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Photoactive transition‐metal complexes are luminophores combining high photostability and long luminescence lifetimes. However, reduced optical performance in aqueous solutions has limited their use in biological systems. Herein, the physicochemical and photophysical properties and bioimaging compatibility of Re diimine complexes and near‐infrared (NIR) emitting Cy5 dyes coencapsulated in polymer nanoparticles (NPs) are investigated. By varying the polymers, NPs with sizes from 20 to 70 nm and encapsulating ≤ 40 wt.% of Re complexes, i.e., ≈11 000 Re complexes per NP, are obtained. The photoluminescence (PL) quantum yields of the Re complexes increase eightfold to ≈50% upon encapsulation (vs 6–7% in acetonitrile), resulting in PL brightness up to 108 m−1 cm−1 and PL lifetimes of 3–4 µs. Coencapsulation of Cy5 yields very bright NIR emission upon Re complex excitation. Very close Re‐to‐Cy5 donor–acceptor distances down to ≤2 nm and FRET efficiencies over 90% are confirmed by PL lifetime measurements. The Re‐Cy5 NPs enter mammalian cells for high‐contrast PL imaging in both visible and NIR. This detailed characterization provides a better understanding of the photophysical properties of the transition‐metal‐dye FRET NPs and presents a vital step toward the efficient design of a new class of bright luminescent NP probes. [ABSTRACT FROM AUTHOR]

Reduced scattering and autofluorescence in the second near‐infrared window (NIR‐II, 1000–1700 nm) hold the promise of high‐resolution photoluminescence (PL) in vivo imaging at depths well beyond the µm scale. Yet, contrast agents with bright emission in this spectral region remain limited. Ultrasmall gold nanoclusters (AuNCs) are of particular interest for NIR‐II PL imaging. However, they exhibit limited brightness. Here, high amounts of NIR‐II emitting AuNCs are encapsulated in small polymer nanoparticles (NPs) made of poly(ethyl methacrylates). Using nanoprecipitation, loadings of up to 50 wt% can be reached, corresponding to over 10 000 AuNCs per 60 nm NP. PL quantum yields up to 1.3% and NP brightnesses up to 3.8 × 106 M−1 cm−1 are accomplished. Increasing inter‐AuNC interactions at higher loading result in a bathochromic shift of the PL emission. According to time‐resolved PL measurements, this can be attributed to distinct inter‐AuNC energy transfer pathways between the core and surface‐centered PL modes. Evaluation of the nanohybrids in tissue‐mimicking models for in vivo blood vessel imaging shows that the ultrabright and red‐shifted NIR‐II PL results in significantly improved detection sensitivity and resolution, which makes AuNC‐loaded polymer NPs highly promising candidates for advanced in vivo imaging. [ABSTRACT FROM AUTHOR]

The performance of fluorescence immunostaining is physically limited by the brightness of organic dyes, whereas fluorescence labeling with multiple dyes per antibody can lead to dye self‐quenching. The present work reports a methodology of antibody labeling by biotinylated zwitterionic dye‐loaded polymeric nanoparticles (NPs). A rationally designed hydrophobic polymer, poly(ethyl methacrylate) bearing charged, zwitterionic and biotin groups (PEMA‐ZI‐biotin), enables preparation of small (14 nm) and bright fluorescent biotinylated NPs loaded with large quantities of cationic rhodamine dye with bulky hydrophobic counterion (fluorinated tetraphenylborate). The biotin exposure at the particle surface is confirmed by Förster resonance energy transfer with dye‐streptavidin conjugate. Single‐particle microscopy validates specific binding to biotinylated surfaces, with particle brightness 21‐fold higher than quantum dot‐585 (QD‐585) at 550 nm excitation. The nanoimmunostaining method, which couples biotinylated antibody (cetuximab) with bright biotinylated zwitterionic NPs through streptavidin, significantly improves fluorescence imaging of target epidermal growth factor receptors (EGFR) on the cell surface compared to a dye‐based labeling. Importantly, cetuximab labeled with PEMA‐ZI‐biotin NPs can differentiate cells with distinct expression levels of EGFR cancer marker. The developed nanoprobes can greatly amplify the signal from labeled antibodies, and thus become a useful tool in the high‐sensitivity detection of disease biomarkers. [ABSTRACT FROM AUTHOR]

Background: Dual-mobility (DM) cups were introduced to minimize the risk of THA dislocation. The overall rate of dislocation of DM cups (including both large and small articulations) is controversial and ranges from 0% to 5% in previous studies. Questions/purposes: We therefore recorded (1) the dislocation rate, (2) loosening and osteolysis, and (3) subsequent related revisions with DM cups. Methods: Between 1998 and 2003, 2480 primary THAs with DM cups were undertaken in 2179 patients. The mean age was 69 years (range, 19–94 years). This group underwent specific clinical and radiographic evaluation at a minimum followup of 0.17 years (mean, 7 years; range, 0.17–11 years) to assess dislocation, reoperation, osteolysis, and cup fixation. Results: There were 22 dislocations (0.88%): 15 dislocations of large articulations (0.6%), with two (0.08%) recurring but only one requiring revision (0.04%), and seven intraprosthetic small articulation dislocations (0.28%), all needing revision surgery. At last followup, mean Harris hip score was 91 (range, 60–100); 2439 cups (98%) showed no signs of loosening; and 141 patients (145 hips) had osteolysis (6%). Osteolysis and cup loosening were more frequent in patients younger than 50 years at the time of surgery. The 10-year survivorship considering revision for any reason was 93% (95% CI, 91%–95%). Conclusions: DM cups had a low dislocation rate in primary THA, with a limited frequency of adverse effects. We recommend DM cups to minimize dislocation in populations at high risk for instability, but they should be avoided in younger, active patients at higher risk for osteolysis. Level of Evidence: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background:: Recent studies have recommended the discontinuation of metal-on-metal (MoM) components in total hip arthroplasty (THA) because of adverse effects reported with large-diameter MoM THA. This is despite favorable long-term results observed with 28 and 32 mm MoM bearings. Questions/purposes:: The aim of this study was to assess the value of calls for an end to MoM bearings as THA components. Specifically, we wish to address the risks associated with MoM bearings including adverse soft tissue reactions, metal ion release, and carcinogenic risk. Methods:: The study evaluates the arguments in the literature reporting on MoM (adverse soft tissue reactions, metal ion release, and carcinogenic risk) and the experience of the current authors who re-introduced these bearings in 1995. They are balanced by a benefit-risk review of the literature and the authors' experience with MoM use. Results:: Adverse reactions to metallic debris as well as metal ion release are predictable and can be prevented by adequate design (arc of coverage, clearance), metallurgy (forged instead of cast alloy, high-carbide content), and appropriate component orientation. There is no scientific evidence that carcinogenicity is increased in subjects with MoM hip prostheses. MoM articulations appear to be attractive allowing safe hip resurfacing, decreasing the risk of THA revision in active patients, and providing secure THA fixation with cement in cages in severely deformed hips. MoM bearings in women of child-bearing age are controversial, but long-term data on metallic devices in adolescents undergoing spinal surgery seem reassuring. Discussion:: Adequate selection of MoM articulations ensures their safe use. These articulations are sensitive to orientation. Fifteen years of safe experience with 28- and 32-mm bearings of forged alloy and high-carbide content is the main reason for retaining them in primary and revision THA. [ABSTRACT FROM AUTHOR]

Background: Dual mobility (DM) cups of mobile polyethylene were introduced to prevent total hip arthroplasty (THA) dislocation, but no large series with this design to treat recurrent instability have been reported. Purpose: Our retrospective investigation ascertained the efficiency of DM cups in correction of recurrent dislocation and assessed any adverse effects. Methods: One hundred eighty THAs with recurrent instability were revised to DM cups in 180 patients (mean age, 67.4 ± 11.7 years; range, 19 to 92 years). Thirty-one patients (17.2%) underwent at least one earlier THA revision, and 15 (10.3%) incurred non-union of the greater trochanter. Of the initial group in 2009, 145 patients had completed evaluations which included assessment of the Harris Hip Score and a radiographic assessment at a mean follow-up of 7.7 ± 2.2 years (range, 4 to 14 years). The rate of survival was calculated considering any reason for revision as failure. Results: At follow-up, Harris hip score was 83.9 ± 16.1 (range, 21 to 100). Dislocation of the large articulation occurred in seven hips (4.8%), and only two recurred (1.4%) (one requiring additional revision). In addition, two intra-prosthetic dislocations of the small articulation (1.4%) were observed and needed revision surgery. The large number of earlier surgeries and non-union of the greater trochanter were related to recurrent instability. Two cups (1.4%) showed signs of definite loosening; six (4.1%) presented signs of possible loosening. Twenty-nine hips manifested femoral or acetabular osteolysis (20%), but only three were severe. Eight-year survival rate considering revision for any reason was 92.6% (95% CI, 85.5-96.4%). Conclusions: This series indicates that DM cups are a viable option to treat recurrent THA instability. Their design provides a low risk of recurrent instability without increasing mechanical complications. [ABSTRACT FROM AUTHOR]