Yields of total RNA and genomic DNA of various sample groups.

<p>Yields of total RNA and genomic DNA of various sample groups.</p

Bioorthogonal Functionalization of Material Surfaces with Bioactive Molecules

The functionalization of material surfaces with biologically active molecules is crucial for enabling technologies in life sciences, biotechnology, and medicine. However, achieving biocompatibility and bioorthogonality with current synthetic methods remains a challenge. We report herein a novel surface functionalization method that proceeds chemoselectively and without a free transition metal catalyst. In this method, a coating is first formed via the tyrosinase-catalyzed putative polymerization of a tetrazine-containing catecholamine (DOPA-Tet). One or more types of molecule of interest containing trans-cyclooctene are then grafted onto the coating via tetrazine ligation. The entire process proceeds under physiological conditions and is suitable for grafting bioactive molecules with diverse functions and structural complexities. Utilizing this method, we functionalized material surfaces with enzymes (alkaline phosphatase, glucose oxidase, and horseradish peroxidase), a cyclic peptide (cyclo[Arg-Gly-Asp-D-Phe-Lys], or c(RGDfK)), and an antibiotic (vancomycin). Colorimetric assays confirmed the maintenance of the biocatalytic activities of the grafted enzymes on the surface. We established the mammalian cytocompatibility of the functionalized materials with fibroblasts. Surface functionalization with c(RGDfK) showed improved fibroblast cell morphology and cytoskeletal organization. Microbiological studies with Staphylococcus aureus indicated that surfaces coated using DOPA-Tet inhibit the formation of biofilms. Vancomycin-grafted surfaces additionally display significant inhibition of planktonic S. aureus growth

Stability of candidate housekeeping gene expression <i>in P. yezoensis</i> (from smallest to largest difference) determined by difference between the gametophytes and the conchospores.

<p>Results are calculated as maximum/minimum. Difference (RNA) is determined by transcript number normalized to total RNA quantity and Difference (DNA) is determined by transcript number normalized to genomic DNA quantity.</p

Stability of candidate housekeeping gene expression <i>in P. yezoensis</i> (from smallest to largest difference) determined by difference across all samples.

<p>Results are calculated as maximum/minimum. Difference (RNA) is determined by transcript number normalized to total RNA quantity and Difference (DNA) is determined by transcript number normalized to genomic DNA quantity.</p

The OD 260/280 ratios of extracted nucleic acid.

<p>The OD 260/280 ratios of extracted nucleic acid.</p

Constructing Multilayer Silk Protein/Nanosilver Biofunctionalized Hierarchically Structured 3D Printed Ti6Al4 V Scaffold for Repair of Infective Bone Defects

Biomaterials-enabled regenerative medicine in orthopedics is challenged with infective bone defects that do not heal normally. Three-dimensional (3D) scaffold biomaterials simultaneously emulating skeletal hierarchy and eliciting sustainable osteogenetic and antibacterial functionalities represent a potent solution holding increasing fascination. Here we describe a simple combinatorial strategy for constructing such scaffolds. Fully porous titanium was first tailor-made by metallic powder 3D printing and subjected to in situ hydrothermal growth of a micro/nanostructured titanate layer, to which nanosilver encapsulated, physically cross-linked silk fibrin multilayer films were anchored through polydopamine-assisted, silk-on-silk self-assembly. The hydrophilicity, protein adsorption, and surface bioactivity of the scaffolds were investigated. Employing clinically relevant pathogenic Staphylococcus aureus bacteria, we tested that the silver immobilized scaffolds not only reduced adherence of bacteria on the surface, they also actively killed those planktonic, and these performances were largely maintained over an extended period of 6 weeks. Additionally, our engineered scaffolds were amenable to 14 days’ continuous, intense bacterial attacks showing little sign of biofilm colonization, and they were interestingly capable of eradicating bacteria in already formed biofilms. High cargo loading, durable topical Ag+ release, and overwhelming oxidative stress were shown to contribute to this sustainable antibacterial system. Irrespective of certain degree of cellular stress at early stages, our scaffolds elicited generally enhanced cell proliferation, alkaline phosphatase enzyme production, and matrix calcification of osteoblastic MC3T3-E1. These multifunctionalities, coupled with the design freedom, shape flexibility, and cost-effectiveness offered by 3D printing, make our scaffold biomaterials a promising option for customized restoration of complicated infective bone defects

Transcript numbers of candidate housekeeping genes in <i>P. yezoensis</i> determined by absolute quantitative analysis normalized to total RNA quantity (copies/μg).

<p>Transcript numbers of candidate housekeeping genes in <i>P. yezoensis</i> determined by absolute quantitative analysis normalized to total RNA quantity (copies/μg).</p

The standard curves constructed for <i>18S</i> (A), <i>Act3</i> (B), <i>EF1alpha</i> (C), <i>GAPDH</i> (D), <i>PUB-2</i> (E), <i>RPS8</i> (F), <i>TubB</i> (G).

<p>The results showed that amplification efficiency was between 96% and 103%, and linear correlation coefficient was >0.99.</p

The melting curve analysis for <i>18S</i> (A), <i>Act3</i> (B), <i>EF1alpha</i> (C), <i>GAPDH</i> (D), <i>PUB-2</i> (E), <i>RPS8</i> (F), <i>TubB</i> (G).

<p>Melting peaks were examined with standard samples and unkown samples (sporophytes, gametophytes and conchospores). The melting curve for each gene had only one peak.</p

Stability of candidate housekeeping gene expression <i>in P. yezoensis</i> (from smallest to largest difference) determined by difference between the sporophytes and the gametophytes.

<p>Results are calculated as maximum/minimum. Difference (RNA) is determined by transcript number normalized to total RNA quantity and Difference (DNA) is determined by transcript number normalized to genomic DNA quantity.</p