydispersity index of 0.094±0.02,and encapsulation rate of 99.75±2.16%.The water solubility of micellarized AES was more than 500-fold higher,and the in vitro release and antioxidant activity were also significantly better than those of AES suspensions.Meanwhile,AES-VA64-TPGS eye drops showed good ocular tolerance and improved corneal permeability in rats.4.AES-VA64-TPGS eye drops were more effective than AES,VA64&TPGS and AES&VA64&TPGS physical suspension in sodium selenite-induced cataracts,and even better than positive control group.There was no significant turbidity in the rat lens after micelle treatment,and the isolated lens was clarified and clear,and oxidative stress and pro-inflammatory cytokines associated with the HMGB1 signaling pathway were basically restored to normal levels.In cultured lens in vitro,AES prevented seleniteinduced cataract development by maintaining redox system components at near normal levels and by preventing the abnormal expression of several oxidative stress proteins in the lens and preventing lens cell death.ConclusionThese results indicate that VA64 micelles can significantly improve the solubility and bioavailability of insoluble drugs,and micellar APO and AES can effectively alleviate ocular inflammation damage by inhibiting oxidative stress and inflammatory cytokines.VA64 is a potential nanoplatform ingredient for ocular drug delivery. |
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