Evaluation of antibacterial and remineralizing nanocomposite and adhesive in rat tooth cavity model

Antibacterial and remineralizing dental composites and adhesives were recently developed to inhibit biofilm acids and combat secondary caries. It is not clear what effect these materials will have on dental pulps in vivo. The objectives of this study were to investigate the antibacterial and remineralizing restorations in a rat tooth cavity model, and determine pulpal inflammatory response and tertiary dentin formation. Nanoparticles of amorphous calcium phosphate (NACP) and antibacterial dimethylaminododecyl methacrylate (DMADDM) were synthesized and incorporated into a composite and an adhesive. Occlusal cavities were prepared in the first molars of rats and restored with four types of restoration: control composite and adhesive; control plus DMADDM; control plus NACP; and control plus both DMADDM and NACP. At 8 or 30 days, rat molars were harvested for histological analysis. For inflammatory cell response, regardless of time periods, the NACP group and the DMADDM + NACP group showed lower scores (better biocompatibility) than the control group (p = 0.014 for 8 days, p = 0.018 for 30 days). For tissue disorganization, NACP and DMADDM + NACP had better scores than the control (p = 0.027) at 30 days. At 8 days, restorations containing NACP had a tertiary dentin thickness (TDT) that was five- to six-fold that of the control. At 30 days, restorations containing NACP had a TDT that was four- to six-fold that of the control. In conclusion, novel antibacterial and remineralizing restorations were tested in rat teeth in vivo for the first time. Composite and adhesive containing NACP and DMADDM exhibited milder pulpal inflammation and much greater tertiary dentin formation than the control adhesive and composite. Therefore, the novel composite and adhesive containing NACP and DMADDM are promising as a new therapeutic restorative system to not only combat oral pathogens and biofilm acids as shown previously, but also facilitate the healing of the dentin–pulp complex.     

Toward potent antibiofilm degradable medical devices: A generic method for the antibacterial surface modification of polylactide

The effects of biomaterials on their environment must be carefully modulated in most biomedical applications. Among other approaches, this modulation can be obtained through the modification of the biomaterial surface. This paper proposes a simple and versatile strategy to produce non-leaching antibacterial polylactide (PLA) surfaces without any degradation of the polyester chains. The method is based on a one-pot procedure that provides a “clickable” PLA surface via anionic activation which is then functionalized with an antibacterial quaternized poly(2-(dimethylamino)ethyl methacrylate) (QPDMAEMA) by covalent immobilization on the surface. The anti-adherence and antibiofilm activities of modified PLA surfaces are assessed for different QPDMAEMA molecular weights and different quaternization agents. Antibacterial PLA surfaces are shown to be very active against Gram-negative and Gram-positive strains, with adherence reduction factors superior to 99.999% and a marked reduction in biofilm on the most potent surfaces. In addition to this substantial antibacterial activity, the proposed PLA surfaces are also cytocompatible, as demonstrated through the proliferation of L929 fibroblasts.     

Nitric oxide-releasing chitosan oligosaccharides as antibacterial agents

Secondary amine-functionalized chitosan oligosaccharides of different molecular weights (i.e., ∼2500, 5000, 10,000) were synthesized by grafting 2-methyl aziridine from the primary amines on chitosan oligosaccharides, followed by reaction with nitric oxide (NO) gas under basic conditions to yield N-diazeniumdiolate NO donors. The total NO storage, maximum NO flux, and half-life of the resulting NO-releasing chitosan oligosaccharides were controlled by the molar ratio of 2-methyl aziridine to primary amines (e.g., 1:1, 2:1) and the functional group surrounding the N-diazeniumdiolates (e.g., polyethylene glycol (PEG) chains), respectively. The secondary amine-modified chitosan oligosaccharides greatly increased the NO payload over existing biodegradable macromolecular NO donors. In addition, the water-solubility of the chitosan oligosaccharides enabled their penetration across the extracellular polysaccharides matrix of Pseudomonas aeruginosa biofilms and association with embedded bacteria. The effectiveness of these chitosan oligosaccharides at biofilm eradication was shown to depend on both the molecular weight and ionic characteristics. Low molecular weight and cationic chitosan oligosaccharides exhibited rapid association with bacteria throughout the entire biofilm, leading to enhanced biofilm killing. At concentrations resulting in 5-log killing of bacteria in Pseudomonas aeruginosa (P. aeruginosa) biofilms, the NO-releasing and control chitosan oligosaccharides elicited no significant cytotoxicity to mouse fibroblast L929 cells in vitro.     

Preparation and characterization of a novel tobramycin-containing antibacterial collagen film for corneal tissue engineering

Corneal disease is a major cause of blindness and keratoplasty is an effective treatment method. However, clinical treatment is limited due to a severe shortage of high-quality allogeneic corneal tissues and the bacterial infection after corneal transplantation. In this study, we develop a novel artificial and antibacterial collagen film (called Col-Tob) for corneal repair. In the Col-Tob film, the tobramycin, which is an aminoglycoside antibiotic to treat various types of bacterial infections, was cross-linked by 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide and N-hydroxysuccinimide onto the collagen. Physical properties, antibacterial property and biocompatibility of the films were characterized. The results indicate that the film is basically transparent and has appropriate mechanical properties. Cell experiments show that human corneal epithelial cells could adhere to and proliferate well on the film. Most importantly, the film exhibits excellent antibacterial effect in vitro. Lamellar keratoplasty shows that the Col-Tob film can be sutured in rabbit eyes and are epithelialized completely in15 ± 5 days, and their transparency is restored quickly in the first month. Corneal rejection reaction, neovascularization and keratoconus are not observed within 3 months. This film, which can be prepared in large quantities and at low cost, should have potential application in corneal repair.     

Mechanical and antibacterial properties of benzothiazole-based dental resin materials

A synthesized benzothiazole containing mono-methacrylate monomer BTTMA was incorporated into Bis-GMA/TEGDMA dental resin system with a series of mass concentration from 5 to 30 wt.% as an antibacterial agent. The influence of BTTMA on physicochemical properties of dental resin system, such as double bond conversion (DC), volumetric shrinkage (VS), flexural strength (FS) and modulus (FM), water sorption (WS) and solubility (SL) were investigated. Direct contact testing and agar diffusion testing were used to evaluate the antibacterial activity of BTTMA containing dental resin. The results showed that BTTMA could endow dental resin with significant antibacterial activity when its concentration reached a certain amount (20 wt.%), and the antibacterial activity of BTTMA containing dental resin was mainly attributed to the immobilized BTTMA instead of the unreacted leachable BTTMA. BTTMA had no negative effect on physicochemical properties of dental resin, and even some BTTMA containing dental resins had advantages like higher DC, lower VS and WS when compared with control resin. Therefore, BTTMA could be considered as a suitable antibacterial agent in dental material, but much more researches concerned about biocompatibility should be done in future to prove whether it could be applied in clinic.     

Fabrication and characterization of bioactive and antibacterial composites for dental applications

There is an increasing clinical need to design novel dental materials that combine regenerative and antibacterial properties. In this work the characterization of a recently developed sol–gel-derived bioactive glass ceramic containing silver ions (Ag-BG) is presented. The microstructural characteristics, ion release profile, zeta potential value and changes in weight loss and pH value as a function of the immersion time of Ag-BG in Tris buffer are evaluated. Ag-BG is also incorporated into natural extracellular matrix (ECM) hydrogel to further enhance its regenerative properties. Then, the micro and macro architectures of these new composites (ECM/Ag-BG) are characterized. In addition, the antibacterial properties of these new composites are tested against Escherichia coli and Enterococcus faecalis, a bacterium commonly implicated in the pathogenesis of dental pulp infections. Cell–material interaction is also monitored in a primary culture of dental pulp cells. Our study highlights the benefits of the successful incorporation of Ag in the bioactive glass, resulting in a stable antibacterial material with long-lasting bactericidal activity. Furthermore, this work presents for the first time the fabrication of new Ag-doped composite materials, with inductive pulp-cell proliferation and antibacterial properties (ECM/Ag-BG). This advanced composite made of Ag-BG incorporated into natural ECM possesses improved properties that may facilitate potential applications in tooth regeneration approaches.     

Desiccation and ethanol resistances of multidrug resistant Acinetobacter baumannii embedded in biofilm: The favorable antiseptic efficacy of combination chlorhexidine gluconate and ethanol

Background/purpose

Globally, multidrug-resistant Acinetobacter baumannii (MDRAB) has emerged as an important pathogen in nosocomial outbreaks. This study aimed to investigate the correlation between the biofilm formation and survival of MDRABs, and to investigate the antiseptic efficacy of hand sanitizers for the MDRABs, embedded with biofilm (MDRAB-Bs).

医用可降解锌合金材料抗菌性能及细胞相容性的体外实验研究

目的研究医用可降解锌合金材料的体外抗菌性能及细胞相容性。 方法大肠杆菌与金黄色葡萄球菌菌株分别与LB培养基混合,采用细菌比浊仪将浓度调节至1.0×10⁸CFU/mL,在二氧化碳恒温箱内37℃下培养24 h,作为细菌原液;各取相同尺寸锌合金与钛合金棒,打磨、除去表面氧化层,在100%乙醇、蒸馏水中超声波震荡洗涤,后用环氧乙烷消毒,备用。(1)大肠杆菌/金黄色葡萄球菌分别与可降解锌合金、钛合金于LB培养基中共培养,培养0、2、4、6、8、12、24、48、72 h后分别用酶标仪测定其在600 nm波长下的吸光度值。(2)将可降解锌合金、钛合金置于含金黄色葡萄球菌的固体培养平板上,培养24、48 h后观察抑菌圈大小。(3)不同浓度锌合金浸提液培养L929细胞,培养1、5 d后观察细胞形态,并用CCK8法检测细胞增殖情况,计算细胞相对增值率(RGR)。(4)将小鼠胚胎成骨细胞前体细胞(MC3T3－E1细胞)接种于可降解锌合金、钛合金表面,培养2 d后观察细胞在不同材料表面的黏附生长情况。组间数据比较采用单因素方差分析(ANOVA)及t检验。 结果不同时相点,大肠杆菌加锌合金共培养组的吸光度值明显低于单纯大肠杆菌培养组、大肠杆菌加钛合金共培养组,差异均有统计学意义(P值均小于0.05);不同时相点,金黄色葡萄球菌加锌合金共培养组吸光度值明显低于单纯金黄色葡萄球菌培养组、金黄色葡萄球菌加钛合金共培养组,差异有统计学意义(P值均小于0.05)。可降解锌合金周围出现抑菌圈,培养24 h后,锌合金圆柱体周围(4.38±0.40)mm范围内无菌落出现,培养48 h后锌合金圆柱体周围(4.75±0.44)mm范围内无菌落出现,培养24 、48 h的抑菌圈大小比较差异无统计学意义(t＝－1.10,P＝0.31),而钛合金周围未出现抑菌圈。不同浓度锌合金浸提液培养组与阴性对照组,L929细胞细胞生长状况良好,CCK8检测提示不同时相点各浸提液组细胞RGR均大于75%,细胞毒性为0～1级,细胞毒性安全性合格。MC3T3－E1细胞能黏附生长于锌合金与钛合金材料表面,细胞形态与钛合金组相比未见异常。 结论锌合金材料具有良好的抗菌性能,对大肠杆菌及金黄色葡萄球菌均有抑菌效果;具有良好的细胞相容性,细胞毒性安全性合格,细胞能在其表面黏附生长。     

Characterization of chlorhexidine-releasing, fast-setting, brushite bone cements

The effect of antibacterial chlorhexidine diacetate powder (CHX) on the setting kinetics of a brushite-forming beta-tricalcium phosphate/monocalcium phosphate monohydrate (beta-TCP/MCPM) cement was monitored using attenuated total reflection Fourier transform infrared spectroscopy. The final composition of the set cement with up to 12 wt.% CHX content before and after submersion in water for 24h, the kinetics of chlorhexidine release and the total sample mass change in water over four weeks was monitored using Raman mapping, UV spectroscopy and gravimetry, respectively. Below 9 wt.%, CHX content had no significant effect on brushite formation rate at 37 degrees C, but at 12 wt.% the half-life of the reaction decreased by one-third. Raman mapping confirmed that brushite was the main inorganic component of the set cements irrespective of CHX content, both before and after submersion in water. The CHX could be detected largely as discrete solid particles but could also be observed partially dispersed throughout the pores of the set cement. The percentage of CHX release was found to follow Fick's law of diffusion, being independent of its initial concentration, proportional to the square root of time and, with 1mm thick specimens, 60% was released at 24h. Total set cement mass loss rate was not significantly affected by CHX content. On average, cements exhibited a loss of 7 wt.% assigned largely to surface phosphate particle loss within the initial 8h followed by 0.36 wt.% per day.     

Characterization and inhibitory effect of antibacterial dental resin composites incorporating silver-supported materials.

Resin composites with antibacterial activity may be useful for preventing the secondary caries frequently seen around restorations. The purposes of this study were to investigate antibacterial light-activated dental resin composites incorporating each of two silver-supported antibacterial materials and evaluate their long-lasting inhibitory effect against Streptococcus mutans. Two types of silver-supported antibacterial materials, Novaron (N) and Amenitop (AM) were used. These antibacterial materials were incorporated into TEGDMA-UDMA-based light-activated resin composites, and the antibacterial activities and mechanical properties of these composites, and also the release of silver ions, were examined. Two silver-supported antibacterial materials inhibited the growth of the major oral pathogen S. mutans. The minimum inhibitory concentration in suspensions of N and AM against S. mutans was 40 microg/mL and 30 microg/mL, respectively. Composites incorporating 5 wt % (N-5) or more of Novaron and 7 wt % (AM-7) or more of Amenitop inhibited the growth of S. mutans after immersion in water for 6 months. There was no or extremely little release of silver ions from the N-5 and AM-7 composites after 1 day or after 6 months of immersion in water. No significant difference in either compressive or flexural strength was observed between the control and the N-5 composites after 1 day or after 6 months of storage in water. However, for the AM-5 composite, there was a significant difference in both strength parameters between the two immersion periods. These results indicate that a light-activated dental resin composite incorporating silver-supported antibacterial material such as Novaron may be useful clinically because of its long-lasting inhibitory effect against S. mutans and its favorable mechanical properties.     

Enhanced antibacterial properties,biocompatibility, and corrosion resistance of degradable Mg-Nd-Zn-Zr alloy

Magnesium (Mg), a potential biodegradable material, has recently received increasing attention due to its unique antibacterial property. However, rapid corrosion in the physiological environment and potential toxicity limit clinical applications. In order to improve the corrosion resistance meanwhile not compromise the antibacterial activity, a novel Mg alloy, Mg–Nd–Zn–Zr (Hereafter, denoted as JDBM), is fabricated by alloying with neodymium (Nd), zinc (Zn), zirconium (Zr). pH value, Mg ion concentration, corrosion rate and electrochemical test show that the corrosion resistance of JDBM is enhanced. A systematic investigation of the in vitro and in vivo antibacterial capability of JDBM is performed. The results of microbiological counting, CLSM, SEM in vitro, and microbiological cultures, histopathology in vivo consistently show JDBM enhanced the antibacterial activity. In addition, the significantly improved cytocompatibility is observed from JDBM. The results suggest that JDBM effectively enhances the corrosion resistance, biocompatibility and antimicrobial properties of Mg by alloying with the proper amount of Zn, Zr and Nd.     

Polycarboxylated microfillers incorporated into light-curable resin-based dental adhesives evoke remineralization at the mineral-depleted dentin

This study aimed at evaluating the remineralizing properties of three experimental light-curable resin-based dental adhesives containing tailored polycarboxylated microfillers. A co-monomers blend was firstly formulated and then mixed with each of the following microfillers: polycarboxylated bioactive glass (PBAG), polycarboxylated calcium silicates (PCS), and polycarboxylated calcium silicates-doped brushite (PDP). The three experimental and a filler-free control resins were applied onto 10% orthophosphoric acid treated dentin discs and light cured. The specimens were soaked in artificial saliva (AS) for 3, 7, and 14?days. Dentin mineral variation was monitored using attenuated total reflection-Fourier transform infrared (ATR-FTIR) and Raman spectroscopy. Confocal laser scanning microscopy (CLSM) was employed to observe the ultra-morphology/nanoleakage along the resin–dentin interface. The bonding ability and the durability of the resin–dentin bonds were investigated through microtensile bond strength (μTBS) test. ATR-FTIR and Raman showed a significant increase of the mineral matrix area ratio and phosphate peak intensity in specimens treated with the experimental resins within 14?days (p?p?>?0.05). Dentin treated using PBAG or PCS exhibited higher level of remineralization than the specimens in PDP group. CLSM showed reduction in nanoleakage, although the remineralization of the hybrid layer induced a significant drop in the μTBS after 3-month storage (p?相似文献   

Degradable, antibacterial silver exchanged mesoporous silica spheres for hemorrhage control

Effective hemorrhage control becomes increasingly significant in today's military and civilian trauma, and current available local hemostatic agents have been reported to have various drawbacks and side effects. Herein in this study, a silver exchanged calcium doped ordered mesoporous silica sphere (AgCaMSS) with good degradability and antibacterial properties was developed for hemorrhage control. The well-ordered and symmetry hexagonal AgCaMSS with pore size of 3.2 nm, BET surface area of 919 m²/g and pore volume of 0.74 m³/g was prepared by one-step based catalyzed self-assembly and subsequent ion-exchange procedures. The degradation behaviors in Tris–HCl solution indicated that the addition of calcium and silver facilitated the dissolution and the weight loss of the prepared AgCaMSS could attain more than 40% after 42 days. The results obtained demonstrated that the optimal AgCaMSS formulation could significantly promote the blood clotting, activate the intrinsic pathway of coagulation cascade, induce platelet adherence. Consequently, effective hemostasis with low exothermic effects was achieved and the mortalities in femoral artery and liver injury models were reduced. The antibacterial experiment using broth culture method revealed that the prepared AgCaMSS had better antibacterial activities against Escherichia coli and Staphylococcus aureus. Based on these results, it can be concluded that the AgCaMSS developed here would be a promising material platform for designing hemostats in more extensive clinical application.     

Novel highly biodegradable biphasic tricalcium phosphates composed of alpha-tricalcium phosphate and beta-tricalcium phosphate

Novel biodegradable biphasic tricalcium phosphates (BTCP) composed of alpha-tricalcium phosphate (alpha-TCP) and beta-tricalcium phosphate (beta-TCP) were successfully synthesized by heating amorphous calcium phosphate precursors with different structures at 800 degrees C for 3 h. The ratio of alpha-TCP and beta-TCP in the calcium phosphate particle can be controlled by aging time and pH value during synthesis of the amorphous precursor.     

<Emphasis Type="Italic">In vitro</Emphasis> study of matrix surface properties of porous granulated calcium phosphate ceramic materials made in Russia

We performed in vitro screening of monophasic (hydroxyapatite, β-tricalcium phosphate, carbonate-substituted hydroxyapatite with 0.59 and 5.9 wt% substitution with CO₃ ²⁻) and biphasic (hydroxyapatite-tricalcium phosphate with various percentage of the components 80/20, 60/40, 20/80, silicon-substituted hydroxyapatite with 0.79 wt% SiO₂) porous granulated ceramics composed of calcium phosphate powders synthesized by methods of heterophasic interaction of reagents and precipitation from aqueous solutions using MTT test and cultured human fibroblasts. Acute toxicity of materials (24-h incubation with cell culture) and matrix properties (3, 5, 7, 14, 18, 21, 28 days in culture) were evaluated. We selected a batch of materials obtained by precipitation from aqueous solutions, which were non-toxic and were characterized by good matrix properties (for cells). Biphasic ceramics with hydroxyapatite-tricalcium phosphate ratio of 80/20 exhibited best characteristics, and ceramics on the basis of silicon-substituted hydroxyapatite showed moderate characteristics. __________ Translated from Kletochnye Tehnologii v Biologii i Meditsine, No. 2, pp. 97–101, April, 2008     

载银水凝胶或载抗生素壳聚糖水凝胶在抑菌性能和细胞毒性方面的研究

目的研究壳聚糖水凝胶,壳聚糖载银水凝胶和壳聚糖载抗生素水凝胶短期的抑菌功效和细胞毒性。方法通过添加交联剂后制备壳聚糖水凝胶,并有效装载银离子或硫酸庆大霉素。进行抑菌实验和累计释放实验了解壳聚糖基水凝胶的抗菌性能和药物控释性。通过使用材料的浸提液检测这三种水凝胶的细胞毒性。结果抑菌实验结果表明壳聚糖水凝胶,壳聚糖载银水凝胶和壳聚糖载抗生素水凝胶均能有效抑制金黄色葡萄球菌的增殖。且壳聚糖载抗生素水凝胶具有最佳的抑菌性能且极大地抑制了生物膜的形成。体外药物释放显示抗生素在7天内的累计释放多于60%;而银离子的释放低于10%。细胞毒性实验表明这三个凝胶材料无明显细胞毒性。结论壳聚糖基水凝胶具有良好的短期抑菌效果,可降解,且无明显细胞毒性,在骨科应用方面有着巨大的前景。     

Two antibacterial C-type lectins from crustacean,Eriocheir sinensis,stimulated cellular encapsulation in vitro

The first step of host fighting against pathogens is that pattern recognition receptors recognized pathogen-associated molecular patterns. However, the specificity of recognition within the innate immune molecular of invertebrates remains largely unknown. In the present study, we investigated how invertebrate pattern recognition receptor (PRR) C-type lectins might be involved in the antimicrobial response in crustacean. Based on our previously obtained completed coding regions of EsLecA and EsLecG in Eriocheir sinensis, the recombinant EsLectin proteins were produced via prokaryotic expression system and affinity chromatography. Subsequently, both rEsLecA and rEsLecG were discovered to have wide spectrum binding activities towards microorganisms, and their microbial-binding was calcium-independent. Moreover, the binding activities of both rEsLecA and rEsLecG induced the aggregation against microbial pathogens. Both microorganism growth inhibitory activities assays and antibacterial activities assays revealed their capabilities of suppressing microorganisms growth and directly killing microorganisms respectively. Furthermore, the encapsulation assays signified that both rEsLecA and rEsLecG could stimulate the cellular encapsulation in vitro. Collectively, data presented here demonstrated the successful expression and purification of two C-type lectins proteins in the Chinese mitten crab, and their critical role in the innate immune system of an invertebrate.     

Inkjet printed antibiotic- and calcium-eluting bioresorbable nanocomposite micropatterns for orthopedic implants

Inkjet printing of antibiotic- and calcium-eluting micropatterns was explored as a novel means of preventing the formation of biofilm colonies and facilitating osteogenic cell development on orthopedic implant surfaces. The micropatterns consisted of a periodic array of ∼50 μm circular dots separated by ∼150 μm. The composition of the micropatterns was controlled by formulating inks with rifampicin (RFP) and poly(d,l-lactic-co-glycolic) acid (PLGA) dissolved in an organic solvent with ∼100 nm biphasic calcium phosphate (BCP) nanoparticles suspended in the solution. During printing RFP and PLGA co-precipitated to form a nanocomposite structure with ∼10-100 nm RFP and the BCP particles dispersed in the PLGA matrix. The rate of RFP release was strongly influenced by the RFP loading in the micropattern, particularly on the first day. The RFP-containing micropatterns effectively prevented the formation of Staphylococcus epidermidis biofilm colonies due to their ability to kill bacteria prior to forming colonies on the patterned surfaces. The BCP-containing micropatterns printed on the surface of the alloy TiAl6V4 significantly accelerated osteoblast cell differentiation, as measured by alkaline phosphatase expression and calcium deposition, without compromising cell proliferation.     

家蝇蛹凝集素的纯化及其免疫调节和抑菌作用

目的　从家蝇蛹中分离纯化一种能结合半乳糖的凝集素 ,并研究其免疫和抑菌活性。方法　家蝇蛹凝集素提取纯化方法包括 :缓冲液浸提、戊二醛固定化红细胞吸附、亲和层析和凝胶过滤。以淋巴细胞转化、溶血空斑和抑菌试验研究此凝集素的性质。结果　本纯化方法使样品的血凝活力提高了 5 39倍 ,纯化后的家蝇蛹凝集素电泳测得其相对分子质量 (Mr)为 84× 10 3,由 3个亚单位组成 ,含有糖成分。纯化凝集素的浓度为 15 .6～ 10 0 0 μg ml时 ,具有刺激T、B细胞的作用 ,与对照组比较差异有显著性 (P <0 .0 1)。对大肠埃希菌 ,枯草芽胞杆菌和伤寒沙门菌的抑制活性分别为39 .8%、4 5 .3%和 6 6 .2 %。结论　家蝇蛹凝集素具有免疫调节功能和抑菌活性 ,为家蝇免疫机制的深入研究提供了资料。     

Two antibacterial C-type lectins from crustacean, Eriocheir sinensis, stimulated cellular encapsulation in vitro

The first step of host fighting against pathogens is that pattern recognition receptors recognized pathogen-associated molecular patterns. However, the specificity of recognition within the innate immune molecular of invertebrates remains largely unknown. In the present study, we investigated how invertebrate pattern recognition receptor (PRR) C-type lectins might be involved in the antimicrobial response in crustacean. Based on our previously obtained completed coding regions of EsLecA and EsLecG in Eriocheir sinensis, the recombinant EsLectin proteins were produced via prokaryotic expression system and affinity chromatography. Subsequently, both rEsLecA and rEsLecG were discovered to have wide spectrum binding activities towards microorganisms, and their microbial-binding was calcium-independent. Moreover, the binding activities of both rEsLecA and rEsLecG induced the aggregation against microbial pathogens. Both microorganism growth inhibitory activities assays and antibacterial activities assays revealed their capabilities of suppressing microorganisms growth and directly killing microorganisms respectively. Furthermore, the encapsulation assays signified that both rEsLecA and rEsLecG could stimulate the cellular encapsulation in vitro. Collectively, data presented here demonstrated the successful expression and purification of two C-type lectins proteins in the Chinese mitten crab, and their critical role in the innate immune system of an invertebrate.