Following a brief introduction to the principle of fluorescent PET (photoinduced electron transfer) sensors and switches, the outputs of laboratories in various countries from the past year or two are categorized and critically discussed. Emphasis is placed on the molecular design and the experimental outcomes in terms of target-induced fluorescence enhancements and input/output wavelengths. The handling of single targets takes up a major fraction of the review, but the extension to multiple targets is also illustrated. Conceptually new channels of investigation are opened up by the latter approach, e.g.'lab-on-a-molecule' systems and molecular keypad locks. The growing trends of theoretically-fortified design and intracellular application are pointed out.

Constructs of fluorophores, receptors, spacers, 1O2 sensitizers, enzymes and oligonucleotides play their part in advancing the field of molecular logic-based computation.

Easy cancer recurrence and wound infections have been clinical challenges after surgical treatment of melanoma. Herein, a silk‐inspired in situ gelation system containing methacrylated silk fibroin (SF) and chlorine e6 for improved cancer therapy with enhanced wound healing is developed. Favored by the macrophage recruitment capacity of the SF hydrogel, promising antitumor immune responses can be turned “on” via near infrared irradiation in a controllable manner to achieve combination therapy with photodynamic therapy to significantly suppress melanoma recurrence. Moreover, the effective photodynamic antibacterial activity of this bioactive system with the capacity of light‐controllable modulating macrophage phenotype promotes remarkable tissue ingrowth with hair follicle regeneration for Staphylococcus aureus infected wound healing. Thus, this multifunctional silk‐based hydrogel system, as a desirable wound dressing, provides a new platform for promising melanoma therapy and skin regeneration.

Genetically engineered bacteria and reactive DNA networks detect edges of objects, as done in our retinas and as also found within computer vision. We now demonstrate that simple molecular logic systems (a combination of a pH sensor, a photo acid generator, and a pH buffer spread on paper) without any organization can achieve this relatively complex computational goal with good fidelity. This causes a jump in the complexity achievable by molecular logic-based computation and extends its applicability. The molecular species involved in light dose-driven "off−on−off" fluorescence is diverted in the "on" state by proton diffusion from irradiated to unirradiated regions where it escapes a strong quencher, thus visualizing the edge of a mask.

By combination of alginate/polyacrylamide/chitosan, tough antibacterial hydrogels are designed for applications as tissues adhesives to promote wound healing.

A lack of effective bioactivity to create a desirable microenvironment for peripheral nerve regeneration has been challenging in successful treatment of long-distance injuries using nerve guidance conduits (NGCs) clinically. Herein, we developed a silk-inspired phototriggered gelation system combining dual therapeutic cues of anisotropic topography and adhesive ligands for improving peripheral nerve regeneration. Importantly, enhanced cell recruitment and myelination of Schwann cells were successfully achieved by the Arg-Gly-Asp (RGD)-peptide-immobilized hydrogel scaffolds to promote axon growth. Moreover, as the orientated growth of Schwann cells and rapid axon growth were facilitated by aligned grooved micropatterns, this multifunctional bioactive system provides remarkable nerve regeneration with function recovery for long-distance nerve injury. Therefore, this bioengineered silk-inspired nerve guidance conduit delivers a platform for desirable peripheral nerve repair.

Like a child with a crayon, logical molecules produce outline drawings from a template.

A population of polymer beads carrying different molecular computational identification (MCID) logic tags are unambiguously assigned following a statistical evaluation.