The recent progress in photonic nanomaterials has contributed greatly to the development of photomedicines. However, the finite depth of light penetration is still a serious limitation, constraining their clinical applications. Here, we developed a poly(allylamine) (PAAm)-modified upconversion nanoparticle/hyaluronate-rose bengal (UCNP/PAAm/HA-RB) conjugate complex for photochemical bonding of deep tissue with near-infrared (NIR) light illumination. Compared to the conventional invasive treatment via suturing and stapling, the UCNP/PAAm/HA-RB conjugate complex could be noninvasively delivered into the deep tissue and accelerate the tissue bonding upon NIR light illumination. HA in the outer layer of the complex facilitated the penetration of RB into the collagen layer of the dermis. The NIR light triggered UCNP of NaYF: Yb/Er (Y:Yb:Er = 78:20:2) in the complex to illuminate visible green light under the skin tissue. The activated RB in the HA-RB conjugate by the green light induced radical formation for the cross-linking of incised collagen matrix. An in vitro light propagation test and collagen fibrillogenesis analysis, an in vivo animal tissue bonding test, and an ex vivo tensile strength test of dissected skin tissues confirmed the successful photochemical tissue bonding effect of the UCNP/PAAm/HA-RB conjugate complex.

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Silk-based biomaterials, which for centuries were primarily used as the raw materials for textile fabrics, are now being used in the medical, food and industrial fields because of their extraordinary properties. Their advantageous characteristics include high strength, extensibility, biocompatibility, biodegradability and minimal production of inflammatory reactions. To date, only silkworm silk has been applied in mass-produced technological applications, but spider silk proteins have been extensively studied because of their superior mechanical stability. Here we report the discovery of a novel silk-like protein (named aneroin) from the sea anemone Nematostella vectensis and the successful fabrication of wet-spun and electrospun silk fibers from purified recombinant aneroins. Aneroin fibers have promising mechanical properties, similar to those of recombinant spider silks with molecular weights of B100 kDa and those of natural mammalian tendon collagen. The results of this study demonstrate that aneroin, a new repertoire of silk-like protein found in sea anemones, has potential for use as a novel fibrous biomaterial. Its use would expand the applications of silk in the development of multifunctional and bio-inspired materials.

The development of intrinsically multicolor‐emitting carbon nanodots (CNDs) has been one of the great challenges for their various fields of applications. Here, the controlled electronic structure engineering of CNDs is performed to emit two distinct colors via the facile surface modification with 4‐octyloxyaniline. The so‐called dual‐color‐emitting CNDs (DC‐CNDs) can be stably encapsulated within poly(styrene‐co‐maleic anhydride) (PSMA). The prepared water‐soluble DC‐CNDs@PSMA can be successfully applied to in vitro and in vivo dual‐color bioimaging and optogenetics. In vivo optical imaging can visualize the biodistribution of intravenously injected DC‐CNDs@PSMA. In addition, the light‐triggered activation of ion channel, channelrhodopsin‐2, for optogenetic applications is demonstrated. As a new type of fluorophore, DC‐CNDs offer a big insight into the design of charge‐transfer complexes for various optical and biomedical applications.

Silk has recently been exploited in various fields due to its superior mechanical properties. However, this material's lack of biological functions and relatively poor biodegradation have hindered its wide use in applications related to cells and tissues. Here, we improved the overall characteristics of silkworm silk fibroin (SF) by introduction of RGD peptide-fused recombinant mussel adhesive protein (MAP-RGD). Simple blending of MAP-RGD provided not only bulk-scale adhesive ability but also microscale adhesiveness to cells and various biomolecules. MAP-RGD-blended SF fibers supported enhanced adhesion, proliferation, and spreading of mammalian cells as well as the efficient attachment of biomolecules, including carbohydrate and protein. In addition, the hydrophilicity, swelling, and biodegradability of the MAP-RGD-blended SF material were improved without notable hampering of the original mechanical properties of SF. Therefore, the adhesive silk fibrous scaffold could be successfully used in diverse biomedical engineering applications.