Collagen biomaterials promote the regenerative repair of abdominal wall defects in Bama miniature pigs.

Due to adhesion and rejection of recent traditional materials, it is still challenging to promote the regenerative repair of abdominal wall defects caused by different hernias or severe trauma. However, biomaterials with a high biocompatibility and low immunogenicity have exhibited great potential in the regeneration of abdominal muscle tissue. Previously, we have designed a biological collagen scaffold material combined with growth factor, which enables a fusion protein-collagen binding domain (CBD)-basic fibroblast growth factor (bFGF) to bind and release specifically. Though experiments in rodent animals have indicated the regeneration function of CBD-bFGF modified biological collagen scaffolds, its translational properties in large animals or humans are still in need of solid evidence. In this study, the abdominal wall defect model of Bama miniature pigs was established by artificial operations, and the defective abdominal wall was sealed with or without a polypropylene patch, and unmodified and CBD-bFGF modified biological collagen scaffolds. Results showed that a recurrent abdominal hernia was observed in the defect control group (without the use of mesh). Although the polypropylene patch can repair the abdominal wall defect, it also induced serious adhesion and inflammation. Meanwhile, both kinds of collagen biomaterials exhibited positive effects in repairing abdominal wall defects and reducing regional adhesion and inflammation. However, CBD-bFGF-modified collagen biomaterials failed to induce the regenerative repair reported in rat experiments. In addition, unmodified collagen biomaterials induced abdominal wall muscle regeneration rather than fibrotic repair. These results indicated that the unmodified collagen biomaterials are a better option among translational patches for the treatment of abdominal wall defects.

Seadragon genome analysis provides insights into its phenotype and sex determination locus.

The iconic phenotype of seadragons includes leaf-like appendages, a toothless tubular mouth, and male pregnancy involving incubation of fertilized eggs on an open "brood patch." We de novo-sequenced male and female genomes of the common seadragon (Phyllopteryx taeniolatus) and its closely related species, the alligator pipefish (Syngnathoides biaculeatus). Transcription profiles from an evolutionary novelty, the leaf-like appendages, show that a set of genes typically involved in fin development have been co-opted as well as an enrichment of transcripts for potential tissue repair and immune defense genes. The zebrafish mutants for scpp5, which is lost in all syngnathids, were found to lack or have deformed pharyngeal teeth, supporting the hypothesis that the loss of scpp5 has contributed to the loss of teeth in syngnathids. A putative sex-determining locus encoding a male-specific amhr2y gene shared by common seadragon and alligator pipefish was identified.

A bioorthogonal nanosystem for imaging and in vivo tumor inhibition.

Bioorthogonal bond-cleavage reactions have emerged as promising tools for manipulating biological processes, still the therapeutic effect of these reactions in vivo needs to be explored. Herein a bioorthogonal-activated prodrug has been developed for bioimaging and therapy, which is composed of a Pd-mediated cleavable propargyl, a coumarin fluorophore and a potent anticancer drug. In vitro investigations show that, the presence of a Pd complex induces the cleavage of propargyl and subsequently trigger the cascade of reactions, thereby activating the coumarin fluorophore for imaging and releasing the anticancer drug for therapy. Both the prodrug and Pd complex were then separately encapsulated into phospholipid liposomes to form a two-component bioorthogonal nanosystem. The lyposomal nanosystem can be readily internalized by HeLa cells and displays strong intracellular fluorescence under one- or two-photon excitation, indicating the release of the active drug in cells as a result of the Pd-mediated bioorthogonal bond-cleavage reaction. More importantly, the nanosystem shows considerable high activity and exerts efficient inhibition towards tumor growth in a mouse model. This work demonstrates that, if properly formulated, a bioorthogonal system can perform well in vivo. This strategy may offer a new approach for designing bioorthogonal prodrugs with imaging and therapeutic capability.