ABSTRACT
Rapidly growing interest in using nanoparticles (NPs) for biomedical applications has increased concerns about their safety and toxicity. In comparison with bulk materials, NPs are more chemically active and toxic due to the greater surface area and small size. Understanding the NPs' mechanism of toxicity, together with the factors influencing their behavior in biological environments, can help researchers to design NPs with reduced side effects and improved performance. After overviewing the classification and properties of NPs, this review article discusses their biomedical applications in molecular imaging and cell therapy, gene transfer, tissue engineering, targeted drug delivery, Anti-SARS-CoV-2 vaccines, cancer treatment, wound healing, and anti-bacterial applications. There are different mechanisms of toxicity of NPs, and their toxicity and behaviors depend on various factors, which are elaborated on in this article. More specifically, the mechanism of toxicity and their interactions with living components are discussed by considering the impact of different physiochemical parameters such as size, shape, structure, agglomeration state, surface charge, wettability, dose, and substance type. The toxicity of polymeric, silica-based, carbon-based, and metallic-based NPs (including plasmonic alloy NPs) have been considered separately.
ABSTRACT
BACKGROUND: With the ongoing coronavirus disease (COVID-19) pandemic, along with the development of new mutations of the virus and an increase in the number of cases among pediatrics, physicians should be aware and alerted on the atypical presentations of the disease, especially in less expected individuals. CASE PRESENTATION: Here we present a 12-year-old obese boy (BMI = 37.5 kg/m2) who presented with empyema, which was following SARS-CoV-2 infection. The patient had no history of fever. Due to the onset of dyspnea, a chest tube was inserted for him which was later altered to a pleural drainage needle catheter. CONCLUSION: Our case is the first report of COVID-19 presenting as empyema among pediatrics. Pleural empyema should be considered as a rare complication of COVID-19. Since there is still no guideline in the management of empyema in the context of COVID-19, delay in diagnosis and intervention may cause morbidity and mortality in children.