Displaying publications 1 - 20 of 228 in total

  1. Liew WC, Muhamad II, Chew JW, Karim KJA
    Int J Biol Macromol, 2023 Dec 31;253(Pt 6):127288.
    PMID: 37813215 DOI: 10.1016/j.ijbiomac.2023.127288
    Incorporating two different nanoparticles in nanocomposite films is promising as their synergistic effects could significantly enhance polymer performance. Our previous work conferred the remarkable antimicrobial (AM) properties of the polylactic acid (PLA)-based film using optimal formulations of synergistic graphene oxide (GO)/zinc oxide (ZnO) nanocomposites. This study further explores the release profile of GO/ZnO nanocomposite and their impact on the antimicrobial properties. A fixed 1.11 wt% GO and different ZnO concentrations were well dispersed in the PLA matrix. Increasing ZnO concentrations tended to increase agglomeration, as evident in rougher surfaces. Agglomeration inhibited water penetration, leading to a significant reduction in water permeability (46.3 %), moisture content (31.6 %) but an improvement in Young's Modulus (52.6 %). The overall and specific migration of GO/ZnO nanocomposites was found to be within acceptable limits. It is inferred that the release of Zn2+ ions followed pseudo-Fickian behavior with an initial burst effect. AM film with the highest concentration of ZnO (1.25 wt%) exhibited the highest inhibition rate against Escherichia coli (68.0 %), Bacillus cereus (66.5 %), Saccharomyces cerevisiae (70.9 %). Results suggest that GO/ZnO nanocomposites with optimal ZnO concentrations have the potential to serve as promising antimicrobial food packaging materials, offering enhanced barrier, antimicrobial properties and a controlled release system.
    Matched MeSH terms: Polyesters/pharmacology
  2. Khan A, Sapuan SM, Siddiqui VU, Zainudin ES, Zuhri MYM, Harussani MM
    Int J Biol Macromol, 2023 Dec 31;253(Pt 5):127119.
    PMID: 37776930 DOI: 10.1016/j.ijbiomac.2023.127119
    Kenaf fiber has recently garnered exponential interest as reinforcement in composite materials across diverse industries owing to its superior mechanical attributes, ease of manufacture, and inherent biodegradability. In the discourse of this review, various methods of manufacturing kenaf/Polylactic acid (PLA) composites have been discussed meticulously, as delineated in recently published scientific literatures. This paper delves into the chemical modification of kenaf fiber, examining its consequential impact on tensile strength and thermal stability of the kenaf/PLA composites. Further, this review illuminates the role of innovative 3D printing techniques and fiber orientation in augmenting the mechanical robustness of the kenaf/PLA composites. Simultaneously, recent insightful explorations into the acoustic properties of the kenaf/PLA composites, underscoring their potential as sustainable alternative to conventional materials have been reviewed. Serving as a comprehensive repository of knowledge, this review paper holds immense value for researchers aiming to utilize the capabilities of kenaf fiber reinforced PLA composites.
    Matched MeSH terms: Polyesters
  3. Vasudevan A, Majumder N, Sharma I, Kaur I, Sundarrajan S, Venugopal JR, et al.
    ACS Biomater Sci Eng, 2023 Nov 13;9(11):6357-6368.
    PMID: 37847169 DOI: 10.1021/acsbiomaterials.3c01216
    Immortalized liver cell lines and primary hepatocytes are currently used as in vitro models for hepatotoxic drug screening. However, a decline in the viability and functionality of hepatocytes with time is an important limitation of these culture models. Advancements in tissue engineering techniques have allowed us to overcome this challenge by designing suitable scaffolds for maintaining viable and functional primary hepatocytes for a longer period of time in culture. In the current study, we fabricated liver-specific nanofiber scaffolds with polylactic acid (PLA) along with a decellularized liver extracellular matrix (LEM) by the electrospinning technique. The fabricated hybrid PLA-LEM scaffolds were more hydrophilic and had better swelling properties than the PLA scaffolds. The hybrid scaffolds had a pore size of 38 ± 8 μm and supported primary rat hepatocyte cultures for 10 days. Increased viability (2-fold increase in the number of live cells) and functionality (5-fold increase in albumin secretion) were observed in primary hepatocytes cultured on the PLA-LEM scaffolds as compared to those on conventional collagen-coated plates on day 10 of culture. A significant increase in CYP1A2 enzyme activity was observed in hepatocytes cultured on PLA-LEM hybrid scaffolds in comparison to those on collagen upon induction with phenobarbital. Drugs like acetaminophen and rifampicin showed the highest toxicity in hepatocytes cultured on hybrid scaffolds. Also, the lethal dose of these drugs in rodents was accurately predicted as 1.6 g/kg and 594 mg/kg, respectively, from the corresponding IC50 values obtained from drug-treated hepatocytes on hybrid scaffolds. Thus, the fabricated liver-specific electrospun scaffolds maintained primary hepatocyte viability and functionality for an extended period in culture and served as an effective ex vivo drug screening platform to predict an accurate in vivo drug-induced hepatotoxicity.
    Matched MeSH terms: Polyesters/metabolism; Polyesters/pharmacology
  4. Kee PE, Chiang YC, Ng HS, Lan JC
    J Biosci Bioeng, 2023 Oct;136(4):312-319.
    PMID: 37500302 DOI: 10.1016/j.jbiosc.2023.07.001
    Poly-3-hydroxybutyrate (P(3HB)), a member of the polyhydroxyalkanoate (PHA) family, is a biodegradable polyester with diverse industrial applications. NADPH-dependent acetoacetyl-CoA reductase (phaB) is the enzyme which plays an essential role in P(3HB) synthesis by catalyzing the conversion of the intermediates. The expression of phaB enzyme using the recombinant Escherichia coli BL-21(DE3) and the purification of the synthesized enzyme were studied. The pET-B3 plasmid harbouring the phaB gene derived from Ralstonia eutropha H16, was driven by the lac promoter in E. coli BL-21(DE3). The enzyme was expressed with different induction time, temperatures and cell age. Results showed that the cell age of 4 h, induction time of 12 h at 37°C were identified as the optimal conditions for the enzyme reductase expression. A specific activity of 0.151 U mg-1 protein and total protein concentration of 0.518 mg mg-1 of dry cell weight (DCW) were attained. Affinity chromatography was performed to purify the His-tagged phaB enzyme, in which enhanced the specific activity (14.44 U mg-1) and purification fold (38-fold), despite relative low yield (44.6%) of the enzyme was obtained. The purified phaB showed an optimal enzyme activity at 30°C and pH 8.0. The findings provide an alternative for the synthesis of the reductase enzyme which can be used in the industrial-scale production of the biodegradable polymers.
    Matched MeSH terms: Polyesters/metabolism
  5. Xie S, Li S, Shaharudin S
    J Sports Sci Med, 2023 Sep;22(3):541-548.
    PMID: 37711701 DOI: 10.52082/jssm.2023.541
    The combined exercise with citrulline (CIT) supplementation is a potential adjuvant treatment approach to address the declining body composition and lower limb function of overweight older adults. However, research on this approach is limited. Thus, this study performed a meta-analysis review to explore the effects of combined exercise with CIT supplementation on body composition and lower limb function among overweight older adults. The search strategy and manuscript development of this study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Eligible studies were first searched through four databases (Web of Science, Scopus, PubMed, and EBSCO) from January 2003 until April 2023, followed by screening. The main inclusion criteria for the article selection are as follows: 1) Randomized Controlled Trial studies; 2) Participants aged over 55; 3) Studies involved exercise with CIT supplementation for the experimental group and exercise with Placebo (PLA) supplementation for the control group; 4) Body composition and lower limb function were measured at pre- and post-intervention. Subsequently, the Cochrane risk of bias assessment tool was utilized to evaluate the selected studies' quality. The Standardized Mean Difference (SMD) was chosen as the suitable effect scale index, and the mean differences of the data from the selected articles were analyzed using Revman 5.4 software with a 95% Confidence Interval (CI). A total of seven studies fulfilled the inclusion criteria and were selected for the meta-analysis. The included studies involved 105 males and 198 females, where 157 belonged to the PLA group and 146 from the CIT group. Significant improvements were observed among overweight older adults with CIT supplementation in 6-Minute Walking Test (6MWT) (P = 0.04, I2 = 4%), SMD (95% CI) = -0.28 (-0.54, -0.01), and Lower Limb Strength (LLS) (P < 0.01, I2 = 30%), SMD (95% CI) = -0.38 (-0.65, -0.12) compared to those with PLA supplementation. Combined exercise with CIT supplementation could be an effective non-pharmaceutical intervention to improve the physical function of overweight older adults by increasing their muscle strength.
    Matched MeSH terms: Polyesters
  6. Alregib AH, Tan HY, Wong YH, Kasbollah A, Wong EH, Abdullah BJJ, et al.
    J Labelled Comp Radiopharm, 2023 Aug;66(10):308-320.
    PMID: 37287213 DOI: 10.1002/jlcr.4046
    Transarterial chemoembolization (TACE) and transarterial radioembolization (TARE) are promising treatments for unresectable liver tumours. Some recent studies suggested that combining TACE and TARE in one treatment course might improve treatment efficacy through synergistic cytotoxicity effects. Nonetheless, current formulations do not facilitate a combination of chemo- and radio-embolic agents in one delivery system. Therefore, this study aimed to synthesise a hybrid biodegradable microsphere loaded with both radioactive agent, samarium-153 (153 Sm) and chemotherapeutic drug, doxorubicin (Dox) for potential radio-chemoembolization of advanced liver tumours. 152 Sm and Dox-loaded polyhydroxybutyrate-co-3-hydroxyvalerate (PHBV) microspheres were prepared using water-in-oil-in-water solvent evaporation method. The microspheres were then sent for neutron activation in a neutron flux of 2 × 1012  n/cm2 /s. The physicochemical properties, radioactivity, radionuclide purity, 153 Sm retention efficiency, and Dox release profile of the Dox-153 Sm-PHBV microspheres were analysed. In addition, in vitro cytotoxicity of the formulation was tested using MTT assay on HepG2 cell line at 24 and 72 h. The mean diameter of the Dox-153 Sm-PHBV microspheres was 30.08 ± 2.79 μm. The specific radioactivity was 8.68 ± 0.17 GBq/g, or 177.69 Bq per microsphere. The 153 Sm retention efficiency was more than 99%, tested in phosphate-buffered saline (PBS) and human blood plasma over 26 days. The cumulative release of Dox from the microspheres after 41 days was 65.21 ± 1.96% and 29.96 ± 0.03% in PBS solution of pH 7.4 and pH 5.5, respectively. The Dox-153 Sm-PHBV microspheres achieved a greater in vitro cytotoxicity effect on HepG2 cells (85.73 ± 3.63%) than 153 Sm-PHBV (70.03 ± 5.61%) and Dox-PHBV (74.06 ± 0.78%) microspheres at 300 μg/mL at 72 h. In conclusion, a novel biodegradable microspheres formulation loaded with chemotherapeutic drug (Dox) and radioactive agent (153 Sm) was successfully developed in this study. The formulation fulfilled all the desired physicochemical properties of a chemo-radioembolic agent and achieved better in vitro cytotoxicity on HepG2 cells. Further investigations are needed to evaluate the biosafety, radiation dosimetry, and synergetic anticancer properties of the formulation.
    Matched MeSH terms: Polyesters/therapeutic use
  7. Kamaruddin HK, Farah NMF, Aziz AR, Mündel T, Che Muhamed AM
    Eur J Appl Physiol, 2023 Jul;123(7):1507-1518.
    PMID: 36920510 DOI: 10.1007/s00421-023-05170-y
    PURPOSE: To determine whether carbohydrate mouth rinsing would improve endurance running performance of tropical natives in a warm-humid (30 °C and 70% relative humidity) environment.

    METHOD: Twelve endurance male runners [age 25 ± 3 years; peak aerobic capacity ([Formula: see text]O2peak) 57.6 ± 3.6 mL.kg-1.min-1] completed three time-to-exhaustion (TTE) trials at ~ 70% [Formula: see text]O2peak while swilling 25 ml of a 6% carbohydrate (CHO) or taste-matched placebo (PLA) as well as no mouth rinse performed in the control (CON) trial.

    RESULTS: TTE performance was significantly longer in both CHO and PLA trials when compared with the CON trial (54.7 ± 5.4 and 53.6 ± 5.1 vs. 48.4 ± 3.6 min, respectively; p  0.05). Similarly, plasma lactate and glucose as well as exercise heart rate were not influenced by the trials.

    CONCLUSIONS: The present study demonstrates that mouth rinsing, whether carbohydrate or placebo, provides an ergogenic benefit to running endurance when compared to CON in a heat stress environment. Nevertheless, the results do not support the notion that rinsing a carbohydrate solution provides a greater advantage as previously described among non-heat acclimated individuals within a temperate condition.

    Matched MeSH terms: Polyesters/pharmacology
  8. Trakunjae C, Boondaeng A, Apiwatanapiwat W, Janchai P, Neoh SZ, Sudesh K, et al.
    Sci Rep, 2023 Jun 02;13(1):9005.
    PMID: 37268758 DOI: 10.1038/s41598-023-36180-7
    Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [P(3HB-co-3HHx)] is a bacterial copolymer in the polyhydroxyalkanoates (PHAs) family, a next-generation bioplastic. Our research team recently engineered a newly P(3HB-co-3HHx)-producing bacterial strain, Cupriavidus necator PHB-4/pBBR_CnPro-phaCRp. This strain can produce P(3HB-co-2 mol% 3HHx) using crude palm kernel oil (CPKO) as a sole carbon substrate. However, the improvement of P(3HB-co-3HHx) copolymer production by this strain has not been studied so far. Thus, this study aims to enhance the production of P(3HB-co-3HHx) copolymers containing higher 3HHx monomer compositions using response surface methodology (RSM). Three significant factors for P(3HB-co-3HHx) copolymers production, i.e., CPKO concentration, sodium hexanoate concentration, and cultivation time, were studied in the flask scale. As a result, a maximum of 3.6 ± 0.4 g/L of P(3HB-co-3HHx) with 4 mol% 3HHx compositions was obtained using the RSM optimized condition. Likewise, the higher 3HHx monomer composition (5 mol%) was obtained when scaling up the fermentation in a 10L-stirrer bioreactor. Furthermore, the produced polymer's properties were similar to marketable P(3HB-co-3HHx), making this polymer suitable for a wide range of applications.
    Matched MeSH terms: Polyesters
  9. Nouri A, Ang WL, Mahmoudi E, Chua SF, Mohammad AW, Benamor A, et al.
    Chemosphere, 2023 May;322:138219.
    PMID: 36828108 DOI: 10.1016/j.chemosphere.2023.138219
    Decorating nanomaterials on graphene oxide (GO) can enhance its adsorption capacity and removal efficiency of water pollutants. In this study, for the first time, nano-sized polylactic acid (PLA) has been successfully decorated on the surface of GO through a facile synthesis approach. The adsorptive efficiency of GO-PLA for removing methylene blue (MB) and tetracycline (TC) from an aqueous solution was examined. The characterization confirmed the successful decoration of PLA on GO nanosheets with the nano size of PLA. It was hypothesized that the PLA was decorated on the surface of GO through covalent bonding between oxygen-containing functional groups and lactide molecules. The optimum adsorption parameters determined were at the adsorbent dose of 0.5 g L-1, pH 4, contact time of 120 min, and temperature of 318 K. The pseudo-second-order kinetic model described the contaminants' adsorption behaviour, and the intraparticle diffusion model revealed that both surface adsorption and intraparticle diffusion controlled the adsorption process. Langmuir isotherm model best described the adsorption behaviour of the pollutants on GO-PLA and demonstrated the maximum monolayer uptake capacities of MB (332.5 mg g-1) and TC (223.7 mg g-1). The adsorption results indicated that the uptake capacities of GO-PLA in comparison to GO have increased by approximately 70% and 110% for MB and TC, respectively. These observations reflect the remarkable role of nano-sized PLA that enhanced the adsorption capacity due to its additional functional group and larger surface area.
    Matched MeSH terms: Polyesters
  10. Wan JH, Ng LM, Neoh SZ, Kajitani R, Itoh T, Kajiwara S, et al.
    Arch Microbiol, 2023 Jan 16;205(2):66.
    PMID: 36645481 DOI: 10.1007/s00203-023-03406-1
    Polyhydroxyalkanoate (PHA) is a type of biopolymer produced by most bacteria and archaea, resembling thermoplastic with biodegradability and biocompatibility features. Here, we report the complete genome of a PHA producer, Aquitalea sp. USM4, isolated from Perak, Malaysia. This bacterium possessed a 4.2 Mb circular chromosome and a 54,370 bp plasmid. A total of 4067 predicted protein-coding sequences, 87 tRNA genes, and 25 rRNA operons were identified using PGAP. Based on ANI and dDDH analysis, the Aquitalea sp. USM4 is highly similar to Aquitalea pelogenes. We also identified genes, including acetyl-CoA (phaA), acetoacetyl-CoA (phaB), PHA synthase (phaC), enoyl-CoA hydratase (phaJ), and phasin (phaP), which play an important role in PHA production in Aquitalea sp. USM4. The heterologous expression of phaC1 from Aquitalea sp. USM4 in Cupriavidus necator PHB-4 was able to incorporate six different types of PHA monomers, which are 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), 4-hydroxybutyrate (4HB), 5-hydroxyvalerate (5HV), 3-hydroxyhexanoate (3HHx) and isocaproic acid (3H4MV) with suitable precursor substrates. This is the first complete genome sequence of the genus Aquitalea among the 22 genome sequences from 4 Aquitalea species listed in the GOLD database, which provides an insight into its genome evolution and molecular machinery responsible for PHA biosynthesis.
    Matched MeSH terms: Polyesters/metabolism
  11. Liew PWY, Jong BC, Sudesh K, Najimudin N, Mok PS
    World J Microbiol Biotechnol, 2023 Jan 06;39(3):68.
    PMID: 36607449 DOI: 10.1007/s11274-022-03503-1
    The production of poly(3-hydroxybutyrate) [P(3HB)] from untreated raw palm oil mill effluent (urPOME), the first wastewater discharge from crude palm oil extraction, is discussed. The mutant strain Azotobacter vinelandii ΔAvin_16040, which lacks the S-layer protein but has a better P(3HB) synthesis capability than the wild type strain ATCC 12,837, was chosen for this study. UrPOME substrate, with high biological oxygen demand (BOD), chemical oxygen demand (COD) and suspended solids, was used without pre-treatment. DSMZ-Azotobacter medium which was devoid of laboratory sugar(s) was used as the basal medium (BaM). Initially, Azotobacter vinelandii ΔAvin_16040 generated 325.5, 1496.3, and 1465.7 mg L-1 of P(3HB) from BaM with 20% urPOME, 2BaM with 20% urPOME and 20 g L-1 sucrose, and 2BaM with 20% urPOME and 2 mL L-1 glycerol, respectively. P(3HB) generation was enhanced by nearly tenfold using statistical optimization, resulting in 13.9 g L-1. Moreover, the optimization reduced the compositions of mineral salts and sugar in the medium by 48 and 97%, respectively. The urPOME-based P(3HB) product developed a yellow coloration most possibly attributed to the aromatic phenolics content in urPOME. Despite the fact that both were synthesised by ΔAvin_16040, thin films of urPOME-based P(3HB) had superior crystallinity and tensile strength than P(3HB) produced only on sucrose. When treated with 10 and 50 kGy of electron beam irradiation, these P(3HB) scissioned to half and one-tenth of their original molecular weights, respectively, and these cleavaged products could serve as useful base units for specific polymer structure construction.
    Matched MeSH terms: Polyesters/metabolism
  12. Revati R, Majid MSA, Ridzuan MJM, Mamat N, Cheng EM, Alshahrani HA
    Int J Biol Macromol, 2022 Dec 31;223(Pt A):479-489.
    PMID: 36368357 DOI: 10.1016/j.ijbiomac.2022.11.041
    This study aimed to evaluate the bioactivities and biocompatibilities of porous polylactic acid (PLA) reinforced with cellulose nanofiber (CNF) scaffolds. The in vitro degradation behaviors of the porous PLA/CNF scaffolds were systematically measured for up to 8 weeks in a phosphate-buffered saline medium at 37 °C. The reinforcement of CNF resisted the biodegradation of the scaffolds. The in vitro cytotoxicity and biocompatibility of the scaffolds were determined using the Beas2B American Type Culture Collection cells. The 3-(4,5-cimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide cytotoxicity and proliferation tests showed that the scaffolds were non-toxic, and epithelial cells grew well on the scaffold after 7 days of culture, whereas the percentage of cell proliferation on the PLA/CNF15 scaffold was the largest, 130 %. A scratch wound-healing assay was performed to evaluate the suitability of the scaffolds for cell migration. The results demonstrated that the scaffolds exhibited good cell migration towards nearly complete wound closure.
    Matched MeSH terms: Polyesters
  13. Kao CY, Lin TL, Lin YH, Lee AK, Ng SY, Huang TH, et al.
    Cells, 2022 Dec 08;11(24).
    PMID: 36552731 DOI: 10.3390/cells11243967
    In scaffold-regulated bone regeneration, most three-dimensional (3D)-printed scaffolds do not provide physical stimulation to stem cells. In this study, a magnetic scaffold was fabricated using fused deposition modeling with calcium silicate (CS), iron oxide nanoparticles (Fe3O4), and poly-ε-caprolactone (PCL) as the matrix for internal magnetic sources. A static magnetic field was used as an external magnetic source. It was observed that 5% Fe3O4 provided a favorable combination of compressive strength (9.6 ± 0.9 MPa) and degradation rate (21.6 ± 1.9% for four weeks). Furthermore, the Fe3O4-containing scaffold increased in vitro bioactivity and Wharton's jelly mesenchymal stem cells' (WJMSCs) adhesion. Moreover, it was shown that the Fe3O4-containing scaffold enhanced WJMSCs' proliferation, alkaline phosphatase activity, and the osteogenic-related proteins of the scaffold. Under the synergistic effect of the static magnetic field, the CS scaffold containing Fe3O4 can not only enhance cell activity but also stimulate the simultaneous secretion of collagen I and osteocalcin. Overall, our results demonstrated that Fe3O4-containing CS/PCL scaffolds could be fabricated three dimensionally and combined with a static magnetic field to affect cell behaviors, potentially increasing the likelihood of clinical applications for bone tissue engineering.
    Matched MeSH terms: Polyesters/pharmacology
  14. Haneef INHM, Buys YF, Shaffiar NM, Abdul Hamid AM, Shaharuddin SIS, Fitriani
    J Mech Behav Biomed Mater, 2022 Nov;135:105423.
    PMID: 36087517 DOI: 10.1016/j.jmbbm.2022.105423
    The need to overcome the secondary surgery to remove implanted metal fixation plate leads to the idea of replacing the material with degradable bionanocomposite. In this research, polylactic acid/polypropylene (PLA/PPC) blends incorporated with halloysite nanotubes (HNT) (0-6 wt %) were considered as the candidate material for mandibular fixation plate. A single-factor design using Design Expert software was used to determine 20 different compositions of PLA/PPC/HNT nanocomposites and their mechanical properties were then measured. The optimization of the PLA/PPC/HNT nanocomposite composition was performed based on the nanocomposite's response to Young's modulus, tensile strength, and elongation at break. Further analysis suggested an optimum composition of 92.5/7.5 PLA/PPC with 6 wt % of HNT. The statistical results predicted that there was a 71.7% possibility that the proposed nanocomposite would have the following mechanical properties: Young's modulus of 2.18 GPa, a tensile strength of 64.16 MPa, and an elongation at break of 106.53%.
    Matched MeSH terms: Polyesters
  15. Kian LK, Jawaid M, Nasef MM, Fouad H, Karim Z
    Int J Biol Macromol, 2021 Dec 01;192:654-664.
    PMID: 34655581 DOI: 10.1016/j.ijbiomac.2021.10.042
    In this study, poly(lactic acid) (PLA)/poly(butylene succinate) (PBS) dual-layer membranes filled with 0-3 wt% cellulose nanowhisker (CNWs) were fabricated with aim to remove metal ions from wastewater. An integrated method was employed in the membrane fabrication process by combining water vapor-induced and crystallization-induced phase inversions. The membrane thickness was measured in between 11 and 13 μm, which did not pose significant flux deviation during filtration process. The 3% CNW filled membrane showed prominent and well-laminated two layers structure. Meanwhile, the increase in CNWs from 0 to 3% loadings could improve the membrane porosity (43-74%) but reducing pore size (2.45-0.54 μm). The heat resistance of neat membrane enhanced by 1% CNW but decreased with loadings of 2-3% CNWs due to flaming behavior of sulphated nanocellulose. Membrane with 3% CNW displayed the tensile strength (23.5 MPa), elongation at break (7.1%), and Young's modulus (0.75 GPa) as compared to other samples. For wastewater filtration performance, the continuous operation test showed that 3% CNW filled membrane exhibited the highest removal efficiency for both cobalt and nickel metal ions reaching to 83% and 84%, respectively. We concluded that CNWs filled dual-layer membranes have potential for future development in the removal of heavy metal ions from wastewater streams.
    Matched MeSH terms: Polyesters/chemistry*
  16. Anita Lett J, Sagadevan S, Léonard E, Fatimah I, Motalib Hossain MA, Mohammad F, et al.
    Artif Organs, 2021 Dec;45(12):1501-1512.
    PMID: 34309044 DOI: 10.1111/aor.14045
    The primary role of bone tissue engineering is to reconcile the damaged bones and facilitate the speedy recovery of the injured bones. However, some of the investigated metallic implants suffer from stress-shielding, palpability, biocompatibility, etc. Consequently, the biodegradable scaffolds fabricated from polymers have gathered much attention from researchers and thus helped the tissue engineering sector by providing many alternative materials whose functionality is similar to that of natural bones. Herein, we present the fabrication and testing of a novel composite, magnesium (Mg)-doped hydroxyapatite (HAp) glazed onto polylactic acid (PLA) scaffolds where polyvinyl alcohol (PVA) used as a binder. For the composite formation, Creality Ender-3 pro High Precision 3D Printer with Shape tool 3D Technology on an FSD machine operated by Catia design software was employed. The composite has been characterized for the crystallinity (XRD), surface functionality (FTIR), morphology (FESEM), biocompatibility (hemolytic and protein absorption), and mechanical properties (stress-strain and maximum compressive strength). The powder XRD analysis confirmed the semicrystalline nature and intact structure of HAp even after doping with Mg, while FTIR studies for the successful formation of Mg-HAp/PVA@PLA composite. The FESEM provided analysis indicated for the 3D porous architecture and well-defined morphology to efficiently transport the nutrients, and the biocompatibility studies are supporting that the composite for blood compatible with the surface being suitable enough for the protein absorption. Finally, the composite's antibacterial activity (against Staphylococcus aureus and Escherichia coli) and the test of mechanical properties supported for the enhanced inhibition of active growth of microorganisms and maximum compressive strength, respectively. Based on the research outcomes of biocompatibility, antibacterial activity, and mechanical resistance, the fabricated Mg-HAp/PVA@PLA composite suits well as a promising biomaterial platform for orthopedic applications by functioning towards the open reduction internal fixation of bone fractures and internal repairs.
    Matched MeSH terms: Polyesters/chemistry*
  17. Chien Bong CP, Alam MNHZ, Samsudin SA, Jamaluddin J, Adrus N, Mohd Yusof AH, et al.
    J Environ Manage, 2021 Nov 15;298:113461.
    PMID: 34435568 DOI: 10.1016/j.jenvman.2021.113461
    Polyhydroxyalkanoate (PHA) is a type of polyesters produced in the form of accumulated intracellular granules by many microorganisms. It is viewed as an environmentally friendly bioproduct due to its biodegradability and biocompatibility. The production of the PHA using oil substrates such as waste oil and plant oil, has gained considerable attention due to the high product yield and lower substrate cost. Nevertheless, the PHA fermentation using oil substrate is complicated due to the heterogenous fatty acid composition, varied bio-accessibility and possible inhibitory effect on the bacterial culture. This review presents the current state-of-the-art of PHA production from oil-based substrates. This paper firstly discusses the technical details, such as the choice of bacteria strain and fermentation conditions, characteristic of the oil substrate as well as the PHA composition and application. Finally, the paper discusses the challenges and prospects for up-scaling towards a cleaner and effective bioprocess. From the literature review, depending on the cell culture and the type of PHA produced, the oil platform can have a PHA yield of 0.2-0.8 g PHA/g oil substrate, with PHA content mostly from 40 to 90% of the cell dry weight. There is an on-going search for more effective oil-utilising PHA producers and lower cost substrate for effective PHA production. The final application of the PHA polymer influences the treatment needed during downstream processing and its economic performance. PHA with different compositions exhibits varied decomposition behaviour under different conditions, requiring further insight towards its management towards a sustainable circular economy.
    Matched MeSH terms: Polyesters
  18. Sucinda EF, Abdul Majid MS, Ridzuan MJM, Cheng EM, Alshahrani HA, Mamat N
    Int J Biol Macromol, 2021 Sep 30;187:43-53.
    PMID: 34271052 DOI: 10.1016/j.ijbiomac.2021.07.069
    A packaging material that is environment-friendly with excellent mechanical and physicochemical properties, biodegradable and ultraviolet (UV) protection and thermal stability was prepared to reduce plastic waste. Six different concentrations of Pennisetum purpureum/Napier cellulose nanowhiskers (NWCs) (i.e. 0, 0.5, 1.0, 1.5, 2.0, and 3.0 wt%) were used to reinforce polylactic acid (PLA) by a solvent casting method. The resulting bionanocomposite film samples were characterised in terms of their morphology, chemical structure, crystallinity, thermal degradation and stability, light transmittance, water absorption, biodegradability, and physical and mechanical properties. Field-emission scanning electron microscopy showed the excellent dispersion of NWC in the PLA matrix occurred with NWC concentrations of 0.5-1.5 wt%. All the bionanocomposite film samples exhibited good thermal stability at approximately 343-359 °C. The highest water absorption was 1.94%. The lowest transparency at λ800 was 16.16% for the PLA/3.0% NWC bionanocomposite film, which also has the lowest UVA and UVB transmittance of 7.49% and 4.02%, respectively, making it suitable for packaging materials. The PLA/1.0% NWC film exhibited the highest crystallinity of 50.09% and high tensile strength and tensile modulus of 21.22 MPa and 11.35 MPa, respectively.
    Matched MeSH terms: Polyesters/chemistry*
  19. Rosli NA, Karamanlioglu M, Kargarzadeh H, Ahmad I
    Int J Biol Macromol, 2021 Sep 30;187:732-741.
    PMID: 34358596 DOI: 10.1016/j.ijbiomac.2021.07.196
    Poly(lactic acid) (PLA), a bio-based polyester, has been extensively investigated in the recent past owing to its excellent mechanical properties. Several studies have been conducted on PLA blends, with a focus on improving the brittleness of PLA to ensure its suitability for various applications. However, the increasing use of PLA has increased the contamination of PLA-based products in the environment because PLA remains intact even after three years at sea or in soil. This review focuses on analyzing studies that have worked on improving the degradation properties of PLA blends and studies how other additives affect degradation by considering different degradation media. Factors affecting the degradation properties, such as surface morphology, water uptake, and crystallinity of PLA blends, are highlighted. In natural, biotic, and abiotic media, water uptake plays a crucial role in determining biodegradation rates. Immiscible blends of PLA with other polymer matrices cause phase separation, increasing the water absorption. The susceptibility of PLA to hydrolytic and enzymatic degradation is high in the amorphous region because it can be easily penetrated by water. It is essential to study the morphology, water absorption, and structural properties of PLA blends to predict the biodegradation properties of PLA in the blends.
    Matched MeSH terms: Polyesters/chemistry*
  20. Wsoo MA, Razak SIA, Bohari SPM, Shahir S, Salihu R, Kadir MRA, et al.
    Int J Biol Macromol, 2021 Jun 30;181:82-98.
    PMID: 33771547 DOI: 10.1016/j.ijbiomac.2021.03.108
    Vitamin D deficiency is now a global health problem; despite several drug delivery systems for carrying vitamin D due to low bioavailability and loss bioactivity. Developing a new drug delivery system to deliver vitamin D3 is a strong incentive in the current study. Hence, an implantable drug delivery system (IDDS) was developed from the electrospun cellulose acetate (CA) and ε-polycaprolactone (PCL) nanofibrous membrane, in which the core of implants consists of vitamin D3-loaded CA nanofiber (CAVD) and enclosed in a thin layer of the PCL membrane (CAVD/PCL). CA nanofibrous mat loaded with vitamin D3 at the concentrations of 6, 12, and 20% (w/w) of vitamin D3 were produced using electrospinning. The smooth and bead-free fibers with diameters ranged from 324 to 428 nm were obtained. The fiber diameters increased with an increase in vitamin D3 content. The controlled drug release profile was observed over 30-days, which fit with the zero-order model (R2 > 0.96) in the first stage. The mechanical properties of IDDS were improved. Young's modulus and tensile strength of CAVD/PCL (dry) were161 ± 14 and 13.07 ± 2.5 MPa, respectively. CA and PCL nanofibers are non-cytotoxic based on the results of the in-vitro cytotoxicity studies. This study can further broaden in-vivo study and provide a reference for developing a new IDDS to carry vitamin D3 in the future.
    Matched MeSH terms: Polyesters/chemistry*
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