Strong antibacterial polydopamine (PDA) coatings prepared by a facile shaking-assisted method is reported for the first time. It was found that a minor modification made to the conventional synthesis procedure of PDA coatings, viz. replacing the static solution condition with a shaking solution condition by using a mechanical shaker, can produce the roughened polydopamine (rPDA) coatings at different substrates, e.g., glass, stainless steel, plastic, and gauze. The resulting rPDA coatings were characterized with Raman spectrum, zeta-potential analysis and contact angle measurement. The antibacterial activity of the rPDA coatings was evaluated by a shake flask test with gram-positive Staphylococcus aureus, and gram-negative Escherichia coli and Pseudomonas aeruginosa as bacteria models. Testing results revealed that, in the absence of any other antibacterial agents, the rPDA coatings exhibited remarkably enhanced antibacterial activities. In addition, such enhanced antibacterial activities of the rPDA coatings were found to be unimpaired by steam sterilization treatments.

regenerated much attention to the search for phases that do not exist in the parent bulk materials. [1] Structures such as vortex pairs, super-tetragonal phase, and polar skyrmions have been experimentally reported. [2][3][4][5][6][7][8] In essence, the formation of ferroelectric domain structures strongly relies on the balance between electrostatic and elastic energies which is sensitively affected by film thickness, substrate mismatch strain, depolarization field, cooling rate, etc. [9][10][11][12][13] Previous works have both experimentally and theoretically studied the size and strain effects in ferroelectric thin films; however, continuously manipulating the strain or tuning the dimensionality without the influence of strain is rarely achieved due to the substrate clamping. [14][15][16][17][18][19] In order to stabilize and manipulate domain structures in ferroelectrics which usually depend on precise control of strain and thickness, as well as to understand the intrinsic evolution of ferroelectricity and domain structures, it is essential to investigate freestanding films that are free of substrate constraints and allow in situ and continuous strain engineering.In principle, several ways are feasible to prepare freestanding films, including the mechanical polishing to micrometer scales, [20][21][22] etching rigid substrates, [23] and "grow-transfer" multi-step methods (first growing films on rigid substrates, and then transferring to other substrates). [24][25][26][27] These techniques are highly selective or difficult to generalize to a wide range of perovskite oxides. Recently, Lu et al. [28] reported a new way to synthesize high-quality freestanding perovskite oxides using water-soluble Sr 3 Al 2 O 6 (SAO) as a sacrificial buffer layer, allowing the synthesis of high-crystalline-quality freestanding films, [29,30] even down to the monolayer limit. [31] Herein, we synthesize freestanding PbTiO 3 (PTO) films with thicknesses from 60 to 4 unit cells (u.c.), showing single-crystalline c-axis oriented domain. The tetragonality and ferroelectricity are suppressed with the decreasing of film thickness, and at the same time, by applying uniaxial tensile strain up to 6.4% along a-axis, we flip the long axis (c-axis) into [100] direction and observe the switchable behavior of these a domains. Our work demonstrates that giant uniaxial strain can be achieved continuously in the freestanding films, paving the way for the usage of high electromechanical conversion efficiency actuators, such as Dimensionality and epitaxial strain have been recently utilized to engineer the interplay between the electrostatic and elastic energies to stabilize exotic ferroelectric domain structures and topological textures in epitaxial heterostructures and superlattices. As the strain state is fixed to the substrate lattice, the strain tunability is discrete and limited, which puts a hard constraint on the exploration and engineering of emergent ferroelectric properties in these thin films and heterostructures. Here, by using water-solub...

Lavandula angustifolia is the most widely cultivated Lavandula species. The extraction of its flower and leaves has been used as herbal medicine. In this study, the in vitro antitumor activities were tested on human prostate cancer PC-3 and DU145 cell lines. Flow cytometry technology was applied to study apoptosis induction and cell cycle arrest. The PC-3 cell line was used to establish subcutaneous xenograft tumors in nude mice. Paraffin sections from xenograft tumor specimens were used in the TUNEL (terminal deocynucleotide transferase dUTP nick end labeling) assay and an immunohistochemistry assay to detect cell proliferation markers Ki67 and PCNA. Lavender essential oil, linalool, and linalyl acetate showed stronger inhibitory effect on PC-3 cells than on DU145 cells. The apoptotic cell populations observed in PC-3 cells treated with lavender essential oil, linalool, and linalyl acetate were 74.76%, 67.11%, and 56.14%, respectively. The PC-3 cells were mainly arrested in the G2/M phase. In the xenograft model with PC-3 cell transplantation, essential oil and linalool significantly suppressed tumor growth. The immunosignals of Ki67 and PCNA in the essential oil, linalool, and linalyl acetate treatment groups were significantly lower than that of the control group in xenograft tumor sections. The TUNEL assay indicated that each of the 3 phytochemicals significantly induced apoptosis compared to the control group. This study provides novel insight and evidence on the antiproliferative effect of L angustifolia essential oil and its major constituents on human prostate cancer. The antitumor effect was associated with cell proliferation inhibition and apoptosis induction in xenograft tumors.

Background: α-Pinene is one of the most widely found terpenoids in nature. Substantial evidence shows that α-pinene has cancer prevention properties. In this study, the PC-3 cell line was used to establish subcutaneous xenograft tumors in nude mice. Methods: Cytotoxicity was measured with the MTT assay, and apoptosis and cell cycle analyses were conducted using flow cytometry in vitro. The PC-3 cell line was used to establish subcutaneous xenograft tumors in nude mice. Results: We found that treatment with α-pinene significantly inhibited human prostate cancer cell growth and induced apoptosis and cell cycle arrest in the cell line-based model. Furthermore, tumor progression was inhibited more in mice treated with α-pinene than in control mice. We detected less Ki67 and proliferation cell nuclear antigen in paraffin sections from xenograft tumor specimens taken from α-pinene-treated mice than in those from the control group. Meanwhile, α-pinene treatment induced apoptosis in xenograft tumors as determined by the TUNEL assay. Conclusions: These data strongly suggest that α-pinene inhibits prostate cancer growth in a xenograft model and may be an effective therapeutic agent for prostate cancer treatment.