Multicenter study of intravitreal dexamethasone implant in noninfectious uveitis: indications, outcomes, and reinjection frequency.

PURPOSE: To identify clinical outcomes and treatment patterns of intravitreal dexamethasone implant (Ozurdex; Allergan, Inc) in noninfectious uveitis in the clinical setting. DESIGN: Multicenter retrospective cohort study. METHODS: Eighty-two eyes (63 patients) receiving 142 implant injections over 35 months were included. Treatment indication, uveitis diagnosis, visual acuity, intraocular pressure, vitreous haze score, central retinal thickness by optical coherence tomography, phakic status, number of injections, time to reinjection, systemic treatments, and complications data were collected. Time to visual acuity and vitreous haze score improvement as per the Standardization of Uveitis Nomenclature guidelines were also determined. RESULTS: The probability of visual acuity improvement (≥0.3 logarithm of the minimal angle of resolution units improvement) was 39% at 1 month, 49% at 3 months, 52% at 6 months, and 58% at 12 months. Eyes with baseline vitritis (vitreous haze score ≥+0.5, n = 45) had a probability of vitreous haze score improvement (2-step decrease or change from +0.5 to 0) at 2 weeks of 41%, at 1 month 63%, at 3 months 73%, at 6 months 79%, and at 12 months 88%. In eyes that completed 12-month follow-up (n = 54), 40.7% underwent 2 injections (mean time to second injection of 6.6 ± 1.9 months) and 11.2% required ≥3 injections (mean time to third injection of 11 ± 1.5 months). CONCLUSIONS: Dexamethasone implant use in uveitis provides favorable visual acuity and vitreous haze score outcomes but requires repeated injections, an important consideration when choosing intraocular treatment as a route to controlling uveitis.

Inhibition of ice crystal growth by synthetic glycopolymers: implications for the rational design of antifreeze glycoprotein mimics.

A series of structurally diverse polymers, containing either peptide or vinyl-derived backbones, was tested for ice recrystallization inhibition activity, which is commonly associated with antifreeze (glyco)proteins. It was revealed that only polymers bearing hydroxyl groups in the side chain could inhibit ice growth. Furthermore, well-defined glycopolymers were shown to have a small but significant recrystallization inhibition effect, showing that it may be possible to design antifreeze glycoprotein mimics based upon polymers derived from vinyl monomers.

Synthesis of well-defined glycopolymers and some studies of their aqueous solution behaviour.

Well-defined polymers with carbohydrate residues pendant to the main chain (glycopolymers) were prepared by reversible addition fragmentation chain transfer (RAFT) polymerisation. Excellent control over molecular weight and narrow polydispersities (1.1-1.2) were achieved over a range of molecular weights. In addition, efficient synthesis of block copolymers by sequential monomer addition with both hydrophilic and hydrophobic non-carbohydrate blocks was demonstrated. The aqueous solution behaviour of amphiphilic block glycopolymers was investigated, revealing the formation of multivalent carbohydrate-bearing aggregates in solution with the capability for the solubilisation of hydrophobic species (a water-insoluble dye). One such amphiphilic glycopolymer shows by TEM the formation of a worm-like micelle phase. Further investigations of these novel bioactive macromolecular assemblies are underway.

Porphyrin, phthalocyanine and porphyrazine derivatives with multifluorenyl substituents as efficient deep-red emitters.

The synthesis and photophysical properties are described for a series of porphyrin, phthalocyanine and pyrazinoporphyrazine derivatives which bear four or eight peripheral fluorenyl substituents as antennae. Representative examples are 5,10,15,20-tetra(9,9-dihexyl-9H-fluoren-2-yl)porphyrin (2), 5,10,15,20-tetrakis[4-(9,9-dihexyl-9H-fluoren-2-yl)phenyl]porphyrin (3), 2,3,9,10,16,17,23,24-octakis(9,9-dihexyl-9H-fluoren-2-yl)-29H,31H-phthalocyanine (8) and 2,3,9,10,16,17,23,24-octakis[4-(9,9-dihexyl-9H-fluoren-2-yl)phenyl]-29H,31H-tetrapyrazinoporphyrazine (9). Palladium-mediated Suzuki-Miyaura cross-coupling reactions have been key steps for attaching the substituents. The compounds are deep-red emitters: lambda(max)(em)=659 (3), 737 (8) and 684 nm (9). Their absorption and emission spectra, their fluorescence lifetimes and quantum yields are correlated with the structures of the macrocycles and the substituents. The solution fluorescence quantum yields of porphyrin derivatives substituted with fluorene (2-4) and terphenyl substituents (7) (Phi(f)=0.21-0.23) are approximately twice that of tetraphenylporphyrin. For phthalocyanine derivative 8, Phi(f) was very high (0.88). Specific excitation of the fluorene units of 8 produced emission from both of them (lambda(max)=480 nm) and also from the phthalocyanine core (lambda(max)=750 nm), indicating a competitive rate of energy transfer and radiative decay of the fluorenes. Organic light-emitting devices (OLEDs) were made by spin-coating techniques by using a polyspirobifluorene (PSBF) copolymer as the host blended with 3 (5 wt. %) in the configuration ITO/PEDOT:PSS/PSBF copolymer:3/Ca/Al. Deep-red emission (lambda(max)=663 nm; CIE coordinates x=0.70, y=0.27) was observed with an external quantum efficiency of 2.5 % (photons/electron) (at 7.5 mA cm(-2)), a low turn-on voltage and high emission intensity (luminance) of 5500 cd m(-2) (at 250 mA/ m(2)).