42 research outputs found

    Repurposing cancer drugs, batimastat and marimastat, to inhibit the activity of a group I metalloprotease from the venom of the Western Diamondback rattlesnake, Crotalus atrox

    Get PDF
    Snakebite envenomation causes over 140,000 deaths every year predominantly in developing countries. As a result, it is one of the most lethal neglected tropical diseases. It is associated with an incredibly complex pathophysiology due to the vast number of unique toxins/proteins found in the venoms of diverse snake species found worldwide. Here, we report the purification and functional characteristics of a group I metalloprotease (CAMP-2) from the venom of the western diamondback rattlesnake, Crotalus atrox. Its sensitivity to matrix metalloprotease inhibitors (batimastat and marimastat) was established using specific in vitro experiments and in silico molecular docking analysis. CAMP-2 shows high sequence homology to atroxase from the venom of Crotalus atrox and exhibits collagenolytic, fibrinogenolytic and mild haemolytic activities. It exerts a mild inhibitory effect on agonist-induced platelet aggregation in the absence of plasma proteins. Its collagenolytic activity was completely inhibited by batimastat and marimastat. Zinc chloride also inhibits the collagenolytic activity of CAMP-2 by around 75% at 50 M, while it is partially potentiated by calcium chloride. Molecular docking studies demonstrate that batimastat and marimastat are able to bind strongly to the active site residues of CAMP-2. This study demonstrates the impact of matrix metalloprotease inhibitors in the modulation of a purified, group I metalloprotease activities in comparison to the whole venom. By improving our understanding of snake venom metalloproteases and their sensitivity to small molecule inhibitors, we can begin to develop novel and improved treatment strategies for snakebites

    Dynamic Mechanical Analysis of Bio-Based and Synthetic Petroleum Based Polymer Foams with Powder Type Organic Filler at Prolonged Ultra-Violet Exposure

    Get PDF
    Wood powder filler that have been added in the bio-based and epoxy polymer foams can be proved that it have ability to strengthen the structure of polymer foams. In this study, ‘Meranti’ type wood filler has been used as the filler. This study was developed to observe the pore size of each sample when expose to different hours of UV irradiation exposure using Optical Microscopy (OM). This study was also to compare the mechanical properties of every sample with different ratio filler of 0 wt%, 5 wt%, 10 wt%, 15wt% and 20 wt% at different hours of UV irradiation exposure which is 0 hour until 6,000 hours with increment of 2,000 hours. The testing was run by DMA Q800 TA machine. The samples that have 40 x 10 x 5 mm size were clamped in the machine to get the result of their mechanical properties. From the DMA testing, the results will show the value of tan delta, loss modulus and storage modulus. The value of tan delta shows that higher ratio filler will give the high value of tan delta. The epoxy polymer foams with powder filler have the highest value of tan delta compare to bio-based polymer foams. It proves that the higher filler ratio, the lower value of tan delta can be recorded.  The result of storage and loss modulus was found to increase as the more filler ratio filler in the polymer foams. The higher the loss modulus and storage modulus, the lower the temperature. Bio-based polymer foams with high powder filler ratio can dissipate more energy as energy are lost as heat during UV irradiation exposure

    Dynamic Mechanical Analysis of Synthetic epoxy (E) and Bio-epoxy Polymer Foam Integrated with Wood Filler Under 8000 hours Exposure to UV Irradiation

    Get PDF
    The  most  common  sustainable  solution  for  polyurethane  (PU)  materials  is  their  production  using renewable resources reducing the dependency on the consumption of petroleum-based oil products. This research presents results from an experimental study on the dynamic mechanical and viscoelastic properties such as storage modulus, E', loss modulus, E'' and damping coefficient, tan δ of syntactic epoxy (E) and bio-epoxy polymer foam loading with different ratio of flakes and powder filler 0, 5, 10, 15 and 20 %wt after exposed to UV irradiation for 8000  h.  Dynamic  mechanical  analysis  (DMA)  of  the  blended  were  performed  over  a  temperature  range  of  25–180°C for (E) and (B) polymer foam  under frequency of 1 Hz. The results demonstrated that the E20L specimen with the highest filler ratio gives the maximum storage modulus and loss modulus value (0.3125 MPa), (0.0625 MPa) respectively among other filler ratio due to bonding between foam and filler resulting in increased viscosity of the synthetic-epoxy PUs foam. Among  others,  the  bio-epoxy  PUs  foam  (B5P)  has  the  highest  storage  value (3.956 MPa) and loss modulus (17.213 MPa) indicating that bio-epoxy PU foams can dissipate energy faster than synthetic-epoxy  polymer  foams.  TG analysis  showed  that  the  synthetic  epoxy  (E)  polymer  foam  had higher  Tg value and E5L (1.2) archived  the highest value compared to the bio-epoxy foams which had much less repeatable results due to the less homogeneous structure of polyols.compulsory

    PROCESSIBILITY OF WASTE TO WEALTH GREEN POLYMER WITH POLYETHYLENE BY INJECTION MOULDING

    Full text link
    Green polymer from waste cooking oils is successfully converted into high functionality of hydroxylated green monomer. The green monomer was used crosslinker and known as Green Polymer. Green Polymer is compounded with High-Density Polyethylene (HDPE) and Low-Density Polyethylene (LDPE). These wastes to wealth green polymer are successfully compounded with HDPE and LDPE by melt-mixing used an injection molding machine known as Pro-GreP. The effect of different ratio of compounding materials on the mechanical properties of Pro-GreP was studied by tensile test. Morphological of surface fracture with magnification 100x on Pro-GreP is revealed the homogenous characteristic with high compatibility properties. Finally, the presence of biopolymer provide biodegradable properties, but it also improves the mechanical properties. It can be showed that the tensile strength and tensile strain is decreased than the neat thermoplastic and they were found to decreased with the increasing of biopolymer compounds. However, LDPE are lower in tensile strength and tensile strain than HDPE.</jats:p

    Renewable Polymer/ Thermoplastics Polyethylene Blended with Enhanced Mechanical and UV Stability Properties

    No full text
    Blends of Renewable Polymer (RP) and thermoplastic polyethylene (LDPE and HDPE) may contribute to make recycling more economically attractive. In this study, the monomer is mixed with flexible isocynate as a crosslinker, these mixture is called Renewable Polymer. Renewable polymers are mixed in a Low-density polyethylene (LDPE) and High-density polyethylene (HDPE) with a ratio of 5%, 10%, 15%, 20%, 25% and 30%. The aim of this work to make LDPE/RP and HDPE/RP blends injected via injection molding and to evaluate their mechanical properties via tensile test. Accelerated weathering test up for 500 hours, 1000 hours, 1500 hours, 2000 hours, 2500 hours and 3000 hours. The blends yielded tensile strength and maximum elongation at break curves very dependent on their composition, especially regarding the presence of necking. The tensile strength increase at 500 hours, while maximum elongation at break were found to decreased with increase of UV irradiation hours. In conclusion, RP content and UV irradiation time play significant roles in controlling mechanical properties of the RP-blended with LDPE and HDPE synthetic polymer, thus providing the opportunity to modulate polymer properties

    Mechanical Properties of Renewable Polymer with Thermoplastics Endurance to Ultraviolet irradiation Exposure

    No full text
    At present the disposal of waste tyre rubber (WTR) has become a major waste management problem in the world. Therefore in this study, polymer blended based on Polyethylene which is Low Density Polyethylene (LDPE) or High Density Polyethylene (HDPE), with Renewable Polymer (RP) and waste tyre rubber (WTR) is prepared via injection molding. Blended polymer such as LDPE/RP/WTR and HDPE/RP/WTR is known as LRT and HRT respectively. The preparation of polymer blend steps start with the preparation of RP. The RP is prepared by crosslinking the renewable monomer with Polymethane Polyphenyl Isocyanate (MDI) at composition ratio of 1:0.5. The second steps involved by adding 10 gm of liquid RP prepared earlier on with fixed amount of LDPE and HDPE of 100 gm. Then the blended LDPE/RP or HDPE/RP namely as LR or HR respectively is further added with WTR with different percentages ratio of 5 %, 10 % and 15 %. The manually blended polymer mixture and filler is then melt mixing using injection moulding to fabricate the tensile specimen for mechanical tensile test and physical determination such as density, distribution of WTR in polymer blend and surface fracture morphology using scanning electron microscope. The samples were then exposed to UV irradiation exposure in UV Accelerated Weathering for 500, 1000, 1500, 2000, 2500 and 3000 hours to evaluate the photostability of the polymer blends. The optimum amount of WTR ratio composition is at 5 % for both LRT and HRT blends which indicate the stability of polymer blends towards UV irradiation exposure at 1000 hours

    Mechanical Properties of Renewable Polymer with Thermoplastics Endurance to Ultraviolet irradiation Exposure

    No full text
    At present the disposal of waste tyre rubber (WTR) has become a major waste management problem in the world. Therefore in this study, polymer blended based on Polyethylene which is Low Density Polyethylene (LDPE) or High Density Polyethylene (HDPE), with Renewable Polymer (RP) and waste tyre rubber (WTR) is prepared via injection molding. Blended polymer such as LDPE/RP/WTR and HDPE/RP/WTR is known as LRT and HRT respectively. The preparation of polymer blend steps start with the preparation of RP. The RP is prepared by crosslinking the renewable monomer with Polymethane Polyphenyl Isocyanate (MDI) at composition ratio of 1:0.5. The second steps involved by adding 10 gm of liquid RP prepared earlier on with fixed amount of LDPE and HDPE of 100 gm. Then the blended LDPE/RP or HDPE/RP namely as LR or HR respectively is further added with WTR with different percentages ratio of 5 %, 10 % and 15 %. The manually blended polymer mixture and filler is then melt mixing using injection moulding to fabricate the tensile specimen for mechanical tensile test and physical determination such as density, distribution of WTR in polymer blend and surface fracture morphology using scanning electron microscope. The samples were then exposed to UV irradiation exposure in UV Accelerated Weathering for 500, 1000, 1500, 2000, 2500 and 3000 hours to evaluate the photostability of the polymer blends. The optimum amount of WTR ratio composition is at 5 % for both LRT and HRT blends which indicate the stability of polymer blends towards UV irradiation exposure at 1000 hours
    corecore