The coronavirus disease 2019 (COVID-19) has become a substantial threat to the international health sector and the global economy. As of 26 December 2021, the number of mortalities resulting from COVID-19 exceeded 5.3 million worldwide. The absence of an effective non-vaccine treatment has prompted the quest for prophylactic agents that can be used to combat COVID-19. This study presents the feasibility of chicken egg yolk antibody (IgY) anti-receptor-binding domain (RBD) spike SARS-CoV-2 as a strong candidate to neutralize the virus for application in passive immunization. For the purpose of preclinical studies, we radiolabeled IgY anti-RBD spike SARS-CoV-2 with radionuclide iodine-131. This allowed us to evaluate several biological characteristics of IgY in vitro, in vivo, and ex vivo. The preclinical data suggest that IgY anti-RBD spike SARS-CoV-2 could specifically bind to the SARS-CoV-2 antigens; however, little uptake was observed in normal cells (MRC-5) (<2%). Furthermore, the ex vivo biodistribution study revealed that IgY predominantly accumulated in the trachea of normal mice compared to other organs. We also found that IgY possessed a good safety profile when used as an intranasal agent. Taken together, we propose that IgY anti-RBD spike SARS-CoV-2 has the potential for application in passive immunization against COVID-19.

Objective: Periodontal dressing is a protective material that is used on post-surgical periodontal to protect the surface of the wound and provides a comfort sense to patient. This study was conducted to determine the effect of periodontal dressings containing silver nanoparticles by evaluating inflammatory parameters using ^99mTc-ciprofloxacin; a radiopharmaceutical that can be used for diagnosing infection and inflammation. Methods: This research was carried out using purely experimental 24 male Sprague Dawley rats and divided into 4 groups. First group is a group without any treatment, second group was the positive control group (excision procedure and given CoePak(R)), third group was negative group (only excision procedure) and fourth group (excision procedure and given CoePak (R) with silver nanoparticles). On second and fourth days after the procedure, each group was observed of inflammation inside of the excision by injecting ^99mTc-ciprofloxacin through vein and after one hour the rat was sacrificed and dextra palate organ of each rat was counted by Single Channel Analyzer to determine the accumulation of ^99mTc-ciprofloxacin. Results: In rats given CoePak (R) with silver nanoparticles showed a tendency or inclination data which is good in giving effect to promote healing compare to positive control group on day 4 with less accumulation of 99mTc-ciprofloxacin in dextra palate. Conclusion: Addition of silver nanoparticles in periodontal dressing gave a good effect for wound tissue healing. Key words: Periodontal dressing, Silver nanoparticles, Wound tissue healing, ^99mTc-ciprofloxacin.

The high rate of incidence and mortality caused by breast cancer encourage urgent research to immediately develop new diagnostic and therapeutic agents for breast cancer. Alpha mangostin (AM) is a natural compound reported to have anti-breast cancer properties. Its electron-donating groups structure allows it to be labeled with an iodine-131 radioisotope to develop a candidate of a diagnostic and therapeutic agent for breast cancer. This study aims to prepare the [^131I]Iodine-α-mangostin ([¹³¹I]I-AM) and evaluate its stability, lipophilicity, and cellular uptake in breast cancer cell lines. The [¹³¹I]I-AM was prepared by direct radiosynthesis with Chloramine-T method in two conditions (A: AM dissolved in NaOH, B: AM dissolved in ethanol). Reaction time, pH, and mass of the oxidizing agent were optimized as crucial parameters that affected the radiosynthesis reaction. Further analysis was conducted using the radiosynthesis conditions with the highest radiochemical purity (RCP). Stability tests were carried out at three storage conditions, including −20, 2, and 25 °C. A cellular uptake study was performed in T47D (breast cancer cell line) and Vero cells (noncancerous cell line) at various incubation times. The results show that the RCP values of [¹³¹I]I-AM under conditions A and B were 90.63 ± 0.44 and 95.17 ± 0.80% (n = 3), respectively. In the stability test, [¹³¹I]I-AM has an RCP above 90% after three days of storage at −20 °C. A significant difference was obtained between [¹³¹I]I-AM uptake in T47D and Vero cells. Based on these results, [¹³¹I]I-AM has been prepared with high RCP, stable at −20 °C, and specifically uptaken by breast cancer cell lines. Biodistribution evaluations in animals are recommended as further research in developing [¹³¹I]I-AM as a diagnostic and therapeutic agent for breast cancer.