Prolongation of the degradation period and improvement of the angiogenesis of zein porous scaffolds in vivo.

Zein porous scaffolds modified with fatty acids have shown great improvement in mechanical properties and good cell compatibility in vitro, indicating the potential application as a bone tissue engineering substitute. The present study was conducted to systematically investigate whether the addition of fatty acids affects the short-term (up to 12 weeks) and long-term (up to 1 year) behaviors of scaffolds in vivo, mainly focusing on changes in the degradation period and inflammatory responses. Throughout the implantation period, no abnormal signs occurred and zein porous scaffolds modified with oleic acid showed good tolerance in rabbits, characterized by the growth of relatively more blood vessels in the scaffolds and only a slight degree of fibrosis histology. Moreover, the degradation period was prolonged from 8 months to 1 year as compared to the control. These results affirmed further that zein could be used as a new kind of natural biomaterial suitable for bone tissue engineering.

Antineoplastic Activity Comparison of Bovine Serum Albumin--Conjugated Sulfides Semiconductor Nanomaterials.

Although tumor is one of the most frequently occurring diseases and a leading cause of death, nanotechnology, one of the frontier sciences, is exhibiting its great potential to tumor treatments. The aim of this study was to design a facile and environmentally-friendly method to prepare bovine serum albumin-conjugated heavy metal sulfides nano-materials, including Ag2S, PbS and CdS. Here, bovine serum albumin was introduced in order to direct the synthesis of nano-materials by using its template effect and supply more sites for further modification in future. The crystal structure and morphology were analyzed by XRD and TEM, respectively. Additionally, the antineoplastic activity of nano-materials was compared by cell viability analysis, optical and electron microscopy observation after exposure of the human hepatoma cell line. The results showed that the inhibition effect of heavy metal sulfides on tumor cells was in the order of nano-PbS > bulk CdS > nano-Ag2S > nano-CdS > bulk PbS > bulk Ag2S. It could be concluded that heavy metal sulfides had significantly negative impact on human hepatoma cells growth but it could not be obviously generalized that nano-particles were always more effective to kill tumor cells than bulk materials. The size and surface reactivity might be the important factors causing the difference.

Anticancer effects of bishydroxycoumarin are mediated through apoptosis induction, cell migration inhibition and cell cycle arrest in human glioma cells.

PURPOSE: To evaluate the cytotoxic and apoptotic effects of bishydroxycoumarin (BHC) against human glioma cells and to study their mode of action. METHODS: Three cells were used in the experiments. MTT and LDH assays were used to assess the cytotoxic effects of BHC while an in vitro wound healing assay was used to study the effect of BHC on cell migration. Fluorescence microscopy and annexin V-FITC assay were used to study the cellular morphology and apoptotic effects while flow cytometry in combination with propidium iodide (PI) were used to study cell cycle arrest induced by BHC. RESULTS: BHC induced substantial and dose-dependent cytotoxic effects against all three cell lines with U87MG cell line being most susceptible. BHC also inhibited cell migration and induced characteristic morphological changes including chromatin condensation, nuclear shrinkage which increased with increasing dose of BHC. The apoptotic cell population (both early and late apoptotic cells) increased with increasing dose of BHC which also induced substantial G0/G1 cell cycle growth arrest in U87MG cells. CONCLUSION: This study provides help to elucidate the translational potential of the in vitro results to be used for further in vivo studies on human glioma using animal or human subjects. The mechanistic pathway studied in this report could be helpful in explaining the mode of action of these classes of natural products.

[A verification study assessing the test method for resistance to dry microbial penetration about surgical gowns and surgical drapes].

By testing the less critical product areas of two different materials, this paper verifies the test method described in ISO 22612.

[Study on the testing methods to determine the resistance to wet bacterial penetration about surgical gowns and drapes].

The essay introduces the study on the performance monitoring tests for the resistance to wet bacterial penetration about surgical gowns and surgical drapes in accordance with ISO 22610.

In vivo biocompatibility and mechanical properties of porous zein scaffolds.

In our previous study, a three-dimensional zein porous scaffold with a compressive Young's modulus of up to 86.6+/-19.9 MPa and a compressive strength of up to 11.8+/-1.7 MPa was prepared, and was suitable for culture of mesenchymal stem cells (MSCs) in vitro. In this study, we examined its tissue compatibility in a rabbit subcutaneous implantation model; histological analysis revealed a good tissue response and degradability. To improve its mechanical property (especially the brittleness), the scaffolds were prepared using the club-shaped mannitol as the porogen, and stearic acid or oleic acid was added. The scaffolds obtained had an interconnected tubular pore structure, 100-380 microm in pore size, and about 80% porosity. The maximum values of the compressive strength and modulus, the tensile strength and modulus, and the flexural strength and modulus were obtained at the lowest porosity, reaching 51.81+/-8.70 and 563.8+/-23.4 MPa; 3.91+/-0.86 and 751.63+/-58.85 MPa; and 17.71+/-3.02 and 514.39+/-19.02 MPa, respectively. Addition of 15% stearic acid or 20% oleic acid did not affect the proliferation and osteogenic differentiation of MSCs, and a successful improvement of mechanical properties, especially the brittleness of the zein scaffold could be achieved.

Aqueous multiphoton lithography with multifunctional silk-centred bio-resists.

Silk and silk fibroin, the biomaterial from nature, nowadays are being widely utilized in many cutting-edge micro/nanodevices/systems via advanced micro/nanofabrication techniques. Herein, for the first time to our knowledge, we report aqueous multiphoton lithography of diversiform-regenerated-silk-fibroin-centric inks using noncontact and maskless femtosecond laser direct writing (FsLDW). Initially, silk fibroin was FsLDW-crosslinked into arbitrary two/three-dimensional micro/nanostructures with good elastic properties merely using proper photosensitizers. More interestingly, silk/metal composite micro/nanodevices with multidimension-controllable metal content can be FsLDW-customized through laser-induced simultaneous fibroin oxidation/crosslinking and metal photoreduction using the simplest silk/Ag(+) or silk/[AuCl4](-) aqueous resists. Noticeably, during FsLDW, fibroin functions as biological reductant and matrix, while metal ions act as the oxidant. A FsLDW-fabricated prototyping silk/Ag microelectrode exhibited 10(4)-Ω(-1 ) m(-1)-scale adjustable electric conductivity. This work not only provides a powerful development to silk micro/nanoprocessing techniques but also creates a novel way to fabricate multifunctional metal/biomacromolecule complex micro/nanodevices for applications such as micro/nanoscale mechanical and electrical bioengineering and biosystems.

The spindle checkpoint protein MAD1 regulates the expression of E-cadherin and prevents cell migration.

Aneuploidy is a common characteristic of human solid tumors. It has been proposed that a defect of the spindle assembly checkpoint (SAC) generates aneuploidy and might facilitate tumorigenesis. However, a direct link between the SAC proteins and tumorigenesis has not yet been elucidated. Here, we demonstrate the association of the SAC protein MAD1 with the RNA polymerase II complex and its role in gene expression. Furthermore, MAD1 binds to the E-cadherin promoter region. Knockdown of endogenous MAD1 by siRNA reduces E-cadherin expression and enhances the migration ability of non-metastatic breast cancer cells, indicating that reduced MAD1 expression is a new potential diagnostic symptom of tumor metastasis.

The promotion of neurological recovery in an intracerebral hemorrhage model using fibrin-binding brain derived neurotrophic factor.

Brain derived neurotrophic factor (BDNF) has been shown to ameliorate recovery after intracerebral hemorrhage (ICH). The injured brain tissue after ICH is surrounded by hematoma formed from hemorrhage. Fibrin is abundant in hematoma, which could be a binding target for BDNF. In this work, we have fused a fibrin-binding domain (FBD) to BDNF (FBD-BDNF), and results demonstrate that FBD-BDNF has specific binding ability to fibrin and is retained in hematoma. Using the rat ICH model induced by bacterial collagenase, injected FBD-BDNF has been concentrated and retained at the hematoma. FBD has facilitated BDNF to exert targeting neuroprotective effect to the injured brain tissue around the hematoma after ICH. FBD-BDNF has significantly reduced the hemotoma volume, reduced tissue loss, promoted neural regeneration, and improved the rat behavioral performance.