Since the advent of digital coding metamaterials, a new paradigm is unfolded to sample, compute and program electromagnetic waves in real time with one physical configuration. However, one inconvenient truth is that actively tunable building blocks such as diodes, varactors, and biased lines must be individually controlled by a computer‐assisted field programmable gate array and physically connected by electrical wires to the power suppliers. This issue becomes more formidable when more elements are needed for more advanced and multitasked metadevices and metasystems. Here, a remote‐mode metasurface is proposed and realized that is addressed and tuned by illuminating light. By tuning the intensity of light‐emitting diode light, a digital coding metasurface composed of such light‐addressable elements enables dynamically reconfigurable radiation beams in a control‐circuitry‐free way. Experimental demonstration is validated at microwave frequencies. The proposed dynamical remote‐tuning metasurface paves a way for constructing unprecedented digital metasurfaces in a noncontact remote fashion.

Polyelectrolyte gels comprising fixed ions exhibit swelling behaviors because of external solution conditions. Such behaviors are usually explained by using the Flory–Rehner model that considers the Donnan equilibrium. However, this model assumes a homogeneous distribution for fixed ions; therefore, its applicability to the case of heterogeneous distributions remains unclear. Here, we successfully designed a hydrogel with alternating neutral/highly charged sequences (i.e., tetrapoly­(acrylic acid)–poly­(ethylene glycol) gel). The Flory–Rehner model with the Donnan equilibrium was found to predict the swelling ratio only below pH 5.6. The distance between two neighboring fixed ions is larger than the Bjerrum length. The swelling behaviors above pH 5.6, where the fixed ions are more closely located than the Bjerrum length, can be explained by considering additionally the counterion condensation in the poly­(acrylic acid) units. These results indicate that the ionic interactions within the length scale of the network strand can determine the counterion condensation and that it is vital to estimate accurately the distance between neighboring fixed ions for predicting the swelling behaviors of polyelectrolyte gels.

Photon correlation spectroscopy and pulsed-field-gradient nuclear magnetic resonance have been utilized in order to investigate the characteristic features of the recently established (both experimentally and theoretically) diffusive "polydispersity" relaxation process for concentration fluctuations in homogeneous diblock copolymer melts and solutions. This is accomplished using semidilute solutions of a symmetric mixture of two diblock copolymers with similar molecular weights and almost mirror compositions in a common good solvent. Mixing of the two asymmetric diblocks leads to a system with almost symmetric composition and with narrow molecular weight distribution, but with large effective composition polydispersity. Above the order to disorder transition (ODT), the theoretical expressions for the amplitude and the relaxation rate of the polydispersity mode can quantitatively describe the observed diffusive relaxation. Similarly to the situation in homopolymer blends, the thermodynamic forces can significantly retard the diffusion coefficient and lead to an increase in the dynamic intensity with increasing copolymer concentration. The intervention of the ODT alters this concentration dependence at copolymer concentrations #J near but below #JODT.

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Specifically targeting glioblastoma multiforme (GBM) blood vessels and actively enhancing the permeability of the brain-blood-tumor barrier (BBTB) are two extremely difficult challenges currently hindering the development of effective therapies against GBM. Herein, a liposome drug delivery system (S1P/JS-K/Lipo) is described, which delivers the nitric oxide (NO) prodrug JS-K, O 2 -(2,4-dinitrophenyl) 1-[(4-ethoxycarbonyl) piperazin-1-yl] diazen-1-ium-1,2-diolate, to GBM tumors using sphingosine-1-phosphate (S1P)-signaling molecules as active targeting lipid ligands. It is revealed that S1P/JS-K/ Lipo actively penetrates the BBTB, aided by caveolin-1-mediated transcytosis, and it is demonstrated that the system specifically interacts with S1P receptors (S1PRs), which are highly expressed on GBM cells. Nondestructive ultrasound imaging in GBM mouse models is also utilized to observe microsized NO bubble production from JS-K, as catalyzed by the glutathione S-transferases (GSTs) resident in GBM cells. Given that these NO bubbles strongly promote GBM cell death in vivo, the S1PR-targeted liposome delivery system-which successfully achieves BBTB penetration and tumor targeted delivery of a complex multicomponent drug regimen-represents a promising approach for targeted therapies against GBM and other carcinomas characterized by elevated S1PR expression.