Publications by authors named "Ahmad Hazri Abdul Rashid"

5 Publications

  • Page 1 of 1

Chitosan scaffold enhances growth factor release in wound healing in von Willebrand disease.

Int J Clin Exp Med 2015 15;8(9):15611-20. Epub 2015 Sep 15.

Industrial Biotechnology Research Centre, SIRIM Berhad No. 1 Persiaran Dato' Menteri, Section 2, P. O. Box 7035, Shah Alam 40700, Selangor, Malaysia.

Chitosan-derived biomaterials have been reported to adhere when in contact with blood by encouraging platelets to adhere, activate and aggregate at the sites of vascular injury, thus enhanced wound healing capacity. This study investigated platelet morphology changes and the expression level of transforming growth factor-β1 (TGF-β1) and platelet-derived growth factor-AB (PDGF-AB) in the adherence of two different types of chitosans in von Willebrand disease (vWD): N,O-carboxymethylchitosan (NO-CMC) and oligo-chitosan (O-C). Fourteen vWD voluntary subjects were recruited, and they provided written informed consent. Scanning electron microscopy and enzyme-linked immunosorbent assay test procedures were employed to achieve the objective of the study. The results suggest that the O-C group showed dramatic changes in the platelet's behaviors. Platelets extended filopodia and generated lamellipodia, leading to the formation of grape-like shaped aggregation. The platelet aggregation occurred depending on the severity of vWD. O-C was bound to platelets on approximately 90% of the surface membrane in vWD type 1; there was 70% and 50% coverage in vWD type II and III, respectively. The O-C chitosan group showed an elevated expression level of TGF-β1 and PDGF-AB. This finding suggests that O-C stimulates these mediators from the activated platelets to the early stage of restoring the damaged cells and tissues. This study demonstrated that the greater expression level of O-C assists in mediating the cytokine complex networks of TGF-β1 and PDGF-AB and induces platelet activities towards wound healing in vWD. With a better understanding of chitosan's mechanisms of action, researchers are able to accurately develop novel therapies to prevent hemorrhage.
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December 2015

Effect of the Novel Biodegradable N, O-Carboxymethylchitosan and Oligo-Chitosan on the Platelet Thrombogenicity Cascade in von Willebrand Disease.

Thromb Res 2015 Sep 30;136(3):625-33. Epub 2015 Jul 30.

Industrial Biotechnology Research Centre, SIRIM Berhad, No. 1 Persiaran Dato' Menteri, Section 2, P.O. Box 7035, 40700 Shah Alam, Selangor, Malaysia. Electronic address:

Introduction: Von Willebrand disease (vWD) is the second least common hemostatic disorder in Malaysia, and it has a low prevalence. This study examined the underlying platelet thrombogenicity cascades in the presence of different formulations of chitosan-derivatives in vWD patients. This paper aimed to determine the significant influence of chitosan biomaterial in stimulating the platelet thrombogenicity cascades that involve the von Willebrand factor, Factor 8, Thromboxane A2, P2Y12 and Glycoprotein IIb/IIIa in vWD.

Materials And Methods: Variable chitosan formulations of N,O-Carboxymethylchitosan (NO-CMC) and Oligo-Chitosan (O-C) were tested. Fourteen vWD subjects voluntarily participated in this study after signing informed consent forms. The patient's demographic profiles, family history, type of vWD, clinical symptoms and laboratory profiles were recorded and analyzed. Enzyme-linked immunosorbent assay, flow cytometry and Western blot tests were used to determine the level of the chitosan-adhered-platelet-mechanisms.

Results: The study revealed that most patients were predominantly affected by vWD type I. The O-C group of chitosan's scaffold pores is sufficient to allow for nutrients and cells. The O-C-stimulated-mediators are capable of initiating the platelet actions and were detected to expedite the blood coagulation processes. The oligo-group of chitosans was capable of amplifying and triggering more platelet activator's pathways via the studied mediators. The present findings suggest that the ability of each type of chitosan to coagulate blood varies depending on its chemical composition.

Conclusion: The oligo group of chitosans is potentially capable of triggering platelet thrombogenicity cascades by activating platelets in vWD patients to form a platelet plug for hemostasis process.
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September 2015

Glycoprotein IIb/IIIa and P2Y12 induction by oligochitosan accelerates platelet aggregation.

Biomed Res Int 2014 28;2014:653149. Epub 2014 Aug 28.

Industrial Biotechnology Research Centre, SIRIM Berhad, No. 1 Persiaran Dato' Menteri, Section 2, P.O. Box 7035, 40700 Shah Alam, Selangor, Malaysia.

Platelet membrane receptor glycoprotein IIb/IIIa (gpiibiiia) is a receptor detected on platelets. Adenosine diphosphate (ADP) activates gpiibiiia and P2Y12, causing platelet aggregation and thrombus stabilization during blood loss. Chitosan biomaterials were found to promote surface induced hemostasis and were capable of activating blood coagulation cascades by enhancing platelet aggregation. Our current findings show that the activation of the gpiibiiia complex and the major ADP receptor P2Y12 is required for platelet aggregation to reach hemostasis following the adherence of various concentrations of chitosan biomaterials [7% N,O-carboxymethylchitosan (NO-CMC) with 0.45 mL collagen, 8% NO-CMC, oligochitosan (O-C), and oligochitosan 53 (O-C 53)]. We studied gpiibiiia and P2Y12 through flow cytometric analysis and western blotting techniques. The highest expression of gpiibiiia was observed with Lyostypt (74.3 ± 7.82%), followed by O-C (65.5 ± 7.17%). Lyostypt and O-C resulted in gpiibiiia expression increases of 29.2% and 13.9%, respectively, compared with blood alone. Western blot analysis revealed that only O-C 53 upregulated the expression of P2Y12 (1.12 ± 0.03-fold) compared with blood alone. Our findings suggest that the regulation of gpiibiiia and P2Y12 levels could be clinically useful to activate platelets to reach hemostasis. Further, we show that the novel oligochitosan is able to induce the increased expression of gpiibiiia and P2Y12, thus accelerating platelet aggregation in vitro.
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June 2015

Physical properties and biocompatibility of oligochitosan membrane film as wound dressing.

J Appl Biomater Funct Mater 2014 Dec 30;12(3):155-62. Epub 2014 Dec 30.

1 Industrial Biotechnology Research Center, SIRIM Berhad, Shah Alam, Selangor - Malaysia.

Background: The physical and biological characteristics of oligochitosan (O-C) film, including its barrier and mechanical properties, in vitro cytotoxicity and in vivo biocompatibility, were studied to assess its potential use as a wound dressing.

Methods: Membrane films were prepared from water-soluble O-C solution blended with various concentrations of glycerol to modify the physical properties of the films. In vitro and in vivo biocompatibility evaluations were performed using primary human skin fibroblast cultures and subcutaneous implantation in a rat model, respectively.

Results: Addition of glycerol significantly influenced the barrier and mechanical properties of the films. Water absorption capacity was in the range of 80%-160%, whereas water vapor transmission rate varied from 1,180 to 1,618 g/m2 per day. Both properties increased with increasing glycerol concentration. Tensile strength decreased while elongation at break increased with the addition of glycerol. O-C films were found to be noncytotoxic to human fibroblast cultures and histological examination proved that films are biocompatible.

Conclusion: These results indicate that the membrane film from O-C has potential application as a wound-dressing material.
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December 2014

In vitro capacity of different grades of chitosan derivatives to induce platelet adhesion and aggregation.

Int J Biol Macromol 2013 Jan 11;52:244-9. Epub 2012 Oct 11.

Reconstructive Sciences Unit, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia.

Chitosan-derived hemostatic agents with various formulations may have distinct potential in hemostasis. This study assessed the ability of different grades and forms of chitosan derivatives as hemostatic agents to enhance platelet adhesion and aggregation in vitro. The chitosan derivatives utilized were 2% NO-CMC, 7% NO-CMC (with 0.45 mL collagen), 8% NO-CMC, O-C 52, 5% O-CMC-47, NO-CMC-35, and O-C 53. Samples of chitosan derivatives weighing 5mg were incubated at 37°C with 50 μL of phosphate buffer saline (PBS) (pH 7.4) for 60 min. The morphological features of the platelets upon adherence to the chitosan were viewed using scanning electron microscope (SEM), and the platelet count was analyzed with an Automated Hematology Analyzer. For platelet aggregation, we added an adenosine diphosphate (ADP) agonist to induce the chitosan-adhered platelets. O-C 52 bound with platelets exhibited platelet aggregates and clumps on the surface of the membrane layer with approximately 70-80% coverage. A statistically significant correlation (p<0.01) for the platelet count was identified between the baseline value and the values at 10 min and 20 min. The results indicate that O-C 53 and O-C 52 were able to promote clotting have the potential to induce the release of platelets engaged in the process of hemostasis.
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January 2013