Contributions of Chinese hamster ovary cell derived extracellular vesicles and other cellular materials to hollow fiber filter fouling during perfusion manufacturing of monoclonal antibodies.

Hollow fiber filter fouling is a common issue plaguing perfusion production process for biologics therapeutics, but the nature of filter foulant has been elusive. Here we studied cell culture materials especially Chinese hamster ovary (CHO) cell-derived extracellular vesicles in perfusion process to determine their role in filter fouling. We found that the decrease of CHO-derived small extracellular vesicles (sEVs) with 50-200 nm in diameter in perfusion permeates always preceded the increase in transmembrane pressure (TMP) and subsequent decrease in product sieving, suggesting that sEVs might have been retained inside filters and contributed to filter fouling. Using scanning electron microscopy and helium ion microscopy, we found sEV-like structures in pores and on foulant patches of hollow fiber tangential flow filtration filter (HF-TFF) membranes. We also observed that the Day 28 TMP of perfusion culture correlated positively with the percentage of foulant patch areas. In addition, energy dispersive X-ray spectroscopy-based elemental mapping microscopy and spectroscopy analysis suggests that foulant patches had enriched cellular materials but not antifoam. Fluorescent staining results further indicate that these cellular materials could be DNA, proteins, and even adherent CHO cells. Lastly, in a small-scale HF-TFF model, addition of CHO-specific sEVs in CHO culture simulated filter fouling behaviors in a concentration-dependent manner. Based on these results, we proposed a mechanism of HF-TFF fouling, in which filter pore constriction by CHO sEVs is followed by cake formation of cellular materials on filter membrane.

Multi-process production occurs in the iron and steel industry, supporting 'dual carbon' target: An in-depth study of CO2 emissions from different processes.

Reducing CO2 emissions of the iron and steel industry, a typical heavy CO2-emitting sector, is the only way that must be passed to achieve the 'dual-carbon' goal, especially in China. In previous studies, however, it is still unknown what is the difference between blast furnace-basic oxygen furnace (BF-BOF), scrap-electric furnace (scrap-EF) and hydrogen metallurgy process. The quantitative research on the key factors affecting CO2 emissions is insufficient. There is also a lack of research on the prediction of CO2 emissions by adjusting industrial structure. Based on material flow analysis, this study establishes carbon flow diagrams of three processes, and then analyze the key factors affecting CO2 emissions. CO2 emissions of the iron and steel industry in the future is predicted by adjusting industrial structure. The results show that: (1) The CO2 emissions of BF-BOF, scrap-EF and hydrogen metallurgy process in a site are 1417.26, 542.93 and 1166.52 kg, respectively. (2) By increasing pellet ratio in blast furnace, scrap ratio in electric furnace, etc., can effectively reduce CO2 emissions. (3) Reducing the crude steel output is the most effective CO2 reduction measure. There is still 5.15 × 108-6.17 × 108 tons of CO2 that needs to be reduced by additional measures.

Characterizing Silicone Oil-Induced Protein Aggregation with Stimulated Raman Scattering Imaging.

Particles in biopharmaceutical products present high risks due to their detrimental impacts on product quality and safety. Identification and quantification of particles in drug products are important to understand particle formation mechanisms, which can help develop control strategies for particle formation during the formulation development and manufacturing process. However, existing analytical techniques such as microflow imaging and light obscuration measurement lack the sensitivity and resolution to detect particles with sizes smaller than 2 µm. More importantly, these techniques are not able to provide chemical information to determine particle composition. In this work, we overcome these challenges by applying the stimulated Raman scattering (SRS) microscopy technique to monitor the C-H Raman stretching modes of the proteinaceous particles and silicone oil droplets formed in the prefilled syringe barrel. By comparing the relative signal intensity and spectral features of each component, most particles can be classified as protein-silicone oil aggregates. We further show that morphological features are poor indicators of particle composition. Our method has the capability to quantify aggregation in protein therapeutics with chemical and spatial information in a label-free manner, potentially allowing high throughput screening or investigation of aggregation mechanisms.

A Stable Irinotecan Liposome with Enhanced Antitumor Activity in a Range of Tumor Models.

PURPOSE: This study aimed to prepare a stable irinotecan liposome (CPT-11 liposome) and evaluate its antitumor efficacy in a range of tumor models. METHODS: CPT-11 liposome was prepared with a Z-average particle size of 110 ~ 120 nm and high entrapment efficiency (> 95%) and had a good stability within 18 months. Then the antitumor efficacy was studied in human colon (Ls-174t), gastric (NCI-N87), pancreatic (BxPC-3) and small cell lung (NCI-H526) cancer xenograft models. The toxicity of high-dose CPT-11 liposome was also evaluated in Beagle dogs. RESULTS: The results showed that the anti-tumor effects of CPT-11 liposome were markedly superior (at least 10 times higher) to those of the CPT-11 injection group in all four xenograft models. The tissue distribution test in the Ls-174t model further demonstrated that the CPT-11 liposome could alter the plasma and tissue distribution of CPT-11, increase the exposure level of its active metabolite SN-38 in tumor, and ultimately improve antitumor efficiency. Meanwhile, CPT-11 liposome showed a much less toxicity than CPT-11 injection in beagle dogs. CONCLUSIONS: Overall, the CPT-11 liposome may be developed as a new clinical alternative for the cancer patients.

Nanoparticles prepared from pterostilbene reduce blood glucose and improve diabetes complications.

BACKGROUND: Diabetes complications are the leading cause of mortality in diabetic patients. The common complications are decline in antioxidant capacity and the onset of micro-inflammation syndrome. At present, glucose-responsive nanoparticles are widely used, as they can release insulin-loaded ultrafine particles intelligently and effectively reduce blood sugar. However, the toxicology of this method has not been fully elucidated. The plant extracts of pterostilbene (PTE) have a wide range of biological applications, such as antioxidation and inflammatory response improvement. Therefore, we have proposed new ideas for the cross application of plant extracts and biomaterials, especially as part of a hypoglycaemic nano-drug delivery system. RESULTS: Based on the PTE, we successfully synthesised poly(3-acrylamidophenyl boric acid-b-pterostilbene) (p[AAPBA-b-PTE]) nanoparticles (NPs). The NPs were round in shape and ranged between 150 and 250 nm in size. The NPs possessed good pH and glucose sensitivity. The entrapment efficiency (EE) of insulin-loaded NPs was approximately 56%, and the drug loading (LC) capacity was approximately 13%. The highest release of insulin was 70%, and the highest release of PTE was 85%. Meanwhile, the insulin could undergo self-regulation according to changes in the glucose concentration, thus achieving an effective, sustained release. Both in vivo and in vitro experiments showed that the NPs were safe and nontoxic. Under normal physiological conditions, NPs were completely degraded within 40 days. Fourteen days after mice were injected with p(AAPBA-b-PTE) NPs, there were no obvious abnormalities in the heart, liver, spleen, lung, or kidney. Moreover, NPs effectively reduced blood glucose, improved antioxidant capacity and reversed micro-inflammation in mice. CONCLUSIONS: p(AAPBA-b-PTE) NPs were successfully prepared using PTE as raw material and effectively reduced blood glucose, improved antioxidant capacity and reduced the inflammatory response. This novel preparation can enable new combinations of plant extracts and biomaterials to adiministered through NPs or other dosage forms in order to regulate and treat diseases.

Micromotors Powered by Enzyme Catalysis.

Active biocompatible systems are of great current interest for their possible applications in drug or antidote delivery at specific locations. Herein, we report the synthesis and study of self-propelled microparticles powered by enzymatic reactions and their directed movement in substrate concentration gradient. Polystyrene microparticles were functionalized with the enzymes urease and catalase using a biotin-streptavidin linkage procedure. The motion of the enzyme-coated particles was studied in the presence of the respective substrates, using optical microscopy and dynamic light scattering analysis. The diffusion of the particles was found to increase in a substrate concentration dependent manner. The directed chemotactic movement of these enzyme-powered motors up the substrate gradient was studied using three-inlet microfluidic channel architecture.

[Repeated injection of mitoxantrone containing thermosensitive liposomes in rat induced ABC phenomenon].

To investigate whether accelerated blood clearance (ABC) phenomenon could be induced after repeated injection of mitoxantrone thermosensitive liposomes, LC-MS/MS and enzyme linked immunosorbent assay (ELISA) were used to measure the concentration of mitoxantrone and the anti-polyethylene glycol (PEG) IgM levels in rat plasma, separately. The drug was rapidly cleared away after the second administration. The anti-PEG IgM was detected after the first dose which was neutralized quickly after the second dose. It is proved that repeated administration of mitoxantrone thermosensitive liposomes in rat caused the ABC phenomenon.

Design, Synthesis, and Antifungal Activity of Polyacetylenic Alcohol Derivatives and Stereoisomers against Phytopathogenic Fungi.

Falcarindiol is active against phytopathogenic fungi. In the present study, racemic falcarindiol analogs (8a-8q) were designed, synthesized, and tested for their activities against eight economically significant phytopathogenic fungal species. The compound 8o displayed the best antifungal activities and up to 54.6-fold in vitro potency improvement against Phytophthora capsici than the natural product stipudiol. Its half-maximum effective concentrations ranged from 4 to 23 µg/mL against all tested fungal species. Racemic 8o was 195-fold more potent than the fungicide carbendazim against P. capsici in vitro. The isomer (1S, 6S)-8o exhibited an EC50 of 1.10 and 2.70 µg/mL against Monilia fructigena and P. capsici, respectively, which was 47 and 11 times lower than (1R, 6S)-8o and (1S, 6R)-8o. In addition, in vivo bioassay results showed that (1S, 6S)-8o had high antifungal activity against infection of M. fructigena and P. capsici to apricot and pepper fruits and pepper plants, which the efficacy was similar or better than carbendazim. The high potency and selectivity of 8o stereoisomers against the phytopathogens warrant an interest in elucidating the molecular target for fungicide development.

Cynanchum komarovii extract for the treatment of rheumatoid arthritis by acting on synovial cells in vitro and in vivo.

ETHNOPHARMACOLOGICAL RELEVANCE: Cynanchum komarovii (CK), the northwest Chinese region's common medicinal herb, was traditionally utilized to treat arthritis, toothache, bald sores and cholecystitis. Various forms of arthritis can be treated with CK, based on "Medicinal Plants of Chinese Desert Areas". However, the exact mechanism of action in rheumatoid arthritis (RA) is uncertain. AIM OF THE STUDY: To evaluate the in vitro and in vivo effects of CK extracts on RA and to preliminarily investigate its anti-RA mechanism of action. MATERIALS AND METHODS: The main components of CK extract were analyzed by HPLC method. The effects of CK on the proliferation and apoptosis of human rheumatoid arthritis fibroblast-like synoviocytes (HFLS-RA) cells and the expression of apoptosis-related proteins in HFLS-RA cells were evaluated by CCK8 assay, flow cytometry and WB assay. To verify the anti-RA effect of CK extracts in vivo, a collagen-induced arthritis (CIA) rat model was established. The rats were divided into six groups: normal group, model group, CK high-dose group (1000 mg/kg, CK-H), CK medium-dose group (500 mg/kg, CK-M), CK low-dose group (250 mg/kg, CK-L) and methotrexate-positive drug group (MTX); the drug was administered continuously for 28 days. Body weight changes, joint swelling, arthritis index, bone density, ankle lesions, immune organ index, splenic lesions and inflammatory factor expression were used to evaluate the in vivo anti-RA activity of the extract. RESULTS: The findings of in vitro experiments showed that 10% CK-containing serum decreased the expression level of Bcl-2, increased the expression levels of Bax and Cleaved Caspase-3 in synovial cells, and prevented TNF-α induced aberrant proliferation and apoptotic antagonism in HFLS-RA cells. According to in vivo studies, CK extract at doses above 250 mg/kg was effective in controlling the levels of inflammatory factors, lowering the arthritis index, and improving foot swelling in CIA rats. When administered at doses up to 1000 mg/kg, CK extract significantly improved synovial lesions, increased bone density, and decreased abnormally elevated immune organ index in CIA rats. CONCLUSIONS: CK has significant anti-RA activity, and its anti-RA mechanism of action may be related to the regulation of the expression levels of apoptosis related proteins and the promotion of apoptosis in synovial cells.

Variables Impacting Silicone Oil Migration and Biologics in Prefilled Syringes.

Prefilled syringes (PFS) as a primary container for parenteral drug products offer significant advantages, such as fast delivery time, ease of self-administration and fewer dosing errors. Despite the benefits that PFS can provide to patients, the silicone oil pre-coated on the glass barrels has shown migration into the drug product, which can impact particle formation and syringe functionality. Health authorities have urged product developers to better understand the susceptibility of drug products to particle formation in PFS due to silicone oil. In the market, there are multiple syringe sources provided by various PFS suppliers. Due to current supply chain shortages and procurement preferences for commercial products, the PFS source may change in the middle of development. Additionally, health authorities require establishing source duality. Therefore, it is crucial to understand how different syringe sources and formulation compositions impact the drug product quality. Here, several design of experiments (DOE) are executed that focus on the risk of silicone oil migration induced by syringe sources, surfactants, protein types, stress, etc. We utilized Resonant Mass Measurement (RMM) and Micro Flow Imaging (MFI) to characterize silicone oil and proteinaceous particle distribution in both micron and submicron size ranges, as well as ICP-MS to quantify silicon content. The protein aggregation and PFS functionality were also monitored in the stability study. The results show that silicone oil migration is impacted more by syringe source, siliconization process and surfactant (type & concentration). The break loose force and extrusion force across all syringe sources increase significantly as protein concentration and storage temperature increase. Protein stability is found to be impacted by its molecular properties and is less impacted by the presence of silicone oil, which is the same inference drawn in other literatures. A detailed evaluation described in this paper enables a thorough and optimal selection of primary container closure and de-risks the impact of silicone oil on drug product stability.

[Development of glipizide push-pull osmotic pump controlled release tablets by using expert system and artificial neural network].

The purpose of this study is to develop glipizide push-pull osmotic pump (PPOP) tablets by using a formulation design expert system and an artificial neural network (ANN). Firstly, the expert system for the formulation design of osmotic pump of poor water-soluble drug was employed to design the formulation of glipizide PPOP, taking the dissolution test results of Glucotrol XL as the goal. Then glipizide PPOP was prepared according to the designed formulations and the in vitro dissolution was carried out. And in vivo evaluation was carried out between the samples which were similar to Glucotrol XL and the Glucotrol XL in Beagle dogs. The range of the factors of formulation and procedure, which could influence the drug release, was optimized using artificial neural network. Finally, the design space was found. It was found that the target formulation which was similar to Glucotrol XL in dissolution test could be obtained in a short period by using the expert system. The samples which were similar to Glucotrol XL were bio-equivalent to the Glucotrol XL in Beagle dogs. The design space of the key parameter coating weight gain was 9.5%-12.0%. It could be concluded that a well controlled product of glipizide PPOP was developed since the dissolution test standard of our product was more strict than that of Glucotrol XL.

Utilization of lignin upon successive fractionation and esterification in polylactic acid (PLA)/lignin biocomposite.

The study presents the preparation of novel biocomposites based on different lignin fractions and polylactic acid (PLA). Based on the improvement of PLA mechanical properties, we proposed a process to assemble a series of lignin samples and PLA matrix using melt blending to investigate the effects on PLA properties from the perspective of the structure and molecular weight for lignin. The lignin was extracted from pine residue using deep eutectic solvent (DES) and was subjected to fractionation with ethanol and acetone as well as esterification modification with succinic anhydride (SAn). The treated lignin samples were used as additives, which not only improved the mechanical properties of PLA on the basis of retaining its thermal stability, but also granted excellent antimicrobial and biocompatibility properties. The results showed that the molecular weight of lignin was negatively correlated with the phenolic hydroxyl content, and the mechanical properties of the composites were also significantly affected by different molecular weights of lignin, indicating that the inhomogeneity of lignin affects its value-added utilization. The enhanced mechanical properties, antibacterial effect, and steady biocompatibility provide potential possibilities for lignin-based composites in biomedical applications.

Photochemically Driven Polymeric Biocompatible and Antimicrobial Thiol-Acrylate Nanocomposite Suitable for Dental Restoration.

The development a photochemically driven polymeric composite for dental restorative materials to restore tooth cavities with antibacterial, biocompatibility, and outstanding mechanical properties is an urgent need for clinical application in stomatology. Herein, a series of polyurethane acrylate (PUA) prepolymers and antibacterial polyurethane acrylate quaternary ammonium salts (PUAQASs) were synthesized, and their mechanical and biological properties were explored. The unique secondary mercaptan with a long shelf life and low odor was used to reduce oxygen inhibition and increase cross-linking density; meanwhile, modified photocurable nano zirconia (nano ZrO2) enhances mechanical properties of the nanocomposites and possesses preeminent dispersion in the matrix. The results show that minimal inhibitory concentrations (MICs) of PUAQASs are 200 and 800 µg/mL for Staphylococcus aureus and Escherichia coli, respectively. The addition of secondary thiols significantly increases the photopolymerization rate and monomer conversion. The highest hardness and modulus reach 1.8 and 8.7 GPa compared to 1.8 and 8.3 GPa for commercial resin. The lap shear stress on the pig bone is 912 MPa, and that on commercial resin is 921 MPa. Most importantly, the photochemically driven polymeric composite has excellent biocompatibility and significantly better antimicrobial properties than commonly used commercial resins.

Greatly enhanced energy density and patterned films induced by photo cross-linking of poly(vinylidene fluoride-chlorotrifluoroethylene).

Greatly enhanced energy density in poly(vinylidene fluoride-chlorotrifluoroethylene) [P(VDF-CTFE)] is realized through interface effects induced by a photo cross-linking method. Being different from nanocomposites with lowered dielectric strength, the cross-linked P(VDF-CTFE)s possess a high breakdown field as well as remarkably elevated polarization, both of which contribute to the enhanced energy density as high as 22.5 J · cm(-3). Moreover, patterned thin films with various shapes and sizes are fabricated by photolithography, which sheds new light on the integration of PVDF-based electroactive polymers into organic microelectronic devices such as flexible pyroelectric/piezoelectric sensor arrays or non-volatile ferroelectric memory devices.

[Case control study on anatomical locking plate and ordinary steel plate for the treatment of closed calcaneal fracture with Sandersâ ¡and â ¢].

OBJECTIVE: To compare clinical efficacy between anatomical locking plate (ALP) and ordinary steel plate (OSP) in treating closed calcaneal fractures with SandersⅡ and Ⅲ. METHODS: From May 2016 to May 2018, 68 patients with closed Sanders typeⅡ and Ⅲ calcaneal fractures were retrospectively analyzed, and were divided into anatomical locking plate group (ALP group) and ordinary steel plate group (OSP group) according to two kinds of plate fixation, and 34 patients in each group. In ALP group, there were 21 males and 13 females aged from 20 to 63 years old with average of (35.16±8.45) years old; 14 patients were typeⅡand 20 patients were type Ⅲaccording to Sanders classification;treated with ALP. In OSP group, there were 20 males and 14 females aged from 19 to 63 years old with average of (35.05±8.39) years old;19 patients were typeⅡand 15 patients were type Ⅲ according to Sanders classification;treated with OSP. Operative time, intraoperative blood loss and complications between two groups were observed and compared;preoperative and postoperative Böhler angle and gissane angle were also compared;American Orthopaedic Foot & Ankle Society (AOFAS) ankle and hind foot scores, foot and ankle disability index (FADI) scores were applied to evaluate clinical effect. RESULTS: All patients were followed up from 11 to 14 months with an average of (12.06±0.81) months. There were no statistical differences in opertive time, intraoperative blood loss, incision infection and refracture rate in complications between two groups (P>0.05);while there was significant difference in the number of screw loosening (P<0.05). Böhler angle and Gissane angle in ALP group at 6 and 12 months after opertaion were higher than that of OSP group (P<0.05), and the degree of improvement of Böhler angle and Gissane angle in ALP group were also higher than that of OSP group (P<0.05). Postopertaive AOFAS score and FADI score at 6 and 12 months in ALP group were higher than that of OSP group (P<0.05), while no statistical difference in AOFAS grading between two groups(P>0.05). CONCLUSION: Compared with OSP, ALP in treating SandersⅡ and Ⅲ calcaneal fractures could achieve better therapeutic effect, avoid screw loosening, reduce complications, and improve limb function in further.

[Pharmacodynamics, pharmacokinetics and tissue distribution of liposomal mitoxantrone hydrochloride].

This study is to compare the pharmacodynamics, pharmacokinetics and tissue distribution of liposomal mitoxantrone (Mit-lipo) and free mitoxantrone (Mit-free). The antineoplastic effect of Mit-lipo was evaluated on PC-3 human xenograft tumor model after repeated intravenous injection at dose levels of 1, 2 and 4 mg x kg(-1). The pharmacokinetic study of Mit-lipo and Mit-free was performed on dogs following a single intravenous injection. The tissue distribution of Mit-lipo and Mit-free was observed on S-180 bearing mice after a single intravenous injection. (1) Pharmacodynamics: Mit-lipo dose-dependently inhibited PC-3 tumor growth at a dose ranging from 1 to 4 mg x kg(-1). The antitumor effect studies showed that Mit-lipo significantly improved the therapeutic effect in comparison with free drug. (2) Pharmacokinetics: in comparison with Mit-free, the AUC and t(1/2) values of Mit-lipo at the same dose level were higher than those of Mit-free in Beagle dogs. The results showed that Mit-lipo had long circulation characteristics. (3) Tissue distribution in S-180 bearing mice: compared to Mit-free, Mit-lipo preferentially accumulated into tumor zones instead of normal tissues. Tumor AUC in Mit-lipo treated animals was 8.7 fold higher than that in mice treated with the same dose of Mit-free. The Cmax values of Mit-lipo in heart, kidney, lung, spleen and intestinal tissue in Mit-lipo were 30.2%, 161.6%, 20.2%, 27.9% and 78.3% lower than those of Mit-free, respectively. The pharmacokinetics and tissue distribution of Mit-lipo changed obviously, thus increasing therapeutic effect and improving drug therapeutic index.

[A structural mechanics study with human maxillary premolar].

OBJECTIVE: To evaluate the stress distribution and offset of dental and periodontal tissues imposed by changes in inner diameter of pulp cavity. METHODS: Six models of maxillary second bicuspid tooth with different inner diameter of pulp cavity were established, including: (1) calcificated pulp without pulp chamberi (2) mostly calcificated pulp chamber with inward reduction of 0. 5 mm in normal pulp cavity; (3) initially calcificated pulp chamber with inward reduction of 0.25 mm in normal pulp cavity; (4) normal pulp cavity; (5) initially absorbed pulp chamber with outward expansion of 0.25 mm in normal pulp cavity; (6) mostly absorbed pulp chamber with outward expansion of 0.5 mm in normal pulp cavity. Vertical and oblique forces with 160 N were loaded on the central fossa, respectively, in order to calculate the stress distribution of dental and periodontal tissues and the maximum incipient offset of the teeth. RESULTS: With loaded vertical and oblique forces on central fossa, increased stress distribution of periodontal tissues and maximum incipient offset of teeth were found in all of the models, which increased with the increase of pulp cavity. CONCLUSION: The change in inner diameter of pulp cavity has an impact on the stress distribution of periodontal tissues and maximum incipient offset of the second upper bicuspid teeth.

From polystyrene waste to porous carbon flake and potential application in supercapacitor.

Due to white pollution related environmental concern and sustainable development requirement, it is desirable to recycle the widely used plastic wastes into products with commercial value, such as high-valued carbon materials which can be applied in electrochemical fields. In this work, porous carbon flakes (PCFs) are produced by direct pyrolysis of polystyrene waste through template method. Furthermore, manganese dioxide (MnO2) nanosheets are selectively deposited on the surface of resultant PCFs to form hybrid (PCF-MnO2). Because of the large specific surface area (1087 m2/g) and high conductivity of PCFs, native high specific capacity of MnO2, and positive synergistic interaction between PCF and MnO2, the resulting hybrid materials show an ultrahigh capacitance of 308 F/g at 1 mV/s and 247 F/g at 1 A/g in LiCl electrolyte, and excellent cycle stability of 93.4% capacitance retention over 10,000 cycles at 10 A/g in symmetric supercapacitor device. This work demonstrates a convenient method for the preparation of cost-effective and high-performance electrode material for electric capacitor. More importantly, it provides a potential way to recycle polystyrene waste into high-valued product in large-scale with disposing of polymeric waste to alleviate environmental concerns.

[Effect of gilding technique on the element release of beryllium ion from Vera Bond titanium alloy].

OBJECTIVE: To research the effect of gilding technique on the element release from Vera Bond Ti alloy exposed to artificial saliva. METHODS: To divided experimental group into 4 groups: common used Ti porcelain crown (controlling group, A1), polished Ti porcelain crown (polished group, A2), gilded Ti porcelain crown (gold-plating group, A3), gilded Ti porcelain crown prolonged 50% (gold-plating prolonged 50% group, A4). T measure the quantity of beryllium ion in artificial saliva after 1 month, 3 months and 6 months by means of ICP-AES. So the efect of released beryllium ion with different treatments and the role of different times with the same treatment were compared. RESULTS: The quantity of released beryllium ion was statistic significant among different treatments. The quantity of released beryllium ion was gradually increased with the same treatment. The speed of released beryllium ion was gradually decreased with the same treatment. CONCLUSION: The gilding treatment can decrease the quantity of beryllium ion which released from Ti porcelain crown,and improve the biocompatibility.

Delayed total hip arthroplasty after failed treatment of acetabular fractures: an 8- to 17-year follow-up study.

BACKGROUND: Delayed total hip arthroplasty (THA) is a reliable procedure following failed treatment of acetabular fractures. The aim of the present study was to evaluate the influence of the type of fracture treatment and modern ceramic bearing on the clinical outcomes of delayed THA. METHODS: Between January 1997 and January 2008, 33 patients (33 hips) underwent cementless THA after failed acetabular fractures. Twenty-one were initially treated by open reduction internal fixation (ORIF) and 12 had non-ORIF. Joint articulation was either conventional metal-on-polyethylene (MOP) or ceramic-on-ceramic (COC). Intraoperative measures and preoperative and follow-up clinical, radiological, and functional outcomes were compared between the ORIF and non-ORIF groups. RESULTS: Surgery duration, blood loss, and transfusion requirement were greater in the ORIF group than in the non-ORIF group (p < 0.05). Significant improvement in Harris Hip Scores was seen post-surgery in both groups. However, a significant difference in the mean Harris Hip Score was not observed between the two groups (p = 0.57). Six patients in the ORIF group required acetabular reconstructive procedures to address bony defects compared to seven patients in the non-ORIF group (p = 0.09). The rate of anatomical restoration was 58.3% (7/12) in the non-ORIF group and 42.9% (9/21) in the ORIF group (p = 0.12). Radiolucent lines were observed in the MOP group and none in the COC group. Overall survival rate was similar in both groups (p = 0.85): 89.3% in the ORIF group and 87.5% in the non-ORIF group. CONCLUSION: Delayed THA with previous acetabular fractures is a challenging procedure. Initial fracture treatment does not influence the outcome of delayed THA, and modern ceramic bearing has promising results in the long-term follow-up.