Construction of folate receptors and mitochondria targeting celastrol-loaded PAMAM nano-drug delivery system and its in vitro anti-inflammatory effect / 药学学报

Pro-inflammatory macrophages play key regulatory role in the occurrence and development of rheumatoid arthritis (RA). In this study, we constructed a celastrol (Cel)-loaded polyamide-amine dendrimer (PAMAM) drug delivery system, which could target folate receptor and mitochondria. It could target inflammatory macrophages and realize chemo-photothermal synergistic therapy. Using PAMAM as the nano-carrier, folate receptor-targeting group folic acid (FA) and mitochondria-targeting group IR808 (also known as the photothermal agent) were conjugated with PAMAM through amide reaction, and then complexed with anti-inflammatory drug Cel to prepare the FA-PAMAM-IR808/Cel nanocomplex. In vitro characterization results showed that the drug loading efficiency of the nanocomplex was 50.90%, particle size was between 130 and 160 nm, average potential was between 1.0 and 3.5 mV, the drug release showed pH sensitivity, temperature reached to 42.5 ℃ after near-infrared (NIR) light irradiation for 10 min. In vitro cellular uptake experiments showed that the nanocomplex had obvious folate receptor-targeting and mitochondria-targeting ability. Following irradiation with NIR light, the cytotoxicity and cellular apoptosis enhanced. The secretion of pro-inflammatory factors tumor necrosis factor α (TNF-α), interleukin (IL)-1β, IL-6 and nitric oxide (NO) decreased in a concentration-dependent manner. This study provided insights for the development of novel anti-RA nanomedicines.

Removal of denture adhesives from PMMA and Polyamide denture base materials

Abstract Denture adhesives need complete removal due to their frequent replacement. Objective Our study investigates the removal of denture adhesives from denture base materials, using different methods. Methodology PMMA and Polyamide denture base materials were used to fabricate 120 samples (15×15×1.5mm). One side of the samples was left as processed and the other polished with a usual procedure, hydrated for 24 h, dried, and weighted. They received 0.2 g of three adhesive creams on their unpolished surface (Corega, Olivafix, Fittydent), pressed on polysulfide material, stored under 37°C and 95% rel. humidity for 1 h and 60 of them, following their separation from polysulfide base, brushed under running water, whereas the rest inserted in a cleanser bath (Fittydent Super) for 5 min. The samples were dried and inserted in the oven (37°C) for additional 10 min and weighted again. Roughness tests of denture materials and light microscopy of adhesives creams were also used to evaluate the materials. Time lapse images of spayed with water adhesives on PMMA base were also taken to evaluate the volumetric changes of adhesives. Weight data before and after adhesive removal, indicating the amount of remaining adhesive, were statistically analyzed using Welch's ANOVA and Games-Howell multiple comparisons tests at α=0.05 level of significance. Results Roughness of Polyamide was higher than PMMA and Fittydent showed greater volumetric changes than the others. Significant differences (p<0.05), were found between PMMA and Polyamide bases, between Olivafix and Fittydent adhesives, and between brushing and cleansing methods but only for PMMA-Olivafix combination. Conclusions Adhesives showed a stronger adherence to PMMA surface, and Fittydent was the most difficult to be removed. Removal methods were not effective for all adhesives or denture base materials. These indicate that removal methods, adhesive type and denture base material are all playing a significant role in the removal of adhesives from denture surfaces.

Nano-hydroxyapatite/polyamide 66 composite filling combined with locking plate in the treatment of fibrous dysplasia of femoral bone / 中国组织工程研究

BACKGROUND: Nano-hydroxyapatite/polyamide 66 composite (n-HA/PA66) has good biocompatibility, osteoinduction, osteoconductivity and osteogenesis. It is widely used in clinical fracture healing, spinal fusion, and other bone repair. OBJECTIVE: To observe the effect of n-HA/PA66 filling combined with locking plate in the treatment of fibrous dysplasia of femoral bone. METHODS: From May 2015 to May 2018, 15 patients with fibrous dysplasia of bone were admitted to Xingtai People’s Hospital Affiliated to Hebei Medical University. There were 4 males and 11 females, aged 16-58 years. The lesions were all located in the femur. They were all treated with n-HA/PA66 filling combined with locking plate. The patients were followed up for 18-40 months. Imaging examination (X-ray and CT scan) was carried out to evaluate the bone healing. Musculoskeletal Tumor Society (MSTS) score and Harris score were used to assess the functional recovery of patients after operation. RESULTS AND CONCLUSION: (1) X-ray films showed that there was a clear boundary between the transplanted bone and the host bone immediately after the operation. At 3 months after the operation, the transplanted bone was replaced partly by crawling. At 6 months, new bone formation was obvious. At 9-12 months, new bone formed completely. The transplanted bone was basically catabolized. At 18 months, the new bone was completely integrated with the host bone. The boundary between the new bone and the host bone disappeared. New bone and host bone are connected by direct trabecula. (2) At the last follow-up, CT images showed that the local lesions were eliminated; no recurrence or metastasis occurred; and the grafts healed completely. The G/N ratio was 0.78±0.09. (3) At the last follow-up, 15 patients’ pain all disappeared, MSTS score was 28.1±0.7. Harris score was 94.3. Daily physical activity was restored. (4) n-HA/PA66 composite material has obvious osteogenic effect on the bone defect caused by the removal of fibrous dysplasia. Locking plate fixation can make patients move early and obtain good postoperative function.

LCMS-IT-TOF Analysis of Retention Behavior of Sanguisorbae Radix Components on D101 Macroporous Resin and Polyamide Resin / 中国实验方剂学杂志

Objective:To study on the material basis of Sanguisorbae Radix by column chromatography and liquid chromatography-ion trap-time-of-flight mass spectrometry (LCMS-IT-TOF), and analyze the distribution of different components in Sanguisorbae Radix water extract on D101 macroporous resin and polyamide resin. Method:Sanguisorbae Radix water extract was separated by D101 macroporous resin and polyamide resin, and LCMS-IT-TOF was used for detection, chromatography separation was achieved on an ACQUITY UPLC HSS T3 column (2.1 mm×100 mm, 1.8 μm) with the mobile phase consisted of water (A) and acetonitrile (B) for gradient elution (0-10 min, 5%-20%B; 10-18 min, 20%-35%B; 18-23 min, 35%-50%B; 23-28 min, 50%-90%B; 28-30 min, 90%B; 30-33 min, 90%-5%B; 33-35 min, 5%B), the flow rate was 0.3 mL·min-1, the column temperature was 30 ℃. Data acquisition was carried out in electrospray ionization (ESI) under the positive and negative ion modes, the scanning range was m/z 100-1 200. According to mass spectrometry data such as accurate molecular mass and fragment information, combined with literature, different chemical components in loading effluents and ethanol eluents of Sanguisorbae Radix water extract were identified. A heat map of the distribution of components in each fraction was drawn by extracting mass spectrum peak intensity data of each sample. The elution rules of various components were compared visually. Result:The enrichment and separation of D101 macroporous resin and polyamide resin were obvious. Tannins in Sanguisorbae Radix water extract was mainly concentrated in loading effluent of macroporous resin and its water eluent, triterpenoids were mainly distributed in the 90% ethanol eluent of macroporous resin. In the above effluents and eluents, a total of 63 compounds (including isomers) were identified. Among them, 6 compounds, ellagic acid-4-pyranoarabinoside or its isomer, 6-O-galloylnorbergerin, 3-O-galloylnorbergerin, (6-acetyloxy-5,7-dihydroxy-8-methoxy-4-oxochromen-2-yl) acetate, ethyl 2-methyl-5,6-bis (sulfooxy) benzofuran-3- carboxylate were first discovered in Sanguisorbae Radix. Conclusion:The method can quickly and accurately identify the distribution of components in aqueous extract of Sanguisorbae Radix after column chromatography, providing experimental basis for exploring the pharmacodynamic components and mechanism of Sanguisorbae Radix.

Research progress on the biomimetic remineralization of hard tooth tissues based on polyamide-amine dendrimer / 华西口腔医学杂志

Polyamide-amine (PAMAM) dendrimer, a new hyperbranched macromolecular polymer, is considered an "artificial protein" by many scholars on account of its excellent chemical and biological characteristics. PAMAM has internal cavities and a large number of reactive terminal groups. These structures allow the polymer to be used as a bionic macromoleculethat could simulate the biomimetic mineralization of the natural organic matrix on the surface of tooth tissue. Specifically, PAMAM can beused as an organic template to regulate mineral nucleation and crystal growth; thus, the polymerisa more ideal dental restoration material than traditional allogenic materials. This article reviews research progress on thePAMAM-induced biomimetic mineralization of hard tooth tissues.

Purification of Periploca forrestii total flavonoids and assay for the in vitro inhibitory activity on xanthine oxidase / 国际药学研究杂志

Objective: To extract and purify total flavonoids from Periploca forrestii Schltr.(P. forrestii),and test the in vitro inhibitory activity of the total flavonoids and two flvaonoidal compounds in P. forrestii,so as to provide a reference for studies on the related medicinal substances in P. forrestii. Methods: Total flavonoids were extracted from P. forrestii and then purified by the column chromatography on macroporous resin and polyamide columns. The content of total flavonoids was determined according to the Lambert-Beer’s law. The in vitro xanthine oxidase(XOD)inhibitory ac- tivity was assayed for total flavonoids and the two flavonoidal compounds by the ultraviolet spectrophotometry. Results The purified total flavonoids had a content of more than 95%. The total flavonoids and two flavonoidal compounds all showed an inhibitory effect on XOD in vitro,with the inhibitory rate enhanced with increasing concentration. The IC50 of the total flavonoids as well as the two flavonoidal compounds,quercetin-3-O-α-L-pyranoside(QP)and quercetin-7-O-β- D-glucopyranoside(QG)were 608.9,221.2 and 261.2 μg/ml,respectively. Conclusion: The total flavonoids as well as the two flvaonoidal compounds QP and QG in P. forrestii all showed the in vitro inhibitory activity on XOD.

Effectiveness of nano-hydroxyapatite/polyamide-66 Cage in interbody fusion for degenerative lumbar scoliosis / 中国修复重建外科杂志

Objective: To explore the effectiveness of nano-hydroxyapatite/polyamide-66 (n-HA/PA66) Cage in interbody fusion for degenerative lumbar scoliosis. Methods: A retrospective analysis was designed and conducted for 43 patients, who underwent posterior decompression and n-HA/PA66 Cage interbody fusion with correction of deformity between January 2013 and June 2016. Eighteen cases were single-level fusion (single-level group) and 25 cases were double-level fusion (double-level group). There was no significant difference in gender, age, body mass index, direction of convex, degree of apical rotation, fusion level, the number of osteoporotic patients, pre-operative intervertebral height of fusion segments, coronal Cobb angle, visual analogue score (VAS), and modified Oswestry Disability Index (ODI) between 2 groups ( P>0.05). The operation time, intraoperative blood loss, postoperative drainage, hospital stay, and complications of the operation were recorded. Modified ODI, VAS score, and MacNab criteria were adopted to assess clinical outcomes. Radiographic indexes, including intervertebral height of fusion segments, coronal Cobb angle, disc insertion depth, and the bone graft fusion rate, were also evaluated. Results: There was no significant difference in operation time, intraoperative blood loss, postoperative drainage, and hospital stay between 2 groups ( P>0.05). All patients were followed up 18-62 months (mean, 30.9 months). Wound complications, postoperative delirium, and Cage retropulsion occurred in 4 cases (2 cases in single-level group, 2 cases in double-level group), 1 case of single-level group, and 1 case of double-level group, respectively. The intervertebral height of fusion segments after operation significantly improved compared with preoperative ones in both groups ( P0.05). The disc insertion depth showed no significant difference between different time points after operation in 2 groups ( P>0.05) and between 2 groups at each time point after operation ( P>0.05). Bony fusion was obtained in all patients at last follow-up. The VAS score and modified ODI after operation in both groups were superior to those before operation ( P0.05). According to the MacNab criteria, the excellent and good rates at last follow-up were 94.4% and 84.0% in single-level group and double-level group, respectively. Conclusion: The n-HA/PA66 Cage can effectively restore and maintain the disc height of fusion segment, normal sequence, and biomechanical stability of the spine, and gain favorable effectivenss for degenerative lumbar scoliosis. And double-level fusion is superior to single-level fusion in maintaining disc height of fusion segment.

Optimization of purification technology of naringin from leaves of Acanthopanax evodiaefolius by response surface methodology / 中草药

Objective: Response surface methodology was used to optimize the purification process of naringin from Acanthopanax evodiaefolius leaves by polyamide resin. Methods: The optimum technological conditions for the purification of naringin in the leaves of Acanthopanax evodiaefolius were screened by single factor investigation and response surface design with five factors, including the concentration of sample, sample loading, the elution system, the amount of eluent, and the flow rate. Results: The optimum purification conditions of naringin in the leaves of A. evodiaefolius were as follow: the concentration of the sample was 4.0 mg/mL, the sample volume was 3.5 BV, the elution system was 30% methanol, the eluant volume was 3.0 BV, and the elution flow rate was 8.0 BV/h. Under this condition, the purity of naringin was improved from 5.08% to 56.12%, and the yield was 41.69%. And mass fraction reached more than 90% after recrystallization, which met the requirements of pharmaceutical raw materials. Conclusion: Purification of naringin from the leaves of A. evodiaefolius by polyamide resin chromatography has the advantages of good purification effect, simple operation, high efficiency, and good stability, which can be used for industrial production.

Biocompatibility of polyamide 12 intramedullary rod after humeral consolidation in white Plymouth Rock birds / Biocompatibilidade de haste intramedular bloqueada de poliamida 12 após consolidação óssea umeral em aves Plymouth Rock branca

Technological and tissue engineering have enabled available, biologically inert, and low cost materials to be considered as viable alternatives in the surgical treatment of long bone fractures in birds. The aim of this study was to microscopically analyse osteotomized humerus of birds following the insertion of solid laser-sintered polyamide 12 rods in order to detect foreign body reaction and, thus, verify the bioinert property of the material in the bone fracture environment. Polyamide 12 intramedullary rods were inserted into the osteotomized humerus of 10 birds (white Plymouth Rock) and blocked using 2mm diameter cortical screws of varying lengths. The birds were operated at 60 days of age and monitored post-operatively for three months. Animals were euthanized at 150 days old and samples of the operated humerus collected for immunohistochemistry, light and scanning electron microscopy analysis. Results show bone consolidation without rejection of the implant and absence of inflammatory cells. Vascular Endothelial Growth Factor (VEGF) was expressed in the endothelial cells of the blood vessels at the site of the newly formed bone surrounding the implant, indicative of local angiogenesis. There was no bone growth on the surface of the rod; however, the implant did not interfere with the circumjacent bone repair. Thus, the findings of this study corroborate with the literature in characterizing polyamide as a bioinert material and, under the studied conditions, it can be concluded that polyamide 12 intramedullary rod is biocompatible and provides adequate bone consolidation in humeral fractures with no signs of rejection.(AU)

Com o desenvolvimento tecnológico e crescimento da engenharia de tecidos, o uso de materiais disponíveis, bioinertes e debaixo custo pode ser alternativa viável para o tratamento cirúrgico de fraturas em ossos longos nas aves. O objetivo do estudo foi realizar avaliação microscópica óssea após a implantação de haste maciça de poliamida, implantada em úmeros osteotomizados de galinhas para detectar reação do tipo corpo estranho, verificando a propriedade "bioinerte" do material no ambiente de fratura óssea. Foram utilizados 10 galos (Plymouth rock branca) e implantou-se a haste perfazendo o bloqueio das mesmas com parafusos corticais de 2 mm de diâmetro com comprimentos de acordo com a necessidade. As aves foram operadas aos 60 dias de vida e o acompanhamento pós-operatório ocorreu por três meses. Após a eutanásia, foram realizadas coletas do úmero operado (local de consolidação óssea) paraexame histopatológico, imuno-histoquímico e de microscopia eletrônica de varredura. Os resultados demonstraram consolidação óssea, sem presença de rejeição do material, com ausência de células inflamatórias. A neoformação óssea ao redor do implante expressou VEGF (fator de crescimento endotelial vascular) nas células endoteliais dos vasos sanguíneos caracterizando angiogênese no local. Na região de interface de tecido ósseo com a poliamida não foram observadas micro fraturas. Não houve crescimento ósseo na superfície da haste, porém a mesma não atrapalhou o reparo ósseo circunjacente. Assim, esse estudo corrobora com a literatura caracterizando a poliamida como um material bioinerte, e nas condições estudadas pode-se concluir que o uso da haste intramedular de poliamida 12 proporcionou consolidação óssea nesse modelo biológico nesse tipo de fratura, não havendo indícios de induzir rejeição.(AU)

Pro - inflammatory cytokines and metalloproteinase activation in polypropylene mesh implant in rat subcutaneous tissue

ABSTRACT Aims and Objectives: Polypropylene meshes have been increasingly adopted for correction of pelvic organ prolapse due to its lower recurrence rate when compared to surgeries without meshes. The study of the interaction of these materials with the host tissue may contribute to the development of materials with best biocompatibility and, consequently, less complication rates. Materials and Methods: The present study compares the inflammatory reaction of standard-weight (SW) and lightweight (LW) meshes (72 g/m216g/m2 respectively), implanted in the abdomen of 20 adult rats, which were euthanized in four or 30 days. Quantification of pro-inflammatory markers, IL-1 and TNF-α, and of metalloproteinases, MMP2 and MMP3, were carried out through immunohistochemistry with AxioVision® software. Results: There were no significant differences in the quantification of IL-1 and TNF-α in LW versus SW meshes. However, IL-1 quantification increased along time (30 days >4 days, p=0.0269). Also, MMP-2 quantification was similar to SW and LW and both presented a significant increase along time (30 days >4 days, p <0.0001). MMP-3 quantification also showed no difference between the SW and LW groups, but increased along time (30 days >4 days, p=0.02). Conclusions: Mesh's density did not influence the quantification of pro-inflammatory cytokines IL-1 and TNF-α and metalloproteinases 2 and 3. The increased expression of IL-1, MMP-2 and MMP-3 over time could represent a longstanding inflammatory response after PP mesh implantation. Possibly, the occurrence of adverse events following PP prosthetic implants can be influenced by other factors, not solely related to the amount of implanted material.

Research on Separation and Purification of Extract from Hyssopus cuspidatus Boriss. with Polyamide Resins / 中国中医药信息杂志

Objective To investigate the optimal process conditions for the separation and purification of extract from Hyssopus cuspidatus Boriss. by polyamide resins. Methods The total flavonoids and rosmarinic acid were used as the indexes. The maximum amount of sample solution, elution volume, concentration of sample solution, adsorption time of resin, loading time of sample solution and the amount of eluting solvent, pH and elution rate in the resin purification process were screened by single factor method. Results The optimal purification parameters were as follows: 10 mg/mL of extract, 12 mL of sample amount, 2 BV of water to remove impurities, 40% ethanol to elute 9 BV; the concentration of rosmarinic acid in sample solution was 86.3 μg/mL, and the total flavonoid concentration was 117.8 μg/mL; the resin adsorption time was 14 h; the pH of sample solution was 6.5; the elution rate was 3.0 BV/h. Conclusion This method is simple and feasible, fit for separating and purifying of extract from Hyssopus cuspidatus Boriss.

Cytotoxicity of non-viral gene vector polyamide amine dendrimers-hyaluronic acid polymer / 中国药理学与毒理学杂志

OBJECTIVE To study the cytotoxicity of polyamide amine dendrimers (PAMAM)-hyaluronic acid(HA)as a non-viral gene delivery vector in vitro. METHODS PAMAM-HA was synthesized by our laboratory. Cytotoxicities of various polymers on HeLa cells,Bel-7402 cells and HepG2 cells were evaluated by MTT assay. Apoptotic rates were determined by flow cytometry. RESULTS The cytotoxicity of PAMAM-HA polymer increased with the concentration of polymer(50-800 mg · L-1),the time of action(24-72 h), the number of generations of PAMAM(G4,G5) and decrease in the molecular mass(3850,17 200)and the graft density(5%-25%)of HA. After incubation with PAMAM G4-HA3850-5%or PAMAM G5-HA3850-5%for 24 h,the apoptotic rate of hepatoma cells—Bel-7402 cells was 4.5%and 9.9%,respectively. After incubation with complexes of PAMAM G4-HA3850-5%/DNA or PAMAM G5-HA3850-5%/DNA for 24 h,the viability of HeLa cells was more than 80%,which was lower than that of PAMAM G4/DNA和PAMAM G5/DNA. CONCLUSION Cytotoxicity of PAMAM modified by HA of different grafting density and quantity can be reduced ,suggesting the PAMAM is a promising non-viral gene vector.

Preface for special issue on bio-based materials (2016) / 生物工程学报

Bio-based materials are new materials or chemicals with renewable biomass as raw materials such as grain, legume, straw, bamboo and wood powder. This class of materials includes bio-based polymer, biobased fiber, glycotechnology products, biobased rubber and plastics produced by biomass thermoplastic processing and basic biobased chemicals, for instance, bio-alcohols, organic acids, alkanes, and alkenes, obtained by bio-synthesis, bio-processing and bio-refinery. Owing to its environmental friendly and resource conservation, bio-based materials are becoming a new dominant industry taking the lead in the world scientific and technological innovation and economic development. An overview of bio-based materials development is reported in this special issue, and the industrial status and research progress of the following aspects, including biobased fiber, polyhydroxyalkanoates, biodegradable mulching film, bio-based polyamide, protein based biomedical materials, bio-based polyurethane, and modification and processing of poly(lactic acid), are introduced.

Effect of surface treatment methods on the shear bond strength of auto-polymerized resin to thermoplastic denture base polymer

PURPOSE: Polyamide polymers do not provide sufficient bond strength to auto-polymerized resins for repairing fractured denture or replacing dislodged denture teeth. Limited treatment methods have been developed to improve the bond strength between auto-polymerized reline resins and polyamide denture base materials. The objective of the present study was to evaluate the effect of surface modification by acetic acid on surface characteristics and bond strength of reline resin to polyamide denture base. MATERIALS AND METHODS: 84 polyamide specimens were divided into three surface treatment groups (n=28): control (N), silica-coated (S), and acid-treated (A). Two different auto-polymerized reline resins GC and Triplex resins were bonded to the samples (subgroups T and G, respectively, n=14). The specimens were subjected to shear bond strength test after they were stored in distilled water for 1 week and thermo-cycled for 5000 cycles. Data were analyzed with independent t-test, two-way analysis of variance (ANOVA), and Tukey's post hoc multiple comparison test (α=.05). RESULTS: The bond strength values of A and S were significantly higher than those of N (P<.001 for both). However, statistically significant difference was not observed between group A and group S. According to the independent Student's t-test, the shear bond strength values of AT were significantly higher than those of AG (P<.001). CONCLUSION: The surface treatment of polyamide denture base materials with acetic acid may be an efficient and cost-effective method for increasing the shear bond strength to auto-polymerized reline resin.

The experimental research of nano-hydroxyapatite/polyamide 66/platelet-rich plasma compound repair of rabbit femoral bone defect / 重庆医学

Objective To investigate the therapeutic effects of nano-hydroxyapatite/polyamide 66/platelet-rich plasma com-pound(n-HA/PA66/PRP)on the recovery of rabbit femur bone defect.Methods 40 New Zealand rabbits were artificially made to be bone defect by resecting the 1 cm substantia ossea with periosteum of femur,and were divided into two groups averagely depen-ding on implanted materials:experimental group(n-HA/PA66/PRP),control group (n-HA/PA66).Every five rabbits were sacri-ficed on week 2,4,8,12,and the femur healing status was observed by X ray,histology,and immunohistochemistry.Results No rabbit was infected or died,no implantation objects dropped.Gross observation,X-ray result and histology results demonstrated that the experimental group began to have a new bone tissue at 2 weeks after the operation,with the extension of time,the experimental group new bone growth speed and the quantity was better than the control group.The Lane-Sandhu method X-ray score showed that the experimental group (6.80±2.05)points and the control group(4.20±1.30)points at 12 weeks after the operation,and there were significant differences between two groups(P 0.05).Conclusion PRP combined with n-HA/PA66 artificial bone could accel-erate the healing of bone defect,and the effect of repair of bone defect is better than that of n-HA/PA66 artificial bone in the early.

In vitro study on new bioactive bone screws affecting biological behavior of osteoblasts / 中华创伤杂志

Objective To detect the effect of a new bioactive bone screws composed of nanohydroxyapatite/polyamid 66/glass fiber (n-HA/PA66/GF) biomaterial on biological behavior of osteoblasts with a view to a later clinical application of the screws.Methods Mice osteoblasts were co-cultured with n-HA/PA66/GF biomaterial or its extract.Cell growth was detected under a microscope,cell proliferation using MTT assay,apoptosis by flow cytometry,osteocalcin by ELISA method,cell migration using Transwell invasion assay,cell adhesion and growth by scanning electron microscope,and cytoskeleton and actin filament distribution using immunofluorescene.Results Direct contact test demonstrated n-HA/PA66/GF material had no obvious cytotoxicity to osteoblasts.Extract of n-HA/PA66/GF material stimulated osteoblast proliferative activity over time with absorbance value of 0.96 ± 0.14,1.54 ± 0.15,and 2.39 ±0.27 respectively after 2,4,and 6 hours of coculture (P ＜ 0.05).The n-HA/PA66/GF material induced more osteoblasts to entering S period without obvious influence on apoptosis rate and promoted osteocalcin secretion.Migrated cells in medium supplied with n-HA/PA66/GF material or FBS was 8.73 ± 3.26 and 9.47 ± 3.29 in each visual field,but there was no significant difference (P ＞ 0.05).Osteoblasts had a regular form on the surface of n-HA/PA66/GF material,closely adhered to the surface,and reproduced and aggregated with each other to form stratified cell layers.However,nHA/PA66/GF material exhibited no obvious influence on distribution of cytoskeleton and actin filament.Conclusion The new n-HA/PA66/GF screws has excellent cytocompatibility with positive regulatory effect on cell growth,proliferation,secretion,adhesion,cycle,and osteocalcin secretion.

Mechanical and thermal properties of polyamide versus reinforced PMMA denture base materials

PURPOSE: This in vitro study intended to investigate the mechanical and thermal characteristics of Valplast, and of polymethyl methacrylate denture base resin in which different esthetic fibers (E-glass, nylon 6 or nylon 6.6) were added. MATERIALS AND METHODS: Five groups were formed: control (PMMA), PMMA-E glass, PMMA-nylon 6, PMMA-nylon 6.6 and Valplast resin. For the transverse strength test the specimens were prepared in accordance with ANSI/ADA specification No.12, and for the impact test ASTM D-256 standard were used. With the intent to evaluate the properties of transverse strength, the three-point bending (n=7) test instrument (Lloyd NK5, Lloyd Instruments Ltd, Fareham Hampshire, UK) was used at 5 mm/min. A Dynatup 9250 HV (Instron, UK) device was employed for the impact strength (n=7). All of the resin samples were tested by using thermo-mechanical analysis (Shimadzu TMA 50, Shimadzu, Japan). The data were analyzed by Kruskal-Wallis and Tukey tests for pairwise comparisons of the groups at the 0.05 level of significance. RESULTS: In all mechanical tests, the highest values were observed in Valplast group (transverse strength: 117.22 +/- 37.80 MPa, maximum deflection: 27.55 +/- 1.48 mm, impact strength: 0.76 +/- 0.03 kN). Upon examining the thermo-mechanical analysis data, it was seen that the E value of the control sample was 8.08 MPa, higher than that of the all other samples. CONCLUSION: Although Valplast denture material has good mechanical strength, its elastic modulus is not high enough to meet the standard of PMMA materials.

Function Study of the Nano-Molecular PAMAM as miR Carrier Targeting Gastric Adenocarcinoma / 天津医药

Objective To study the function of the nano-molecular polyamide-amine (PAMAM) as microRNA(miR) carrier targeting gastric adenocarcinoma, and the foundation of developing an efficient delivery of small molecule drugs tar-geting gastric cancer thereof. Methods The folic acid (FA)/PAMAM comoles compound was prepared by dialysis method. After transfection of miR-7 or liposomes into SGC-7901 cell line, fluorescence microscope was used to detect the gene trans-fect efficiency. Real-time quantitative polymerase chain reaction (qRT-PCR) was used to detect the miR-7 level. The immu-nocytochemistry assay was used to test the protein expressions of epidermal growth factor receptor (EGFR), protein kinase B (PKB) and proliferating cell nuclearantigen (PCNA). The transwell system was utilized to explore the migration ability of tu-mor cells. Results Compared with liposme, FA/PAMAN complex compound can significantly improve the level of miR-7 in SGC-7901 cells,reduce the protein levels of EGFR, PKB and PCNA in SGC-7901 cells, and also reduce the percentage of cancer cell migration (P<0.05). Conclusion PAMAM can effectively transfect miR into gastric cancer cells, which is expected to become an efficient delivery of small molecule drugs.

Clinical application of a bioactive nano-hydroxyapatite/polyamide 66 interbody fusion cage / 中国组织工程研究

BACKGROUND:There are various commonly used interbody fusion methods, such as autologous bone, al ograft bone and titanium-based posterior lumbar interbody fusion, and each method has its own advantages and disadvantages. OBJECTIVE:To observe the clinical efficacy of a bioactive nano-hydroxyapatite/polyamide 66 fusion cage in posterior lumbar interbody fusion for the treatment of lumbar disease. METHODS:A retrospective case analysis was conducted on 16 cases treated with posterior lumbar interbody fusion at the Department of Orthopedic, the First Affiliated Hospital of Gannan Medical University from July 2010 to December 2011, and al the patients were implanted with nano-hydroxyapatite/polyamide 66 biological activity fusion cage. RESULTS AND CONCLUSION:Al the patients were fol owed-up for 10-24 months, and the lumbar pain was significant improved, the lumbar visual analogue score, lumbar Japanese Orthopaedic Association score and Oswestry disability index score were significantly improved during the final fol ow-up period (Pfusion without nano-hydroxyapatite/polyamide 66 fusion cage displacement or subsidence. The results indicate that nano-hydroxyapatite/polyamide 66 fusion cage for the treatment of posterior lumbar interbody fusion can reconstruct the lumbar stability and provide immediate stability after implantation, and has good biological activity.

Surface roughness and Candida albicans adhesion to flexible denture base according to various polishing methods / 대한치과보철학회지

PURPOSE: The purpose of this study was to compare the effect of 3 chairside polishing methods and laboratory polishing methods on surface roughness and C. albicans adhesion of polyamide denture base. MATERIALS AND METHODS: Using contact profilometer, the surface of polyamide specimens (25x15x2 mm) was studied after conventional polishing without finishing and after chiarside polishing with 2 chiarside polishing kits and chairside-pumice polishing following finishing with tungsten carbide bur. To evaluate the adhesion of C. albicans, C. albicans suspension was overlayed on the test specimen. And the specimens were incubated for 2 hours. Imprint culture method was achieved and counted the colony on the agar plate. Polished polyamide were evaluated using a scanning electron microscope. The statistics were conducted using one-way ANOVA and in case of difference, Scheffe test and Tamhane's T2 test were used. RESULTS: Surface roughness (Ra) of surfaces polished with 2 chairside polishing kits had higher than conventional polishing and pumice polishing. The highest roughness value was 0.32 +/- 0.10 microm, and the lowest was 0.02 +/- 0.00 microm. The adhesion of C. albicans on the specimens polished with chairside polishing group and pumice polishing group were increased than conventional polishing group (P.01).