Fast Curing Research Articles

Development of a fast curing tissue adhesive for meniscus tear repair

Isocyanate-terminated adhesive amphiphilic block copolymers are attractive materials to treat meniscus tears due to their tuneable mechanical properties and good adhesive characteristics. However, a drawback of this class of materials is their relatively long curing time. In this study, we evaluate the use of an amine cross-linker and addition of catalysts as two strategies to accelerate the curing rates of a recently developed biodegradable reactive isocyanate-terminated hyper-branched adhesive block copolymer prepared from polyethylene glycol (PEG), trimethylene carbonate, citric acid and hexamethylene diisocyanate. The curing kinetics of the hyper-branched adhesive alone and in combination with different concentrations of spermidine solutions, and after addition of 2,2-dimorpholinodiethylether (DMDEE) or 1,4-diazabicyclo [2.2.2] octane (DABCO) were determined using FTIR. Additionally, lap-shear adhesion tests using all compositions at various time points were performed. The two most promising compositions of the fast curing adhesives were evaluated in a meniscus bucket handle lesion model and their performance was compared with that of fibrin glue. The results showed that addition of both spermidine and catalysts to the adhesive copolymer can accelerate the curing rate and that firm adhesion can already be achieved after 2 h. The adhesive strength to meniscus tissue of 3.2–3.7 N was considerably higher for the newly developed compositions than for fibrin glue (0.3 N). The proposed combination of an adhesive component and a cross-linking component or catalyst is a promising way to accelerate curing rates of isocyanate-terminated tissue adhesives.

Accurate Cure Modeling for Isothermal Processing of Fast Curing Epoxy Resins.

In this work a holistic approach for the characterization and mathematical modeling of the reaction kinetics of a fast epoxy resin is shown. Major composite manufacturing processes like resin transfer molding involve isothermal curing at temperatures far below the ultimate glass transition temperature. Hence, premature vitrification occurs during curing and consequently has to be taken into account by the kinetic model. In order to show the benefit of using a complex kinetic model, the Kamal-Malkin kinetic model is compared to the Grindling kinetic model in terms of prediction quality for isothermal processing. From the selected models, only the Grindling kinetic is capable of taking into account vitrification. Non-isothermal, isothermal and combined differential scanning calorimetry (DSC) measurements are conducted and processed for subsequent use for model parametrization. In order to demonstrate which DSC measurements are vital for proper cure modeling, both models are fitted to varying sets of measurements. Special attention is given to the evaluation of isothermal DSC measurements which are subject to deviations arising from unrecorded cross-linking prior to the beginning of the measurement as well as from physical aging effects. It is found that isothermal measurements are vital for accurate modeling of isothermal cure and cannot be neglected. Accurate cure predictions are achieved using the Grindling kinetic model.

Experimental study of the effect of microspheres and milled glass in the adhesive on the mechanical adhesion of single lap joints

ABSTRACTThis article describes several experiments conducted on single lap joints (SLJ) subjected to tensile mechanical loads. Two epoxy adhesives, with slow and fast curing, were used, with a weight of 0%, 3%, and 10% of glass microspheres and milled glass particles, respectively. The adherends used in the construction of the specimens were fiber-reinforced polymers. The types of failures produced in the SLJ specimens were classified according to ASTM standards. The results of the experimental tests on the SLJ with fast-curing epoxy adhesive showed that the use of milled glass and glass microspheres improved the strength of the joint compared with the neat fast-curing epoxy adhesive. As for the experimental test on the joint with slow-curing epoxy adhesive, the results showed that the use of milled glass and glass microspheres decreased its strength when using different additive concentrations compared with the neat slow-curing epoxy adhesive.

A novel material for in situ construction on Mars: experiments and numerical simulations

A significant step in space exploration during the 21st century will be human settlement on Mars. Instead of transporting all the construction materials from Earth to the red planet with incredibly high cost, using Martian soil to construct a site on Mars is a superior choice. Knowing that Mars has long been considered a “sulfur-rich planet”, a new construction material composed of simulated Martian soil and molten sulfur is developed. In addition to the raw material availability for producing sulfur concrete and a strength reaching similar or higher levels of conventional cementitious concrete, fast curing, low temperature sustainability, acid and salt environment resistance, 100% recyclability are appealing superior characteristics of the developed Martian Concrete. In this study, different percentages of sulfur are investigated to obtain the optimal mixing proportions. Three point bending, unconfined compression and splitting tests were conducted to determine strength development, strength variability, and failure mechanisms. The test results show that the strength of Martian Concrete doubles that of sulfur concrete utilizing regular sand. It is also shown that the particle size distribution plays an important role in the mixture’s final strength. Furthermore, since Martian soil is metal rich, sulfates and, potentially, polysulfates are also formed during high temperature mixing, which might contribute to the high strength. The optimal mix developed as Martian Concrete has an unconfined compressive strength of above 50MPa. The formulated Martian Concrete is simulated by the Lattice Discrete Particle Model (LDPM), which exhibits excellent ability in modeling the material response under various loading conditions.

Inductively cured glued-in rods in timber using Curie particles

Commonly used adhesives for glued-in rods in timber engineering, cold curing two-component (2K) epoxies or polyurethanes, only harden relatively slowly (usually in hours to days), which is magnitudes of times longer than mechanical fastening. Additional constraints associated with aforementioned 2K adhesives arise from the fact that they usually necessitate some minimum temperature below which polymerisation can take place, respectively that pot life is strongly affected by (higher) ambient temperature; both limitations restrict the possibilities to bond onsite, depending on the location to a limited number of months of a year. Induction heating was investigated in the light of a potential timber engineering application, herein fast curing of glued-in glass fibre reinforced rods in timber. As none of the materials involved is susceptible to electromagnetic induction, metallic particles were mixed to a 1C epoxy. Induction of adhesives with particles has long been plagued by issues related to non-uniformity of heat distribution in the bondline, unless extensive temperature monitoring and control is exerted. To overcome these issues, metallic particles consisting of Mn–Zn-Ferrite, a Curie material that is not susceptible to induction heating beyond its Curie temperature, were used. The experiments showed that, by matching Curie temperature with the temperatures at which the adhesive cures, induction heating can be performed without any external control, thus freeing the process from monitoring equipment. Inductively cured glued-in rods reached shear strengths at the upper end of what is usually reported in literature. Compared to current practice of cold curing 2K polyurethanes or epoxies, the proposed method leads to bonded joints achieving full strength within minutes, instead of hours, or days, which represents a substantial gain in processing time, almost unaffected from outside temperature conditions.

Separation of toluene–methanol mixtures by pervaporation using filled elastomeric membranes

Hybrid type elastomeric membranes were prepared by mixing natural rubber (NR) with 10wt% of (of rubber) three different types of organophilic fillers, i.e., carbon black, organophilic clay and organophilic zeolite. These elastomeric membranes were cured (crosslinked) by semi efficient vulcanization technique using sulfur (S) and zinc diethyl dithio carbamate (ZDC), an ultra fast room temperature curing accelerator to obtain three membranes designated as NRCB, NRC and NRZ, respectively. The membranes were characterized by crosslink density, FT-IR, SEM analysis, and mechanical properties and used for pervaporative removal of low concentration of toluene from its mixtures with methanol at different feed toluene concentrations and temperatures. The NRCB membrane was found to show the best result with respect to toluene flux and selectivity over the entire feed concentration of 3–40wt% of toluene in methanol.

Fast curing of thick components of epoxy via modified UV-triggered frontal polymerization propagating horizontally

This work aims at exploring a fast and facile technique for epoxy curing. Modified UV-triggered frontal polymerization propagating horizontally (hFP) is herein adopted to cure thick component of an alicyclic epoxy in a rapid fashion. The front velocity Vf and maximum temperature Tmax are found to increase with the augment of the concentration of the thermal initiator (TI). The obtained condensates are characterized and found to have a high curing degree, good mechanical property and thermal stability. Especially, a propagating angle θ is observed clearly for the first time during the curing process. The hFP approach is believed to exhibit great potential applications in preparation of low-cost, high-performance epoxy-based coating and composite materials.

Benzophenone 가교제를 이용한 수분산 폴리우레탄 개질

Production of eco-friendly and biologically harmless materials is strongly required in all industries. In particular, reducing volatile organic compounds in coating processes is extremely important to secure worker’s safety. During recent two decades, extensive research works on water-borne polyurethane dispersion (PUD) have been continuously developed as an alternative to solvent-borne polyurethane. However, PUD was shown inferior mechanical properties to the organic solvent-borne polyurethane due to a limit to the molecular weight increase, which resulted in the limit of applications. To overcome this drawback, several approaches have been examined such as polymer blends and thermal/radiation induced crosslinking. Among these methods, the radiation curing system was suitable for industrialization because of the high crosslinking density and fast curing speed. In this study, we overcame the drawback for PUD via introducing benzophenone radiation curable units to PUD. We synthesized PUD films which possessed good dispersion in water for 30 days, increased Tg and Td more than 5 °C after UV curing film as well as improved young’s modulus more than double.

Colloidal processing using UV curable resin under high magnetic field for textured ceramics

A novel colloidal processing method using UV curable resin was examined in colloidal processing under a high magnetic field. This technique can help shorten the shaping time under the magnetic field as a result of fast UV curing. We prepared the dispersed (Sr,Ca)2NaNb5O15 (SCNN) slurry with a UV curable resin and fabricated c-axis-oriented SCNN ceramics within a short time under a rotating high magnetic field. The Lotgering factor was 0.81 for (00l) in the green compact and increased to 0.94 after sintering. The colloidal processing under the high magnetic field was thus effective not only in shortening the drying time under the magnetic field but also in obtaining highly particle-oriented structures.

Transparent Films from CO2 -Based Polyunsaturated Poly(ether carbonate)s: A Novel Synthesis Strategy and Fast Curing.

Transparent films were prepared by cross‐linking polyunsaturated poly(ether carbonate)s obtained by the multicomponent polymerization of CO2, propylene oxide, maleic anhydride, and allyl glycidyl ether. Poly(ether carbonate)s with ABXBA multiblock structures were obtained by sequential addition of mixtures of propylene oxide/maleic anhydride and propylene oxide/allyl glycidyl ether during the polymerization. The simultaneous addition of both monomer mixtures provided poly(ether carbonate)s with AXA triblock structures. Both types of polyunsaturated poly(ether carbonate)s are characterized by diverse functional groups, that is, terminal hydroxy groups, maleate moieties along the polymer backbone, and pendant allyl groups that allow for versatile polymer chemistry. The combination of double bonds substituted with electron‐acceptor and electron‐donor groups enables particularly facile UV‐ or redox‐initiated free‐radical curing. The resulting materials are transparent and highly interesting for coating applications.

Abstract C92: Clinical trial accrual: Training Latina patient navigators

Abstract In today's clinical trial arena interest in accrual and retention is extremely high among investigators. There have been various efforts to determine the reasons why underrepresented populations enter clinical trials at a much lower percentage than their Caucasian counterparts. Recent data gathered at the Clinical Trial Summit documented that 67% of professionals consenting patients have less than 6 hours of psychosocial training. This data does not take into account the added difficulty of meeting the needs of the underrepresented. Racial and ethnic disparities in the incidence, prevalence, mortality and burden of cancer are well documented. Participation in clinical trials is also beginning to be studied in this context. Hypothesis: A new approach will increase accrual and retaining underserved participants in clinical trials. In particular, we will develop, train and pilot an approach focused on: 10 Providing Spanish speaking women with trainied navigators who will included information about clinical trials during their initial treatment decision meetings; and 2) Continue the navigation through the consent process if a clinical trial is chosen, as well as provide patients with clear, understandable, culturally sensitive information in Spanish about clinical trials including decision aids to help them though the consent process. Action Taken: CISN principals are now working with our partner (Dia de la Mujer Latina, a long standing nonprofit who has many partners working with Latina women) on developing a navigator training that will provide patients with better ways to understand clinical trials. Special attention is paid to language barriers, cultural issues that need to be understood and respected, as well as age and distrust of the medical system. This training will be integrated into an existing training for navigators that has been recognized as a model and used widely in Texas and several other states. Joining a clinical trial is a critical decision that many cancer patients will face. Language and cultural barriers make this an even more difficult decision for non-English speaking women of Latina origin. Having well trained staff assist patients should be considered a component of quality care. Outcome: Interest in our methods and materials continues to grow. Faster Cures recently identified CISN as having ‘best practice’ methods in the area of informed consent. We work closely with academic, government, other non-profits and industry researchers to help foster public awareness about the importance of medical research to daily life. CISN addresses these issues and present various strategies that might be applied to cooperative group and industry trials so as to bridge the research gap, move research forward and adopt the best course to serve the needs of the community, researchers and all patients, regardless of race/ethnicity, language and/or cultural needs. Citation Format: Peggy Devine. Clinical trial accrual: Training Latina patient navigators. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr C92.

Effects of moisture on the long-term performance of adhesively bonded FRP/steel joints used in bridges

Concerns regarding the durability of adhesively-bonded fibre-reinforced-polymer (FRP)/steel joints in bridges have been a major obstacle to their growing application. On the one hand, the available long-term data of FRPs used in bridges is rare and, on the other hand, the existing assessment approaches have mainly been developed to address the needs of industries, such as the aviation sector, with distinct differences. This paper uses both experimental and numerical approaches to investigate the effects of moisture, as one of the most influential factors, on the long-term performance of FRP/steel joints used in bridges. Gravimetric measurements are used to characterise the 3D moisture-diffusion properties for different FRPs and an adhesive material in various ageing conditions. Fast curing of the adhesive was found to have no significant effect on the diffusion properties of fully cured epoxy specimens. Salt water was found to degrade the mechanical properties of adhesive to a lesser degree than distilled water. The tested double-lap-shear joints of FRP/steel showed ca. 5% strength gain after eight months and ca. 9% reduction in the failure load after 12 months of ageing. While the elastic modulus of adhesive was found to decrease significantly with increasing moisture content, the stiffness reduction was found to be trivial in the joint-level. The results of coupled diffusion-mechanical finite element analyses indicate the importance of adherend permeability on moisture ingression into the joints. Moreover, the presence of small amounts of moisture at the steel/adhesive interface for less than a critical period is found to increase the joint strength. However, prolonged exposure to the same moisture content degrades the strength of the joint, and is, thus, time dependent.

Abstract P5-10-02: Clinical trials: "A holistic approach"

Abstract Goal: New and improved treatments depend on the completion of successful clinical trials. Our goal is to impact all aspects of the clinical trial process to enhance accrual and outcomes. 1) To provide patient focused feedback at the design phase of clinical trials 2) To increase health literacy about clinical trials at both the national and community level 3) To provide decision aids for individual trials 4) To provide patient focused staff communication trainings Strategy: CISN principals are currently working with the following groups National Clinical Trial Network Academic Medical Centers: UCSF and Mayo Industry: Genentech, Pfizer, Novartis, and Lilly Nonprofit Organizations: AACR, Faster Cures, Susan G. Komen, SOCRA CISN principals are working within the NCTN to accomplish strategies one and two. The goal is to branch out to more community venues in the future. A 2001 study by Lara et. al. reported that the consent process with its legalistic and confusing forms is itself a barrier to patient participation with 49% of eligible patients declining enrollment. We address these concerns by accomplishing strategies 3 and 4 above. Action Taken CISN is introducing the medical community to an array of issues affecting patients considering participation in clinical trials. They are also developing patient-centered, study specific, educational materials included as part of the informed consent process. These interventions may enhance patient literacy, improve patient satisfaction and advance public trust in the research enterprise, leading to responsible increased accrual and retention. Additionally, CISN has worked as a contractor for several biotech companies to develop patient educational materials for several studies. Work done at the Clinical Trial Summit documented that 67% of professionals consenting patients have less than 6 hours of psychosocial training. To address that issue, CISN developed a training program for those professionals who administer consent. Two PhD psychologists where brought onboard as consultants to assist in the development of the training. To date CISN has conducted many trainings for various groups and will soon submit grants to partner with other organizations to translate the materials into Spanish and work with patient navigators to further ensure proper training in all communities. Outcome Interest in our methods and materials continues to grow. CISN was identified by Faster Cures as having "best practice" methods in the area of informed consent. We work closely with academic, government, other non-profits and industry researchers to help foster public awareness about the importance of medical research to daily life. CISN addresses these issues and presents various strategies that might be applied to NCI network group and industry trials so as to bridge the research gap, move research forward, and adopt the best course to serve the needs of the community, researchers and patients. Citation Format: Spears PA, Devine P, Finestone S, Carbine N. Clinical trials: "A holistic approach". [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-10-02.

Biodegradable polyanhydrides from thiol-ene polymerizations: fast, robust and reliable curing yields surface eroding materials

Event Abstract Back to Event Biodegradable polyanhydrides from thiol-ene polymerizations: fast, robust and reliable curing yields surface eroding materials Katie L. Poetz1, Halimatu S. Mohammed1, Lina Bian1, Sergii Domanskyi2, Vladimir Privman2, Paul J. Goulet1 and Devon Shipp1 1 Clarkson University, Department of Chemistry and Biomolecular Science, United States 2 Clarkson University, Department of Physics, United States Introduction: Polyanhydrides have long been known as surface-eroding biomaterials, and thus have realized their potential in drug-release devices such as the Gliadel Wafer™. However, despite extensive efforts there have been several significant roadblocks to the further application of these materials in the biomedical arena. One of the primary problems is the demanding curing process of the monomers used in the majority of studies since these monomers are often diacids (or their acyl chloride derivatives). Therefore, such reactions need high vacuum and temperatures, rendering in situ curing impossible. We have recently[1][2] shown that thiol-ene radical polymerization is ideally suited for the polymerization of polyanhydrides (Scheme 1). Here we discuss the synthesis, characterization and erosion characteristics of these materials. Materials: 4-Pentenoic anhydride (PNA), 1,6-hexanedithiol (HDT), pentaerythritol tetrakis(3-mercaptopropionate) (PETMP), 1-hydroxycyclohexyl phenyl ketone were purchased from Sigma-Aldrich. Methods: Example synthesis using PNA:HDT:PETMP = 100:70:30 (mole ratios of functional groups): 1-hydroxycyclohexyl phenyl ketone (1.4 mg, 0.0069 mmol, 0.1 wt%), PETMP (0.22 mL, 0.57 mmol), HDT (0.41 mL, 2.68 mmol) and PNA (0.7 mL, 3.83 mmol) were weighed into a small vial. After mixing to establish a homogenous solution it was transferred to a mold for polymerization and irradiated by UV light for 15 minutes. Samples were degraded by placing them into 100 mL of aqueous PBS solution at 37°C. At select time intervals, the polymer was removed from the buffered solution, the surface quickly dried and polymer weighed and new buffer solution added. Results: Thiol-ene polymerizations were photoinitiated using to yield crosslinked polyanhydrides with essentially 100% conversion of thiol and ene groups. The inclusion of HDT at amounts of >60% thiol groups (but <100%) yielded semicrystalline crosslinked polyanhydrides, as determined by differential scanning calorimetry (DSC), which showed crystalline melt temperatures of approximately 60oC, and wide-angle x-ray diffraction. Erosion of these materials showed qualitative surface erosion behavior; with mass-loss curves exhibiting a short induction period (~24 hours) before erosion being compete in around 10 days (Figure 1). Discussion: In comparison with traditional approaches to polyanhydride synthesis, thiol-ene ‘click’ chemistry has many advantages: many monomers are simple and readily available, and there is low susceptibility to oxygen, low shrinkage, and uniform cross-link density. Furthermore, because thiol-ene polymerization occurs via a step-growth mechanism, the degradable anhydride functionality resides in the main chain, rather than a side chain, which reduces the molecular weight of the degradation products compared to biomaterials synthesized by chain growth polymerizations. Initiation can be achieved using purely thermal, redox, or photochemical methods, or some combination of these. We have also found that surface erosion occurs, [1][3] and the materials have very high cytocompatibility, even at elevated concentrations [2][4]. Conclusions: Thiol-ene chemistry can be reliably applied to the rapid production of polyanhydrides that are surface-eroding in aqueous environments, and presents significant opportunities for potentially broad use of these materials in many applications, including biomedical devices, adaptable surfaces, shape memory materials, drug delivery, erodible/resorbable adhesives, self-cleaning surfaces, adaptable and patternable surfaces, functionalized surfaces/particles, hierarchical structures, and scaffolds for cell growth.

3D-printed polymers for biomedical applications

cant technology leaps take place simultaneously in several complementary areas. This is the case in polymeric biomaterials’ technology. Amazing advances have been made in the additive manufacturing technologies, i.e. 3D-printing. It is a family of different layer by layer manufacturing methods like fused deposition modeling, powder laser sintering, ink-jet printing, stereo lithography, two or multi photon polymerization and hydrogel 3D-printing. All of them applicable for processing of polymeric materials. Essential developments have taken place also in biomedical imaging and 3D-design to create the necessary digital models needed for the 3D-printing. At the same time great progress has been achieved in biopolymers’ development. They can be tailored to be biostable or bioresorbable in a controlled way, or in some cases even bioactive. Bioactivity has been achieved through addition of bioactive compounds like bioactive glass or through functionalization of the polymeric structure (www.kunststoffe-international.com/1332070, DOI: 10.1016/j.actbio.2011.06. 039, DOI: 10.1016/j.compscitech.2012.10.014, DOI: 10.1002/jbm.b.32863, DOI: 10.1002/pola.27400, DOI: 10.1039/C5TB01468A). The parallel advance which has taken place in the biomedical sciences has significantly improved the options in regenerative medicine and may even enable tissue engineering. For polymer research this important and fast developing area offers great opportunities of high societal impact. However, the demands for polymer properties are strict for the novel biomaterials. They should meet the various physical criteria set by the needs of the application, but in addition the demand of non-toxicity is a self-evident must in biomedical applications. Successful 3D-additive manufacturing sets requirements to master the viscosities and liquid to solid transitions in the printing process. In stereo lithography the oligomeric low viscosity prepolymers need to be fast photo curing; with photo curing chemistry that is non-toxic in the biological environment and can get approved by the authorities. Especially for resorbable polymers there is a need to find alternative curing chemistries in addition to acrylate or methacrylate based systems. (www.kunststoffe-international.com/1325854) Complementary research interplay is essential in this field of science. An excellent example of such an effort has been the ArtiVasc 3D-project funded by the 7 Framework Program of the European Union to prepare polymeric scaffolds for vascularized, cell tissue cultivated skin like tissue. Outcome of the project is presented in the video: ArtiVasc 3D on the Way to Bio-Artificial Tissue. Novel technologies, breakthroughs in biomedical sciences together with innovative novel polymers enable jointly significant enhancements for life!

SODIUM CITRATE INFLUENCE ON FORMATION OF CEMENT STONE IN THE ALUMINOUS BINDER

The paper deals with the effect of sodium citrate on the formation of a cement stone in the aluminous binder. Formation of cement stone framework in cement hydraulic binder is accompanied with complicated physical and chemical processes of interphase interactions and dispersion, these processes are predicated on qualitative and quantitative composition of the cement mortar, continuous changes in its properties from preparation stage till curing. Addition of sodium citrate to tempering water enhances hydration of both Portland cement and calcium aluminate cement. Process pertaining to an increase of cement hydration rate is considered as a consequence of destruction in surface formations and exclusion of damping effect in respect of hydration rate and hydrolysis of products resulted from interaction of clinker material with tempering. It has been established that sodium citrate makes it possible to control processes of hydration, hydrolysis, binding and curing for cement mass. High degree of hydration of aluminous cement in the presence of sodium citrate provides fast binding and curing of binder, low porosity and rather high compression breaking strength of cement stone for all curing stages. An increase in concentration of sodium citrate in cement mixture up to 10 % of the cement mass exerts an influence not only on the process of cement mortar liquefaction, reduction of time for cement mass setting and hardening but also increases compression strength of cement stone. An analysis of the structure for cleavage surface of cement stone gives ground to declare that the addition of sodium citrate provides cement stone sealing and reduces its water absorption.

New insights of cyanoacrylate glues in surgical applications. A comparative study of akyl cyanoacrylates.

Event Abstract Back to Event New insights of cyanoacrylate glues in surgical applications. A comparative study of akyl cyanoacrylates. Julio San Román1, Mar Fernandez-Gutierrez1, Gemma Pascual2, Barbara Perez-Kholer2 and Juan M Bellon2 1 Institute of Polymers and CIBER-BBN, Biomaterials, Spain 2 University of Alcala de Henares and CIBER-BBN, Faculty of Medicine, Spain Alkyl cyanoacrylates have been applied since 1965 as self-adhesives for biomedical applications because of their good properties and very fast curing process in physiological conditions, associated to the ionic polymerization catalysed by water. However the stability of the poly(alkyl cyanoacrylate)s after the application in contact with living tissues depends on the chemical structure of the corresponding alkyl cyanoacrylates and poly(alkyl cyanoacrylates) formed by the polymerization reaction, being the reaction of the ethyl derivative faster than butyl, hexyl or longer alkyl segments. In addition, the toxicity of these systems is also associated to the nature of the alkyl residue, being the ethyl cyanoacrylate much more toxic that the butyl, hexyl or longer hydrocarbon substituents. The aim of the present work is the comparative analysis in vitro and in vivo of two commercial akyl cyanoacrylate monomers, Glubran 2 (n-butyl cyanoacrylate) and Ifabond (n-hexyl cyanoacrylate) in comparison with an experimental bioadhesive based on n-octyl cyanoacrylate, different from Dermabond (2-octyl cyanoacrylate) indicated for topical applications in dermal defects. The three systems were tested “in vitro” with different cell lines , and “in vivo” by the fixation of surgical meshes of polypropylene applied to abdominal hernias repair, using rabbits as experimental animal model and a methodology previously validated by the group. Adhesion of the mesh by the application of the three adhesives and comparison with suture, fibrosis and tissue integration as well as inflammation and local effects of the three adhesives were determined after periods post-implantation of 14 , 30 and long term 90 days. In addition the biomechanical properties of the meshes integrated into the abdominal wall of the rabbit were determined according to a well-defined protocol using strips of the integrated meshes prepared from the implants. The results demonstrated that the Glubrand and Ifabond glues give a more inflammatory response than the n-octyl cyanoacrylate after the study of the histological sections of the points of application and the biomechanical behaviour is very good for the octyl derivative even after the 90 days of implantation. The resorption of the polymer generated by the systems is also dependent of the nature of the adhesives, being the n-octyl derivative more stable than the commercial glues. The “in vitro” test based on standard analysis MTT and Alamar Blue, indicate a good tolerance and biocompatibility of the three alkyl cyanoacrylates studied, but it is clear that the viability of n-octyl cyanoacrylate is better than the other commercial glues, Glubrand 2 and Ifabond. A detailed study of the cell behaviour and histological evaluation of the implants will be presented. projects SAF2014-55022-P and MAT2014-51918-C2-1R Keywords: Tissue Engineering, Scaffold, in vivo tissue engineering, bioactive interface Conference: 10th World Biomaterials Congress, Montréal, Canada, 17 May - 22 May, 2016. Presentation Type: Poster Topic: Surface and interfacial characterization Citation: San Román J, Fernandez-Gutierrez M, Pascual G, Perez-Kholer B and Bellon J (2016). New insights of cyanoacrylate glues in surgical applications. A comparative study of akyl cyanoacrylates.. Front. Bioeng. Biotechnol. Conference Abstract: 10th World Biomaterials Congress. doi: 10.3389/conf.FBIOE.2016.01.02828 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 27 Mar 2016; Published Online: 30 Mar 2016. Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Julio San Román Mar Fernandez-Gutierrez Gemma Pascual Barbara Perez-Kholer Juan M Bellon Google Julio San Román Mar Fernandez-Gutierrez Gemma Pascual Barbara Perez-Kholer Juan M Bellon Google Scholar Julio San Román Mar Fernandez-Gutierrez Gemma Pascual Barbara Perez-Kholer Juan M Bellon PubMed Julio San Román Mar Fernandez-Gutierrez Gemma Pascual Barbara Perez-Kholer Juan M Bellon Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Fast Curing of Cyanate Ester Resin with Aromatic Diamines and Development of Various Novolak Type Cyanate Ester Resins

<b>Fast Curing of Cyanate Ester Resin with Aromatic Diamines and Development of Various Novolak Type Cyanate Ester Resins </b>

Preparation and characterization of lignin demethylated at atmospheric pressure and its application in fast curing biobased phenolic resins

Agricultural crop-based lignin was utilized to modify phenol-formaldehyde (PF) resin to prepare fast curing biobased phenolic resins by copolymerization.

TEM-1-encoding small plasmids impose dissimilar fitness costs on Haemophilus influenzae and Haemophilus parainfluenzae.

Only two beta-lactamases, TEM-1 and ROB-1, have been observed in Haemophilus influenzae, while four different TEM but no ROB enzymes have been found in Haemophilus parainfluenzae. In order to investigate the mechanisms behind the dissemination of small beta-lactamase-encoding plasmids in H. influenzae and H. parainfluenzae, we assessed the fitness cost of three TEM-1- (pPN223, pA1209, pA1606), one TEM-15- (pSF3) and one ROB-1-bearing (pB1000) plasmid when expressed in either bacterial species. All plasmids were stable in H. influenzae and H. parainfluenzae except pB1000, which showed on average (sample mean) 76% curing in H. parainfluenzae after 5 days of subculture. Competition assays between isogenic strains with and without plasmid showed no competitive disadvantage of pPN223 and pA1606 in H. influenzae, or of pA1209 in H. parainfluenzae. In contrast, pSF3 and pB1000 were associated with significant competitive disadvantages in both species. Some of the competitive disadvantages may be related to differences in plasmid copy number and mRNA expression of the beta-lactamase genes, as revealed by quantitative PCR analysis. In conclusion, plasmids encoding TEM beta-lactamases isolated from H. influenzae and H. parainfluenzae can be stably transferred between species. The fast curing of pB1000 in H. parainfluenzae observed in this study correlates to the fact that ROB-1 has never been reported for this species. TEM-1-encoding plasmids are associated with the lowest level of fitness cost, but different TEM-1 plasmids confer different levels of fitness cost on the two hosts.