Poloxamer 407/188 Binary Thermosensitive Gel as a Moxidectin Delivery System: In Vitro Release and In Vivo Evaluation.

Moxidectin (MXD) is an antiparasitic drug used extensively in veterinary clinics. In this study, to develop a new formulation of MXD, a thermosensitive gel of MXD (MXD-TG) was prepared based on poloxamer 407/188. Furthermore, the gelation temperature, the stability, in vitro release kinetics and in vivo pharmacokinetics of MXD-TG were evaluated. The results showed that the gelation temperature was approximately 27 °C. MXD-TG was physically stable and can be released continuously for more than 96 h in vitro. The Korsmeyer−Peppas model provided the best fit to the release kinetics, and the release mechanism followed a diffusive erosion style. MXD-TG was released persistently for over 70 days in sheep. Part of pharmacokinetic parameters had a difference in female and male sheep (p < 0.05). It was concluded that MXD-TG had a good stability, and its release followed the characteristics of a diffusive erosion style in vitro and a sustained release pattern in vivo.

Sensitive SERS detection of oral squamous cell carcinoma-related miRNAs in saliva via a gold nanohexagon array coupled with hybridization chain reaction amplification.

In this work, a highly specific and sensitive method for the detection of dual miRNAs was successfully developed by a hybridization chain reaction (HCR) amplification coupled with surface-enhanced Raman scattering (SERS) on Au-Ag hollow nanoparticles (Au-Ag HNPs) and a gold nanohexagon (AuNH) array. Two Raman reporter-labelled and hairpin DNA-modified Au-Ag HNPs acted as SERS probes (Au-Ag HNPs@4-MBA@HP1-1, Au-Ag HNPs@4-MBA@HP2-1, Au-Ag HNPs@DTNB@HP1-2, and Au-Ag HNPs@DTNB@HP2-2), and the hairpin DNA-modified AuNH array acted as the capture substrate. The HCR process could be triggered by the presence of target miRNAs, and long DNA hybridization chains on the substrate were formed by self-assembly rapidly, causing significant signal enhancement. Using the mentioned strategy, a low detection limit (LOD) of 6.51 aM for miR-31 and 6.52 aM for miR-21 in human saliva were obtained, showing the biosensor's remarkable sensitivity. The proposed biosensor also displays a significant specificity in detecting target miRNAs by introducing different interfering factors. This method has been successfully applied to detect and identify miR-21 and miR-31 in saliva from oral squamous cell carcinoma (OSCC) patients and healthy subjects. The results were consistent with those of the traditional test method in detecting target miRNAs, which confirmed the good accuracy of our method. Hence, the new assay method has great potential to be a valuable platform for detecting miRNAs in the early diagnosis of OSCC.