Hemocompatibility of bioprosthetic heart valve materials respectively based on glutaraldehyde and non-glutaraldehyde treatment / 中国胸心血管外科临床杂志

@#Objective    To study the hemocompatibility of bioprosthetic heart valve materials respectively based on glutaraldehyde and non-glutaraldehyde treatment. Methods    Fresh bovine pericardium was treated with glutaraldehyde or non-glutaraldehyde after adipose tissue was removed. To evaluate the hemocompatibility of the two bioprosthetic heart valve materials, hemolysis test, in vitro fibrinogen adsorption experiment, platelet adhesion experiment, thrombin-antithrombin complex (TAT) test, complement activation assay and ex vivo circulation experiment were performed. Results    The hemolysis test results demonstrated that both of the materials showed hemolytic rates lower than 5%. The results of TAT test and complement activation assay showed no statistical differences among the two materials and the blank control group. Compared to the bioprosthetic heart valve materials with glutaraldehyde-based treatment, the materials with non-glutaraldehyde-based treatment showed significantly decreased fibrinogen adsorption, platelet adhesion and thrombosis. Conclusion    Compared to the bioprosthetic heart valve materials with glutaraldehyde-based treatment, the materials with non-glutaraldehyde-based treatment show better hemocompatibility.

Effects of different crosslinking treatments on the properties of decellularized small intestinal submucosa porous scaffolds / 北京大学学报(医学版)

OBJECTIVE@#To compare the effects of three different crosslinkers on the biocompatibility, physical and chemical properties of decellularized small intestinal submucosa (SIS) porous scaffolds.@*METHODS@#The SIS porous scaffolds were prepared by freeze-drying method and randomly divided into three groups, then crosslinked by glutaraldehyde (GA), 1-ethyl-3-(3-dimethylaminopropyl) carbodi-imide (EDC) and procyanidine (PA) respectively. To evaluate the physicochemical property of each sample in different groups, the following experiments were conducted. Macroscopic morphologies were observed and recorded. Microscopic morphologies of the scaffolds were observed using field emission scanning electron microscope (FESEM) and representative images were selected. Computer software (ImageJ) was used to calculate the pore size and porosity. The degree of crosslinking was determined by ninhydrin experiment. Collagenase degradation experiment was performed to assess the resistance of SIS scaffolds to enzyme degradation. To evaluate the mechanical properties, universal mechanical testing machine was used to determine the stress-strain curve and compression strength was calculated. Human bone marrow mesenchymal cells (hBMSCs) were cultured on the scaffolds after which cytotoxicity and cell proliferation were assessed.@*RESULTS@#All the scaffolds remained intact after different crosslinking treatments. The FESEM images showed uniformed interconnected micro structures of scaffolds in different groups. The pore size of EDC group[(161.90±13.44) μm] was significantly higher than GA group [(149.50±14.65) μm] and PA group[(140.10±12.06) μm] (P < 0.05). The porosity of PA group (79.62%±1.14%) was significantly lower than EDC group (85.11%±1.71%) and GA group (84.83%±1.89%) (P < 0.05). PA group showed the highest degree of crosslinking whereas the lowest swelling ratio. There was a significant difference in the swelling ratio of the three groups (P < 0.05). Regarding to the collagenase degradation experiment, the scaffolds in PA group showed a significantly lower weight loss rate than the other groups after 7 days degradation. The weight loss rates of GA group were significantly higher than those of the other groups on day 15, whereas the PA group had the lowest rate after 10 days and 15 days degradation. PA group showed better mechanical properties than the other two groups. More living cells could be seen in PA and EDC groups after live/dead cell staining. Additionally, the proliferation rate of hBMCSs was faster in PA and EDC groups than in GA group.@*CONCLUSION@#The scaffolds gained satisfying degree of crosslinking after three different crosslinking treatments. The samples after PA and EDC treatment had better physicochemical properties and biocompatibility compared with GA treatment. Crosslinking can be used as a promising and applicable method in the modification of SIS scaffolds.

Biocompatibility of bioprosthetic heart valve materials with a non-glutaraldehyde-based chemical treatment / 中国胸心血管外科临床杂志

@#Objective    To study the biocompatibility of bioprosthetic heart valve material with a non-glutaraldehyde-based treatment, and to provide the safety data for the clinical application. Methods    All the tests were conducted according to GB/T16886 standards. The in vitro cytotoxicity was determined by methyl thiazolyl tetrazolium assay. Fifteen guinea pigs were divided into a test group (n=10) and a control group (n=5) in the skin sensitization test. Three New Zealand white rabbits were used in the intradermal reactivity test. Five sites on both sides of the rabbit back were set as test sites and control sites, respectively. In the acute systemic toxicity test, a total of 20 ICR mice were randomly assigned to 4 groups: a test group (polar medium), a control group (polar medium), a test group (non-polar medium) and a control group (non-polar medium), 5 in each group. Forty SD rats were divided into a test group (n=20) and a control group (n=20) in the subchronic systemic toxicity test. Results    The viability of the 100% extracts of the bioprosthetic heart valve material with a non-glutaraldehyde-based treatment was 75.2%. The rate of positive reaction was 0.0%. The total intradermal reactivity test score was 0. There was no statistical difference in the body weight between the test group and control group in the acute systemic toxicity test. There was no statistical difference in the body weight, organ weight, organ weight/body weight ratio, blood routine test or blood biochemistry between the test group and control group in the subchronic systemic toxicity test. Conclusion    The bioprosthetic heart valve material with a non-glutaraldehyde-based treatment has satisfying biocompatibility, which conforms to relevant national standards. The material might be a promising material for application in valve replacement.

Effects of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide on adhesion of posts in teeth obturated with different sealers

Abstract The aim of this study was to evaluate the effect of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) on bond strength of fiberglass posts in root canals obturated with different endodontic sealers. Seventy-eight mandibular premolars were obturated with three sealers (n=26): Endofill (END), AH Plus (AHP), and Endosequence BC Sealer (EBS). After preparation of the post space, two subgroups were formed according to the cementation of the posts (n=13): with EDC (EDC), and without EDC (control - CON). The specimens were submitted to a pull-out test, failure mode classification, and root canal surface evaluation by scanning electron microscopy after post displacement. Regarding the bond strength, a significant difference between the EDC and CON subgroups occurred only in the END (p=0.001). No difference was detected among the CON subgroups (p=0.339). However, among the EDC subgroups, AHP presented significantly higher values (END versus AHP: p=0.001; AHP versus EBS: p=0.016). Upon classification of failure modes, score 1 (≥ 50% of cement) was the most commonly observed, except for the END + EDC. Remains of endodontic sealers and resin cements were found in the cervical third, but without statistical difference (p=0.269), while in the middle third, difference occurred (p=0.004). In conclusion, EDC decreases bond strength when associated with END sealer, without changing the failure mode between the resin cement and fiberglass post. The best performance was observed when EDC was combined with AHP sealer.

Resumo O objetivo deste estudo foi avaliar o efeito da 1-etil-3- (3-dimetilaminopropil) carbodiimida (EDC) na resistência de união de pinos de fibra de vidro em canais radiculares obturados com diferentes cimentos endodônticos. Setenta e oito pré-molares inferiores foram obturados com três cimentos endodônticos (n=26): Endofill (END), AH Plus (AHP) e Endosequence BC Sealer (EBS). Após o preparo do espaço para pino, dois subgrupos formaram-se conforme a cimentação dos pinos (n=13): com EDC e sem EDC (controle - CON). Os espécimes foram submetidos ao teste pull-out, classificação do modo de falha e avaliação da superfície do canal radicular por microscopia eletrônica de varredura após o deslocamento. Quanto à força de resistência de união, uma diferença estatisticamente significativa ocorreu entre os subgrupos EDC e CON apenas no END (p=0,001). Não foi detectada diferença entre os subgrupos CON (p=0,339). Contudo, no subgrupo EDC, o AHP apresentou maiores valores (END versus AHP: p=0,001; AHP versus EBS: p=0,016). Acerca da classificação dos modos de falha, o escore 1 (≥50% de cimento) foi o mais comumente observado, exceto para END + EDC. Restos de cimentos endodônticos e cimentos resinosos foram encontrados no terço cervical, mas sem diferença estatística (p=0,269), enquanto no terço médio, houve diferença (p=0,004). Em conclusão, o EDC diminui a resistência de união quando associado ao cimento END, sem alterar o modo de falha entre o cimento resinoso e o pino de fibra de vidro. O melhor desempenho foi observado quanto o EDC foi usado com o cimento AHP.

Effect of dentin biomodifiers on the immediate and long-term bond strengths of a simplified etch and rinse adhesive to dentin

OBJECTIVES: This in vitro study evaluated the effect of dentin biomodifiers on the immediate and long-term bond strengths of a simplified etch and rinse adhesive to dentin. MATERIALS AND METHODS: Flat coronal dentin surfaces were prepared in 120 extracted human molars. Teeth were randomly divided into 5 groups (n = 24) according to 5 different surface pre-treatments: No pre-treatment (control); 1M carbodiimide (EDC); 0.1% epigallocatechin-3-gallate (EGCG); 2% minocycline (MI); 10% sodium ascorbate (SA). After surface pre-treatment, adhesive (Adper Single Bond 2 [SB], 3M ESPE) was applied. Composite was applied into transparent plastic tubes (2.5 mm in diameter), which was placed over the bonded dentin surface. From each group, 10 samples were subjected to shear bond strength (SBS) evaluation at 24 hours (immediate) and remaining 10 samples were tested after 6 months (delayed). Additionally, 4 samples per group were subjected to scanning electron microscopic analysis for observation of resin-dentin interface. The data were statistically analysed with Shaperio‑Wilk W test, 2-way analysis of variance (ANOVA), and post hoc Tukey's test. RESULTS: At 24 hours, SBS of all surface pre-treatment groups were comparable with the control group, with significant differences found between EDC and SA groups only (p = 0.009). After 6 months storage, EDC, EGCG, and MI pre-treatments preserved the resin-dentin bond strength with no significant fall. CONCLUSIONS: Dentin pre-treatment with all the dentin biomodifiers except SA resulted in significant preservation of resin-dentin bond over 6 months storage period, without negatively affecting the immediate bond strength of the etch and rinse adhesive tested.

Influence of EDC ethanol solution on dentin shear bond strength with a self-etch adhesive system / 北京大学学报(医学版)

Objective:To evaluate the bonding ability of one representative self-etch adhesive system by applying the micro-shear bond strength test method with different concentrations of carbodiimide [1-ethyl3-(3-dimethylaminopropyl) carbodiimide,EDC] ethanol solution pretreatment.Methods:Extracted sound human third molars were collected from patients ranging 18 to 40 years.In the study,80 molars were first sectioned to prepare a flat middle coronal dentin surface and then were randomly divided into 5 groups (n =16) according to without/with different surface treatments [blank control;80％ (volume fraction) ethanol control;EDC ethanol solution of three concentrations (0.01 mol/L,0.3 mol/L and 0.5 mol/L)].Each specimen underwent a micro-shear bond strength test and failure mode observation.The data collected were subjected to statistical analysis using one-way ANOVA and post hoc Tukey's test to analyze the difference of the micro-shear bond strength,and chi-square test/Fisher's exact test for the failure mode frequency of the micro-shear bond strength test specimens at a significance level of P =0.05.Results:The micro-shear bond strength of the three concentration EDC treatments were (35.29 ± 8.97) MPa (0.01 mol/L EDC treatment group),(40.24 ±9.68) MPa (0.3 mol/L EDC treatment group),(37.38 ±9.66) MPa (0.5 mol/L EDC treatment group) separately;and that of the 80％ ethanol group was (37.49 ± 7.76) MPa.All micro-shear bond strength value of the above four groups was statistically higher than that of the blank control group [(33.81 ± 7.98) MPa].The immediate microshear bond strength and failure mode was of no statistically significant difference among all the groups.It was noticed that the immediate micro-shear bond strength of 0.3 mol/L was higher than that of all the other groups,especially higher than that of the 80％ ethanol pretreatment group despite that there was no significant difference among all the groups.And the test of failure mode indicated that the cohesive failure was more common,while the frequency of adhesive failure was rare in each experimental group.Conclusion:EDC pretreatment had no adverse effect on the immediate micro-shear bond strengths of Clearfil SE Bond.Meanwhile,EDC treatment did not cause more adhesive failure in immediate micro-shear test,which had further denoted what was said above.However,it needs more research to illustrate the antienzymatic role of EDC in dentin bonding.

Preparation of matrine nanoparticles and their wheat germ agglutinin-modified product / 中成药

AIM To prepare the matrine nanoparticles and their wheat germ agglutinin-modified product.METHODS Double emulsification-solvent evaporation method was employed to prepare matrine nanoparticles.In consideration of influencing factors of ratio of poly (lactic-co-glycolic acid) to matrine,rotational speed and polyvinyl alcohol concentration,as well as the evaluation indices of particle size,potential,encapsulation efficiency and drug load,the preparation was optimized by central composite design.Wheat germ agglutinin-modified matrine nanoparticles were prepared by carbodiimide method.In addition to the influencing factors of ratio of carbodiimide to N-hydroxysuccinimide,wheat germ agglutinin addition and incubation time,evaluation indices of particle size,potential and modification rate were also taken into account in the preparation optimization by uniform design.RESULTS The optimal conditions for matrine nanoparticles were determined to be 0.594 ∶ 1 for ratio of poly (lactic-co-glycolic acid) to matrine,815 r/min for rotational speed,and 0.46％ for polyvinyl alcohol concentration.The average particle size,potential,encapsulation efficiency and drug loading were 112.04 nm,-15.38 mV,90.05％ and 27.14％,respectively.The optimal conditions for their wheat germ agglutinin-modified product were found to be 2.8 ∶ 0.12 for ratio of carbodiimide to N-hydroxysuccinimide,3 mg for wheat germ agglutinin consumption,and 14 h for incubation time.The average particle size,potential and modification rate were 474.7 nm,-5.2 mV and 69.51％,respectively.CONCLUSION The preparation techniques are reliable,and the matrine nanoparticles and their wheat germ agglutinin-modified product show their stable properties.

Atividade antimicrobiana da carbodiimida (EDC) sobre microorganismos presentes em lesões cariosas / Antimicrobial activity of carbodiimide (EDC) against caries-related microorganisms

Tem sido demonstrado que a carbodiimida (EDC) apresenta notável potencial inibidor de proteases (MMPs) e de melhorar as propriedades mecânicas do colágeno quando aplicada sobre a dentina desmineralizada. Entretanto, não existem informações a respeito de sua ação antimicrobiana sobre microrganismos comumente encontrados em lesões de cárie ou mesmo após a sua remoção. Objetivo: Investigar a atividade antimicrobiana do EDC em diferentes concentrações sobre microrganismos presentes em cavidades cariosas. Métodos: Soluções de EDC foram preparadas e testadas contra S. mutans e sobrinus, L. acidophilus e Candida albicans. Inicialmente, foi utilizado o teste de difusão em ágar, no qual discos de papel filtro foram impregnados com EDC 2, 1, 0,5, 0,3 ou 0,1 mol/L, clorexidina 0,12%, nistatina 1% ou tampão Sorensen pH 6,2 (n=6). Em seguida, foi determinada a concentração inibitória mínima (CIM) e bactericida mínima (CBM) do EDC sobre L. acidophilus em suspensão planctônica (n=9), por meio de turvamento. Por fim, a atividade do EDC (de 0,01 à 2 mol/L) sobre L. acidophilus em biofilme monoespécie foi definida por meio do ensaio de XTT (n=6). Os dados foram submetidos aos testes estatísticos de ANOVA e Tukey ou Mann-Whitney (p<0,05). Resultados: No teste de difusão em ágar, nenhuma atividade antimicrobiana foi observada para EDC nas concentrações de 0,1 e 0,3 mol/L, assim como para o grupo controle. EDC 0,5, 1 e 2 mol/L exerceu efeito antimicrobiano apenas sobre L. acidophilus. A CIM do EDC foi de 0,01 mol/L e a CBM foi de 0,03 mol/L. Todas as concentrações de EDC igual ou superiores a 0,05 mol/L foram capazes de reduzir significantemente o metabolismo do biofilme formado por L. acidophilus. Essa redução variou de 84,2 para 0,05 mol/L até 93,4% para 2 mol/L. Conclusão: O EDC apresentou atividade antimicrobiana apenas contra L. acidophilus reduzindo significantemente o crescimento deste microrganismo quando em suspensão planctônica e o seu metabolismo quando em biofilme monoespécie a partir de 0,05 mol/L

It has been demonstrated that carbodiimide (EDC) is a potent protease inhibitor (MMPs) and is able to improve the mechanical properties of collagen when applied on the demineralized dentin. However, there is no information about its antimicrobial effect on microorganisms commonly found in caries lesions or even after its removal. Objective: To investigate the antimicrobial activity of different concentrations of EDC against microorganisms present in caries lesions. Methods: EDC solutions were prepared and tested against S. mutans and sobrinus, L. acidophilus and Candida albicans. Initially, the agar diffusion test was used, where paper discs were impregnated with 2, 1, 0.5, 0.3 or 0.1 mol/L EDC, 0.12% chlorhexidine, nistatin 1% or Sorensen's buffer pH 6.2 (control) (n=6). Then, the minimum inhibitory (MIC) and bactericide concentrations (MBC) of EDC were determined against L. acidophilus using turbidity. Finally, the growth inhibitory activity of EDC (from 0.01 to 2 mol/L) against L. acidophilus in monoespecies biofilm was defined using the XTT assay (n=6). Data were submitted to ANOVA and Tukey tests or Mann-Whitney (p<0.05). Results: For the agar diffusion test, lack of antimicrobial activity was seen for EDC at 0.1 and 0.3 mol/L, as well as for the control group. 0.5, 1 and 2 mol/L EDC exerted a growth inhibitory effect only against L. acidophilus. The MIC for EDC was set as 0.01 mol/L and the MBC as 0.03 mol/L. Concentrations equal to or greater than 0.05 mol/L were capable of significantly reducing the metabolism of L. acidophilus when in monospecies biofilm. This reduction ranged from 84.2% for 0.05 mol/L to 93.4% for 2 mol/L. Conclusion: EDC exerted antibacterial activity only against L. acidophilus significantly reducing its growth in planktonic suspension and its metabolism in biofilms in the concentration of 0.05 mol/L or higher

Synthesis of artificial chlorogenic acid antigen and preparation of polyclonal antibodies / 中草药

Objective: To synthesize artificial chlorogenic acid (CHA) antigen, to prepare CHA polyclonal antibody, and to lay the foundation for the preparation of immune chip for allergic component analysis. Methods: CHA-bovine serum albumin (CHA-BSA) and CHA-ovalbumin (CHA-OVA) were synthesized by carbodiimide method. The characterization of the synthesis was examined by UV spectrometry and TLC method. The titer and specificity of the antibody in serum of immunised mice were detected by indirect enzyme-linked immunosorbent assay (I-ELISA) and indirect competitive enzyme-linked immunosorbent assay (I-CELISA), respectively. Results: According to the UV and TLC determination, the CHA was successfully conjugated with BSA. The serum antibody titer was 1:128 000 with the linear range of 15.6-250 ng/mL, R2 = 0.995, and Y = -0.10 lnX+1.158. No cross-reaction was detected with glycyrrhizic acid, parietic acid and so on, which were commonly used in the combination with CHA. Conclusion: The preparation of multi-clonal antibody with good sensitivity and specificity against CHA is successful, which provides a foundation for the trace detection and allergy research of CHA.

Characteristics of EDC/NHS-crosslinked collagen type Ⅱmatrix / 中国矫形外科杂志

[Objective]Porous collagen type Ⅱ matrices crosslinked by 1-ethyl-3-(3-dimethyl aminopropyl)carbodⅡmide(EDC) and N-hydroxysucinimide(NHS) were developed as scaffolds for cartilage tissue engineering.[Method]Collagen type Ⅱ matrix was crosslinked by EDC/NHS,and then freeze-dried to achieve collagen scaffolds.The porous characteristics of the prepared scaffolds were tested by using diffenent methods,including laser scanning confocal microscopy (LSCM),scanning electron microscopy (SEM) and mechanical testing machine.The chondrocytes labeled by GFP were planted in crosslinked collagen type Ⅱ,and observed by LSCM.[Result](1) The mechanical properties of cross-linked matrices increased significantly,reaching 2.18?0.47MPa.(2)The degradation of cross-linked matrices decreased by 8.28% after 4 hours.The pore size was about 90?m,and their average porosity and water capacity reached 93.39% and 97.78%,respectively.3.Chondrocytes were in good condition in the crosslinked collagen.[Conclusion]The present work indicates that EDC/NHS-crosslinked collagen type Ⅱ could keep the properties and biocompatibility of collagen,besides,the mechanical strength increased and the degradation was decreased.It will be suitable for cartilage tissue engineering purposes.