In this study, we demonstrated a unique application of our Metal-Assisted and Microwave-Accelerated Evaporative Crystallization (MA-MAEC) technique for the de-crystallization of uric acid crystals, which causes gout in humans when monosodium urate crystals accumulate in the synovial fluid found in the joints of bones. Given the shortcomings of the existing treatments for gout, we investigated whether the MA-MAEC technique can offer an alternative solution to the treatment of gout. Our technique is based on the use of metal nanoparticles (i.e., gold colloids) with low microwave heating to accelerate the de-crystallization process. In this regard, we employed a two-step process; (i) crystallization of uric acid on glass slides, which act as a solid platform to mimic a bone, (ii) de-crystallization of uric acid crystals on glass slides with the addition of gold colloids and low power microwave heating, which act as “nano-bullets” when microwave heated in a solution. We observed that the size and number of the uric acid crystals were reduced by >60% within 10 minutes of low power microwave heating. In addition, the use of gold colloids without microwave heating (i.e. control experiment) did not result in the de-crystallization of the uric acid crystals, which proves the utility of our MA-MAEC technique in the de-crystallization of uric acid.

We present a platform technology, called Metal-Assisted and Microwave-Accelerated Decrystallization (MAMAD), which is based on the use of dispersion of gold colloids with low power microwave heating to decrystallize organic and biological crystals attached to surfaces. Uric acid crystals were chosen as model target crystals to be decrystallized using MAMAD technique. A two-step procedure was employed: 1) growth of uric acid crystals on a model surface (collagen films coated on to glass slides to simulate a human joint) at room temperature and 2) de-crystallization of uric acid crystals in synovial fluid (in vitro) using silver and gold colloids in conjunction with low power microwave heating. Using the MAMAD technique with gold colloids, the number of uric acid crystals was drastically reduced by 80% after 10 min, where the average size of the uric acid crystals was reduced from 125 μm to 50 μm. In control experiments and with silver colloids that aggregated from the solution, the size and number of uric crystals remained unchanged, indicating that the combined use of only metal colloids in solution and microwave heating is effective for the de-crystallization of uric acid crystals in biological media.