Analysis of Morphological Changes in Monosodium Urate Monohydrate Crystals for Gout Treatment

Abstract

Gout is arthritis induced by monosodium urate monohydrate (MSU) crystals. The treatment of gout is mainly a symptomatic treatment, by suppressing the blood uric acid concentration with drugs. Here, the changes in crystal morphology in the process of MSU crystallization were investigated. Experiments were conducted to clarify the mechanisms of nucleation and growth of the MSU crystals, revealing that MSU first precipitated as granular crystals. Thereafter, nucleation and growth of needle-like crystals were observed concomitant with the disappearance of the granular crystals. These results suggest that it is necessary to suppress the nucleation of granular crystals and the change in morphology from granular to needlelike of the MSU crystals that cause gout.

Adsorption of DNA and Aptamers to Sodium Urate Crystals and Inhibition of Crystal Growth

“…Similar morphologies were also observed with the rDNA (Figure S2). Previous literature 27 pointed out that at low concentrations and in a short time, sodium urate takes on a shape similar to that in Figure 3D, and granular crystals appear earlier than needle-shaped crystals. This result shows that DNA can be adsorbed on granular crystals and inhibit the transformation from granular to needle-shaped crystals.…”

“…Needle-shaped sodium urate crystals can stimulate the immune system and induce inflammation. For the treatment of gout, controlling the transformation of the morphology from granular to needle-like crystals is critical . Therefore, using DNA to inhibit the transformation of granular to needle crystals has the potential to treat gout.…”

“…The monosodium urate crystals exhibited a needle-like appearance, with an average length of 33 ± 8 μm (Figure 1B), and appeared white (Figure 1C), which was consistent with the literature. 26,27 One of the aptamers required sodium ions for binding UA, and its secondary structure is shown in Figure 1D. This is a short 40nucleotide single-stranded DNA sequence with a simple secondary structure, whose sequence is 5′-ACG ACA TTA CGG GAC CTT GCT AAA GGT GGA ATT ATG TCG T-3′.…”

Hydrogel Nanoparticles Enable Nucleation Barrier Regulation and Ion Anchoring as an Alternative Pathway for Monosodium Urate Monohydrate Crystallization Control

“…For the detailed preparation process of artificial fluid, one can refer to our previous work . To simulate the crystallization environment of MSUM, the experiments were run for about 150 h at 20 °C and 150 mL h –1 flow speed (joint temperature: about 20 °C; fluid flow speed: 120–180 mL h –1 ). In addition, the crystallization experiments were repeated three times at different times by using HCM prepared from different batches.…”