Phosphate-Trapping Liposomes for Long-Term Management of Hyperphosphatemia

Abstract

Hyperphosphatemia is a typical complication of end-stage renal disease, characterized by elevated and life-threatening serum phosphate levels. Hemodialysis does not enable sufficient clearance of phosphate, due to slow cell-to-plasma kinetics of phosphate ions; moreover, dietary restrictions and conventional treatment with oral phosphate binders have low success rates, together with adverse effects. Here, we developed a new concept of phosphate-trapping liposomes, to improve and prolong the control over serum phosphate levels. We designed liposomes modified with polyethylene glycol and encapsulated with the phosphate binder ferric citrate (FC liposomes). These liposomes were found to trap phosphate ions in their inner core, and thereby lower free phosphate ion concentrations in solution and in serum. The FC liposomes showed higher phosphate binding ability as phosphate concentrations increased. Moreover, these liposomes showed a time-dependent increase in uptake of phosphate, up to 25 h in serum. Thus, our findings demonstrate effective long-term phosphate trapping by FC liposomes, indicating their potential to reduce serum phosphate toxicity and improve current management of hyperphosphatemia.

Biomedical Nanosystems for <i>in vivo</i> Detoxification: From Passive Delivery Systems to Functional Nanodevices and Nanorobots

“…Polyethylene glycol-modified liposomes encapsulated with phosphate-binding iron (III) citrate trap the circulating phosphate ions into the inner liposomal core. These traps reduce the concentration of free phosphate ions in solution and in serum [ 83 ] ( Table 1 ).…”

“…Липосомы, модифицированные полиэтиленгликолем с инкапсулированным фосфатсвязывающим цитратом железа (III), представляли собой ловушки для ионов фосфата в кровотоке во внутреннем липосомальном ядре и снижали концентрацию свободных ионов фосфата в растворе и в сыворотке [83] (табл. 1).…”