The Synergistic Effects between Liquid Crystal and Crystalline Phase on Photo-Responsive Elastomers toward Quick Photo-Responsive Performance.

Adopting only a small amount of azobenzene molecular to design liquid crystal photo-responsive materials capable of quick response and flexible adjustability is in high demand but is challenging. Herein, azobenzenemolecules into polyurethane elastomer containing crystalline structure for preparing azobenzene liquid-crystal elastomers (ALCEs) are demonstrated and this phenomenon of the synergistic effects between liquid crystal and crystalline phase is discovered. The key point of the work is that the synthetic ALCEs can utilize the reversible isomerism capability of azobenzene molecules under light irradiation, which can pry the motion of the macromolecular crystalline region in system to realize the large macroscopic deformation of the photo-responsive behavior. Obviously, the ALCEs sample containing azobenzene molecule and polyethylene glycol crystallization can quickly bend, illuminated by ultraviolet light and rapidly straighten under green light. Under the same ultraviolet irradiation, the bending speed, final bending angle, recovery rate and recovery ratio of ALCEs are larger than that of ALCEs without any crystalline structure. This ALCEs based on the synergistic effects between liquid crystal and crystalline phase can break through the current dilemma that the application of traditional azobenzene photo-responsive materials is limited by their concentration, greatly expanding the design thought and their scope of application.

Identification and functional study of AA11 family polysaccharide monooxygenase genes in filamentous fungus Podospora anserina.

The lytic polysaccharide monooxygenase (LPMO) in the auxiliary active protein family (AA family) catalyzes the oxidative depolymerization of various refractory carbohydrates including cellulose, chitin and starch. While accumulating studies investigate the enzymology of LPMO, the research on the inactivation of LPMO genes has been rarely explored. In this study, five LPMO genes PaLPMO11A (Pa_4_4790), PaLPMO11B (Pa_1_5310), PaLPMO11C (Pa_2_7840), PaLPMO11D (Pa_2_8610) and PaLPMO11E (Pa_3_9420) of the AA11 family in the filamentous fungus Podospora anserina were knocked out by homologous recombination. Single mutants ΔPaLPMO11A (ΔA), ΔPaLPMO11B (ΔB), ΔPaLPMO11C (ΔC), ΔPaLPMO11D (ΔD) and ΔPaLPMO11E (ΔE) were constructed, and then all polygenic mutants were constructed via genetic crosses. The differences in the growth rate and sexual reproduction between wild type and mutant strains were observed on different carbon source media. The alteration of oxidative stress and cellulose degradation ability were found on DAB and NBT staining and cellulase activity determination. These results implicated that LPMO11 genes play a key role in the growth, development, and lignocellulose degradation of P. anserina. The results showed that the spore germination efficiency, growth rate and reproductive capacity of mutant strains including ΔBΔCΔE, ΔAΔBΔCΔE, ΔAΔCΔDΔE and ΔAΔBΔCΔDΔE was significantly decreased on different cellulose carbon sources and the remaining strains have no difference. The reduced utilization of various carbon sources, the growth rate, the spore germination rate, the number of fruiting bodies, the normal fruiting bodies, the shortened life span and the ability to degrade cellulose were found in strains which all five genes in the PaLPMO11 family were deleted. However, the strain still had 45% cellulase activity compared to wild type. These results suggest that LPMO11 genes may be involved in the growth and development, sexual reproduction, senescence and cellulose degradation of P. anserina. This study provides information for systematically elucidating the regulatory mechanism of lignocellulose degradation in filamentous fungus P. anserina.

Oxime-Urethane Structure-Based Dynamically Crosslinked Polyurethane with Robust Reprocessing Properties.

Crosslinked polyurethane with excellent mechanical property, solvent resistance, and transparency has become one of the most widely used materials. However, the presence of chemical crosslinks makes it difficult to be reprocessed once molded, which largely restricts its recycling and reusing, resulting in the serious waste problems. Therefore, it is of great significance to prepare a new type of crosslinked polyurethane with reprocessing function. In this work, a novel reprocessable polyurethane (DOPU) based on reversible dibutanone oxime-carbamate bonds is facilely prepared. The gel fraction of DOPUs is all higher than 95%, endowing it with excellent solvent resistance. Meanwhile, the visible light transmittance of DOPUs can reach up to 97.48%. After four thermal recycles, the tensile strength and elongation at break of recycled DOPUs can still remain at 3.21 MPa and 219.09%, respectively. Importantly, the synthesized DOPUs exhibit excellent elastic shape memory and permanent shape reconstruction properties under thermal stimulation. The dibutanone oxime-carbamate bonds can also be degraded under UV irradiation, making this material easily degradable. Hence, this material has potential applications in coatings, elastomers, and some other fields.

Determination of PEGylation homogeneity of polyethylene glycol-modified canine uricase.

Polyethylene glycol-modified canine uricase (PEG-UHC) was prepared by modifying the ε-amino group of lysine residues on the canine uricase (UHC) protein to near-saturation with 5 kDa monomethoxyl-polyethylene glycol succinimide (mPEG-SPA-5k). In order to accurately determine the PEGylation uniformity of PEG-UHC, CZE, 3-8% gradient gel SDS-PAGE, and imaging CIEF (iCIEF) analyses were compared. CZE could not effectively separate PEG-UHC proteins with different degrees of modification, 3-8% gradient gel SDS-PAGE could separate PEG-UHC into seven gel bands; however, most of the gel bands were smeared or blurred, and the separation of PEG-UHC samples by iCIEF was significantly better than that by 3-8% gradient gel SDS-PAGE. Under denatured conditions, iCIEF separated 12 pI peaks, and could also accurately quantify the relative monomer PEG-UHC content. More than 85% of the total monomeric PEG-UHC was conjugated with 7-12 PEG molecules; of this 85%, approximately 40% was conjugated with 9-10 PEG molecules. These results demonstrated that iCIEF exhibits good potential for determining the PEGylation homogeneity of PEGylated protein drugs.

Fabrication of polysiloxane-modified polyurethane sponge as low-cost organics/water separation and selective absorption material.

Through sol-gel and dip-coating processes, commercial polyurethane sponge modified by polysiloxane was fabricated under low temperature (60 °C) and atmosphere. The contact angle of the obtained polysiloxane/polyurethane sponge is 145 ± 5°. Hence, the polysiloxane/polyurethane sponge could float on water and selectively absorb organics from the surface of the water, indicating simultaneous properties of hydrophobicity and oleophilicity. The absorbent maximum value is 50-150 times of its own weight. The polysiloxane/polyurethane sponge exhibited excellent recyclability, which could be reused by squeezing the sponge due to its high mechanical stability and flexibility. Thermogravimetry-differential thermal analysis test indicated that the polysiloxane/polyurethane sponge exhibited good thermal stability and the stable contact angle of samples tested under increasing temperature indicated its good weather resistance. Due to the commercial property of polyurethane sponge and easy-handling of polysiloxane, the polysiloxane/polyurethane sponge can be easily scaled up to recover a large-area oil spill in water and further work based on the designed equipment has been under consideration.

Interfacial Polarization Strategy to Electroactive Poly(lactic acid) Nanofibers for Humidity-Resistant Respiratory Protection and Machine Learning-Assisted Monitoring.

The advancement of intelligent and biodegradable respiratory protection equipment is pivotal in the realm of human health engineering. Despite significant progress, achieving a balance between efficient filtration and intelligent monitoring remains a great challenge, especially under conditions of high relative humidity (RH) and high airflow rate (AR). Herein, we proposed an interfacial stereocomplexation (ISC) strategy to facilitate intensive interfacial polarization for poly(lactic acid) (PLA) nanofibrous membranes, which were customized for machine learning-assisted respiratory diagnosis. Theoretical principles underlying the facilitated formation of the electroactive phase and aligned PLA chains were quantitatively depicted in the ISC-PLA nanofibers, contributing to the increased dielectric constant and surface potential (as high as 2.2 and 5.1 kV, respectively). Benefiting from the respiration-driven triboelectric mechanisms, the ISC-PLA demonstrated a high PM0.3 filtration efficiency of over 99% with an ultralow pressure drop (75 Pa), even in challenging circumstances (95 ± 5% RH, AR of 85 L/min). Furthermore, we implemented the ISC-PLA with multifunction respiratory monitoring (response time of 0.56 s and recovery time of 0.25 s) and wireless transmission technology, yielding a high recognition rate of 83% for personal breath states. This innovation has practical implications for health management and theoretical advancements in respiratory protection equipment.

Biodegradable poly(lactic acid) blocked polyurethane/carbon nanotubes coated cotton fabric prepared by ultrasonic-assisted inkjet printing for high performance strain sensors.

In order to fulfill the demands for degradability, a broad working range, and heightened sensitivity in flexible sensors, biodegradable polyurethane (BTPU) was synthesized and combined with CNTs to produce BTPU/CNTs coated cotton fabric using an ultrasonic-assisted inkjet printing process. The synthesized BTPU displayed a capacity for degradation in a phosphate buffered saline solution, resulting in a weight loss of 25 % after 12 weeks of degradation. The BTPU/CNTs coated cotton fabric sensor achieved an extensive strain sensing range of 0-137.5 %, characterized by high linearity and a notable sensitivity (gauge factor (GF) of 126.8). Notably, it demonstrated a low strain detection limit (1 %), rapid response (within 280 ms), and robust durability, enabling precise monitoring of both large and subtle human body movements such as finger, wrist, neck, and knee bending, as well as swallowing. Moreover, the BTPU/CNTs coated cotton fabric exhibited favorable biocompatibility with human epidermis, enabling potential applications as wearable skin-contact sensors. This work provides insight into the development of degradable and high sensing performance sensors suitable for applications in electronic skins and health monitoring devices.

Reducing Target Volumes of Intensity Modulated Radiation Therapy After Induction Chemotherapy in Locoregionally Advanced Nasopharyngeal Carcinoma: Long-Term Results of a Prospective, Multicenter, Randomized Trial.

PURPOSE: The objective of this study was to estimate the long-term survival, late toxicity profile, and quality of life of patients with locoregionally advanced nasopharyngeal carcinoma (NPC) treated with combined induction chemotherapy (IC) and concurrent chemoradiotherapy from a clinical trial focused on reducing the target volume of intensity modulated radiation therapy (IMRT). METHODS AND MATERIALS: This prospective, randomized clinical trial was conducted across 6 Chinese hospitals and included 212 patients with stage III-IVB NPC who were randomly allocated to a pre-IC or post-IC group. Eligible patients were treated with 2 cycles of IC + CCRT. All patients underwent radical IMRT. Gross tumor volumes of the nasopharynx were delineated according to pre-IC and post-IC tumor extent in the pre-IC and post-IC groups, respectively. RESULTS: After a median follow-up of 98.4 months, 32 of 97 (32.9%) and 33 of 115 (28.7%) patients experienced treatment failure or died in the pre-IC and post-IC groups, respectively. None of the patients developed grade 4 late toxicity. Late radiation-induced toxicity predominantly manifested as grade 1 to 2 subcutaneous fibrosis, hearing loss, tinnitus, and xerostomia, whereas grade 3 late toxicity included xerostomia and hearing loss. The 5-year estimated overall, progression-free, locoregional recurrence-free, and distant metastasis-free survival rates in the pre-IC and post-IC groups were 78.2% versus 83.3%, 72.0% versus 78.1%, 90.2% versus 93.5%, and 78.1% versus 82.1%, respectively. The pre-IC group had a significantly higher incidence of xerostomia and hearing damage than the post-IC group. In terms of quality of life, compared with the pre-IC group, the post-IC group showed significant improvement in cognitive function (P = .045) and symptoms including dry mouth (P = .004), sticky saliva (P = .047), and feeling ill (P = .041). CONCLUSIONS: After long-term follow-up, we confirmed that reducing the target volumes of IMRT after IC in locoregionally advanced NPC showed no inferiority in terms of the risk of locoregional relapse and potentially improved quality of life and alleviated late toxicity.

UV-modulated substrate rigidity for multiscale study of mechanoresponsive cellular behaviors.

Mechanical properties of the extracellular matrix (ECM) have profound effects on cellular functions. Here, we applied novel photosensitive polydimethylsiloxane (photoPDMS) chemistry to create photosensitive, biocompatible photoPDMS as a rigidity-tunable material for study of mechanoresponsive cellular behaviors. By modulating the PDMS cross-linker to monomer ratio, UV light exposure time, and postexposure baking time, we achieved a broad range of bulk Young's modulus for photoPDMS from 0.027 to 2.48 MPa. Biocompatibility of photoPDMS was assayed, and no significant cytotoxic effect was detected as compared to conventional PDMS. We demonstrated that the bulk Young's modulus of photoPDMS could impact cell morphology, adhesion formation, cytoskeletal structure, and cell proliferation. We further fabricated photoPDMS micropost arrays for multiscale study of mechanoresponsive cellular behaviors. Our results suggested that adherent cells could sense and respond to changes of substrate rigidity at a subfocal adhesion resolution. Together, we demonstrated the potential of photoPDMS as a photosensitive and rigidity-tunable material for mechanobiology studies.

Polydopamine-coated nanocomposite theranostic implants for localized chemotherapy and MRI imaging.

Sustained and localized delivery of chemotherapeutics in postoperative cancer treatment leads to a radical improvement in prognosis and a much decreased risk of tumor recurrence. In this work, polydopamine (PDA)-coated superparamagnetic iron oxide nanoparticle (SPION)-loaded polycaprolactone and poly(lactic-co-glycolic acid) fibers were developed as a potential implant to ensure safe and sustained release of the chemotherapeutic drug methotrexate (MTX), as well as provide local contrast for magnetic resonance imaging (MRI). Fibres were prepared by co-axial electrospinning and loaded with MTX-layered double hydroxide (LDH) nanocomposites in the core, yielding organic-inorganic hybrids ranging from 1.23 to 1.48 µm in diameter. After surface coating with PDA, SPIONs were subsequently loaded on the fibre surface and found to be evenly distributed, providing high MRI contrast. In vitro drug release studies showed the PDA coated fibres gave sustained release of MTX over 18 days, and the release profile is responsive to conditions representative of the tumor microenvironment such as slightly acidic pH values or elevated concentrations of the reducing agent glutathione (GSH). In vitro studies with Caco-2 and A549 cells showed highly effective killing with the PDA coated formulations, which was further enhanced at higher levels of GSH. The fibres hence have the potential to act as an implantable drug-eluting platform for the sustained release of cytotoxic agents within a tumor site, providing a novel treatment option for post-operative cancer patients.

High-heat and UV-barrier poly(lactic acid) by microwave-assisted functionalization of waste natural fibers.

The application of poly(lactic acid) (PLA) in the packaging area is frequently dwarfed by the inadequate gas/water barrier properties, low heat resistance and high UV transmittance. Herein, an environmentally friendly and high-efficiency microwave-assisted functionalization (MAF) approach was proposed to aqueous grafting waste bamboo fibers with the bridging agent. It permitted significant promotion of interfacial interactions between the MAF bamboo fibers (MAFBs) and neighboring PLA chains, contributing to uniform dispersion and intimate interphase. Featuring the morphological features, the MAFB-reinforced (5, 10 and 20 wt%) PLA biocomposites achieved an unexpected combination of high mechanical properties, exceptional resistance to heat deflection and UV irradiation, and excellent water barrier performance. Upon addition of only 5 wt% MAFBs, the tensile strength and toughness of PLA composite films were increased to 46.5 MPa and 0.6 MJ/m3, increasing over 52 % and nearly 107 % compared to those of the counterpart loaded pristine bamboo fibers (PBFs), respectively. This was favorably accompanied by the remarkably reduced water vapor permeability, falling down to the lowest value of 3.5 × 10-11 g∙m/Pa∙s∙m2 for PLA/MAFB (80/20) with a decrease of nearly 79 % compared to the counterpart. It is of interest to note the MAFB-enabled nearly 100 % UV-blocking ratio for PLA loaded 10 and 20 wt% fibers, as well as excellent resistance to heat deflection even at high temperatures like 120 °C. This effort paves the way to multifunctional natural fibers with high affinity to PLA for elegant implementation of high-heat and UV-resistant packaging materials in an ecofriendly manner.

Syringomyelia with irreducible atlantoaxial dislocation, basilar invagination and Chiari I malformation.

A 27-year-old woman presented with bilateral weakness of her all extremities for 5 years. She had a spastic gait and was unable to ambulate without assistance. Neurologic examination revealed increased deep tendon reflexes and positive pathologic reflexes. Radiographs showed occipitalization of the atlas, C2-C3 congenital fusion and fixed atlantoaxial dislocation with an atlanto-dental interval of 10 mm. MRI demonstrated cervicomedullary junction (CMJ) compression from the odontoid, a Chiari type I malformation, and syringomyelia extending from the foramen magnum to C5. The patient underwent transoral atlantoaxial release followed by posterior internal fixation from the occiput to the axis, which resulted in a significant improvement in motor function in all extremities. Post-operative images showed anatomical reduction of the atlantoaxial joint. However, an MRI performed 8 days following surgery showed a new retro-odontoid pannus had developed that was compressing the spinal cord at CMJ. A follow-up CT scan performed at 6 months post-operatively demonstrated a solid bony fusion between the occiput and C2, while an MRI at that time showed complete resolution of the retro-odontoid soft tissue mass with correction of the Chiari I malformation, and resolution of the syringomyelia. Final follow-up at 2-years revealed an excellent clinical outcome.

Langerhans cell histiocytosis of the atlas in an adult.

Langerhans cell histiocytosis (LCH), formerly known as histiocytosis X, is a rare disorder (approximately 1:1,500,000 inhabitants) characterized by clonal proliferation and excess accumulation of pathologic Langerhans cells causing local or systemic effects. The exact etiology of LCH is still unknown. LCH could affect patients of any age, although most present when they are children. The most frequent sites of the bony lesions are the skull, femur, mandible, pelvis and spine. A variety of treatment modalities has been reported, but there was no evidence suggesting that any one treatment was more advantageous than another. We present an adult with LCH of the atlas. A 26-year-old young man presented with a 2-month history of neck pain and stiffness. CT revealed osteolytic lesion in the left lateral mass of atlas with compression fracture. Histopathological diagnosis was Langerhans cell histiocytosis by percutaneous needle biopsy under CT guidance. The patient underwent conservative treatment, including Halo-vest immobilization and radiotherapy. At 7-year follow-up, the patient was asymptomatic except for mild motion restriction of the neck. CT revealed a significant reconstruction of the C1 lateral mass.

Pharmacokinetics of Polyethylene Glycol-Modified Canine Uricase Following Single and Multiple Intravenous Injections in Cynomolgus Monkeys.

BACKGROUND AND OBJECTIVE: Polyethylene glycol-modified canine uricase (PEG-UHC) prepared with a lower-molecular-weight (5 kDa) PEG is used to treat gout. This study investigated the comparative pharmacokinetics of single and multiple doses of PEG-UHC administered intravenously and a single dose of uricase (UHC) administered intravenously in cynomolgus monkeys. METHODS: A noncompartmental model was used to fit the plasma drug concentration-time curve and calculate the pharmacokinetic parameters of PEG-UHC, which were compared with those obtained for UHC at the equivalent dose (2 mg/kg). To study the pharmacokinetics after multiple dose administration, cynomolgus monkeys were administered five intravenous injections of PEG-UHC (0.5 mg/kg), with one injection performed every 15 days. RESULTS: The area under the curve (AUC) and the maximum plasma concentration (Cmax) of PEG-UHC were positively correlated with dose, whereas plasma half-life (t1/2) and clearance (CL) did not change significantly with increasing dose, suggesting that these pharmacokinetic characteristics are linear. Intravenous PEG-UHC exhibited an average t1/2 that was 125.79 times longer and an AUC0-t that was 64.45 times larger than the corresponding values for UHC at the same dose (2 mg/kg), while the CL of PEG-UHC was 1/72.73 times the CL of intravenous UHC. The plasma drug concentration reached a steady state after five injections, and the t1/2 values following the first and last drug administration did not differ significantly. CONCLUSION: Our data show that PEG-UHC is markedly superior to UHC in terms of duration of action, and that the pharmacokinetics of PEG-UHC in cynomolgus monkeys are linear. Sequential administration of PEG-UHC did not accelerate drug clearance. Our findings provide the basis for future clinical studies of PEG-UHC.

A novel method in the removal of impacted mandibular third molar: buccal drainage.

Food impaction after impacted mandibular third molar extraction is a serious problem that should not be ignored. Incomplete suturing of the distal incision in the conventional method is the main cause of food impaction and delayed wound healing. The present study introduces a novel suture and drainage technology that requires hermetic suturing of the distal incision and rubber drainage for buccal drainage. 76 patients with horizontally/mesially impacted third molars (bilateral) were enrolled in this prospective study. An impacted tooth on one side of each patient was extracted by occlusal drainage using the conventional method, whereas the other side tooth was extracted by buccal drainage using the novel method. The differences in wound healing, facial swelling, bleeding and dry socket between the two sides of each patient were compared postoperatively, and the trends for patient selection of the surgical method were also compared. The results indicated that buccal drainage had obvious advantages in wound healing and reduced the risk of postoperative bleeding, and most patients preferred this technique; there were no significant differences in postoperative facial swelling or pain. Thus, buccal drainage can solve the problem of long-term food impaction induced by traditional incision postoperatively and is worthy of clinical promotion.

Investigation into the electromechanical properties of dielectric elastomers subjected to pre-stressing.

Dielectric elastomers (DEs) are being exploited for biological applications such as artificial blood pumps, biomimetic grippers and biomimetic robots. Generally, polyacrylate and silicone rubber (SR) are the most widely used materials for fabricating DEs in terms of mixing with other polymers or compounding them with highly dielectric particles. Furthermore, pre-stretch offers an effective approach to increasing actuated strain and dielectric strength and eliminating 'pull-in' instability. In the work described here, a comparison in electromechanical properties was made between SR/10% barium titanate (BaTiO3) and commercial VHB 4910. Trends in these dielectric parameters are shown graphically for variation in pre-stretch ratio (λpre). It was found that permittivity of SR/10% BaTiO3 was independent of frequency, whereas permittivity was frequency-independent due to the polarization of polymer chains. The maximum deformation and the coupling efficiency for SR/10% BaTiO3 can be achieved at a pre-stretch ratio between 1.6 and 1.9. For VHB 4910, they can be obtained in the pre-stretch ratio range from 2.6 to 3.0. A maximum energy density of 0.05MJ/m(3) was achieved by SR/10% BaTiO3 (λpre=1.6) and VHB 4910 (λpre=3.4). The findings provide an insight into critical pre-stretch ratios required for a range of applications of DEs based on silicone and the commercially available polyacrylate VHB 4910.

[Series orthodontic treatment on teeth transposition of maxillary canine and lateral incisor].

OBJECTIVE: To explore the treatment on teeth transposition of maxillary canine and lateral incisor in order to improve the clinical treatment effect. METHODS: Eleven patients with transposition maxillary canine and lateral incisor were treated with the method: Expand space, artificial reverse occlusion of transpositional lateral incisor to give way, transpositional lateral canine distalization and controlling root, mesial movement of lateral incisor with tongue arch, interactive controlling roots and retention with tongue fixed retaining appliance. RESULTS: Eleven patients had satisfactory treatment effect, with tidy dentition and parallel teeth roots of transpositional canine and lateral incisor. CONCLUSION: Series orthodontic treatment on teeth transposition of maxillary canine and lateral incisor can effectively improve the clinical treatment effect and shorten the treatment time.

[The fabrication and clinical application of semi-fixed mandibular lingual arch expansion appliance].

Semi-fixed mandibular lingual arch expansion appliance is composed of a mandibular molar band, a keyway and arch expansion spring. The arch expansion spring are used to expand maxillary arch symmetrically or asymmetrically when bolts of the two ends are inset into keyways. Dental arch expansion appliance for 25 patients with mandibular arch stenosis showed that semi-fixed mandibular lingual arch expansion had good effect and could be used to expand mandibular arch.

Antitumor effects of polysorbate-80 coated gemcitabine polybutylcyanoacrylate nanoparticles in vitro and its pharmacodynamics in vivo on C6 glioma cells of a brain tumor model.

Polybutylcyanoacrylate (PBCA) nanoparticles coated with polysorbate-80 have been extensively studied for delivery of drugs into the animal models; however, 1% polysorbate-80 coated gemcitabine PBCA nanoparticles (GCTB-PBCA-NPs) remain unknown. In this study, we investigated the inhibitory effects of brain targeted 1% polysorbate-80 coated GCTB-PBCA-NPs on C6 glioma cells in vitro and in vivo. GCTB-PBCA-NPs were prepared by emulsion polymerization and freeze drying. C6 glioma cells treated with 1% polysorbate-80 coated GCTB-PBCA-NPs showed poor growth with less cell density and increased detachment. Cell morphology was also greatly altered with nuclear vacuoles, ruptured cells and dead cells. Meanwhile, by flow cytometry, the numbers of cells treated with 1% polysorbate-80 coated GCTB-PBCA-NPs showed increase in G0/G1 phase and decreased in the S phase (P<0.01) compared with the blank control. CCK-8 assay also showed that GCTB could significantly inhibited cell proliferation in a concentration dependent manner. Finally, various preparations were injected (90 mg preparation per kg body weight) into the brain tumor model, which was produced after inoculating C6 glioma cells into Sprague Dawley (SD) rats for 14 days, it was shown that 1% polysorbate-80 coated GCTB-PBCA-NPs could significantly extend the survival time compared with the saline control (P<0.05). Taken together, 1% polysorbate-80 coated GCTB-PBCA-NPs can effectively inhibit the growth of C6 glioma cells in vitro and enhance antitumor activity on brain tumor in vivo.

[A biomechanical study of anterior screw fixation for type II odontoid fracture with anteroinferior-posterosuperior fracture line].

OBJECTIVE: To investigate the biomechanical effect of anterior screw fixation on the type II fractured odontoid process. METHODS: Twenty fresh human C1-C2 vertebrae specimens were harvested and randomly divided into three groups. The angle of type II fracture line was 0 degree in group I (n=6), 17 degrees in group II (n=8) and 25 degrees in group III (n=6). The fractures were treated by anterior screw fixation. Insertion torque,maximal axial pullout force and stiffness of the bone-screw were tested. RESULTS: There was no significant difference of screw insertion torque and the pull-out strength between each group. The displacement of the odontoid fragment had an association to the angle of the fracture line,the displacement of the small angle was significantly higher than that of the large one (P < 0.5). No significant difference of structure stiffness of the bone-screw was found between each group. CONCLUSION: Anterior screw fixation is feasible for type II odontoid fracture with certain fracture line extends from anteroinferior to posterosuperior.