NIR-triggered upconversion nanoparticles@thermo-sensitive liposome hybrid theranostic nanoplatform for controlled drug delivery.

Posterior segment ocular diseases are highly prevalent worldwide due to the lack of suitable noninvasive diagnostic and therapeutic tactics. Herein, concerning this predicament, we designed a hybrid retina-targeted photothermal theranostic nanoplatform (UCNPs@Bi@SiO2@GE HP-lips), based on the unique upconversion luminescence (UCL) imaging of upconversion nanoparticles (UCNPs), efficient photothermal conversion ability of Bi nanoparticles, and thermal-induced phase transition properties of the liposomes (lips). The nanoplatform was functionalized with penetratin (PNT) and hyaluronic acid (HA), to obtain retina-targeted liposomes (HP-lips). Lipophilic genistein (GE) was entrapped into the liposomes (GE HP-lips). An in vitro release study showed NIR irradiation could photothermally trigger controlled release of GE from the liposomal platform. Moreover, cellular uptake evaluation via UCL imaging demonstrated UCNPs@Bi@SiO2@GE HP-lips represented the brightest UCL, compared with other formulations, which is beneficial for the accurate evaluation of the prognosis and severity of angiogenesis-related posterior segment disorders. Therefore, UCNPs@Bi@SiO2@GE HP-lips exhibit promising potential as a theranostic nanoplatform for posterior segment ocular diseases.

A DREB1 gene from zoysiagrass enhances Arabidopsis tolerance to temperature stresses without growth inhibition.

The DREB (dehydration-responsive element binding) protein family comprises transcription factors that can increase the survivability of a plant under abiotic stresses by regulating expression of multiple genes and altering downstream metabolism at the cost of growth retardation and developmental delay. In this study, a gene for the DREB1-type transcription factor, designated ZjDREB1.4, was isolated from zoysiagrass (Zoysia japonica Steud.), a popular warm-season turfgrass. This gene contains a conserved AP2/ERF DNA-binding domain flanking the signature sequence of DREB1 and belongs to a DREB1 branch in the grass family that expands in the warm-season species. The expression of ZjDREB1.4 was significantly induced by chilling stress (4-15 °C), moderately induced by salt stress, and only slightly induced by drought stress. The product of ZjDREB1.4 was targeted to the nucleus and showed strong transactivation activity but weak binding to the DRE with ACCGAC as the core sequence. The ZjDREB1.4 protein bound to GCCGAC more preferentially than to ACCGAC. Overexpression of ZjDREB1.4 in Arabidopsis induced the expression of multiple genes including a part of the CBF-regulon, and moderately increased the levels of proline and soluble sugars under normal growth conditions. The transgenic Arabidopsis plants showed an increase in tolerance to high and freezing temperature stresses without obvious growth inhibition and with only a few days delay in bolting. ZjDREB1.4 is potentially useful for producing transgenic plants that are tolerant to high temperature and/or cold stresses with few negative effects.