Tadpole-Like Carbon Nanotube with Fe Nanoparticle Encapsulated at the Head and Zn Single-Atom Anchored on the Body: One-Pot Carbonization for Tetramodal Synergistic Cancer Therapy.

Precise integration of diverse therapeutic approaches into nanomaterials is the key to the development of multimodal synergistic cancer therapy. In this work, tadpole-like carbon nanotubes with Fe nanoparticle encapsulated at the head and Zn single-atom anchored on the body (Fe@CNT-Zn) is precisely designed and facilely prepared via one-pot carbonization. In vitro studies revealed the integration of chemotherapy (CT), chemodynamic therapy (CDT), photothermal therapy (PTT), and photodynamic therapy (PDT) in Fe@CNT-Zn as well as the near-infrared light (NIR)-responsive cascade therapeutic efficacy. Furthermore, in vivo studies demonstrated the NIR-triggered cascade-amplifying synergistic cancer therapy in a B16 tumor-bearing mouse model. The results not only showcased the Fe@CNT-Zn as a potential tetramodal therapeutic platform, but also demonstrated a proof-of-concept on metal-organic framework-based "one stone for multiple birds" strategy for in situ functionalization of carbon materials.

Photoactive Self-Shaping Hydrogels as Noncontact 3D Macro/Microscopic Photoprinting Platforms.

A photocleavable terpolymer hydrogel cross-linked with o-nitrobenzyl derivative cross-linker is shown to be capable of self-shaping without losing its physical integrity and robustness due to spontaneous asymmetric swelling of network caused by UV-light-induced gradient cleavage of chemical cross-linkages. The continuum model and finite element method are used to elucidate the curling mechanism underlying. Remarkably, based on the self-changing principle, the photosensitive hydrogels can be developed as photoprinting soft and wet platforms onto which specific 3D characters and images are faithfully duplicated in macro/microscale without contact by UV light irradiation under the cover of customized photomasks. Importantly, a quick response (QR) code is accurately printed on the photoactive hydrogel for the first time. Scanning QR code with a smartphone can quickly connect to a web page. This photoactive hydrogel is promising to be a new printing or recording material.

Nano-silver in situ hybridized collagen scaffolds for regeneration of infected full-thickness burn skin.

Nano hybrid materials have attracted extensive attention in the biomedical field. However, it is still a challenge to make biofunctional nanoparticles homogenously distributed in 3D scaffolds. In this research, histidine (His) was covalently cross-linked into collagen (Coll) scaffolds and the imidazole derived from His was employed as a template to chelate silver ions which were then reduced in situ to form silver nanoparticle (Ag NP)-hybridized Coll scaffolds. The resultant nanocomposite demonstrated an increased mechanical strength and the Ag NPs showed a narrow size distribution and were dispersed homogeneously in the 3D Coll/His scaffolds. Moreover, these hybrid scaffolds exhibited better biocompatibility and antibacterial properties against both Gram positive and Gram negative bacteria than Coll scaffolds. The Coll/His/Ag NPs scaffolds were transplanted to the infected full-thickness burn skin of the SD rat model; the results revealed excellent regeneration effects after three weeks compared with the groups not treated with Ag NPs. This study has offered a facile method to construct functional nanoparticle hybridized scaffolds for efficiently healing infected wounds.

An anti-inflammatory cell-free collagen/resveratrol scaffold for repairing osteochondral defects in rabbits.

Inflammatory factor overexpression is the major cause of cartilage and osteochondral damage. Resveratrol (Res) is known for its anti-inflammatory, antioxidant and immunmodulatory properties. However, these effects are hampered by its water insolubility and rapid metabolism in vivo. To optimize its therapeutic efficacy in this study, Res was grafted to polyacrylic acid (PAA, 1000Da) to obtain a macromolecular drug, PAA-Res, which was then incorporated into atelocollagen (Coll) hydrogels to fabricate anti-inflammatory cell-free (Coll/Res) scaffolds with improved mechanical strengths. The Coll/Res scaffolds demonstrated the ability to capture diphenylpicrylhydrazyl free radicals. Both pure Coll and Coll/Res scaffolds could maintain their original shape for 6weeks in phosphate buffered saline. The scaffolds were degraded by collagenase over several days, and the degradation rate was slowed down by Res loading. The Coll and Coll/Res scaffolds with excellent cytocompatibility were shown to promote the proliferation and maintain the normal phenotype of the seeded chondrocytes and bone marrow stromal stem cells (BMSCs). In addition, the Coll/Res scaffold exhibited the capacity to protect the chondrocytes and BMSCs against reactive oxygen species. The acellular Coll/Res scaffolds were transplanted into the rabbit osteochondral defects. After implantation for 2, 4 and 6weeks, the samples were retrieved for quantitative real-time polymerase chain reaction, and the inflammatory related genes interleukin-1ß, matrix metalloproteinases-13, COX-2 and bone and cartilage related genes SOX-9, aggrecan, Coll II and Coll I were determined. Compared with the untreated defects, the inflammatory related genes were down-regulated and those bone and cartilage related genes were up-regulated by filling the defect with an anti-inflammatory scaffold. After 12weeks, the osteochondral defects were completely repaired by the Coll/Res scaffold, and the neo-cartilage integrated well with its surrounding tissue and subchondral bone. Immunohistochemical and glycosaminoglycan staining confirmed the distribution of Coll II and glycosaminoglycans in the regenerated cartilage. The anti-inflammatory acellular Coll/Res scaffolds are convenient to administer in vivo, holding a greater potential for future clinical applications.