A sustainable packaging composite of waste paper and poly(butylene succinate-co-lactate) with high biodegradability.

The challenge of global climate change has drawn people's attention to the issue of carbon emissions. Reducing the use of petroleum-derived materials and increasing the use of biodegradable materials is a current focus of research, especially in the packaging materials industry. This study focused on the use of environmentally friendly plastics and waste paper as the main materials for packaging films. Poly(butylene succinate-co-lactate) (PBSL) was modified with maleic anhydride (MA) to form a biobased compatibilizer (MPBSL), which was then blended with a mixture (WPS) of waste-paper powder (WP) and silica aerogel powder (SP) to form the designed composite (MPBSL/WPS). The modification of PBSL with MA improved interfacial adhesion between PBSL and WPS. The structure, thermal, and mechanical properties, water vapor/oxygen barrier, toxicity, freshness, and biodegradability of MPBSL/WPS films were evaluated. Compared with the PBSL/WP film, the MPBSL/WPS film exhibited increased tensile strength at break of 4-13.5 MPa, increased initial decomposition loss at 5 wt% of 14-35 °C, and decreased water/oxygen permeabilities of 18-105 cm3/m2·d·Pa. In the water absorption test, the MPBSL/WPS film displayed about 2-6 % lower water absorption than that of the PBSL/WP film. In the cytocompatibility test, both MPBSL/WPS and PBSL/WP membrane were nontoxic. In addition, compared with PBSL/WP film and the control, the MPBSL/WPS film significantly reduced moisture loss, extended the shelf life, and prevented microbial growth in vegetable and meat preservation tests. Both MPBSL/WPS and PBSL/WP films were biodegradable in a 60-day soil biodegradation test; the degradation rate was 50 % when the WP or WPS content was 40 wt%. Our findings indicate that the composites would be suitable for environmentally sustainable packaging materials.

A new composite fabricated from hydroxyapatite, gelatin-MgO microparticles, and compatibilized poly(butylene succinate) with osteogenic functionality.

In this study, thermally processed recycled fish teeth (FT) and fish scales, magnesium oxide (MgO), and biobased polyesters were fabricated into new bioactive and environmentally friendly composites. The magnesium oxide was encapsulated into laboratory-made fish scale-derived gelatin to form gelatin-MgO microparticles. Hydroxyapatite (HA) and gelatin were obtained by heat-treating FTs and fish scales, respectively. Compatibilized poly(butylene succinate) (CPBS), i.e., poly(butylene succinate) (PBS) to which had been added acrylic acid-grafted PBS (PBS-g-AA) compatibilizer, was combined with HA/gelatin-MgO (GHA) to form CPBS/GHA composites. The structure and tensile properties of the composites were investigated. The CPBS/GHA composites improved the adhesion and proliferation of osteoblast cells. Osteoblast growth, osteoclast growth inhibition, and the antibacterial effect of CPBS/GHA composites were primarily due to the slow release of magnesium ions into the environment from the gelatin-MgO microparticles. Higher levels of calcium and phosphorus species were observed for various PBS/HA and CPBS/GHA composites immersed in simulated body fluid. Mineralization measurements indicated that calcium and phosphate ions precipitated in osteoblasts placed on PBS/HA and CPBS/GHA composites. The study successfully developed a new composite material containing 5 wt% gelatin/MgO (phr), CPBS/HA 10 wt% and 1.0 % gelatin/MgO (an optimum formula of MgO). This composite exhibited superior tensile strength, antibacterial effect, osteoclast growth enhancement, and osteoclast growth reduction. These results suggest that the composites may facilitate the formation of new bone formation in vivo. The CPBS/GHA composites displayed good bone tissue repair ability in engineering applications.

Preparation and Characterization of Polylactic Acid/Bamboo Fiber Composites.

The development of green and renewable materials has attracted increasing attention in recent years. Hence, biocomposite-based packaging materials have been investigated to replace petrochemical materials in several industries, such as the food packaging and electronics packaging industries. The tensile and thermal properties of biocomposite-based packaging materials composed of polylactic acid and plant fiber were mainly investigated in the current literature, but fewer studies on the improvement of water resistance and water vapor/oxygen barrier properties of composite materials were performed. Herein, we describe a composite film comprising TBFP [a mixture of bamboo fiber powder (BFP) and silica aerogel powder] that was combined with modified polylactic acid (MPLA) in a melt-mixing process. The structure, morphology, tensile strength, thermal properties, water absorption properties, water vapor/oxygen barrier effect, cytocompatibility, and biodegradability of the composites were characterized. MPLA and TBFP improved the properties of these composites. Fourier transform infrared and X-ray diffraction spectra have shown interfacial adhesion of MPLA/TBFP, resulting in a tighter structure. Hence, the MPLA/TBFP composite had higher elongation at failure (ε), tensile strength at failure (δ), Young's modulus (E), initial decomposition temperature at 5 wt % loss (T5%), residual yields, oxygen transmission rate, contact angles, lower thermal conductivity (k) values, water vapor transmission rate, and water absorption and biodegradability compared with PLA and PLA/BFP. It indicates that the MPLA/TBFP composites exhibited more favorable tensile strength, water resistance, and water vapor/oxygen barrier than the PLA and PLA/BFP composites. Cell growth analysis showed that the MPLA/TBFP and PLA/BFP composites own good cytocompatibility. Moreover, the biodegradability of the PLA/BFP and MPLA/TBFP composites increased with the filler (BFP or TBFP) concentration. Because of these improvements in their properties, composites can be used as packing materials in many perspectives.

Biodegradable Composite Nanofiber Containing Fish-Scale Extracts.

A biodegradable composite nanofiber containing polyhydroxyalkanoate (PHA) or modified PHA (MPHA) and treated fish-scale powder (TFSP) was prepared and characterized. The powder (20-80 nm) was prepared by grinding after treating FSP with water, acid, and heat (450 °C) to yield the TFSP. Composite nanofibers (100-500 nm long) of TFSP/PHA and TFSP/MPHA were fabricated by electrospinning using a biaxial feed method. The TFSP, which had a high hydroxyapatite content, was suitable as a filler for composites. The Ca/P ratio of the TFSP was similar to that of the human bone. Particle size analysis and analysis of scanning electron microscopy images indicated that, compared with the PHA/TFSP composite, the MPHA/TFSP nanofibers were more uniform and bonded more strongly in the matrix. The tensile strength at failure of the MPHA/TFSP specimens was enhanced and increased with increasing TFSP content. The elongation at failure was lower and decreased with increasing TFSP concentration. The water contact angle decreased with increasing TFSP content in PHA/TFSP and MPHA/TFSP nanofiber membranes. The TFSP enhanced the hydrophilic effect of the PHA/TFSP and MPHA/TFSP nanofiber membranes and provided a more suitable environment for cell growth. This composite nanofiber has potential in many biomedical applications.

Antibacterial properties and cytocompatibility of biobased nanofibers of fish scale gelatine, modified polylactide, and freshwater clam shell.

We report herein new nanofibers prepared from fish scale gelatine (FSG), modified polylactide (MPLA), and a natural antibacterial agent of freshwater clam (Corbicula fluminea Estefanía) shell powder (FCSP). A preparation of FSG from Mullet scales is also described. To improve the biocompatibility and antibacterial activity of the non-woven nanofibers, MPLA/FCSP was added to enhance their antibacterial properties. FSG was then combined with MPLA/FCSP using an electrospinning technique to improve the biocompatibility of the as-fabricated 100-500-nm-diameter non-woven MPLA/FCSP/FSG nanofibers. The resulting tensile properties and morphological characteristics indicated enhanced adhesion among FSG, FCSP, and MPLA in the MPLA/FCSP/FSG nanofibers, as well as improved water resistance and tensile strength, compared with the PLA/FSG nanofibers. MTT assay, cell-cycle, and apoptosis analyses showed that both PLA/FSG and MPLA/FCSP/FSG nanofibers had good biocompatibility. Increasing the FSG content in PLA/FSG and MPLA/FCSP/FSG nanofibers enhanced cell proliferation and free-radical scavenging ability, but did not affect cell viability. Quantitative analysis of bacteria inhibition revealed that FCSP imparts antibacterial activity.

Bio-based polymer nanofiber with siliceous sponge spicules prepared by electrospinning: Preparation, characterisation, and functionalisation.

Sponges, which are parasitic on plants widely found in lakes and oceans, represent a vast resource that has yet to be effectively utilised. Sponge spicules (SS), which contain high amounts of silica dioxide, form after long-term biomineralisation. In this study, SS attached to plant bodies were subjected to acid and heat treatments, followed by grinding, to obtain 10-40-nm siliceous sponge spicules (SSS). SSS and polylactic acid (PLA) were then combined to create 50-450-nm PLA/SSS composite nanofibers. The morphology and bioactivity of the electrospun PLA/SSS nanofibers were examined; the tensile, thermal, and water-resistant properties of the fibers were also evaluated. Our results showed a dramatic enhancement in the thermal and tensile properties of PLA with increasing SSS content; specifically, a 3 wt% increase in SSS content resulted in a 47 °C increase in the initial decomposition temperature and a 73.3-MPa increase in Young's modulus. The water resistance of PLA/SSS increased with SSS content, as indicated by the increase in the water contact angle compared with PLA nanofibers. PLA/SSS nanofibers also exhibited slightly enhanced human foreskin fibroblast cell proliferation, good cytocompatibility, and an antibacterial effect. The enhanced antibacterial and biodegradable properties of PLA/SSS are expected to be useful in biomedical material applications.

Antibacterial Properties of Biobased Polyester Composites Achieved through Modification with a Thermally Treated Waste Scallop Shell.

Novel antibacterial properties of composites prepared from thermally treated waste white scallop shell powder (TWWSSP) and modified polylactide (MPLA) are reported. The waste shell (calcium carbonate, CaCO3) was calcined at 1000 °C to completely form calcium oxide (CaO) and calcium hydroxide (Ca(OH)2). The composition and structure of the calcined product were characterized using energy dispersive spectrometry, Fourier transform infrared spectroscopy, and X-ray diffraction. The TWWSSP was studied to determine its effectiveness as a bactericidal agent when incorporated into MPLA to form composites. Infrared, tensile, and morphological characterizations indicated an enhanced adhesion between the TWWSSP and the MPLA in the composites and an improved compatibility compared with the PLA/WWSSP composites. The MTT assay and cell adhesion tests on the composites revealed that the relative growth rate of Mus dunni fibroblast (MDFB) cells increased with an increasing TWWSSP content, which indicated that the composites were not cytotoxic. Moreover, TWWSSP containing CaO and Ca(OH)2 enhanced the antibacterial activity of the composites; MPLA composites that contained TWWSSP had a better antibacterial activity. The antibacterial and biodegradable properties of the MPLA/TWWSSP and PLA/WWSSP composites have a great potential for many applications, especially food packaging and biomedical materials.

Bio-Based Electrospun Nanofiber of Polyhydroxyalkanoate Modified with Black Soldier Fly's Pupa Shell with Antibacterial and Cytocompatibility Properties.

We report on the antibacterial and cytocompatibility properties of a bio-based electrospun polyhydroxyalkanoate (PHA) nanofiber modified with Black Soldier Fly (BSF) pupa shell. A 5-50 µm chitosan powder (CSP) was made by grinding BSF pupa shell in water, acid, alkali. CSP was combined with PHA in an electrospinning machine using a biaxial feed method and manufactured into a 50-500 nm antibacterial nanofiber. We studied the morphology, mechanical properties, water absorption, and antibacterial properties of the electrospun PHA/CSP nanofiber. To improve the fiber's compatibility and functionality, acrylic acid (AA) was grafted onto PHA. The resulting tensile properties and morphological characterizations indicated enhanced adhesion between CSP and PHA- g-AA nanofiber, as well as an improvement in its water resistance and tensile strength, compared with the PHA/CSP nanofiber. To study the cytocompatibility of the material, human foreskin fibroblasts were seeded onto the nanofiber specimens with 3.0 and 6.0 wt % CSP. Increasing the CSP content in PHA/CSP and PHA- g-AA/CSP nanofibers enhanced cell proliferation; additionally, the nanofibers with CSP showed strong inhibition of bacteria. The enhanced antibacterial and biodegradable properties of PHA- g-AA/CSP and PHA/CSP nanofibers demonstrate their potential for biomedical material applications.

Efficacy and Safety Evaluation of a Chlorine Dioxide Solution.

In this study, a chlorine dioxide solution (UC-1) composed of chlorine dioxide was produced using an electrolytic method and subsequently purified using a membrane. UC-1 was determined to contain 2000 ppm of gaseous chlorine dioxide in water. The efficacy and safety of UC-1 were evaluated. The antimicrobial activity was more than 98.2% reduction when UC-1 concentrations were 5 and 20 ppm for bacteria and fungi, respectively. The half maximal inhibitory concentrations (IC50) of H1N1, influenza virus B/TW/71718/04, and EV71 were 84.65 ± 0.64, 95.91 ± 11.61, and 46.39 ± 1.97 ppm, respectively. A 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test revealed that the cell viability of mouse lung fibroblast L929 cells was 93.7% at a 200 ppm UC-1 concentration that is over that anticipated in routine use. Moreover, 50 ppm UC-1 showed no significant symptoms in a rabbit ocular irritation test. In an inhalation toxicity test, treatment with 20 ppm UC-1 for 24 h showed no abnormality and no mortality in clinical symptoms and normal functioning of the lung and other organs. A ClO2 concentration of up to 40 ppm in drinking water did not show any toxicity in a subchronic oral toxicity test. Herein, UC-1 showed favorable disinfection activity and a higher safety profile tendency than in previous reports.

Growth suppression of HER2-overexpressing breast cancer cells by berberine via modulation of the HER2/PI3K/Akt signaling pathway.

Berberine (BBR) is a natural alkaloid with significant antitumor activities against many types of cancer cells. This study investigated the molecular mechanisms by which BBR suppresses the growth of HER2-overexpressing breast cancer cells. The results show that BBR induces G1-phase cell cycle arrest by interfering with the expression of cyclins D1 and E and that it induces cellular apoptosis through the induction of a mitochondria/caspase pathway. The data also indicate that BBR inhibits cellular growth and promotes apoptosis by down-regulating the HER2/PI3K/Akt signaling pathway. Furthermore, it is also shown that a combination of taxol and BBR significantly slows the growth rate of HER2-overexpressing breast cancer cells. In conclusion, this study suggests that BBR could be a useful adjuvant therapeutic agent in the treatment of HER2-overexpressing breast cancer.

The N-terminal domain of EBNA1 acts as a suppressor of the HER2/neu oncogene.

HER2/neu oncogene-mediated malignancy is clearly associated with various human cancers. Therefore, HER2/neu targeting is an effective approach to cancer therapy. We have previously demonstrated that Epstein-Barr virus nuclear antigen-1 (EBNA1) can suppress HER2/neu oncogene expression, although EBNA1 itself has oncogenic potential. Here, we found that the N-terminal domain of EBNA1 alone, named EBNA1-NT, which contains the N-terminal region of amino acid residues 1-86 of EBNA1, is required and sufficient to suppress HER2/neu oncogene expression at the transcriptional level. Furthermore, in EBNA1-NT-transfected HER2/neu-overexpressing cells, we found EBNA1-NT could down-regulate the endogenous production of p185(HER2/neu), lower transformation ability, sensitize paclitaxel-induced apoptosis and decrease tumorigenic potential. These data suggest that EBNA1-NT may act as a repressor of the HER2/neu oncogene.

Linker-modified triamine-linked acridine dimers: synthesis and cytotoxicity properties in vitro and in vivo.

The preparation and cytotoxicity properties of a series of N(epsilon)-substituted triamine-linked acridine dimers are described. Most acridine dimer derivatives reveal highly potent in vitro cytotoxicity properties and DNA binding activity. Several acridine dimers were selected to study their action in vivo. These acridine dimers have demonstrated a narrow safe margin, as has adriamycin, but higher maximum tolerate dose (MTD) in comparison with that of adriamycin in ICR mice. The acridine dimers also demonstrated various anit-COLO 205 solid tumor activities in vivo. Compound 1 has shown the most potent solid tumor inhibition.

Autocrine and paracrine regulation of interleukin-8 expression in lung cancer cells.

We had previously demonstrated that lung cancer cells, upon contact with macrophages, could be induced to secrete angiogenic factors to promote tumor angiogenesis. In this study, we focused on the paracrine and autocrine regulation of interleukin (IL)-8 expression in sensitized lung cancer cells after interacting with macrophages. We found that the IL-8 mRNA expression in lung cancer cells significantly increased after coculture with phorbol myristate acetate-treated THP-1 cells and human primary lung macrophages. Fresh lung cancer CL1-5 cells cocultured with macrophage-sensitized lung cancer cells still had a 35% of increase in IL-8 mRNA expression. The addition of anti-inflammatory agents pyrrolidine dithiocarbamate, pentoxifylline, aspirin, and dexamethasone could completely suppress the expression of IL-8 mRNA in fresh/sensitized lung cancer cell cocultures. Human recombinant tumor necrosis factor (TNF)-alpha and IL-1alpha could induce IL-8 expression in lung cancer cells in a dose-dependent manner. Neutralization with TNF-alpha and IL-1alpha antibodies in cocultures decreased the levels of IL-8 expression in sensitized lung cancer cells. Nuclear factor-kappaB transcriptional activity was also suppressed by the same antibodies, as confirmed by a reporter gene assay and the electrophoretic mobility shift assay. Our results highly suggest that both autocrine and paracrine regulation are involved in IL-8 expression of lung cancer cells cocultured with macrophage. Also, the regulations of IL-8 expression in lung cancer cells were through the nuclear factor-kappaB pathway and modulated by TNF-alpha and IL-1alpha.

The N-terminal domain of SV40 large T antigen represses the HER2/neu-mediated transformation and metastatic potential in breast cancers.

HER2/neu is known to be overexpressed in approximately 40% of human breast and ovarian cancers and it is associated with increased metastasis and poor prognosis. We have shown previously that the N-terminal domain of simian virus 40 large T antigen (LT425) can act as a transforming suppressor of the HER2/neu oncogene in human ovarian cancer. In the present study, we demonstrate that LT425 can also repress the transforming properties of HER2/neu-overexpressing human breast cancer cells. In addition, the results of a chemotaxis assay and an in vitro chemoinvasion assay further suggest that LT425 can also suppress the metastatic potential of the HER2/neu-transformed breast cancer cells. Taken together, these data clearly suggest that the inhibition of the expression of p185 HER2/neu tyrosine kinase by LT425 is capable of suppressing the HER2/neu-mediated transformation and metastatic potential in breast cancers.