The delivery of personalised, precision medicines via synthetic proteins

Introduction: The design of advanced drug delivery systems based on synthetic and su-pramolecular chemistry has been very successful. Liposomal doxorubicin (Caelyx®), and liposomal daunorubicin (DaunoXome®), estradiol topical emulsion (EstrasorbTM) as well as soluble or erodible polymer systems such as pegaspargase (Oncaspar®) or goserelin acetate (Zoladex®) represent considerable achievements. The Problem: As deliverables have evolved from low molecular weight drugs to biologics (currently representing approximately 30% of the market), so too have the demands made of advanced drug delivery technology. In parallel, the field of membrane trafficking (and endocytosis) has also matured. The trafficking of specific receptors i.e. material to be recycled or destroyed, as well as the trafficking of protein toxins has been well characterized. This, in conjunction with an ability to engineer synthetic, recombinant proteins provides several possibilities. The Solution: The first is using recombinant proteins as drugs i.e. denileukin diftitox (Ontak®) or agalsidase beta (Fabrazyme®). The second is the opportunity to use protein toxin architecture to reach targets that are not normally accessible. This may be achieved by grafting regulatory domains from multiple species to form synthetic proteins, engineered to do multiple jobs. Examples include access to the nucleocytosolic compartment. Herein the use of synthetic proteins for drug delivery has been reviewed

Simultaneous occurrence of multiple aetiologies of polycythaemia: renal cell carcinoma, sleep apnoea syndrome, and relative polycythaemia in a smoker with masked polycythaemia rubra vera

A 58 year old male heavy smoker presented with intracranial haemorrhage and erythrocytosis. Four aetiologies of polycythaemia—polycythaemia rubra vera (PRV), renal cell carcinoma, sleep apnoea syndrome, and relative polycythaemia—were found to be associated with the underlying causes of erythrocytosis. He did not fulfill the diagnostic criteria for PRV at initial presentation, but an erythropoietin independent erythroid progenitor assay identified the masked PRV, and the low post-phlebotomy erythropoietin concentration also suggested the likelihood of PRV evolution. This case demonstrates that a search for all the possible causes of erythrocytosis is warranted in patients who already have one aetiology of polycythaemia. Key Words: erythrocytosis • polycythaemia rubra vera • renal cell carcinoma • sleep apnoea syndrome • relative polycythaemia • endogenous erythroid colon