Displaying publications 21 - 40 of 450 in total

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  1. Thermal and dynamic mechanical properties of cellulose nanofibers reinforced epoxy composites
    Saba N, Safwan A, Sanyang ML, Mohammad F, Pervaiz M, Jawaid M, et al.
    Int J Biol Macromol, 2017 Sep;102:822-828.
    PMID: 28455253 DOI: 10.1016/j.ijbiomac.2017.04.074
    The current study presents about the effect of cellulose nanofibers (CNFs) filler on the thermal and dynamic mechanical analysis (DMA) of epoxy composites as a function of temperature. In this study hand lay-up method was used to fabricate CNF reinforced Epoxy nanocomposites with CNF loading of 0.5%, 0.75%, and 1% into epoxy resin. The obtained thermal and DMA results illustrates that thermal stability, char content, storage modulus (E'), loss modulus (E") and glass transition temperature (Tg) increases for all CNF/epoxy nanocomposites compared to the pure epoxy. Thermal results revealed that 0.75% offers superior resistance or stability towards heat compared to its counterparts. In addition, 0.75% CNF/epoxy nanocomposites confers highest value of storage modulus as compared to 0.5% and 1% filler loading. Hence, it is concluded that 0.75% CNFs loading is the minimal to enhance both thermal and dynamic mechanical properties of the epoxy composites and can be utilized for advance material applications where thermal stability along with renewability are prime requirements.
  2. The synergistic effects of cinnamon essential oil and nano TiO2 on antimicrobial and functional properties of sago starch films
    Arezoo E, Mohammadreza E, Maryam M, Abdorreza MN
    Int J Biol Macromol, 2020 Aug 15;157:743-751.
    PMID: 31805325 DOI: 10.1016/j.ijbiomac.2019.11.244
    This study describes a sago starch-based film by incorporation of cinnamon essential oil (CEO) and nano titanium dioxide (TiO2-N). Different concentrations (i.e., 0%, 1%, 3%, and 5%, w/w) of TiO2-N and CEO (i.e., 0%, 1%, 2%, and 3%, v/w) were incorporated into sago starch film, and the physicochemical, barrier, mechanical, and antimicrobial properties of the bionanocomposite films were estimated. Incorporation of CEO into the sago starch matrix increased oxygen and water vapor permeability of starch films while increasing TiO2-N concentration decreased barrier properties. Moisture content also decreased from 12.96% to 8.04%, solubility in water decreased from 25% to 13.7%, and the mechanical properties of sago starch films improved. Sago starch bionanocomposite films showed excellent antimicrobial activity against Escherichia coli, Salmonella typhimurium, and Staphylococcus aureus. Results also showed that incorporation of TiO2-N and CEO had synergistic effects on functional properties of sago starch films. In summary, sago starch films incorporated with both TiO2-N and CEO shows potential application for active packaging in food industries such as fresh pistachio packaging.
  3. The structural characterization and antioxidant properties of oil palm fronds lignin incorporated with p-hydroxyacetophenone
    Latif NHA, Rahim AA, Brosse N, Hussin MH
    Int J Biol Macromol, 2019 Jun 01;130:947-957.
    PMID: 30851323 DOI: 10.1016/j.ijbiomac.2019.03.032
    This study reports on the effects of unmodified autohydrolyzed ethanol organosolv lignin (AH EOL) and modified autohydrolyzed ethanol organosolv lignin on the structural characteristics and antioxidant properties upon incorporation of p-hydroxyacetophenone (AHP EOL). The lignin samples isolated from black liquor of oil palm fronds (OPF) were evaluated and compared using various complementary analyses; FTIR, 1H and 13C NMR spectroscopy, 2D-NMR spectroscopy (HMBC and HSQC), CHN, GPC, HPLC and thermal analyses (TGA and DSC). Chemically modified organosolv lignin (AHP EOL) provided lignin with lower molecular weight (Mw), which has smaller fragments that leads to higher solubility rate in water in comparison to unmodified organosolv lignin, AH EOL (DAHP EOL: 19.8% > DAH EOL: 14.0%). It was evident that the antioxidant properties of modified organosolv lignin has better reducing power in comparison to the unmodified organosolv lignin. Therefore, the functionalization of lignin polymers enhanced their antioxidant properties and structural features towards a various alternative approach in lignin-based applications.
  4. The significant sex-biased expression pattern of Sp-Wnt4 provides novel insights into the ovarian development of mud crab (Scylla Paramamosain)
    Farhadi A, Fang S, Zhang Y, Cui W, Fang H, Ikhwanuddin M, et al.
    Int J Biol Macromol, 2021 Jul 31;183:490-501.
    PMID: 33957197 DOI: 10.1016/j.ijbiomac.2021.04.186
    The wingless-type MMTV integration site family member-4 (Wnt4), a member of the wingless-related integration site (Wnt) family, is widely accepted as a key regulator of ovarian development in mammals. In this study, a full-length cDNA of Wnt4 (designated as Sp-Wnt4) was cloned, characterized, and functionally studied in mud crab (Scylla paramamosain). The full-length cDNA of Sp-Wnt4 consists of 2659 bp with an open reading frame (ORF) encoding 359 amino acids, a 907 bp 5'-UTR and a 672 bp 3'-UTR. Sp-Wnt4 contains 25 cysteine (Cys) residues and three potential N-glycosylation sites. Sp-Wnt4 protein shared the highest identity (98.9%) to the Wnt4 protein of Portunus trituberculatus. The phylogenetic tree showed that Sp-Wnt4 and Wnt4 protein of Malacostracan crustaceans clustered together, indicating that they had a close genetic distance. Sp-Wnt4 was expressed at a higher level in the ovary compared to other tissues, with the highest expression level at the third stage (O-III) of the ovarian development (P < 0.05). A downward trend was observed in the expression level of Sp-Wnt4 from the embryo stage to crablet stages (P < 0.05). After unilateral eyestalk ablation, the expression level of Sp-Wnt4 significantly increased in testis (14-fold) and downregulated (3.1-fold) in the gill (P < 0.05) of females. In situ hybridization (ISH) assay revealed that Sp-Wnt4 transcripts were mainly localized in the cytoplasm of oocyte cells. These findings showed that Sp-Wnt4 play crucial roles in the ovarian development of S. paramamosain. In conclusion, our study provides novel insights into the evolution and roles of the Wnt4 gene.
  5. The preparation of graphene ink from the exfoliation of graphite in pullulan, chitosan and alginate for strain-sensitive paper
    Kasim NFA, W Idris WF, Abdullah AH, Yusoh K, Ismail Z
    Int J Biol Macromol, 2020 Jun 15;153:1211-1219.
    PMID: 31756469 DOI: 10.1016/j.ijbiomac.2019.10.251
    A sonication of graphite in polysaccharide (pullulan, chitosan and alginate) is one of the viable methods for the preparation of few-layer graphene. However, the effect of these adsorbed polysaccharides on the electrical performance of the produced graphene so far is not yet clear. In order to investigate the present effect of pullulan, chitosan and alginate on the electrical characteristic of resulted graphene, we have produced few-layer graphene using bath sonication of graphite in pullulan, chitosan and alginate medium for the application as electrical conductive ink in strain-sensitive. Data from the TEM reveals the appearance of folded few-layer graphene flakes after sonication for 150 min while the XPS data shows that the chitosan-based graphene possesses the highest carbon-oxygen ratio of 7.2 as compared to that of the pullulan and alginate-based graphene. By subjecting the produced graphene as the ink for paper-based strain sensor, we have discovered that the chitosan-graphene has the best resistivity value (1.66 × 10-3 Ω⋅cm) and demonstrate the highest sensitivity towards strain (GF: 18.6). This result interestingly implies the potential of the reported chitosan-based conductive ink as a strain-sensitive material for future food packaging.
  6. The endothelial nitric oxide synthase gene G894T, glutathione S-transferase (GSTM1 and GSTT1) polymorphisms as a risk factor in the patient with nephrolithiasis
    Mehdi WA, Mehde AA, Yusof F, Raus RA, Resen AK, Ghazali H
    Int J Biol Macromol, 2019 Nov 01;140:719-726.
    PMID: 31445152 DOI: 10.1016/j.ijbiomac.2019.08.184
    BACKGROUND: The genetic features indicate a crucial role in nephrolithiasis. The present study was aimed to investigate the role of Glutathione-S-transferase Mu (GSTM1), Glutathione-S- transferase Theta (GSTT1) and endothelial nitric oxide synthase (eNOs) gene polymorphism in nephrolithiasis.

    METHODS: We involved a case-control study in which 480 individuals were divided into 240 healthy control and 240 patients with nephrolithiasis. For each patient and control, we measured biochemical criteria, levels of glutathione S-transferase, eNOs, GSTM1, GSTT1genes and eNOS genes polymorphism by PCR-RFLP.

    RESULTS: GSTM1 and GSTT1 null genotypes are not a risk features for nephrolithiasis. The eNOS frequency GG, GT, and TT genotypes by using Ban II enzyme as restriction enzyme were found to be (48.33, 36.67, and 15.00) %. The eNOS frequency TT, GT, and GG genotypes by using the Ban II enzyme as restriction enzyme were found to be 15.84, 25.83, and 58.33%, respectively. The result showed an increase in serum eNOs levels were in the patient's group comparing to control.

    CONCLUSIONS: This work is the first in the literature to study the relation between eNOs genes polymorphisms and nephrolithiasis. The results conclude that TT genotypes in the eNOs genes are associated with an increase the oxidative stress in patients.

  7. The effects of Naja sumatrana venom cytotoxin, sumaCTX on alteration of the secretome in MCF-7 breast cancer cells following membrane permeabilization
    Hiu JJ, Yap MKK
    Int J Biol Macromol, 2021 Aug 01;184:776-786.
    PMID: 34174307 DOI: 10.1016/j.ijbiomac.2021.06.145
    Naja sumatrana venom cytotoxin (sumaCTX) is a basic protein which belongs to three-finger toxin family. It has been shown to induce caspase-dependent, mitochondrial-mediated apoptosis in MCF-7 cells at lower concentrations. This study aimed to investigate the alteration of secretome in MCF-7 cells following membrane permeabilization by high concentrations of sumaCTX, using label-free quantitative (LFQ) approach. The degree of membrane permeabilization of sumaCTX was determined by lactate dehydrogenase (LDH) assay and calcein-propidium iodide (PI) assays. LDH and calcein-PI assays revealed time-dependent membrane permeabilization within a narrow concentration range. However, as toxin concentrations increased, prolonged exposure of MCF-7 cells to sumaCTX did not promote the progression of membrane permeabilization. The secretome analyses showed that membrane permeabilization was an event preceding the release of intracellular proteins. Bioinformatics analyses of the LFQ secretome revealed the presence of 105 significantly distinguished proteins involved in metabolism, structural supports, inflammatory responses, and necroptosis in MCF-7 cells treated with 29.8 μg/mL of sumaCTX. Necroptosis was presumably an initial stress response in MCF-7 cells when exposed to high sumaCTX concentration. Collectively, sumaCTX-induced the loss of membrane integrity in a concentration-dependent manner, whereby the cell death pattern of MCF-7 cells transformed from apoptosis to necroptosis with increasing toxin concentrations.
  8. The effect of spent coffee ground (SCG) loading, matrix ratio and biological treatment of SCG on poly(hydroxybutyrate) (PHB)/poly(lactic acid) (PLA) polymer blend
    Boey JY, Kong U, Lee CK, Lim GK, Oo CW, Tan CK, et al.
    Int J Biol Macromol, 2024 May;266(Pt 2):131079.
    PMID: 38537860 DOI: 10.1016/j.ijbiomac.2024.131079
    This study investigates the effects of SCG embedded into biodegradable polymer blends and aimed to formulate and characterise biomass-reinforced biocomposites using spent coffee ground (SCG) as reinforcement in PHB/PLA polymer blend. The effect of SCG filler loading and varying PHB/PLA ratios on the tensile properties and morphological characteristics of the biocomposites were examined. The results indicated that tensile properties reduction could be due to its incompatibility with the PHB/PLA matrixSCG aggregation at 40 wt% content resulted in higher void formation compared to lower content at 10 wt%. A PHB/PLA ratio of 50/50 with SCG loading 20 wt% was chosen for biocomposites with treated SCG. Biological treatment of SCG using Phanerochaete chrysosporium CK01 and Aspergillus niger DWA8 indicated P. chrysosporium CK01 necessitated a higher moisture content for optimum growth and enzyme production, whereas the optimal conditions for enzyme production (50-55 %, w/w) differed from those promoting A. niger DWA8 growth (40 %, w/w). SEM micrographs highlighted uniform distribution and effective wetting of treated SCG, resulting in improvements of tensile strength and modulus of biocomposites, respectively. The study demonstrated the effectiveness of sustainable fungal treatment in enhancing the interfacial adhesion between treated SCG and the PHB/PLA matrix.
  9. The effect of p-nitrophenol toward the structural characteristics and antioxidant activity of oil palm fronds (OPF) lignin polymers
    Sa'don NA, Rahim AA, Hussin MH
    Int J Biol Macromol, 2017 May;98:701-708.
    PMID: 28174085 DOI: 10.1016/j.ijbiomac.2017.01.137
    This article reports on the structural characteristics and antioxidant activity of unmodified autohydrolyzed ethanol organosolv lignin (AH EOL) extracted from oil palm fronds (OPF) and modified autohydrolyzed ethanol organosolv lignin via incorporation of p-nitrophenol (AHNP EOL). The isolated lignin were analyzed by FTIR, (1)H and (13)C NMR spectroscopy, 2D NMR; HSQC and HMBC, CHN analysis, molecular weight distribution using GPC analyzer, thermal analysis; TGA and DSC. The chemical modification by utilizing an organic scavenger during delignification process provided smaller lignin fragments and enhanced the solubility of lignin by reducing its hydrophobicity properties. It was revealed that the antioxidant properties increased as compared to the unmodified organosolv lignin. Additionally, the modified lignin has better solubility in water (DAHNP EOL=35%>DAH EOL=25%).
  10. The effect of alkaline extraction and drying techniques on the physicochemical, structural properties and functionality of rice bran protein concentrates
    Abd Rahim FN, Wan Ibadullah WZ, Saari N, Brishti FH, Mustapha NA, Ahmad N, et al.
    Int J Biol Macromol, 2023 Jul 01;242(Pt 3):124908.
    PMID: 37217045 DOI: 10.1016/j.ijbiomac.2023.124908
    Rice bran protein concentrates (RBPC) were extracted using mild alkaline solvents (pH: 8, 9, 10). The physicochemical, thermal, functional, and structural aspects of freeze-drying (FD) and spray-drying (SD) were compared. FD and SD of RBPC had porous and grooved surfaces, with FD having non-collapsed plates and SD being spherical. Alkaline extraction increases FD's protein concentration and browning, whereas SD inhibits browning. According to amino acid profiling, RBPC-FD9's extraction optimizes and preserves amino acids. A tremendous particle size difference was prominent in FD, thermally stable at a minimal maximum of 92 °C. Increased pH extraction gives FD greater exposal surface hydrophobicity and positively relates to denaturation enthalpy. Mild pH extraction and drying significantly impacted solubility, improved emulsion properties, and foaming properties of RBPC as observed in acidic, neutral, and alkaline environments. RBPC-FD9 and RBPC-SD10 extracts exhibit outstanding foaming and emulsion activity in all pH conditions, respectively. Appropriate drying selection, RBPC-FD or SD potentially employed as foaming/emulsifier agent or meat analog.
  11. Targeting chemical and thermal stability of ovalbumin by simulated honey sugar cocktail
    Wong YH, Kadir HA, Tayyab S
    Int J Biol Macromol, 2015 Feb;73:207-14.
    PMID: 25434804 DOI: 10.1016/j.ijbiomac.2014.11.015
    Effect of simulated honey sugar cocktail (SHSC) on chemical and thermal stability of ovalbumin (OVA) was investigated using multiple-spectroscopic techniques. Urea-induced denaturation of OVA produced a transition, characterized by the start-, the mid- and the end-points at 3.2 M, 5.9/5.6 M and 8.5/8.0 M urea, respectively, when studied by MRE222nm and tryptophan fluorescence measurements. Presence of 10% or 20% (w/v) SHSC in the incubation mixture shifted the transition curve towards higher urea concentration in a concentration dependent manner. A comparison of far- and near-UV CD, UV-difference, ANS fluorescence and 3-D fluorescence spectral results of native OVA and 5.9 M urea-denatured OVA (U-OVA), obtained in the absence and the presence of 20% (w/v) SHSC suggested SHSC-induced stabilization of U-OVA. Furthermore, a significant shift towards higher denaturant concentration was also noticed in the GdnHCl and thermal transition curves of OVA in the presence of 20% (w/v) SHSC. Taken together, all these results suggested stabilization of OVA against chemical and thermal denaturations by SHSC.
  12. Target DNA detection of human papilloma virus-16 E7 gene by capture-target-reporter sandwich on interdigitated electrode sensor
    Lin J, Gopinath SCB, Lakshmipriya T, Chen Y, Yuan WR, Yang M
    Int J Biol Macromol, 2019 Dec 01;141:564-569.
    PMID: 31493451 DOI: 10.1016/j.ijbiomac.2019.09.012
    Human papilloma virus (HPV) affects predominantly the genital area, which includes vagina, cervix, penis, vulva scrotum, rectum and anus. Among 100 types of HPV, 14 types are considered to cause the risky cancer. The gene HPV-16 E7 is responsible for the development of cancer with the infected women. Earlier identification of this gene sequence avoids the cancer progression. The targeted HPV-16 E7 sequence was sandwiched by capture and reporter sequences on the carbodiimidazole-modified interdigitated electrode (IDE) surface. Target sequence at 100 f. was paired to the capture sequence immobilized on IDE sensing surface. To this surface, different concentrations of reporter sequence with and without gold rod (GNR) were evaluated. In both cases the detections were attained 1 aM by the reporter sequence pairing and with GNR increments in current were found. This enhancement was found to be 1000 folds, considering the condition was revealed in the absence of reporter. This sandwich detection strategy of capture-target-reporter sequences for HPV-16 detection on the IDE sensing surface helps to diagnose the association of cervical cancer.
  13. TL15 of Arthrospira platensis sulfite reductase scavenges free radicals demonstrated in oxidant induced larval zebrafish (Danio rerio) model
    Sarkar P, Lite C, Kumar P, Pasupuleti M, Saraswathi NT, Arasu MV, et al.
    Int J Biol Macromol, 2020 Oct 31.
    PMID: 33137391 DOI: 10.1016/j.ijbiomac.2020.10.222
    The antioxidant role of sulfite reductase (SiR) derived from Arthrospira platensis (Ap) was identified through a short peptide, TL15. The study showed that the expression of ApSiR was highly expressed on day ten due to sulfur deprived stress in Ap culture. TL15 peptide exhibited strong antioxidant activity when evaluated using antioxidant assays in a concentration ranging from 7.8 and 125 μM. Further, the cytotoxicity of TL15 peptide was investigated, even at the higher concentration (250 μM), TL15 did not exhibit any toxicity, when tested in vitro using human leucocytes. Moreover, a potential reduction in reactive oxygen species (ROS) production was observed due to the treatment of TL15 peptide (>15.6 μM) to H2O2 exposed leucocytes. For the in vivo assessment of TL15 toxicity and antioxidant ability, experiments were performed in zebrafish (Danio rerio) larvae to analyse the developmental toxicity of TL15 peptide. Results showed that, exposure to TL15 peptide in tested concentrations ranging from 10, 20, 40, and 80 μM, did not affect the development and physiological parameters of the zebrafish embryo/larvae such as morphology, survival, hatching and heart rate. Fluorescent assay was performed using DCFH-DA (2,7-dichlorodihydrofluorescein diacetate) to examine the production of intracellular reactive oxygen species (ROS) in zebrafish treated with TL15 peptide during the embryo-larval stages. Fluorescent images showed that pre-treatment with TL15 peptide to attenuate the H2O2 induced ROS levels in the zebrafish larvae in a dose-dependent manner. Further to uncover the underlying biochemical and antioxidant mechanism, the enzyme activity of superoxide dismutase (SOD), catalase (CAT) and lipid peroxidation (LPO) levels were studied in zebrafish larvae. TL15 pre-treated groups showed enhanced antioxidant enzyme activity, while the hydrogen peroxide (H2O2) exposed larvae showed significantly diminished activity. Overall results from the study revealed that, TL15 act as a potential antioxidant molecule with dose-specific antioxidant property. Thus, TL15 peptide could be an effective and promising source for biopharmaceutical applications.
  14. TEMPO-oxidized nanocellulose films derived from coconut residues: Physicochemical, mechanical and electrical properties
    Hassan SH, Velayutham TS, Chen YW, Lee HV
    Int J Biol Macromol, 2021 Jun 01;180:392-402.
    PMID: 33737185 DOI: 10.1016/j.ijbiomac.2021.03.066
    The present work focuses on the development of cellulose nanofibrils (CNF) film that derived from sustainable biomass resources, which potentially to work as bio-based conductive membranes that assembled into supercapacitors. The chemically purified cellulose was isolated from different parts of coconut (coconut shell and its husk) and further subjected to 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation for CNF preparation. Physicochemical properties of prepared CNFs were studied in terms of chemical characteristics & crystallinity, surface functionalities, surface morphology, and thermal properties. Both coconut shell-derived CNF and coconut husk-derived CNF fulfilled with nanocellulose's characteristics with fibres width ranged of 70-120 nm and 150-330 nm, respectively. CNF films were further prepared by solvent casting method to measure the modulus elasticity, piezoelectric and dielectric properties of the films. Mechanical study indicated that coconut shell-derived CNF film showed a higher value of elastic modulus than the coconut husk-derived CNF film, which was 8.39 GPa and 5.36 GPa, respectively. The effectiveness of electrical aspects for CNF films are well correlated with the crystallinity and thermal properties, associated with it's composition of different coconut's part.
  15. TCR-like domain antibody against Mycobacterium tuberculosis (Mtb) heat shock protein antigen presented by HLA-A*11 and HLA-A*24
    Dass SA, Norazmi MN, Acosta A, Sarmiento ME, Tye GJ
    Int J Biol Macromol, 2020 Jul 15;155:305-314.
    PMID: 32240734 DOI: 10.1016/j.ijbiomac.2020.03.229
    T cell receptor (TCR)-like antibodies, obtained with the use of phage display technology, sandwich the best of the both arms of the adaptive immune system. In this study, in vitro selections against the latency associated Mycobacterium tuberculosis (Mtb) heat shock protein 16 kDa antigen (16 kDa) presented by HLA-A*011 and HLA-A*24 were carried out with the use of a human domain phage antibody library. TCR-like domain antibodies (A11Ab and A24Ab) were successfully generated recognizing 16 kDa epitopes presented by HLA-A*011 and HLA-A*24 molecules respectively. Both antibodies were found to be functional in soluble form and exhibited strong binding capacity against its targets. The results obtained support the future evaluation of these ligands for the development of diagnostic and therapeutic tools for tuberculosis infection.
  16. Synthesis, modification and application of fish skin gelatin-based hydrogel as sustainable and versatile bioresource of antidiabetic peptide
    Munawaroh HSH, Pratiwi RN, Gumilar GG, Aisyah S, Rohilah S, Nurjanah A, et al.
    Int J Biol Macromol, 2023 Mar 15;231:123248.
    PMID: 36642356 DOI: 10.1016/j.ijbiomac.2023.123248
    Gelatin hydrogel is widely employed in various fields, however, commercially available gelatin hydrogels are mostly derived from mammalian which has many disadvantages due to the supply and ethical issues. In this study, the properties of hydrogels from fish-derived collagen fabricated with varying Glutaraldehyde (GA) determined. The antidiabetic properties of salmon gelatin (SG) and tilapia gelatin (TG) was also evaluated against α-glucosidase. Glutaraldehyde-crosslinked salmon gelatin and tilapia gelatin were used, and compared with different concentrations of GA by 0.05 %, 0.1 %, and 0.15 %. Water absorbency, swelling, porosity, pore size and water retention of the hydrogels were dependent on the degree of crosslinking. The synthesis of hydrogels was confirmed by FTIR study. Scanning electron microscope (SEM) observation showed that all hydrogels have a porous structure with irregular shapes and heterogeneous morphology. Performance tests showed that gelatin-GA 0.05 % mixture had the best performance. Antidiabetic bioactivity in vitro and in silico tests showed that the active peptides of SG and TG showed a high binding affinity to α-glucosidase enzyme. In conclusion, SG and TG cross-linked GA 0.05 % have the potential as an antidiabetic agent and as a useful option over mammalian-derived gelatin.
  17. Synthesis of indole derivatives as diabetics II inhibitors and enzymatic kinetics study of α-glucosidase and α-amylase along with their in-silico study
    Taha M, Alrashedy AS, Almandil NB, Iqbal N, Anouar EH, Nawaz M, et al.
    Int J Biol Macromol, 2021 Nov 01;190:301-318.
    PMID: 34481854 DOI: 10.1016/j.ijbiomac.2021.08.207
    In this study, we have investigated a series of indole-based compounds for their inhibitory study against pancreatic α-amylase and intestinal α-glucosidase activity. Inhibitors of carbohydrate degrading enzymes appear to have an essential role as antidiabetic drugs. All analogous exhibited good to moderate α-amylase (IC50 = 3.80 to 47.50 μM), and α-glucosidase inhibitory interactions (IC50 = 3.10-52.20 μM) in comparison with standard acarbose (IC50 = 12.28 μM and 11.29 μM). The analogues 4, 11, 12, 15, 14 and 17 had good activity potential both for enzymes inhibitory interactions. Structure activity relationships were deliberated to propose the influence of substituents on the inhibitory potential of analogues. Docking studies revealed the interaction of more potential analogues and enzyme active site. Further, we studied their kinetic study of most active compounds showed that compounds 15, 14, 12, 17 and 11 are competitive for α-amylase and non- competitive for α-glucosidase.
  18. Synthesis of carboxylated cellulose nanocrystal/ZnO nanohybrids using Oxytenanthera abyssinica cellulose and zinc nitrate hexahydrate for radical scavenging, photocatalytic, and antibacterial activities
    Worku LA, Tadesse MG, Bachheti RK, Bachheti A, Husen A
    Int J Biol Macromol, 2024 Mar 28.
    PMID: 38554923 DOI: 10.1016/j.ijbiomac.2024.131228
    The extremely low antioxidant, photocatalytic, and antibacterial properties of cellulose limit its application in the biomedical and environmental sectors. To improve these properties, nanohybrides were prepared by mixing carboxylated cellulose nanocrystals (CCNCs) and zinc nitrate hexahydrate. Data from FTIR, XRD, DLS, and SEM spectra showed that, ZnO nanoparticles, with a size ranging from 94 to 351 nm and the smallest nanoparticle size of 164.18 nm, were loaded onto CCNCs. CCNCs/ZnO1 nanohybrids demonstrated superior antibacterial, photocatalytic, and antioxidant performance. More considerable antibacterial activity was shown with a zone of inhibition ranging from 26.00 ± 1.00 to 40.33 ± 2.08 mm and from 31.66 ± 3.51 to 41.33 ± 1.15 mm against Gram-positive and Gram-negative bacteria, respectively. Regarding photodegradation properties, the maximum value (~91.52 %) of photocatalytic methylene blue degradation was observed after 75 min exposure to a UV lamp. At a concentration of 125.00 μm/mL of the CCNC/ZnO1 nanohybrids sample, 53.15 ± 1.03 % DPPH scavenging activity was obtained with an IC50 value of 117.66 μm/mL. A facile, cost-effective, one-step synthesis technique was applied to fabricate CCNCs/ZnO nanohybrids at mild temperature using Oxytenanthera abyssinica carboxylated cellulose nanocrystals as biotemplate. The result showed that CCNCs/ZnO nanohybrids possess potential applications in developing advanced functional materials for dye removal and antibacterial and antioxidant applications.
  19. Synthesis of ZnO nanoparticles with chitosan as stabilizing agent and their antibacterial properties against Gram-positive and Gram-negative bacteria
    Yusof NAA, Zain NM, Pauzi N
    Int J Biol Macromol, 2019 Mar 01;124:1132-1136.
    PMID: 30496864 DOI: 10.1016/j.ijbiomac.2018.11.228
    Antibacterial activity of zinc oxide (ZnO) nanoparticles have received significant interest, particularly by the implementation of nanotechnology to synthesize particles in nanometer region. ZnO nanoparticles were successfully synthesized through microwave heating by using chitosan as a stabilizing agent and characterized by UV-vis, FTIR, XRD and FESEM-EDX. The aim of the present study is to determine the antibacterial activity of ZnO nanoparticles against Gram-positive bacterium Staphylococcus aureus (S. aureus) and Gram-negative bacterium Escherichia coli (E. coli). The antibacterial effect of ZnO nanoparticles was investigated for the inhibition zone and inactivation of cell growth. The absorption of ZnO nanoparticles was found to be around 360 nm. FTIR results showed the stretching mode of ZnO nanoparticles at 475 cm-1 of the absorption band. EDX results indicated that ZnO nanoparticles have been successfully formed with an atomic percentage of zinc and oxygen at 23.61 and 46.57% respectively. X-ray diffraction result was confirmed the single-phase formation of ZnO nanoparticles and the particle sizes were observed to be around 50 to 130 nm. The results showed that ZnO nanoparticles have displayed inhibition zone of 16 and 13 mm against S. aureus and E. coli respectively. Gram-negative bacteria seemed to be more resistant to ZnO nanoparticles than Gram-positive bacteria.
  20. Synthesis and evaluation on pH- and temperature-responsive chitosan-p(MAA-co-NIPAM) hydrogels
    Rasib SZM, Ahmad Z, Khan A, Akil HM, Othman MBH, Hamid ZAA, et al.
    Int J Biol Macromol, 2018 Mar;108:367-375.
    PMID: 29222015 DOI: 10.1016/j.ijbiomac.2017.12.021
    In this study, chitosan-poly(methacrylic acid-co-N-isopropylacrylamide) [chitosan-p(MAA-co-NIPAM)] hydrogels were synthesized by emulsion polymerization. In order to be used as a carrier for drug delivery systems, the hydrogels had to be biocompatible, biodegradable and multi-responsive. The polymerization was performed by copolymerize MAA and NIPAM with chitosan polymer to produce a chitosan-based hydrogel. Due to instability during synthesis and complexity of components to produce the hydrogel, further study at different times of reaction is important to observe the synthesis process, the effect of end product on swelling behaviour and the most important is to find the best way to control the hydrogel synthesis in order to have an optimal swelling behaviour for drug release application. Studied by using Fourier transform infra-red (FTIR) spectroscopy found that, the synthesized was successfully produced stable chitosan-based hydrogel with PNIPAM continuously covered the outer surface of hydrogel which influenced much on the stability during synthesis. The chitosan and PMAA increased the zeta potential of the hydrogel and the chitosan capable to control shrinkage above human body temperature. The chitosan-p(MAA-co-NIPAM) hydrogels also responses to pH and temperature thus improved the ability to performance as a drug carrier.
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