Background:
Rheumatoid arthritis (RA) is an inflammatory chronic disease characterized by inflammation,
pain, swelling and disability and radiosynovectomy is one of the disease treatment lines. In this study, the possibility of
providing rhenium-186/rhenium-188 chitosan radiopharmaceuticals, optimization of conditions for their production and
bio-distribution.
Objective:
In order to build perrhenic acid for labeling, natural rhenium was exposed to radiation.
Radionuclidic and radiochemical purities of (186/188Re)-NaReO4 were examined by gamma spectroscopy and paper
chromatography methods, respectively.
Methods:
Labeling of chitosan with rhenium was done in different acidic
situations. The radiochemical purity 186/188Re-chitosan was applied by radio thin layer chromatography (RTLC). Lastly,
the bio-distribution of the radiolabeled chitosan was studied in various organs after intra articular injection of the complex
to lab rats. Gamma spectrometry confirmed the high rhenium radionuclidic purity. Chromatography results showed that
perrhenic acid was produced with purity greater than 97% and rhenium chitosan labeling was done over 98% in pH = 3.
Dissection results showed high bio-distribution of 186/188Re-chitosan after injection into the joint with no leakage to
surrounding organs.
Conclusion:
According to the results, there is a possibility of labeling rhenium with chitosan in very
high radiochemical purity. Regarding the high retention of these radiopharmaceuticals in joints with no leakage to
surrounding organs, 186/188Re-chitosan can be applied as new radiosynovectomy drugs for rheumatoid arthritis treatment.