Construction of cryomicroneedles loaded with milk-derived exosomes encapsulated TNF-α siRNA and efficacy of percutaneous acupoint administration in rheumatoid arthritis.

Inhibiting the expression of tumor necrosis factor-α (TNF-α), a pro-inflammatory cytokine widely distributed in the serum and synovial fluid, is important for managing rheumatoid arthritis (RA). Despite the good therapeutic effects of TNF-α small interfering RNA (TNF-α siRNA) in RA animal models, safe and efficient siRNA delivery systems that retain stability are lacking. We introduced a novel therapy using milk-derived exosomes(mEXOs)-encapsulated TNF-α siRNA-coated cryomicroneedle (cryoMN) patch and evaluated its efficacy via local transdermal administration through acupoints in RA treatment. The loading of TNF-α siRNAs into mEXOs was achieved by sonication, the loading rate, stability, and in vitro release of mEXOs-TNF-α siRNA were determined. The cryoMNs were prepared by micromolding, morphology, drug loading, and mechanical strength of the cryoMN array were analyzed. The loading efficiency of TNF-α siRNA was up to 21% and each cryoMN contained 39.6 ± 1.29 µg of TNF-α siRNA. Frozen sections penetrated 523 ± 63 µm deep. In vitro experiments have shown that mEXOs-TNF-α siRNA cryoMNs have good biocompatibility and inhibit the proliferation of HFLS-RA cells. In vivo pharmacodynamics studies found that general conditions, changes in microcirculation indexes, synovial histopathological changes, and expression of related proteins in the synovial tissue in RA rabbits were effectively alleviated by mEXOs-TNF-α siRNA cryoMNs. Improvement of each index at acupoints was greater than that at non-acupoints. Our findings facilitate the development of cryoMNs combined with exosomes and acupoints drug delivery for the treatment of RA. The combination of exosomes and cryoMNs will enable the development of new-generation microneedle-based treatments.

[Recent advances in nanocarrier-based drug delivery systems in treatment of rheumatoid arthritis].

Rheumatoid arthritis(RA) is a widely prevalent autoimmune inflammatory disease that severely affects patients' quality of life. Currently, conventional formulations against RA have several limitations, such as nonspecificity, poor efficacy, large drug dosages, frequent administration, and systemic side effects. Nanotechnology-based drug delivery systems have emerged as a promising stra-tegy for the diagnosis and treatment of RA since nanotechnology can overcome the limitations of traditional treatments and simplify the complexity of the disease. These systems enable targeted delivery of anti-inflammatory drugs to the inflamed areas through active and passive targeting, achieving specificity to the joints, overcoming the need for increased dosage and administration frequency, and reducing associated adverse reactions. This article aimed to review nanocarrier-based drug delivery systems in the field of RA and elucidate how nanosystems can be utilized to deliver therapeutic drugs to inflamed joints for controlling RA progression. By discussing the current issues and challenges faced by nanodrug delivery systems and highlighting the urgent need for solutions, this article offers theoretical support for further research on nanotechnology-based co-delivery systems in the future.

[Treatment of rheumatoid arthritis by injection of sinomenine solid lipid nanoparticles under a fluorescence endoscopic laser confocal microscope].

A fluorescence endoscopic laser confocal microscope(FELCM) was used to direct the injection of sinomenine solid lipid nanoparticles(Sin-SLN) into the joint, and the in vitro effectiveness of Sin-SLN in the treatment of rheumatoid arthritis(RA) was evaluated. Sin-SLN was prepared with the emulsion evaporation-low temperature curing method. The Sin-SLN prepared under the optimal conditions showed the encapsulation efficiency of 64.79%±3.12%, the drug loading of 3.84%±0.28%, the average particle size of(215.27±4.21) nm, and the Zeta potential of(-32.67±0.84) mV. Moreover, the Sin-SLN demonstrated good stability after sto-rage for 30 days. The rabbit model of RA was established by the subcutaneous injection of ovalbumin and complete Freund's adjuvant. Five groups were designed, including a control group, a model group, a Sin(1.5 mg·kg~(-1)) group, a Sin-SLN(1.5 mg·kg~(-1)) group, and a dexamethasone(positive drug, 1.0 mg·kg~(-1), ig) group. The control group and the model group only received puncture treatment without drug injection. After drug administration, the local skin temperature and knee joint diameter were monitored every day. The knee joint diameter and the local skin temperature were lower in the drug administration groups than in the model group(P<0.05, P<0.01). FELCM recorded the morphological alterations of the cartilage of knee joint. The Sin-SLN group showed compact tissue structure and smooth surface of the cartilage. Enzyme-linked immunosorbent assay(ELISA) was employed to determine the serum le-vels of interleukin-1(IL-1) and tumor necrosis factor-α(TNF-α). The findings revealed that the Sin-SLN group had lower IL-1 and TNF-α levels than the model group(P<0.05, P<0.01). Hematoxylin-eosin(HE) staining was employed to reveal the pathological changes of the synovial tissue, which were significantly mitigated in the Sin-SLN group. The prepared Sin-SLN had uniform particle size and high stability. Through joint injection administration, a drug reservoir was formed. Sin-SLN effectively alleviate joint swelling and cartilage damage of rabbit, down-regulated the expression of inflammatory cytokines, and inhibited the epithelial proliferation and inflammatory cell infiltration of the synovial tissue, demonstrating the efficacy in treating RA.

[PK/PD model of Chuanxiong gel plaster in treatment of rheumatoid arthritis].

In this experiment, the PK/PD fitting model of Chuanxiong(Chuanxiong Rhizoma) in the treatment of rheumatoid arthritis was established in the form of acupoint combined with external application gel paste. Firstly, the rheumatoid arthritis model was induced by ovalbumin, and the articular fluid of rabbits was extracted by microdialysis. The pharmacokinetic process of Chuanxiong in rabbit articular fluid was analyzed by UPLC-MS/MS, and the pharmacokinetic model was established. The pharmacodynamic effects of Chuanxiong on inflammatory factors IL-1ß, TNF-α, and IL-6 were analyzed by enzyme-linked immunosorbent assay(ELISA). The pharmacodynamic model was established, and the PK/PD model was obtained by fitting the data of pharmacokinetics and pharmacodynamics. The results of pharmacokinetics showed that the concentration of ligustrolide A in the articular cavity by drug administration on classical acupoint Zusanli(ST 36) was higher than that by Yanglingquan(GB 34), which reflected the advantage of typical acupoint, while ligustrazine concentration was higher after administration through Yanglingquan than through Zusanli, which was different from the traditional acupoint theory. The results of pharmacodynamics showed that the drug had lag effect. The PK/PD model was constructed by fitting the data. When IL-1ß was taken as the efficacy index, the PK/PD models of Chuanxiong in typical acupoint Zusanli group, atypical acupoint Yanglingquan group, and non-acupoint group were E=115.28C_e/(3 316.72+C_e), E=108.73C_e/(2 993.47+C_e), and E=101.34C_e/(3 028.51+C_e). When TNF-α was taken as the efficacy index, the PK/PD models of Chuanxiong in typical acupoint Zusanli group, atypical acupoint Yanglingquan group, and non-acupoint group were E=68.31C_e/(3 285.16+C_e), E=59.27C_e/(2 919.86+C_e), and E=53.61C_e/(2 862.87+C_e). When IL-6 was taken as the efficacy index, the PK/PD models of Chuanxiong in typical acupoint Zusanli group, atypical acupoint Yanglingquan group, and non-acupoint group were E=59.92C_e/(3 461.17+C_e), E=58.34C_e/(2 723.51+C_e), and E=49.17C_e/(2 862.76+C_e). The parameters showed that there were significant differences in E_(max), EC_(e50) and k_(eo). The analysis of data found that the PK/PD fitting effect of Zusanli, a typical acupoint, was the best, which proved that it was still the best site for drug administration. To sum up, it shows that there may be bidirectional selectivity between drugs and acupoints.