Thermo-sensitive PLGA-PEG-PLGA hydrogel for sustained release of EGF to inhibit cervical cancer recurrence.

Overexpression of epidermal growth factor receptor (EGFR) in cancer is a key cause of recurrence of cervical cancer (CC). Although the EGF-EGFR pathway has been studied for decades, preventing tumor growth and recurrence caused by peripheral EGF remains a great challenge. In this work, a strategy is proposed to reduce the stimulation of high concentration EGF on tumor growth by using a thermo-sensitive hydrogel. The hydrogel is a triblock copolymer composed of polyethylene glycol (PEG) and poly (lactide glycolide) (PLGA). Based on the excellent temperature sensitivity, carrier capacity, swelling property and biocompatibility, the hydrogel can absorb the liquid around the tumor by injection and release EGF continuously at low concentration. The inhibitory effect of hydrogel on tumor growth is fully confirmed by an implanted tumor mouse model with human cervical cancer cell lines (HeLa) using triple-immunodeficient NCG mice. Compared with free EGF, the EGF-loaded hydrogel can hardly induce surface plasmon resonance (SPR) response, which proves that hydrogel can effectively weaken cytoskeleton rearrangement and inhibit cell migration by continuously releasing low concentration EGF. In addition, the EGF-loaded hydrogel can reduce cell proliferation by delaying the progress of cell cycle progression. Taken together, the hydrogel can effectively protect tumor microenvironment from the stimulation of high concentration EGF, delay cancer cellular processes and tumor growth, and thus providing an approach for inhibiting tumor recurrence of CC.

A novel bacterial combination for efficient degradation of polystyrene microplastics.

This study aimed to investigate the combined decomposition of polystyrene (PS) microplastics using three bacterial cultures: Stenotrophomonas maltophilia, Bacillus velezensis, and Acinetobacter radioresistens. The ability of all three strains to grow on medium containing PS (Mn 90,000 Da, Mw 241,200 Da) microplastics as the sole carbon source was examined. After 60 days of A. radioresistens treatment, the maximum weight loss of the PS microplastics was found to be 16.7 ± 0.6% (half-life 251.1 d). After 60 days of treatment with S. maltophilia and B. velezensis, the maximum weight loss of PS microplastics was 43.5 ± 0.8% (half-life 74.9 d). After 60 days of treatment with S. maltophilia, B. velezensis, and A. radioresistens, the weight loss of the PS microplastics was 17.0 ± 0.2% (half-life 224.2 d). The S. maltophilia and B. velezensis treatment showed a more significant degradation effect after 60 days. This result was attributed to interspecific assistance and interspecific competition. Biodegradation of PS microplastics was confirmed using scanning electron microscopy, water contact angle, high-temperature gel chromatography, Fourier transform infrared spectroscopy and thermogravimetric analysis. This study is the first to explore the degradation ability of different bacterial combinations on PS microplastics, providing a reference for future research on the biodegradation technology of mixed bacteria.

Adipose mesenchymal stem cells and gingival mesenchymal stem cells have a comparable effect in endothelium repair.

Restenosis is the major factor influencing the long-term success rate of angioplasty and stent implantation and effective strategies to prevent restenosis remain limited. Mesenchymal stem cells (MSCs) are pluripotent stem cells capable of self-renewal and multidirectional differentiation, which may be able to promote endothelium repair, thereby reducing restenosis. The present study aimed to evaluate the effects of adipose MSCs (AMSCs) and gingival MSCs (GMSCs) on endothelium repair. MSCs were isolated from two human tissue types, namely adipose tissue and gingival tissue, and the effects of AMSCs and GMSCs in ex vivo endothelium repair and on vascular smooth muscle cell (SMC) growth were examined. To compare the feasibility of using AMSCs and GMSCs for the repair of endothelium damage in endothelial cell (EC) damage and vasoproliferative disorders, an ex vivo model of endothelium repair in a co-culture system was developed. It was indicated that AMSCs and GMSCs expressed characteristic MSC markers (CD105 and CD166). 3H-thymidine incorporation in the co-culture group of AMSCs and SMCs in the presence of ECs was lower compared with that in the GMSC and SMC co-culture group. The protein expression level of proliferating cell nuclear antigen in the co-culture group of AMSCs and SMCs in the presence of ECs were lower compared with that in the GMSC and SMC co-culture group. After co-culture with ECs for 5 days, 25.71±3.08% of AMSCs began to express CD31 protein and 20.06±2.09% of GMSCs began to express CD31 protein. Furthermore, anti-VEGF antibody was able to inhibit MSC differentiation. Collectively, the present results suggested that seeding of AMSCs had a stronger effect to inhibit the proliferation and migration of SMCs compared with GMSCs.

Structural and functional studies of Aspergillus oryzae cutinase: enhanced thermostability and hydrolytic activity of synthetic ester and polyester degradation.

Cutinases are responsible for hydrolysis of the protective cutin lipid polyester matrix in plants and thus have been exploited for hydrolysis of small molecule esters and polyesters. Here we explore the reactivity, stability, and structure of Aspergillus oryzae cutinase and compare it to the well-studied enzyme from Fusarium solani. Two critical differences are highlighted in the crystallographic analysis of the A. oryzae structure: (i) an additional disulfide bond and (ii) a topologically favored catalytic triad with a continuous and deep groove. These structural features of A. oryzae cutinase are proposed to result in an improved hydrolytic activity and altered substrate specificity profile, enhanced thermostability, and remarkable reactivity toward the degradation of the synthetic polyester polycaprolactone. The results presented here provide insight into engineering new cutinase-inspired biocatalysts with tailor-made properties.

A bathypelagic ostracod Conchoecissa nigromaculatus sp. nov. (Myodocopa, Halocyprididae) from the South China Sea.

Pelagic ostracods are one of the main groups of zooplankton and are abundant in marine ecosystems worldwide. The record of marine planktonic ostracod species in the central and southern part of the South China Sea accounts over for one-third of the total recorded marine planktonic ostracods in seas around China. In this study, we examined and compared the specimens from a recent cruise in this region that appeared to be different from previously described species of genus Conchoecissa, and then confirmed them as a new bathypelagic species Conchoecissa nigromaculatus. These specimens clearly differed from the other species of genus Conchoecissa with differences observed in the size, carapace, locations of glands, mandible, maxilla, sixth limb, and furca. In this species, mandibular coxal endite has no ventral finger process, maxilla has prominently large endites and has only two claws on the tip, the sixth limb has very simple endites, and this species has distinctive features not previously observed in the tribe Conchoeciini before. It is therefore necessary to emend the diagnosis of this group.

Euphilomedes biacutidens (Ostracoda, Myodocopida, Philomedidae), a new species from China Sea.

Ostracods are one of the major groups of marine benthos, inhabiting virtually all oceanic environments worldwide, and a total of 31 species have been recorded in genus Euphilomedes Kornicker, 1967. In the present study, we describe a new species Euphilomedes biacutidens collected from the Taiwan Strait and South China Sea. E. biacutidens sp. nov. differs from the related species of the genus Euphilomedes in having a unique combination of the characteristics of spines on carapace, the filaments on sensory seta, the arrangement of setae on tip of the first antenna, the numbers of setae on appendages, the claws on fifth limb, the teeth on the comb of the seventh limb and furcal claws. It is particularly obvious that it has a bifurcated and pointed ventral corner of the rostrum, two spines on the posterior margin of right valve, a row of teeth along the inner margin of article 3 of the endopod of the second antenna, and some long claws instead of setae on the fifth limb.

Two new benthic Euphilomedes Kornicker, 1967 (Ostracoda, Myodocopida, Philomedidae) from the Taiwan Strait (East China Sea).

Ostracods are small bivalved crustaceans widely distributed in aquatic environments and in total 99 species have been recorded in genus Euphilomedes Kornicker, 1967. In this study, we further describe two new species of benthic ostracods in this genus, Euphilomedes liuruiyii sp. nov. and Euphilomedes pentacanthos sp. nov., collected from the Taiwan Strait in China. These two species can be easily distinguished from their congeners by some crucial morphological characteristics, including the carapace shape, the numbers of main and secondary furcal claws, and their arrangement of furcal claws. In addition the first antenna, endopod of second antenna, frontal organ, mandible and the seventh limb also differentiate these two species from related species.

Randomized controlled trial of 3 days fasting and oral senna, combined with mannitol and simethicone, before capsule endoscopy.

BACKGROUND AND STUDY AIMS: The approach to small bowel preparation before capsule endoscopy (CE) is still suboptimal. PATIENTS AND METHODS: One hundred eighty patients were randomly allocated to 3 groups. Patients in Group A took 250 mL 20% mannitol and 1 L 0.9% saline orally at 05:00 hours on the day of the procedure. In Group B the same preparation was taken at 20:00 on the day before, and at 05:00 on the day of CE; in addition, 20 mL oral simethicone was taken 30 minutes before CE. Group C was treated identically to Group B, except that the patients fasted for 3 days and took 3 g senna orally 3 times daily before CE. The length of bowel containing green luminal contents was assessed by ImageJ software and bowel cleanliness was evaluated by computed assessment of the cleansing score. RESULTS: Cleansing of the whole small bowel and the distal small bowel were significantly different between the 3 groups (χ = 22.470, P = .000; χ = 17.029, P = .000, respectively). There were also significant differences between the 3 groups in the length of small bowel and specifically the length of the distal small bowel containing green luminal contents (χ = 12.390, P = .000, χ = 15.141, P = .000, respectively), but not with regard to the proximal small bowel (χ = 0.678, P = .509). CONCLUSIONS: Three days fasting and oral senna, combined with 20% mannitol and simethicone, before CE, can reduce the effects of bile on the small bowel and improve small bowel cleansing, especially in the distal small intestine.

[Research advances in molecular epidemiology and vaccines of Coxsackievirus A16].

Epidemics of hand, foot and mouth disease (HFMD) have mainly been caused by Coxsackievirus A16 (CVA16) and Enterovirus A 71 (EV-A71), which circulated alternatively or together in the affected area. CVA16 has caused numerous outbreaks and epidemics in multiple countries and geographical regions, and has become an important public health problem. Based on an analysis of the complete VP1 coding region, all CVA16 strains can be divided into genotypes A, B1, and B2. Furthermore, genotype B1 can be divided into subgenotypes B1a, B1b, and B1c. After 2000, no reports of genotype B2 virus strains have been reported. All of the CVA16 strains reported in mainland China have belonged to subgenotypes B1a and B1b. Most CVA16-associated infections cause only mild symptoms; however, some CVA16 infections can lead to severe complications and even death. Vaccination is considered to be the most effective method to control the transmission and infection rate of this virus. A number of research groups are studying various vaccine types, including inactivated vaccines, genetic engineering vaccines, and DNA vaccines, amongst others. In this review, an overview is provided of the research advances in molecular epidemiology and vaccines of CVA16.

Designing polyethylenes of complex chain architectures via Pd-diimine-catalyzed "living" ethylene polymerization.

Polymer chain architecture is a critically important chain parameter governing intrinsically the properties and applications of polymers. The rapid developments in "living"/controlled polymerization techniques, particularly the controlled radical polymerization techniques, in the past two decades have enabled the precision synthesis of novel polymers having a great variety of complex yet well-defined chain architectures from various monomer stocks. For polyolefins synthesized via catalytic coordination polymerization, the design of complex chain architectures, however, has only started recently because of the relatively limited advancements in the catalytic "living" olefin polymerization technique. In this regard, the versatile Pd-diimine catalysts have provided some unprecedented opportunities, due to their outstanding features, in rendering successfully a novel class of polyethylenes of various new complex chain architectures through the "living" ethylene polymerization protocol. The complex chain architectures designed to date have included hyperbranched, hybrid hyperbranched-linear, block, gradient and block-gradient, star, telechelic, graft and comb, and surface-tethered polymer brushes. This Feature Article attempts to summarize the recent developments achieved in the area, with an emphasis on the synthetic strategies for the architectural design. These developments demonstrate the great potential for further advancements of this new exciting research area.

Laser-guidance-based cell deposition microscope for heterotypic single-cell micropatterning.

Cell patterning methods enable researchers to control specific homotypic and heterotypic contact-mediated cell-cell and cell-ECM interactions and to impose defined cell and tissue geometries. To micropattern individual cells to specific points on a substrate with high spatial resolution, we have developed a cell deposition microscope based on the laser-guidance technique. We discuss the theory of optical forces for generating laser guidance and the optimization of the optical configuration (NA ≈ 0.1) to manipulate cells with high speed in three dimensions. Our cell deposition microscope is capable of patterning different cell types onto and within standard cell research devices and providing on-stage incubation for long-term cell culturing. Using this cell deposition microscope, rat mesenchymal stem cells from bone marrow were micropatterned with cardiomyocytes into a substrate microfabricated with polydimethylsiloxane on a 22 mm × 22 mm coverglass to form a single-cell coculturing microenvironment, and their electrophysiological property changes were investigated during the coculturing days.

Atomic force microscopy of Mammalian urothelial surface.

The mammalian urothelium apical surface plays important roles in bladder physiology and diseases, and it provides a unique morphology for ultrastructural studies. Atomic force microscopy (AFM) is an emerging tool for studying the architecture and dynamic properties of biomolecular structures under near-physiological conditions. However, AFM imaging of soft tissues remains a challenge because of the lack of efficient methods for sample stabilization. Using a porous nitrocellulose membrane as the support, we were able to immobilize large pieces of soft mouse bladder tissue, thus enabling us to carry out the first AFM investigation of the mouse urothelial surface. The submicrometer-resolution AFM images revealed many details of the surface features, including the geometry of the urothelial plaques that cover the entire surface and the membrane interdigitation at the cell borders. This interdigitation creates a membrane zipper, likely contributing to the barrier function of the urothelium. In addition, we were able to image the intracellular bacterial communities of type 1-fimbriated bacteria grown between the intermediate filament bundles of the umbrella cells, shedding light on the bacterial colonization of the urothelium.