Correlation Study Of Different Characteristics Of Nanoparticles Across The Corneal Barrier

Triamcinolone is a glucocorticoid that has a good therapeutic effect on a variety of eye diseases.And topical eye drop administration is a non-invasive way of administration,which has low side effects,good compliance and high safety.However,due to the special structure of the eye,it is difficult to achieve an effective therapeutic concentration by the local eye drop administration method.In order to increase the bioavailability of triamcinolone acetonide for eye drops,triamcinolone trichloride PLGA-NPs with different characteristics such as transmembrane peptide and hyaluronic acid were prepared,and compared with the presence or absence of 2-HP-?-CD in the PLGA-NPs nanoparticles system,and its correlation with different characteristics of nanoparticles to increase eye bioavailability and its ability to cross the corneal barrier.Nanoparticles were prepared by emulsification solvent evaporation method,and the particle size potential and morphological characteristics were analyzed.The particle size potential results showed that the average particle diameters of PLGA-NPs,CPP-PLGA-NPs,HA-PLGA-NPs,and PLGA-NPs without CD were 83.03±1.4 nm,75.17±0.47 nm,103.1±1.1 nm,and 96.17±0.93 nm,respectively;Zate potentials are-?10.94±0.46?mV,2.6±0.31 mV,-?33.53±2.07?mV and-?12.89±2.09?mV;Transmission electron microscopy results showed that the four nanoparticles were spherical and the edges were significantly different.The surface tension of the four different preparations is in the range of 40-46 mN/m;the pH value is in the range of 7.13?7.42 and the osmotic pressure is in the range of 281 to 278 mOsmol·kg^-1.The prepared nanoparticle eye drops have good light transmittance and have a small effect on vision.Containing HA in the system can increase the bioadhesion of nanoparticles.The addition of 2-HP-?-CD is a key factor to effectively improve the encapsulation efficiency of the system.The dialysis bag method was used to examine the release situation;the results showed that the addition of 2-HP-?-CD promoted the release of the drug,but the modification of CPP and HA did not have much effect on the release,and the nanoparticles maintained good release behavior.Fitting the release model,the release model of the four nanoparticles belongs to the Ritger-Peppas kinetic release model.The corneal penetration of the preparation was evaluated using rabbit isolated corneas.The results show that the curve of the cumulative amount of drug penetration versus time is linearly approximated.The cumulative 8 h infiltration of HA-PLGA-NPs,CPP-PLGA-NPs and PLGA-NPs were 3.9,3.0 and 2.7 times that of PLGA-NPs without CD,respectively.There was no significant difference in the penetration results of CPP-PLGA-NPs and PLGA-NPs,which may be related to the low biological activity of the isolated cornea.The CCK-8 method was used to determine the cytotoxicity of the preparations.The results showed that the cell survival rate was above 90%within 8 hours,and the cytotoxicity of the four nanoparticles was low.Cellular function inhibitors and flow cytometry were used to analyze the uptake mechanism.The results show that during the uptake of PLGA-NPs without CD,giant cell drink is the main,and caveolin/lipid raft-structured endocytosis and clathrin-mediated endocytosis play a certain role,and the process is close to the Golgi Related.In the process of ingestion of PLGA-NPs,giant cell drinks are also mainly used,and caveolin/lipid raft structure-mediated endocytosis and endocytosis play a certain role.Compared with PLGA-NPs without 2-HP-?-CD,the addition of 2-HP-?-CD strengthens the giant cell drinking effect and weakens the caveolin/lipid raft-mediated endocytosis,and the ingestion process is not so closely related to the Golgi apparatus.Compared with PLGA-NPs,the modification of CPP strengthens giant cell-drinking effect and clathrin-mediated endocytosis.The HA modification makes the uptake process more closely related to the Golgi apparatus and enhances clathrin-mediated endocytosis.The MDCK epithelial cell barrier model was used to study the epithelial barrier permeability of the preparations.The results showed that the 4 h infiltration of CPP-PLGA-NPs,HA-PLGA-NPs and 2PLGA-NPs increased by 103.1%,68.87%and 44.0%over PLGA-NPs without CD,respectively.Using cell function inhibitors and MDCK epithelial cell barrier models to study the transmembrane transport mechanism.The transmembrane transport of different surface-modified nanoparticles is an energy-dependent process.Inhibition of caveolin and clathrin-mediated endocytosis,giant pectin,and Golgi-related transport have little effect on transmembrane transport of PLGA-NPs without CD,and the transmembrane transport process is closely related to plasma membrane cholesterol.Compared with PLGA-NPs without CD,2-HP-?-CD modification enhanced the cell's caveolin and clathrin-mediated endocytosis and giant cellocytosis to a certain extent.Modification of CPP on the basis of PLGA-NPs further enhances the link between the uptake process and the Golgi apparatus,and the plasma membrane cholesterol distribution significantly reduces the enhancement of transmembrane transport.HA modification did not have much effect on the transmembrane mechanism of nanoparticles.The filter strip method method was used to evaluate the elimination of tears in the preparation.The results showed that HA-PLGA-NPs,PLGA-NPs,and CPP-PLGA-NPs all increased the retention time and retention on the ocular surface.Among them,HA-PLGA-NPs were the most significant.The results showed that the C_max of HA-PLGA-NPs,CPP-PLGA-NPs,and PLGA-NPs were 5.73,4.19 and 3.03?g·mL^-1,and the AUC_0?360 were 8.06,5.05 and 3.46?g·mL^-1·min,respectively.Through the discussion of the characterization,in vitro release and in vitro corneal permeability of rabbits,cell uptake and transepithelial barrier mechanisms,tear fluid elimination kinetics,and pharmacokinetics of aqueous humor of the four types of nanoparticles,Optimizing the prescription composition that can enhance permeability and cross the epithelial cell barrier lays a foundation for the study of prolonging ocular surface retention time and improving ocular bioavailability.