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Light-responsive liposomes have been developed for the on-demand release of drugs. However, efficient delivery of chemotherapeutic drugs to tumor for cancer theranostics remains a challenge. Herein, folic acid (FA), an established ligand for targeted drug delivery, was used to decorate light-sensitive porphyrin-phospholipid (PoP) liposomes, which were assessed for FA-targeted chemophototherapy (CPT). PoP liposomes and FA-conjugated PoP liposomes were loaded with Doxorubicin (Dox), and physical properties were characterized. In vitro, FA-PoP liposomes that were incubated with FA receptor-overexpressing human KB cancer cells showed increased uptake compared to non-targeted PoP liposomes. Dox and PoP contributed towards chemophototherapy (CPT) in vitro, and PoP and FA-PoP liposomes induced cell killing. In vivo, mice bearing subcutaneous KB tumors treated with PoP or FA-PoP liposomes loaded with Dox, followed by 665 nm laser treatment, had delayed tumor growth and improved survival. Dox delivery to tumors increased following laser irradiation for both PoP and FA-PoP liposomes. Thus, while Dox-FA-PoP liposomes were effective following systemic administration and local light irradiation in this tumor model, the FA targeting moiety did not appear essential for anti-tumor responses. [ABSTRACT FROM AUTHOR]

The structure of the host lattice has a substantial influence on the optical properties of lanthanide-doped luminescent materials. Hexagonal-phase (β-phase) NaREF4 (RE = rare earth) is the most commonly used crystal structure for lanthanide-doped upconversion nanoparticles (UCNPs) owing to its high upconversion (UC) efficiency. In this work, we report, for the first time, that more efficient cooperative sensitization upconversion (CSU) can be achieved in cubic-phase (α-phase) NaREF4 UCNPs instead of their β-phase counterparts. With the passivation of an inert shell, the UC emission intensity of α-NaYbF4:Tb40%@CaF2 is 10.5 times higher than that of β-NaYbF4:Tb40%@NaYF4. We propose that the high-symmetry crystal structure of the α phase facilitates the formations of [Yb–Yb] dimers and [Yb–Yb–Tb] clusters, which are particularly beneficial for CSU. Moreover, we prove that such Tb3+-based UCNPs are almost impervious to water quenching because of the large energy gap (∼15,000 cm−1) that existed in Tb3+ between its lowest emit-ting level (5D4) and next low-lying level (7F0). Finally, their potential application for single-nanoparticle imaging has also been demonstrated. As expected, the α-core-shell UCNPs measured at the single-nanoparticle level are estimated to be 9-fold brighter than their β-core-shell counterparts. Importantly, the α-NaYbF4:Tb40%@CaF2 UCNPs offer exciting opportunities for realizing single-nanoparticle imaging at ultralow irradiance (30 W/cm2). [ABSTRACT FROM AUTHOR]

We report a one‐step strategy to synthesize, in situ, highly water‐dispersible NaYF4 : Yb/Er upconversion nanoparticles (UCNPs) by employing dicarboxylic acids. The dicarboxylic acids serve as a type of dual‐purpose surface ligand for both controlling the growth and enabling the water dispersibility of the NaYF4 : Yb/Er UCNPs. It is found that the carbon chain length of the dicarboxylic acids has a marked effect on the size and morphology of the UCNPs. Among the dicarboxylic acids studied, adipic acid shows a superior performance. The UCNPs functionalized with adipic acid exhibit comparatively uniform size and morphology, as well as excellent water dispersibility. Our results also demonstrate their minimal toxicity and great potential for bioimaging applications. Two sides of the same coin: Dicarboxylic acid is used as a dual‐purpose surface ligand for the synthesis of high‐quality water‐dispersible upconversion nanoparticles. The adipic acid functionalized upconversion nanoparticles can be used for bioimaging applications directly without further surface modification. [ABSTRACT FROM AUTHOR]

The abundance and potential functional roles of intrinsically disordered regions in aquaporin-4, Kir4.1, a dystrophin isoforms Dp71, α-1 syntrophin, and α-dystrobrevin; i.e., proteins constituting the functional core of the astrocytic dystrophin-associated protein complex (DAPC), are analyzed by a wealth of computational tools. The correlation between protein intrinsic disorder, single nucleotide polymorphisms (SNPs) and protein function is also studied together with the peculiarities of structural and functional conservation of these proteins. Our study revealed that the DAPC members are typical hybrid proteins that contain both ordered and intrinsically disordered regions. Both ordered and disordered regions are important for the stabilization of this complex. Many disordered binding regions of these five proteins are highly conserved among vertebrates. Conserved eukaryotic linear motifs and molecular recognition features found in the disordered regions of five protein constituting DAPC likely enhance protein-protein interactions that are required for the cellular functions of this complex. Curiously, the disorder-based binding regions are rarely affected by SNPs suggesting that these regions are crucial for the biological functions of their corresponding proteins. [ABSTRACT FROM AUTHOR]