Primary Adhesion Research Articles

Safety and Tolerability of Office Hysteroscopic Adhesiolysis for Asherman's Syndrome

Study Objective The primary objective of our study was to assess the proportion of patients who successfully tolerated a primary office-based hysteroscopic lysis adhesions (LOA). Additionally, we assessed the incidence of procedural adverse events associated with office-based hysteroscopic LOA and adjusted for both March classification severity and utilization of ultrasound guidance. Design A retrospective chart review of patients who underwent hysteroscopic LOA during their evaluation and management for Asherman's syndrome. Setting A community teaching hospital. Patients or Participants 355 Asherman's syndrome patients who underwent hysteroscopic LOA from 01/01/2015 to 03/01/2019. Interventions Hysteroscopic adhesiolysis. Measurements and Main Results The 355 Asherman's syndrome patients underwent a total of 813 hysteroscopic LOA (primary and follow-up) at our institution during the study period. The mean number of hysteroscopic procedures performed for all patients in this time period was 2.3 ± 1.5 procedures per patient. When assessed by March classification, mild severity patients underwent 1.5 ± 1.0 procedures/patient, moderate severity underwent 2.8 ± 1.4 procedures/patient, and severe severity underwent 3.3 ± 1.9 procedures/patient. Of the 335 primary hysteroscopies, 93.5% (332 cases) were performed within the office, and 92.8% (308 patients) of these procedures were well tolerated and without any adverse events. Adverse events amongst primary office-based hysteroscopic LOA included 6.3% (21 cases) incomplete procedures due to patient intolerance, 0.6% (2 patients) false passage creation and 0.3% (1 patient) uterine perforation. Multivariable logistic regression analyses were performed and determined that March classification and utilization of ultrasound guidance were not directly associated with adverse events. Conclusion Hysteroscopy in the office is well tolerated and able to be completed safely in patients who have a diagnosis of Asherman's Syndrome which suggests more operative hysteroscopic should be attempted in the office rather than the operating room.

In Vitro and in Vivo Analysis of Adhesive, Anti-Inflammatory, and Proangiogenic Properties of Novel 3D Printed Hyaluronic Acid Glycidyl Methacrylate Hydrogel Scaffolds for Tissue Engineering.

In this study, we prepared hydrogel scaffolds for tissue engineering by computer-assisted extrusion three-dimensional (3D) printing with photocured (λ = 445 nm) hyaluronic acid glycidyl methacrylate (HAGM). The developed product was compared with the polylactic-co-glycolic acid (PLGA) scaffolds generated by means of the original antisolvent 3D printing methodology. The cytotoxicity and cytocompatibility of the scaffolds were analyzed in vitro by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide tests, flow cytometry, and scanning electron microscopy. Anti-inflammatory and proangiogenic properties of the scaffolds were evaluated in the dorsal skinfold chamber mouse model by means of intravital fluorescence microscopy, histology, and immunohistochemistry throughout an observation period of 14 days. In vitro, none of the scaffolds revealed cytotoxicity on days 1, 2, and 5 after seeding with umbilical cord-derived multipotent stromal cells, and the primary cell adhesion to the surface of HAGM scaffolds was low. In vivo, implanted HAGM scaffolds showed enhanced vascularization and host tissue ingrowth, and the inflammatory response to them was less pronounced compared with PLGA scaffolds. The results indicate excellent biocompatibility and vascularization capacity of the developed 3D printed HAGM scaffolds and position them as strong candidates for advanced tissue engineering applications.

Important Aspects of Staging of Biofilm’s Formation and Justification of Time Intervals of Conduction of Prophylactics of Infectious Complications

In this article there are presented materials regarding problems of infectious complications, that appear as the result of formation of microbial biofilms, which is especially actual in medical practice nowadays because of wide usage of different invasive materials in surgical and traumatological and orthopedical departments of clinics. Classifications, which are based on works of many authors, of surgical infections are given, and also of pathogens, known nowadays, of which Staphylococcus aureus и S. epidermidis are superior. Stages of process and laboratory-experimental proven time intervals and special features of biofilm’s formation are determined, which points to an importance and perspectivity of prophylaxis of infectious complications at moments of contaminations and primary adhesion. In light of usage in implantational surgery of constantly advancing materials, the contemplation is necessary of biofilmforming features of known pathogenic and opportunistic bacterias and potentially dangerous, in particular, pathogens that lead to generalization of process.

The effect of thermal treatment on the neuronal cell biocompatibility of SU-8

Future in vitro life science studies that require in situ functionalities—going beyond the common glass petri dish—can potentially be realized by using microsystems technologies to fabricate bio-microelectromechanical systems (BioMEMS) and laboratory-on-a-chip (LOC). One such material used to construct these microsystems is the commercial photoresist SU-8. Here, the neuronal biocompatibility of SU-8 is examined as a function of its hard-baking thermal treatment. The SU-8 surfaces were non-patterned large uniform thin films—this allowed the biocompatibility and cell adhesion of the SU-8 to be fully tested. In total, 75 SU-8 samples were fabricated for the study using spin-coating and lithography techniques. We observe that a single hard-baking step of 180 °C for 2 h coupled with a coating (poly-d-lysine + laminin) is enough to detoxify SU-8 and promote primary cortical cell adhesion and survival up to 28 days in vitro (DIV). Therefore, the protocol described here makes SU-8 surfaces compatible with the development of neuronal networks from primary neural cells.

Berberine prevents primary peritoneal adhesion and adhesion reformation by directly inhibiting TIMP-1

Peritoneal adhesions are fibrous tissues that tether organs to one another or to the peritoneal wall and represent the major cause of postsurgical morbidity. Enterolysis at repeat surgeries induces adhesion reformation that is more difficult to prevent than primary adhesion. Here we studied the preventive effects of different approaches of berberine treatment for primary adhesion, and its effects on adhesion reformation compared to Interceed. We found the primary adhesion was remarkably prevented by berberine through intraperitoneal injection 30 min before abrasive surgery (pre-berberine) or direct addition into injured cecum immediately after the surgery (inter-berberine). Rats with adhesion reformation had a more deteriorative collagen accumulation and tissue injury in abrasive sites than rats with primary adhesion. The dysregulated TIMP-1/MMP balance was observed in patients after surgery, as well as adhesion tissues from primary adhesion or adhesion reformation rats. Inter-berberine treatment had a better effect for adhesion reformation prevention than Interceed. Berberine promoted the activation of MMP-3 and MMP-8 by directly blocking TIMP-1 activation core, which was reversed by TIMP-1 overexpression in fibroblasts. In conclusion, this study suggests berberine as a reasonable approach for preventing primary adhesion formation and adhesion reformation.

Electrolytic Chromate Films Prepared via Pulse Electrodeposition as a Cu-Epoxy Adhesion Promoter

Chromate films with nanometer-scale thicknesses typically act as secondary adhesive layers between Cu and a polymer film to produce a copper clad laminate (CCL); chromate films provide surface hydroxyl (–OH) that ensures strong binding with the silane coupling agent (primary adhesion promoter). To improve the adhesive strength between Cu and epoxy substrates, in this study, Cr(OH)3 films with high surface coverages were deposited via the pulse electrodeposition technique. In comparison with conventional direct current modes, pulse plating enables the development of high densities of Cr(OH)3 nuclei, resulting in a uniform film growth. Thus, the use of pulse plating leads to good coverage of Cr(OH)3 on a Cu surface, and in turn, a higher peel strength with epoxy, and excellent corrosion protection. These observations indicate that chromate films generated via pulse plating may be a good option for post-treatment of Cu foils to ensure their reliable application for 5 G electronic devices.

Study on Bacterial Antiadhesiveness of Stiffness and Thickness Tunable Cross-Linked Phospholipid Copolymer Thin-Film.

Bacterial adhesion on material surfaces is a significant problem in many areas, especially on medical devices. Upon colonizing a surface, bacteria tend to form biofilms and become difficult to eradicate. A multistep process is involved in bacterial biofilm formation, including primary adhesion to material surface and accumulation of bacterial cells. Controlling the primary adhesion of bacteria is an efficient way to manage biofilms. This study focused on the primary adhesion of bacteria on a copolymer thin-film composed of 2-methacryloyloxyethyl phosphorylcholine (MPC), 3-methacryloxypropyl trimethoxysilane (MPTMSi), and 3-(methacryloyloxy) propyl-tris(trimethylsilyloxy) silane (MPTSSi), which has anti-biofouling and thickness and stiffness tunable properties. We modulated the thickness (5-90 nm) and stiffness of the thin-film via changing the polymer concentration in the coating solution (dip coating). All polymer thin-films inhibited Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa primary adhesions. Interestingly, S. aureus adhesion was affected by the thickness and/or stiffness of the thin-film. We conclude that the mechanical property of the thin-film is one of the influential factors determining bacterial adhesion. These findings would be of significance in designing antibacterial materials.

Lineage Commitment, Signaling Pathways, and the Cytoskeleton Systems in Mesenchymal Stem Cells.

Mesenchymal stem cells (MSCs) from adult tissues are promising candidates for personalized cell therapy and tissue engineering. Significant progress was achieved in our understanding of the regulation of MSCs proliferation and differentiation by different cues during the past years. Proliferation and differentiation of MSCs are sensitive to the extracellular matrix (ECM) properties, physical cues, and chemical signaling. Sheath stress, matrix stiffness, surface adhesiveness, and micro- and nanotopography define cell shape and dictate lineage commitment of MSCs even in the absence of specific chemical signals. We discuss mechanotransduction as the major route from ECM through the cytoskeleton toward signaling pathways and gene expression. All components of the cytoskeleton from primary cilium and focal adhesions (FAs) to actin, microtubules (MTs), and intermediate filaments (IFs) are involved in the mechanotransduction. Differentiation of MSCs is regulated via the complex network of interrelated signaling pathways, including RhoA/ROCK, Akt/Erk, and YAP/TAZ effectors of Hippo pathway. These pathways could be regulated both by chemical and mechanical stimuli. Attenuation of these pathways in MSCs results in specific changes in FAs and actin cytoskeleton. Besides, differentiation of MSCs affects MTs and IFs. Recent findings highlight the role of intranuclear actin in the regulation of transcription factors in response to mechanical environmental stimuli. Alterations of cytoskeletal components reflect the MSC senescence state and their migratory capacity. In this review, we discuss the relationships between the molecular interactions in signaling pathways and morphological response of cytoskeletal components and reveal the complex interrelations between cytoskeleton systems and signaling pathways during lineage commitment of MSCs. Impact Statement This review describes the complex network of relationships between mechanical and biochemical stimuli in mesenchymal stem cells (MSC) and their balance which defines the morphological changes of cell shape due to rearrangement of cytoskeletal systems during lineage commitment of MSCs.

Impacts of platelet-rich fibrin and platelet-rich plasma on primary osteoblast adhesion onto titanium implants in a bisphosphonate in vitro model.

Osteoblast adhesion is a crucial step in osseointegration of dental implants and can be influenced by modification of implant surface or the addition of bioactive agents. Bisphosphonates affect bone turnover, attenuating bone healing in implants patients. PRP and PRF are sources of growth factors involved in osteoblast adhesion, improving subsequent bone healing. The aim of the study was to investigate the impacts of PRP and PRF on adhesion of bisphosphonate-pretreated osteoblasts on titanium implant surfaces using the cell-count wash assay, the MTT-assay as well as real-time-cell analyser assay and scanning electronic microscopy. Titanium implants were colonised for 24hours with osteoblasts and zolendronic acid, PRP or PRF in different combinations. Afterwards, primary osteoblast adhesion was evaluated by counting the number of attached cells using a wash-assay cell analysis. Scanning electronic microscopy was performed and evaluated semi-quantitatively to assess the influence of the different groups on the ultrastructural cell morphology, such as cell size and shape as well as length and number of filopodia. Zoledronic acid led to a decrease of osteoblast adherence onto implant surface. This effect was reversed by adding PRP or PRF. Scanning electronic microscopy showed that both PRP and PRF increased number and length of filopodia in adherent osteoblasts. Zoledronic acid decreased osteoblast adhesion on implant surfaces, and PRF as well as PRP increased primary adhesion of zoledronic acid-treated osteoblasts on implant surfaces in vitro. Therefore, PRP and PRF may improve initial bone apposition and primary healing of dental implants in patients with bisphosphonate treatment.

PF797 APAC, A DUAL ANTIPLATELET AND ANTICOAGULANT ‐ TOWARDS A LOCAL, VASCULAR TARGETING ANTITHROMBOTIC

Background:APAC, is developed as a mimic of heparin proteoglycans, and has unique antiplatelet and anticoagulant action (collagen and thrombin) in several in vitro and in vivo models (Lassila & Jouppila, Semin Thromb Hemost, 2014). APAC as the only anticoagulant in blood inhibits both platelet and fibrin accumulation on collagen and tissue factor under a high shear rate (1000 1/s), and retains primary adhesion (Chen et al. Thromb Res, 2018). Moreover, APAC protects kidneys from ischemic reperfusion injury (Tuuminen et al. Clin Exp Nephrol 2017). APAC is eliminated via kidneys and liver as unfractionated heparin.Aims:We present APAC and its antithrombotic data on platelet aggregation and global coagulation in vitro, vascular targeting and antithrombotic role in vivo, including toxicology margins.Methods:1. Blood was collected from healthy volunteers. APAC was studied in human platelet aggregation in response to collagen and ristocetin in whole blood (Multiplate), platelet‐rich plasma (PRP) and in rotational thromboelastometry (ROTEM) compared with citrated (3.2%) blood and spiking. APAC's antiplatelet efficacy with acetylsalicylic acid (ASA) was estimated in collagen‐, arachidonic acid (AA)‐ or ADP‐induced platelet aggregation in PRP or whole blood, 2. Porcine arterio‐venous fistula of femoral arterial and venous anastomosis sites and balloon denudation of iliac and carotid arteries were exposed to biotin‐labelled APAC to study APAC binding and localization. 3. Single and repeated dose toxicology of rodents and monkeys was assessed.Results:APAC dose‐dependently attenuates platelet aggregation to collagen and ristocetin, unlike heparin, in citrated whole blood at 150 μg/mL by 58 ± 15% (n = 6) (mean ± SD) and by 25 ± 2%, respectively. In PRP, inhibition of collagen‐induced aggregation was 55 ± 31% at 1 μg/mL APAC and 85 ± 11% at 30 μg/mL APAC (n = 9). APAC alone, also dose‐dependently attenuated aggregation and ROTEM variables in whole blood. In ROTEM, APAC alone (at 3–16 μg/mL) reduces intrinsic pathway of coagulation (INTEM), and acts as a broad platelet‐dependent procoagulant. ASA dose‐dependently inhibited collagen‐induced platelet aggregation, clearly potentiated by APAC requiring up to 4‐fold higher collagen concentration to induce aggregation in PRP. In turn, ADP‐ or AA‐induced aggregation was unaffected. APAC co‐localized with Von Willebrand Factor and laminin in porcine arterial injuries, but not with intact endothelium, which stained positive for PECAM or podocalyxin. Upon targeting vessels, APAC locally decreased platelet accumulation and overt thrombosis in a rat model of anastomosis, but retained at anastomosis sites despite high shear blood flow. Single and multiple (7–14 day) doses (3–20 mg/kg in monkeys and rodents) indicate wide safety without APAC accumulation in the toxicology program.Summary/Conclusion:APAC, inhibits collagen‐ and ristocetin‐, but not ADP‐induced, platelet aggregation in citrated blood and PRP, and synergizes with ASA. In citrated whole blood, and if used as a sole anticoagulant, APAC globally attenuates platelet procoagulant activity and fibrin elasticity. With APAC's unique profile, local integration and inhibition of platelet‐mediated thrombosis may benefit vascular interventions.

Omega‐3 polyunsaturated fatty acids protect endothelial adhesion of monocytes through FFA4 in monocytes

A G protein‐coupled receptor (GPCR) named free fatty acid receptor 4 (FFA4, also known as GPR120) was found to act as a GPCR for omega‐3 polyunsaturated fatty acids (n−3 PUFA). Recently, FFA4 is known to participate in the progression of atherosclerosis, however, the underlying mechanisms are unclear. Thus, this study investigated the molecular mechanisms responsible for monocyte adhesion to the vascular endothelium, which is a key early event in macrophage foam cell formation. In ex vivo study, LPS‐induced the primary monocyte adhesion to the vascular endothelial cells were significantly attenuated by pretreatment of EPA and DHA, a representative n−3 PUFA. This EPA and DHA‐induced inhibition were blunted by primary monocytes isolated from FFA4 (−/−) mice. In in vitro study, The LPS‐induced monocyte adhesion to the endothelial cells and adhesion molecule, Mac‐1 expression were significantly attenuated by pretreatment of EPA and DHA in monocytes. This EPA and DHA‐induced inhibition was blunted by pretreatment of AH7614 (a FFA4 antagonist) and by transfection of FFA4 siRNA, suggesting a pivotal role of FFA4 on LPS‐induced monocyte adhesion to the endothelial cells and Mac‐1 expression. In addition, in promoter activity analysis and chromatin immunoprecipitation assays to identify transcription factors involved in EPA and DHA inhibited LPS‐induced Mac‐1 expression, both AP‐1 and NF‐κB played central roles to increase Mac‐1 transcription in LPS‐treated monocytes. The results of this study suggest that n‐3 PUFA protect monocyte adhesion to vascular endothelial cells and Mac‐1 expression via signaling pathways involving AP‐1 and NF‐κB by activating FFA4 in monocytes, leading to increased foam cell formation in the development of atherosclerosis.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Application of hysteroscopy combined with laparoscopic pelvic exploration in the diagnosis and treatment of primary and secondary infertility

Objective To observe the different manifestations and differences of pelvic laparoscopy in primary and secondary infertility patients, and to clarify the application of hysteroscopy combined with laparoscopy in the diagnosis and treatment of infertility. Methods A total of 120 infertile women were enrolled in Yiwu Central Hospital from January 2015 to January 2017, of which 66 cases were primary infertility and 54 cases were secondary infertility. The infertility group was divided into 1 time, 2 times, 3 times and above according to previous maternity. Hysteroscopy combined with laparoscopy was used for pelvic exploration in infertility patients. The detection of the type of disease, pelvic adhesions, tubal fluid and treatment were analyzed. Results (1)Infertile patients were complicated with endometriosis, pelvic tuberculosis, polycystic ovary, uterine fibroids, ovarian tumors, endometrial polyps and other diseases. (2)There were 94 cases of pelvic adhesions(78.3%), 50 cases of primary infertility(75.8%), and 44 cases in Secondary infertility group(81.5%). (3) Primary infertility adhesion ratio of 75.8%, secondary infertility adhesion ratio of 81.5%, the proportion of adhesions in maternal 1 time patients was 80.6%, the proportion of adhesions in pregnant women with 2 times was 83.3%, the proportion of adhesions in pregnant women with more than three times was 90.0%, and the median adhesion rate was 36.4% in the secondary infertility cases, the proportion of severe adhesion was 45.5%. (4) Intraoperative treatment of tubal fluid examination conducted in 240 strips.The probability of recanalization of the primary infertility group was 17.78%, and the probability of recanalization was 18.75%. Conclusion (1) Pelvic adhesion is an important factor in causing infertility, primary infertility patients also have a greater proportion of pelvic, fallopian tube disease.(2) Repeated maternal history significantly increased pelvic, fallopian tube disease, which is an important factor caused the increased incidence of secondary infertility. Key words: Infertility, female; Hysteroscopy; Laparoscopy; Tissue adhesions; Pelvic inflammatory disease; Fallopian tube diseases

ADHESION OF PERIODONTAL PATHOGENS TO MATERIALS USED FOR LONG-TERM TEMPORARY CROWNS

Provisional crowns are widely used in prosthodontic treatment in dentistry, and new materials for temporary crowns, including polyetheretherketone, have emerged, which have high-quality requirements for use in long-term temporary prosthetics. Of particular importance in prosthetics are the features of adhesion of pathogenic oral microflora to orthodontic structures. This study evaluated the adhesion of cariogenic and pathogenic periodontal bacterial flora and Candida species to unpolished and polished Dentokeep polyetheretherketone (PEEK), polished polymethyl methacrylate (PMMA) material (Re-Fine Acrylic), and hotcuring acrylic plastic ─ a powder-liquid type, where the powder is a suspension graft fluorine-containing copolymer, and the liquid is a mixture of acrylic monomers, and oligomers─(Sinma-M) recommended for manufacturing long-term temporary crowns. The effect of polishing or un-polishing the study material on the adhesion of various microorganisms was studied. Polishing of Dentokeep PEEK significantly influenced primary adhesion. Microbial adhesion to sample materials was studied using ultrasonic cavitation. Adhesion of microorganisms to each material was categorized as low (0–0.27), moderate (0.28–0.69), or high (0.70–1). Streptococcus sanguinis, Prevotella intermedia, and Candida albicans adhered moderately to unpolished Dentokeep PEEK, whereas Porphyromonas gingivalis and Candida krusei were highly adherent. Candida species and P. intermedia pathogenic periodontal strain moderately adhered to polished Dentokeep PEEK, whereas S. sanguinis and P. gingivalis were highly adherent. Temporary crowns require additional hygienic measures to eradicate cariogenic (acidogenic), pathogenic periodontal, and fungal microbiota and maintain the normal qualitative and quantitative composition of oral microbiocenosis during prosthodontic treatment. In conclusion, PEEK is a promising material for the manufacture of long-term temporary crowns.

Bactericidal Activity of Superhydrophobic and Superhydrophilic Copper in Bacterial Dispersions.

A method based on nanosecond laser processing was used to design superhydrophilic and superhydrophobic copper substrates. Three different protocols were used to analyze the evolution of the bactericidal activity of the copper substrates with different wettability. Scanning electron microscopy was used to study the variation of cell morphology after the attachment to superhydrophilic and superhydrophobic surfaces. The dispersions of Escherichia coli K12 C600 and Klebsiella pneumoniae 811 in Luria Bertani broth in contact with the superhydrophilic copper surface showed enhanced bacterial inactivation, associated with toxic action of both hierarchically textured copper surface and high content of Cu2+ ions in the dispersion medium. In contrast, the bacterial dispersions in contact with the superhydrophobic copper substrates demonstrated an increase in cell concentration with time until the development of corrosion processes. The resistance of bacterial cells to contact the copper substrates is discussed on the basis of surface forces, determining the primary adhesion and of the protective action of a superhydrophobic state of the surface against electrochemical and biological corrosion.

Self-assembled monolayers of phosphonates promote primary chondrocyte adhesion to silicon dioxide and polyvinyl alcohol materials

The optimal solution for articular cartilage repair has not yet been identified, in part because of the challenges in achieving integration with the host. Coatings have the potential to transform the adhesive features of surfaces, but their application to cartilage repair has been limited. Self-assembled monolayer of phosphonates (SAMPs) have been demonstrated to increase the adhesion of various immortalized cell types to metal and polymer surfaces, but their effect on primary chondrocyte adhesion has not been studied. The objective of this study was to investigate the response of primary chondrocytes to SAMP coatings. We hypothesized a SAMP terminated with an α,ω-bisphosphonic acid, in particular butane-1,4-diphosphonic acid, would increase the number of adherent primary chondrocytes to polyvinyl alcohol (PVA). To test our hypothesis, we first established our ability to successfully modify silicon dioxide (SiO2) surfaces to enable chondrocytes to attach to the surface, without substantial changes in gene expression. Secondly, we applied identical chemistry to PVA, and quantified chondrocyte adhesion. SAMP modification to SiO2 increased chondrocyte adhesion by ×3 after 4 hr and ×4.5 after 24 hr. PVA modification with SAMPs increased chondrocyte adhesion by at least ×31 after 4 and 24 hours. Changes in cell morphology indicated that SAMP modification led to improved chondrocyte adhesion and spreading, without changes in gene expression. In summary, we modified SiO2 and PVA with SAMPs and observed an increase in the number of adherent primary bovine chondrocytes at 4 and 24 hr post-seeding. Mechanisms of chondrocyte interaction with SAMP-modified surfaces require further investigation.

ANALYSIS OF THE ADHESION OF MICROORGANISMS TO MODERN BASIC MATERIALS IN PROSTHETIC DENTISTRY

Aim.The research was conducted for the study of the adhesion of samples of the domestic modern photopolymerizable base composite material in comparison with other materials for the manufacture of the denture bases.Materials and methods.Five samples of the materials were tested to conduct a microbiological study on the subject of primary adhesion of microorganisms to the surface of the base materials. The adhesion of microorganisms to the samples of the base composite materials was assessed using the index method.Results.As a result of a laboratory research, it can be concluded that the new photopolymerization material «Sample 1» used for the manufacture of the bases for the removable dentures has 1, 19 times lower adhesive activity to the colonyforming Prevotella intermedia microorganisms and Candida krusei mushrooms in comparison with the acrylic plastics and thermoplastic materials «Sample 2»; 1,14 times in comparison with the nylon material «Sample 3» and with the monomer material «Sample 4» with a statistically reliable variable number. It should be noted that the Axil-LC topcoat varnish supplied with the Sample 1 basic material kit increases microbial adhesion by 1.36 times.Conclusion.The adhesion of microorganisms to the materials that are used in dental practice is due to the surface tension coefficient – the greater the surface tension coefficient, the higher the probability of adhesion of microorganisms on the surface of these materials. The investigated new photopolymerization material «Sample 1» without coating with a protective varnish showed low adhesion to all major pathogens. Covering with a protective lacquer design, which is a part of the set of the material, significantly increases the adhesion of microorganisms on the surface of the material. The established indexes of microorganisms adhesion to the material «Sample 1» allow us to recommend it for the manufacture of bases for temporary dentures and immediate dentures in the treatment at the stages of dental implantation.

The Role of Transmembrane Glycoproteins, Integrins and Serpentines in Platelet Adhesion and Activation

Platelets are unique cells of human body: they lack nucleus, are rather small in size (1–2 μm) and involved in several physiological functions, including hemostasis, immunity and angiogenesis. Platelets play a key role in the initiation of thrombosis upon injury of the blood vessels of the arterial bed, in which blood flows with high shear rates are observed. According to the generally accepted concepts, the reaction of platelets to endothelial injury at local shear rates of more than 1000 s–1 is the primary binding of the GPIb-IX-V receptor complex glycoproteins with von Willebrand factor, a large multimeric blood protein which can specifically bind to collagen fibers. For further performance of their functions, and first of all, for stable attachment to the injured surface, platelet has to be activated. There are more than ten types of receptors on the platelet membrane, which trigger several cascades of intracellular signaling that leads to the restructuring of the cytoskeleton, granule secretion and activation of integrins, which provide the ability of platelets to strong adhesion and aggregation. This review is focused on the biophysical aspects of the interaction of transmembrane glycoproteins and integrins with extracellular ligands, as well as modern ideas about the mechanisms of platelet activation that is necessary to stabilize their primary adhesion and aggregation.

In vitro Reactive-Accelerated-Aging (RAA) Assessment of Tissue-Engineered Electronic Nerve Interfaces (TEENI).

A reactive-accelerated-aging (RAA) soak-test has been employed to challenge microfabricated neural interface devices against an aggressive environment that mimics worstcase chronic physiological inflammation. The RAA tests were able to determine the ability of different materials to increase the adhesive strength of the polyimide and platinum-goldplatinum metallization thin-film interface. It was found that a 3-day RAA soak-test at 87 °C in phosphate buffered saline with 10 to 20 mM hydrogen peroxide resulted in adhesive failure of the metal-polyimide interface when titanium was used as the primary adhesion promotor. The addition of hydrogenated amorphous silicon carbide was able to eliminate the onset of adhesive failure of the metal-polyimide interface during 7-day RAA soak tests. However, sporadic cracking of the silicon carbide layer resulted in a minority of broken metal interconnects that resulted in failed electrodes. These tests have demonstrated the ability of RAA soak tests to provide rapid in vitro assessment of microfabricated neural interfaces and thereby reduce the time needed to develop synthetic methods to fabricate chronically reliable devices.

Thermoresponsive polysaccharide-based composite hydrogel with antibacterial and healing-promoting activities for preventing recurrent adhesion after adhesiolysis

Postoperative adhesions are very common complications after general abdominal surgery. Although adhesiolysis has been proven effective in eliminating the preexisting adhesions, the new trauma caused by surgical lysis can induce recurrent adhesion. The prevention of recurrent adhesion after adhesiolysis is more difficult because the injury is more severe and adhesion mechanism is more complicated compared with the primary adhesion. In this study, a thermoresponsive hydrogel contained galactose modified xyloglucan (mXG) and hydroxybutyl chitosan (HBC) was developed as a barrier device for recurrent adhesion prevention after adhesiolysis due to its injectability and spontaneous gelling behaviors at the body temperature without any chemical reactions or extra driving factors. First, mXG and HBC were synthesized via enzymatic modification and etherification reaction, respectively. Rheological measurements indicated that the mXG/HBC composite system showed excellent thermosensitivity properties, and their gelation temperature and time can be modulated via adjusting the mXG/HBC ratio. Moreover, the mXG/HBC hydrogel exhibited excellent cytocompatibility and hemocompatibility in vitro. Furthermore, the mXG/HBC hydrogel could promote wound healing in the rat skin wound model. Finally, the efficacy of the mXG/HBC composite hydrogel in the prevention of recurrent adhesion was evaluated in a more rigorous rat repeated-injury adhesion model. The results demonstrated that the composite hydrogel could not only effectively prevent recurrent adhesion after adhesiolysis, but also promote wound healing and reduce scare formation. These results suggested that the mXG/HBC composite hydrogel may be a promising candidate as an injectable anti-adhesion system for clinical applications. Statement of SignificanceAlthough adhesiolysis has been proven effective in eliminating the preexisting adhesions, the new trauma caused by surgical lysis can induce recurrent adhesion. So far, most of the existing barrier systems and pharmacological approaches were developed for primary adhesion prevention while few attention has paid on prevention of recurrent adhesion after adhesiolysis. In the present study, we developed a thermoresponsive polysaccharide-based composite hydrogel by simple mixing galactose modified xyloglucan (mXG) and hydroxybutyl chitosan (HBC). The resulting mXG/HBC composite hydrogel not only was easy to handle and highly effective in preventing the recurrent adhesion after adhesiolysis, but also could promote wound healing and reduce scare formation. Our study provide an effective anti-adhesion system for preventing recurrent adhesion after adhesiolysis.

Molecular epidemiological survey of Streptococcus agalactiae in neonatal nosocomial infection

Objective The present study aimed to investigate the molecular characterizations and virulence factors mediating adhesion of S. agalactiae. Methods All the 6 GBS strains from maternity ward, 4 isolated from the blood of neonates and 2 isolated from the vaginal secretions of their mothers, were performed antimicrobial susceptibility tests through disk diffusion method, and analyzed by multilocus sequence typing (MLST) and pulse field gel electrophoresis typing(PFGE) to determine the relationship between the strains and whether it was nosocomial infection or not. The S. agalactiae isolates were subjected to capsular genotyping by PCR. Determinants of adherence factors were also detected by PCR and sequencing, including surface proteins and pilus-like structures. Results The results of antimicrobial susceptibility tests of 7 /13/37/66 are the same, while 142 and 158 are the same but different from the other 4 strains. The MLST results indicate that 7 /13/37/66 are of the same sequence type ST-12, while 142 and 158 are ST-19. PFGE results have further proved that 7/13/37/66 are of the same clone type, and 142 and 158 were another clone type. The strains of 7/13/37/66 are serotype Ib, and contain bac, bca, and alp2/3 genes, while 142 and 158 are serotype III and contain e gene. All the six strains contain PI-1 and PI-2a genes. Conclusions There are not only vertical but also horizontal transmissions in the 4 cases, which may be a nosocomial infection event. Six strains all contained primary adhesion factor of S. agalactiae: surface proteins and pilus-like structures, which indicates that all the 6 strains has a strong toxicity in adhesion and spread. The hospitals should reinforce the prenatal examination of S. agalactiae and control the nosocomial infection.(Chin J Lab Med, 2018, 41: 352-355) Key words: Bacteremia; Streptococcus agalactiae; Virulence factors; Infant, newborn; Molecular epidemiology