The PD-1:PD-L1 axis in Inflammatory Arthritis

The activation of antigen specific T cells during an immune response is a tightly regulated process at the level of both costimulatory and coinhibitory receptors. One such coinhibitory receptor or checkpoint inhibitor which has received much attention in the field of oncology is the programmed cell death protein 1 (PD-1). Blockade of PD-1 or its ligand PD-L1 has proven successful in the treatment of a wide variety of cancers, therefore highlighting an important role for this pathway in anti-tumour immune responses. However, a caveat of PD-1 therapy and boosting anti-tumour immune responses is the development of self-reactive T cells which can lead to the induction of various autoimmune or inflammatory diseases, referred to as immune- related adverse events (irAEs). The emergence of rheumatological irAEs such as Inflammatory Arthritis (IA) in recent years has highlighted the importance of PD-1 in maintaining self-tolerance. Furthermore, the emergence of rheumatology related irAEs raises an important question as to how defects in this pathway can contribute to spontaneous rheumatological disease. In this review, we describe the biological distribution, function and regulation of the PD-1 pathway, its potential role in IA and irAE related IA.

Advances in Aptamer Screening and Drug Delivery

Chemotherapy is the most commonly used treatment for cancer. However, due to their short circulation time and lack of specific biological distribution, chemotherapeutic drugs cause severe systemic toxicity. Using the agents specifically binding to the targeted molecules might resolve this dilemma. Aptamers can directly connect with the drugs or couple with the nano-carrier to reduce systemic toxicity. In this review, we elucidated the definition, characteristics and screening process of aptamers. The methods of drug delivery by aptamers were illustrated in details. Furthermore, clinical application of aptamers in recent years was briefly summarized and its long-term prospects were put forward.

The biological fate of gadolinium-based MRI contrast agents: a call to action for bioinorganic chemists

Gadolinium retention in tissues: description of our state of knowledge, and physical methods to investigate the biological distribution and chemical speciation of retained gadolinium.

Radioiodination, diagnostic nuclear imaging and bioevaluation of olmesartan as a tracer for cardiac imaging

The present work has been oriented to prepare radioiodinated olmesartan for a potential cardiac imaging. Olmesartan has been labeled using 125I or 131I with N-bromosuccinimide (NBS) as an oxidizing agent. Many factors like amount of N-bromosuccinimide, amount of substrate, pH, reaction temperature and reaction time, have been systematically studied to optimize high yield of [125I]iodoolmesartan. The biological distribution indicates the suitability of [125I]iodoolmesartan as a novel tracer to image heart.