Engineering Bacillus licheniformis for the production of meso-2,3-butanediol

Additional file 1: Figure S1. Multiple sequence alignments of GDH from B. licheniformis WX-02 (WX-02 GDH) with GDHs from other strains

Direct Laser Writing of Graphene Made from Chemical Vapor Deposition for Flexible, Integratable Micro-Supercapacitors with Ultrahigh Power Output

High‐performance yet flexible micro‐supercapacitors (MSCs) hold great promise as miniaturized power sources for increasing demand of integrated electronic devices. Herein, this study demonstrates a scalable fabrication of multilayered graphene‐based MSCs (MG‐MSCs), by direct laser writing (DLW) of stacked graphene films made from industry‐scale chemical vapor deposition (CVD). Combining the dry transfer of multilayered CVD graphene films, DLW allows a highly efficient fabrication of large‐areal MSCs with exceptional flexibility, diverse planar geometry, and capability of customer‐designed integration. The MG‐MSCs exhibit simultaneously ultrahigh energy density of 23 mWh cm−3 and power density of 1860 W cm−3 in an ionogel electrolyte. Notably, such MG‐MSCs demonstrate an outstanding flexible alternating current line‐filtering performance in poly(vinyl alcohol) (PVA)/H2SO4 hydrogel electrolyte, indicated by a phase angle of −76.2° at 120 Hz and a resistance–capacitance constant of 0.54 ms, due to the efficient ion transport coupled with the excellent electric conductance of the planar MG microelectrodes. MG–polyaniline (MG‐PANI) hybrid MSCs fabricated by DLW of MG‐PANI hybrid films show an optimized capacitance of 3.8 mF cm−2 in PVA/H2SO4 hydrogel electrolyte; an integrated device comprising MG‐MSCs line filtering, MG‐PANI MSCs, and pressure/gas sensors is demonstrated

Screening and Stability Evaluation of Angiotensin Converting Enzyme Inhibitory Peptides from Bangia fusco-purpurea

In this study, peptide fractions (F1-F4) with different molecular masses were obtained from Bangia fusco-purpurea through enzymatic hydrolysis and ultrafiltration. F2, with molecular masses of 800–2 000 Da, exhibited the highest in vitro angiotensin-converting enzyme (ACE) inhibitory activity as determined by high performance liquid chromatography (HPLC). The amino acid sequence of F2 was identified through liquid chromatography-tandem mass spectrometry (LC-MS/MS) and de novo sequencing using PEAKS Studio software. Six ACE inhibitory peptides that stably bind to ACE were selected through molecular docking. The predicted peptides were synthesized by solid-phase synthesis and their in vitro ACE inhibitory activity was verified. Among them, L1 (LVLLFLFGE) showed the highest ACE inhibitory activity with a half maximal inhibitory concentration (IC50) value of 14.22 μg/mL. Molecular docking results indicated that the inhibition of ACE by L1 was mainly attributed to its ability to form hydrogen bond interactions with the active site of ACE. Finally, the effects of temperature, pH, metal ions, light exposure, and simulated gastrointestinal digestion on the stability of L1 were investigated. The results revealed that L1 was highly stable to heat and ionic strength. However, its activity gradually decreased at pH > 2, and was affected by ultraviolet treatment. The ACE inhibitory activity of L1 decreased after simulated gastric and intestinal digestion, but was still significant

A review on current research status of the surface modification of Zn-based biodegradable metals

Recently, zinc and its alloys have been proposed as promising candidates for biodegradable metals (BMs), owning to their preferable corrosion behavior and acceptable biocompatibility in cardiovascular, bone and gastrointestinal environments, together with Mg-based and Fe-based BMs. However, there is the desire for surface treatment for Zn-based BMs to better control their biodegradation behavior. Firstly, the implantation of some Zn-based BMs in cardiovascular environment exhibited intimal activation with mild inflammation. Secondly, for orthopedic applications, the biodegradation rates of Zn-based BMs are relatively slow, resulting in a long-term retention after fulfilling their mission. Meanwhile, excessive Zn2+ release during degradation will cause in vitro cytotoxicity and in vivo delayed osseointegration. In this review, we firstly summarized the current surface modification methods of Zn-based alloys for the industrial applications. Then we comprehensively summarized the recent progress of biomedical bulk Zn-based BMs as well as the corresponding surface modification strategies. Last but not least, the future perspectives towards the design of surface bio-functionalized coatings on Zn-based BMs for orthopedic and cardiovascular applications were also briefly proposed

Eco-friendly bacteria-killing by nanorods through mechano-puncture with top selectivity

Nanorods can induce mechano-puncture of Staphylococcus aureus (S. aureus) that often impairs osseointegration of orthopedic implants, while the critical nanorod top sharpness able to puncture S. aureus and the predominant contributor between top sharpness and length to mechano-puncture activity remains elusive. Herein, we fabricated three kinds of Al2O3-wrapped nanorods patterned arrays with different lengths and top sharpness. The top-sharp nanorods have lengths of 469 and 884 nm and the shorter show a length identical to the top-flat nanorods. Driven by the equivalent adhesive force of S. aureus, the top-flat nanorods deform cell envelops, showing a bacteriostatic rate of 29% owing to proliferation-inhibited manner. The top-sharp nanorods puncture S. aureus, showing a bactericidal rate of 96% for the longer, and 98% for the shorter that simultaneously exhibits fair osseointegration in bacteria-infected rat tibias, identifying top sharpness as a predominate contributor to mechano-puncture activity. Based on finite-element simulation, such top-flat nanorod derives the maximum stress (Smax) of 5.65 MPa on cell wall, lower than its ultimate-tensile-strength (13 MPa); while such top-sharp and shorter nanorod derives Smax of 20.15 MPa to puncture cell envelop. Moreover, a critical top conical angle of 138° is identified for nanorods able to puncture S. aureus

The modulation of stem cell behaviors by functionalized nanoceramic coatings on Ti-based implants

Nanoceramic coating on the surface of Ti-based metallic implants is a clinical potential option in orthopedic surgery. Stem cells have been found to have osteogenic capabilities. It is necessary to study the influences of functionalized nanoceramic coatings on the differentiation and proliferation of stem cells in vitro or in vivo. In this paper, we summarized the recent advance on the modulation of stem cells behaviors through controlling the properties of nanoceramic coatings, including surface chemistry, surface roughness and microporosity. In addition, mechanotransduction pathways have also been discussed to reveal the interaction mechanisms between the stem cells and ceramic coatings on Ti-based metals. In the final part, the osteoinduction and osteoconduction of ceramic coating have been also presented when it was used as carrier of BMPs in new bone formation

Controlled release and biocompatibility of polymer/titania nanotube array system on titanium implants

Bacterial infection and tissue inflammation are the major causes of early failure of titanium-based orthopedic implants; thus, surgical implants with tunable drug releasing properties represent an appealing way to address some of these problems of bacterial infection and tissue inflammation in early age of orthopedic implants. In this work, a hybrid surface system composed of biodegradable poly(lactic-co-glycolic acid) (PLGA) and titania nanotubes (TNTs) has been successfully constructed on Ti implants with the aim of preventing bacterial infection via long-term drug release. By varying the size of the TNTs and the thickness of the polymer film, the drug release profile can be tuned to achieve the optimal therapeutic action throughout the treatment time. The size of TNTs plays a dominant role in the drug loading dose of TNTs/PLGA hybrid coatings. In this work, TNTs with an average size of 80 nm can achieve the largest loading dose. Depending on the polymer thickness, significant improvement in the drug release characteristics is attained, for instance, reduced burst release (from 84% to 27%) and overall release time extended from 5 to over 40 days. In addition, the PLGA layers may favor the proliferation and osteogenesis of MC3T3-E1 mouse cells at an earlier stage. Therefore, this TNT/PLGA hybrid surface system can be employed as an effective bioplatform for improving both self-antibacterial performance and biocompatibility of Ti-based biomaterials

Differential gene expression in pepper (<i style="">Capsicum annuum</i>) exposed to UV-B

429-437In the present paper, complementary DNA-amplified fragment length polymorphism (cDNA-AFLP) was used to examine and identify differentially expressed genes in Capsicum annuum exposed to UV-B irradiation. Around 4000 transcript derived fragments (TDFs) were visualized and in total 183 TDFs were isolated, sequenced and analyzed by Blast 2 go. Among these TDFs, 84 of them showed homology to known genes. There were 43 TDFs showing up-regulated expression, 24 TDFs showing down-regulated expression and 27 TDFs showing both up-regulated and down-regulated expression, respectively. Some of these TDFs were found to be in response/related to UV-B stress, including carbonic anhydrase, calcium-dependent protein, thionin-like protein, bzip protein and so on. In particular, chlorophyll a/b binding protein (Capcab) responding to UV-B stress was cloned. It was concluded that Capcab could play a protective role in plant anti-UV-B and maintaining photosynthetic rate under UV-B stress