Objective To prepare a dissolvable microneedle(DMN)with a tip-layer loaded with hyaluronic acid(HA)modified sinomenine hydrochloride liposomes(HA-SMH-Lip),as well as characterize,evaluate its in vitro transdermal permeability,cellular uptake ability,and anti-inflammatory ability.Methods HA-SMH-Lip-DMNs were prepared by a two-step casting method,and the drug loading capacity was determined using HPLC.The morphology,skin permeation properties and in vitro transdermal ability were investigated by scanning electron microscopy,puncture assay and Franz diffusion cell method.Fluorescent microneedles were prepared by replacing HA-SMH-Lip with fluorescein isothiocyanate liposomes(HA-FITC-Lip/FITC-Lip).The uptake behavior of inflammation cells on HA-FITC-Lip-DMNs/FITC-Lip-DMNs was investigated using a flow cytometer and a fluorescence microscope.To evaluate the anti-inflammatory activity of HA-SMH-Lip-DMNs,the levels of inflammatory factors including nitric oxide(NO),tumor necrosis factor α(TNF-α),interleukin 1β(IL-1β),and IL-10 in cell supernatants were measured using an ELISA kit.Results The prepared HA-SMH-Lip-DMNs have uniform shape and size,integral and visually pleasing array,and an average drug loading of(114.01±1.04)μg.Additionally,they have good puncture ability.The results of in vitro transdermal experiments showed that the accumulated amounts of HA-SMH-Lip-DMNs were(101.47±2.91)μg·cm-2 at 36 hours.Its transdermal ability was better than that of the SMH solution group and SMH liposome group.In vitro cellular uptake results indicated that HA-FITC-Lip-DMNs were more effectively taken up by RAW 264.7 cells(P＜0.01).Compared to the model group,HA-SMH-Lip-DMNs group significantly reduced TNF-α,IL-1β,and NO levels while increase IL-10 levels(P＜0.01).Conclusion The prepared HA-SMH-Lip-DMNs have a complete and beautiful morphology with excellent cellular uptake capability,remarkable in vitro transdermal performance,and potent anti-inflammatory properties.HA-SMH-Lip-DMNs are expected to become a new type of transdermal drug delivery system.

Porphyromonas gingivalis peptidylarginine deiminase (PPAD), an isoenzyme of animal endogenous peptidylarginine deaminase, is secreted by the Por system and catalyzes the citrullination of arginine. Recent studies have found that PPAD can affect the formation of Porphyromonas gingivalis biofilm and reduce the body′s immune defense function, which is related to the occurrence and development of many diseases such as periodontal diseases and rheumatoid arthritis. In this paper, we reviewed the molecular characteristics of PPAD, including the genetic and functional characteristics, as well as the mechanisms related to the inflammatory and autoimmune diseases. We also pointed some issues that should be pay attention to in the further study.