Calcium binding peptide motifs from calmodulin confer divalent ion selectivity to elastin-like polypeptides.

Calcium-sensitive elastin-like polypeptides (CELPs) were synthesized by periodically interspersing a calcium-binding peptide sequence from calmodulin within an elastin-like polypeptide (ELP) with the goal of creating thermal and calcium responsive peptide polymers. The CELPs exhibit high sensitivity to calcium compared to monovalent cations but do not exhibit the exquisite selectivity for calcium over other divalent cations, such as magnesium, that is displayed by calmodulin. The CELPs were further used as a building block for the synthesis of calcium-sensitive nanoparticles by fusing a hydrophilic, noncalcium-sensitive ELP block with a CELP block that becomes more hydrophobic upon calcium binding. We show that addition of calcium at concentrations between 50 and 500 mM imparts sufficient amphiphilicity to the diblock polypeptide between 33 and 46 °C to trigger its self-assembly into monodisperse spherical micelles with a hydrodynamic radius of ∼50 nm.

Long-term outcomes after management of restenosis or thrombosis of drug-eluting stents.

OBJECTIVES: The purpose of this study was to examine the outcomes of patients who developed coronary in-stent restenosis (ISR) or stent thrombosis (STH) inside drug-eluting stents (DES). BACKGROUND: Drug-eluting stents have markedly reduced the incidence of restenosis. However, when restenosis occurs within a DES, its optimal management remains unclear. METHODS: We retrospectively analyzed clinical and angiographic data from 92 patients who underwent revascularization for ISR (n = 84) or STH (n = 8) within a DES at our institution. Regular follow-ups were available up to 2 years. We recorded the occurrence of major adverse cardiac events (MACE), defined as deaths from all causes, myocardial infarction (MI), or target lesion revascularization (TLR), among patients treated by the "DES sandwich" technique or by other treatment methods. RESULTS: In-hospital MACE included 1 periprocedural MI and 2 deaths. Over a mean follow-up of 15 +/- 6 months, the overall rates of death, MI, and TLR were 8.7%, 2.2%, and 30.6%, respectively. By actuarial analysis, the 12-month TLR and MACE rates were 28.2% and 42.9%, respectively. CONCLUSIONS: Current treatments of ISR or STH in DES are associated with a high long-term rate of MACE.