Flexible and stretchable electronics, e.g., graphite-nanoplatelet-based (GNP-based) nanocomposite devices, have attracted great interest due to their potential application in health care, robotics, and mechatronics technology. However, the deficient sensors with manipulation of low sensitivity, sluggish responsivity, sophisticated fabrication process, and poor repeatability notoriously limit their industrial applications. For an enhancement in the spontaneous sensitivity, flexibility, and wearability in GNP-based strain sensors, in this report, synergistic crack and elastic effect engineering is employed and in turn significantly enhances the sensitivity with a gauge factor of 20 at a strain of 30% and the stability in our developed sheath–core fiber (SCF) strain sensors. Upon reliable device integration, it is demonstrated that the developed SCF strain sensor could detect the movement of a human joint effectively with generating a resistance change rate ΔR/R 0 up to 600%. Furthermore, a controlling device system based on the SCF strain sensor has been manufactured at the circuit level to realize the real-time control of a robot hand, such as copying gestures and playing piano.

Damage to the skin causes physiological and functional issues. The most effective treatment approach is the use of wound dressings. Silk fibroin (SF) is a promising candidate biomaterial for regulating wound healing; however, its antibacterial properties and biological activity must be further improved. In this study, a photocrosslinking hydrogel was developed to treat full-thickness cutaneous wounds. The composite hydrogel (Ag-AV-SF-hydrogel) was prepared by introducing the silver nanoparticles (AgNPs) and aloe vera (AV) as the modifiers. In vitro study, it exhibited great antibacterial ability, biocompatibility, and cell-proliferation and -migration-promoting capacities. It also showed the pH-response releasing properties which release more AgNPs in a simulated chronic infection environment. The healing effect evaluation in vivo showed the healing-promoting ability of the Ag-AV-SF-hydrogel was stronger than the single-modifiers groups, and the healing rate of the it reached 97.02% on day 21, higher than the commercial wound dressing, silver sulfadiazine cream (SS) on sale. Additionally, the histological and protein expression results showed that the Ag-AV-SF-hydrogel has a greater effect on the pro-healing regenerative phenotype with M2 macrophages at the early stage, reconstructing the blood vessels networks and inhibiting the formation of scars. In summary, the Ag-AV-SF-hydrogel developed in this study had good physical properties, overwhelming antibacterial properties, satisfactory biocompatibility and significantly promoting effect on cell proliferation, migration and wound healing. Overall, our results suggest that the Ag-AV-SF-hydrogel we developed has great potential for improving the wound healing in clinical treatment.

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P19 enhanced baculovirus production and transgene expression, and thus has potential applications in baculovirus-based gene therapy and vaccine studies.

Background: Canine parvovirus (CPV) is now recognized as a serious threat to the dog breeding industry worldwide. Currently used CPV vaccines all have their specific drawbacks, prompting a search for alternative safe and effective vaccination strategies such as subunit vaccine. VP2 protein is the major antigen targeted for developing CPV subunit vaccine, however, its production in baculovirus expression system remains challenging due to the insufficient yield. Therefore, our study aims to increase the VP2 protein production by using an improved baculovirus expression system and to evaluate the immunogenicity of the purified VP2 protein in mice. Results: The results showed that high-level expression of the full length VP2 protein was achieved using our modified baculovirus expression system. The recombinant virus carrying two copies of VP2 gene showed the highest expression level, with a productivity of 186 mg/L, which is about 1.4-1.6 fold that of the recombinant viruses carrying only one copy. The purified protein reacted with Mouse anti-His tag monoclonal antibody and Rabbit anti-VP2 polyclonal antibody. BALB/c mice were intramuscularly immunized with purified VP2 protein twice at 2 week intervals. After vaccination, VP2 protein could induce the mice produce high level of hemagglutination inhibition antibodies. Conclusions: Full length CPV VP2 protein was expressed at high level and purified efficiently. Moreover, it stimulated mice to produce high level of antibodies with hemmaglutination inhibition properties. The VP2 protein expressed in this study could be used as a putative economic and efficient subunit vaccine against CPV infection.