Displaying publications 61 - 80 of 84 in total

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  1. Badran MM, Alomrani AH, Harisa GI, Ashour AE, Kumar A, Yassin AE
    Biomed Pharmacother, 2018 Oct;106:1461-1468.
    PMID: 30119220 DOI: 10.1016/j.biopha.2018.07.102
    In the present study, docetaxel (DTX)-loaded poly(lactic-co-glycolic acid) (PLGA) and polycaprolactone (PCL) nanoparticles were successfully prepared and coated with chitosan (CS). The prepared nanoparticles (NPs) were evaluated for their particle size, zeta potential, particle morphology, drug entrapment efficiency (EE%), and in vitro drug release profile. The anticancer activity of DTX-loaded NPs was assessed in human HT29 colon cancer cell line utilizing MTT assay. The pharmacokinetics of DTX-loaded NPs was monitored in Wistar rats in comparison to DTX solution. The prepared NPs exhibited particle sizes in the range 177.1 ± 8.2-287.6 ± 14.3 nm. CS decorated NPs exhibited a significant increase in particle size and a switch of zeta potential from negative to positive. In addition, high EE% values were obtained for CS coated PCL NPs and PLGA NPs as 67.1 and 76.2%, respectively. Moreover, lowering the rate of DTX in vitro release was achieved within 48 h by using CS coated NPs. Furthermore, a tremendous increase in DTX cytotoxicity was observed by CS-decorated PLGA NPs compared to all other NPs including DTX-free-NPs and pure DTX. The in vivo study revealed significant enhancement in DTX bioavailability from CS-decorated PLGA NPs with more than 4-fold increase in AUC compared to DTX solution. In conclusion, CS-decorated PLGA NPs are a considerable DTX-delivery carrier with magnificent antitumor efficacy.
    Matched MeSH terms: Polyesters/chemistry*
  2. Martla M, Umsakul K, Sudesh K
    J Basic Microbiol, 2018 Nov;58(11):977-986.
    PMID: 30095175 DOI: 10.1002/jobm.201800279
    Polyhydroxyalkanoates (PHAs) has been paid great attention because of its useful thermoplastic properties and complete degradation in various natural environments. But, at industrial level, the successful commercialization of PHAs is limited by the high production cost due to the expensive carbon source and recovery processes. Pseudomonas mendocina PSU cultured for 72 h in mineral salts medium (MSM) containing 2% (v/v) biodiesel liquid waste (BLW) produced 79.7 wt% poly(3-hydroxybutyrate) (PHB) at 72 h. In addition, this strain produced 43.6 wt% poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with 8.6 HV mol% at 60 h when added with 0.3% sodium propionate. The synthesized intracellular PHA granules were recovered and purified by the recently reported biological method using mealworms. The weight average molecular weight (Mw ) and number average molecular weight (Mn ) of the biologically extracted PHA were higher than that from the chloroform extraction with comparable melting temperature (Tm ) and high purity. This study has successfully established a low-cost process to synthesize PHAs from BLW and subsequently confirmed the ability of mealworms to extract PHAs from various kinds of bacterial cells.
    Matched MeSH terms: Polyesters/chemistry
  3. Pakalapati H, Arumugasamy SK, Jewaratnam J, Wong YJ, Khalid M
    Biopolymers, 2018 Dec;109(12):e23240.
    PMID: 30489632 DOI: 10.1002/bip.23240
    A statistical approach with D-optimal design was used to optimize the process parameters for polycaprolactone (PCL) synthesis. The variables selected were temperature (50°C-110°C), time (1-7 h), mixing speed (50-500 rpm) and monomer/solvent ratio (1:1-1:6). Molecular weight was chosen as response and was determined using matrix-assisted laser desorption/ionization time of flight (MALDI TOF). Using the D-optimal method in design of experiments, the interactions between parameters and responses were analysed and validated. The results show a good agreement with a minimum error between the actual and predicted values.
    Matched MeSH terms: Polyesters/chemistry
  4. Vijayan V, Shalini K, Yugesvaran V, Yee TH, Balakrishnan S, Palanimuthu VR
    Curr Pharm Des, 2018;24(28):3366-3375.
    PMID: 30179118 DOI: 10.2174/1381612824666180903110301
    BACKGROUND: Triple-Negative Breast Cancer is an aggressive type of breast cancer, which is not treatable by chemotherapy drugs, due to the lack of Estrogen Receptor (ER), Progesterone Receptor (PR) expression and Human Epidermal Growth Factor Receptor 2 (HER2) on the cell surface.

    OBJECTIVE: The aim of this study was to compare the effect of paclitaxel loaded PLGA nanoparticle (PTX-NPs) on the cytotoxicity and apoptosis of the different MDA-MB type of cell lines.

    METHOD: PTX-NPs were prepared by nanoprecipitation method and characterized earlier. The cytotoxicity of PTX-NPs was evaluated by MTT and LDH assay, later apoptosis was calculated by flow cytometry analysis.

    RESULTS: The prepared NP size of 317.5 nm and zetapontial of -12.7 mV showed drug release of 89.1 % at 48 h. MDA-MB-231 type cell showed significant cytotoxicity by MTT method of 47.4 ± 1.2 % at 24 h, 34.6 ± 0.8 % at 48 h and 23.5 ± 0.5 % at 72 h and LDH method of 35.9 ± 1.5 % at 24 h, 25.4 ± 0.6 % at 48 h and 19.8 ± 2.2 % at 72 h with apoptosis of 47.3 ± 0.4 %.

    CONCLUSION: We have found that PTX-NPs showed the cytotoxic effect on all the MDA-MB cancer cell lines and showed potent anticancer activities against MDA-MB-231 cell line via induction of apoptosis.

    Matched MeSH terms: Polyesters/chemistry*
  5. Ezhilarasu H, Sadiq A, Ratheesh G, Sridhar S, Ramakrishna S, Ab Rahim MH, et al.
    Nanomedicine (Lond), 2019 01;14(2):201-214.
    PMID: 30526272 DOI: 10.2217/nnm-2018-0271
    AIM: Atherosclerosis is a common cardiovascular disease causing medical problems globally leading to coronary artery bypass surgery. The present study is to fabricate core/shell nanofibers to encapsulate VEGF for the differentiation of mesenchymal stem cells (MSCs) into smooth muscle cells to develop vascular grafts.

    MATERIALS & METHODS: The fabricated core/shell nanofibers contained polycaprolactone/gelatin as the shell, and silk fibroin/VEGF as the core materials.

    RESULTS: The results observed that the core/shell nanofibers interact to differentiate MSCs into smooth muscle cells by the expression of vascular smooth muscle cell (VSMC) contractile proteins α-actinin, myosin and F-actin.

    CONCLUSION: The functionalized polycaprolactone/gelatin/silk fibroin/VEGF (250 ng) core/shell nanofibers were fabricated for the controlled release of VEGF in a persistent manner for the differentiation of MSCs into smooth muscle cells for vascular tissue engineering.

    Matched MeSH terms: Polyesters/chemistry
  6. Kian LK, Saba N, Jawaid M, Sultan MTH
    Int J Biol Macromol, 2019 Jan;121:1314-1328.
    PMID: 30208300 DOI: 10.1016/j.ijbiomac.2018.09.040
    The utilization of nanocellulose has increasingly gained attentions from various research fields, especially the field of polymer nanocomposites owing to the growing environmental hazardous of petroleum based fiber products. Meanwhile, the searching of alternative cellulose sources from different plants has become the interests for producing nanocellulose with varying characterizations that expectedly suit in specific field of applications. In this content the long and strong bast fibers from plant species was gradually getting its remarkable position in the field of nanocellulose extraction and nanocomposites fabrications. This review article intended to present an overview of the chemical structure of cellulose, different types of nanocellulose, bast fibers compositions, structure, polylactic acid (PLA) and the most probable processing techniques on the developments of nanocellulose from different bast fibers especially jute, kenaf, hemp, flax, ramie and roselle and its nanocomposites. This article however more focused on the fabrication of PLA based nanocomposites due to its high firmness, biodegradability and sustainability properties in developed products towards the environment. Along with this it also explored a couple of issues to improve the processing techniques of bast fibers nanocellulose and its reinforcement in the PLA biopolymer as final products.
    Matched MeSH terms: Polyesters/chemistry*
  7. Yuan X, Amarnath Praphakar R, Munusamy MA, Alarfaj AA, Suresh Kumar S, Rajan M
    Carbohydr Polym, 2019 Feb 15;206:1-10.
    PMID: 30553301 DOI: 10.1016/j.carbpol.2018.10.098
    Natural polymer guar gum has one of the highest viscosities in water solution and hence, these are significantly used in pharmaceutical applications. Guar gum inter-connected micelles as a new carrier has been developed for poor water soluble rifampicin drug. The hydrogel inter-connected micelle core was formulated as a hydrophilic inner and hydrophobic outer core by using guar gum/chitosan/polycaprolactone and the carrier interaction with rifampicin was confirmed by FT-IR. The morphological observations were carried out through TEM, SEM and AFM analysis. The encapsulation efficiency and in-vitro drug release behavior of prepared hydrogel based micelle system was analyzed by UV-vis spectrometry. The anti-bacterial activity against K. pneumoniae and S. aureus was studied by observing their ruptured surface by SEM. The cytotoxicity study reveals that the pure polymeric system has no toxic effect whereas drug loaded ones showed superior activity against THP-1 cells. From the cell apoptosis analyses, the apoptosis was carried out in a time dependent manner. The cell uptake behavior was also observed in THP-1 cells which indicate that the hydrogel based micelle system is an excellent material for the mucoadhesive on intracellular alveolar macrophage treatment.
    Matched MeSH terms: Polyesters/chemistry
  8. Nizamuddin S, Jadhav A, Qureshi SS, Baloch HA, Siddiqui MTH, Mubarak NM, et al.
    Sci Rep, 2019 Apr 01;9(1):5445.
    PMID: 30931991 DOI: 10.1038/s41598-019-41960-1
    Polymer composites are fabricated by incorporating fillers into a polymer matrix. The intent for addition of fillers is to improve the physical, mechanical, chemical and rheological properties of the composite. This study reports on a unique polymer composite using hydrochar, synthesised by microwave-assisted hydrothermal carbonization of rice husk, as filler in polylactide matrix. The polylactide/hydrochar composites were fabricated by incorporating hydrochar in polylactide at 5%, 10%, 15% and 20 wt% by melt processing in a Haake rheomix at 170 °C. Both the neat polylactide and polylactide/hydrochar composite were characterized for mechanical, structural, thermal and rheological properties. The tensile modulus of polylactide/hydrochar composites was improved from 2.63 GPa (neat polylactide) to 3.16 GPa, 3.33 GPa, 3.54 GPa, and 4.24 GPa after blending with hydrochar at 5%, 10%, 15%, and 20%, respectively. Further, the incorporation of hydrochar had little effect on storage modulus (G') and loss modulus (G″). The findings of this study reported that addition of hydrochar improves some characteristics of polylactide composites suggesting the potential of hydrochar as filler for polymer/hydrochar composites.
    Matched MeSH terms: Polyesters/chemistry*
  9. Sologashvili T, Saat SA, Tille JC, De Valence S, Mugnai D, Giliberto JP, et al.
    Eur J Pharm Biopharm, 2019 Jun;139:272-278.
    PMID: 31004790 DOI: 10.1016/j.ejpb.2019.04.012
    OBJECTIVE: Vascular prostheses for small caliber bypass grafts in cardiac and vascular diseases or for access surgery are still missing. Poly (Ɛ-caprolactone) (PCL) has been previously investigated by our group and showed good biocompatibility and mechanical properties in vitro and rapid endothelialisation, cellular infiltration and vascularisation in vivo yielding optimal patency in the abdominal aortic position. The aim of the present study is to evaluate our PCL graft in the carotid position and to compare its outcome to the grafts implanted in the abdominal aortic position.

    METHODS: PCL grafts (1 mm ID/10 mm long) were implanted into the left common carotid artery in 20 Sprague-Dawley rats and compared to our previously published series of abdominal aortic implants. The animals were followed up to 3, 6, 12 and 24 weeks. At each time point, in vivo compliance, angiography and histological examination with morphology were performed.

    RESULTS: PCL grafts showed good mechanical properties and ease of handling. The average graft compliance was 14.5 ± 1.7%/ mmHg compared to 7.8 ± 0.9% for the abdominal position and 45.1 ± 3.2%/ mmHg for the native carotid artery. The overall patency for the carotid position was 65% as compared to 100% in the abdominal position. Complete endothelialisation was achieved at 3 weeks and cell invasion was more rapid than in the aortic position. In contrast, intimal hyperplasia (IH) and vascular density were less pronounced than in the aortic position.

    CONCLUSION: Our PCL grafts in the carotid position were well endothelialised with early cellular infiltration, higher compliance, lower IH and calcification compared to the similar grafts implanted in the aortic position. However, there was a higher occlusion rate compared to our abdominal aorta series. Anatomical position, compliance mismatch, flow conditions may answer the difference in patency seen.

    Matched MeSH terms: Polyesters/chemistry
  10. Pachiyappan S, Shanmuganatham Selvanantham D, Kuppa SS, Chandrasekaran S, Samrot AV
    IET Nanobiotechnol, 2019 Jun;13(4):416-427.
    PMID: 31171747 DOI: 10.1049/iet-nbt.2018.5053
    In this study, polyhydroxybutyrate (PHB) nanoparticles were synthesised following nanoprecipitation method having different solvents and surfactant (Tween 80) concentrations. In this study, PHB nanoparticles were encapsulated with curcumin and subjected for sustained curcumin delivery. Both the curcumin loaded and unloaded PHB nanoparticles were characterised using FTIR, SEM, and AFM. Sizes of the particles were found to be between 60 and 300 nm. The drug encapsulation efficiency and in vitro drug release of the nanoparticles were analysed. Antibacterial activity and anticancer activity were also evaluated. The LC50 values of most of the nanoparticles were found to be between 10 and 20 µg/100 µl, anticancer activity of curcumin loaded PHB nanoparticles were further confirmed by AO/PI staining and mitochondrial depolarisation assay.
    Matched MeSH terms: Polyesters/chemistry
  11. Rizwan M, Yahya R, Hassan A, Yar M, Abd Halim AA, Rageh Al-Maleki A, et al.
    J Mater Sci Mater Med, 2019 Jun 11;30(6):72.
    PMID: 31187295 DOI: 10.1007/s10856-019-6273-3
    The success of wound healing depends upon the proper growth of vascular system in time in the damaged tissues. Poor blood supply to wounded tissues or tissue engineered grafts leads to the failure of wound healing or rejection of grafts. In present paper, we report the synthesis of novel organosoluble and pro-angiogenic chitosan derivative (CSD) by the reaction of chitosan with 1,3-dimethylbarbituric acid and triethylorthoformate (TEOF). The synthesized material was characterized by FTIR and 13C-NMR to confirm the incorporated functional groups and new covalent connectivities. Biodegradability of the synthesized chitosan derivative was tested in the presence of lysozyme and was found to be comparable with CS. The cytotoxicity and apoptosis effect of new derivative was determined against gastric adenocarcinoma (AGS) cells and was found to be non-toxic. The CSD was found to be soluble in majority of organic solvents. It was blended with polycaprolactone (PCL) to form composite scaffolds. From an ex ovo CAM assay, it was noted that CSD stimulated the angiogenesis.
    Matched MeSH terms: Polyesters/chemistry
  12. Mohd Sabee MMS, Kamalaldin NA, Yahaya BH, Abdul Hamid ZA
    J Mater Sci Mater Med, 2020 May 04;31(5):45.
    PMID: 32367409 DOI: 10.1007/s10856-020-06380-y
    Recently, surface engineered biomaterials through surface modification are extensively investigated due to its potential to enhance cellular homing and migration which contributes to a successful drug delivery process. This study is focused on osteoblasts response towards surface engineered using a simple sodium hydroxide (NaOH) hydrolysis and growth factors conjugated poly(lactic acid) (PLA) microspheres. In this study, evaluation of the relationship of NaOH concentration with the molecular weight changes and surface morphology of PLA microspheres specifically wall thickness and porosity prior to in vitro studies was investigated. NaOH hydrolysis of 0.1 M, 0.3 M and 0.5 M were done to introduce hydrophilicity on the PLA prior to conjugation with basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF). Morphology changes showed that higher concentration of NaOH could accelerate the hydrolysis process as the highest wall thickness was observed at 0.5 M NaOH with ~3.52 µm. All surface modified and growth factors conjugated PLA microspheres wells enhanced the migration of the cells during wound healing process as wound closure was 100% after 3 days of treatment. Increase in hydrophilicity of the surface engineered and growth factors conjugated PLA microspheres provides favorable surface for cellular attachment of osteoblast, which was reflected by positive DAPI staining of the cells' nucleus. Surface modified and growth factors conjugated PLA microspheres were also able to enhance the capability of the PLA in facilitating the differentiation process of mesenchymal stem cells (MSCs) into osteogenic lineage since only positive stain was observed on surface engineered and growth factors conjugated PLA microspheres. These results indicated that the surface engineered and growth factors conjugated PLA microspheres were non-toxic for biological environments and the improved hydrophilicity made them a potential candidate as a drug delivery vehicle as the cells can adhere, attach and proliferate inside it.
    Matched MeSH terms: Polyesters/chemistry*
  13. Kamath SM, Sridhar K, Jaison D, Gopinath V, Ibrahim BKM, Gupta N, et al.
    Sci Rep, 2020 10 23;10(1):18179.
    PMID: 33097770 DOI: 10.1038/s41598-020-74885-1
    Modulation of initial burst and long term release from electrospun fibrous mats can be achieved by sandwiching the drug loaded mats between hydrophobic layers of fibrous polycaprolactone (PCL). Ibuprofen (IBU) loaded PCL fibrous mats (12% PCL-IBU) were sandwiched between fibrous polycaprolactone layers during the process of electrospinning, by varying the polymer concentrations (10% (w/v), 12% (w/v)) and volume of coat (1 ml, 2 ml) in flanking layers. Consequently, 12% PCL-IBU (without sandwich layer) showed burst release of 66.43% on day 1 and cumulative release (%) of 86.08% at the end of 62 days. Whereas, sandwich groups, especially 12% PCLSW-1 & 2 (sandwich layers-1 ml and 2 ml of 12% PCL) showed controlled initial burst and cumulative (%) release compared to 12% PCL-IBU. Moreover, crystallinity (%) and hydrophobicity of the sandwich models imparted control on ibuprofen release from fibrous mats. Further, assay for cytotoxicity and scanning electron microscopic images of cell seeded mats after 5 days showed the mats were not cytotoxic. Nuclear Magnetic Resonance spectroscopic analysis revealed weak interaction between ibuprofen and PCL in nanofibers which favors the release of ibuprofen. These data imply that concentration and volume of coat in flanking layer imparts tighter control on initial burst and long term release of ibuprofen.
    Matched MeSH terms: Polyesters/chemistry*
  14. Mohamad N, Mazlan MM, Tawakkal ISMA, Talib RA, Kian LK, Fouad H, et al.
    Int J Biol Macromol, 2020 Nov 15;163:1451-1457.
    PMID: 32738328 DOI: 10.1016/j.ijbiomac.2020.07.209
    The growing global awareness for environmental protection has inspired the exploration on producing active packaging films from bio-based materials. In present work, three types of active agents were studied by incorporating thymol(T), kesum(K), and curry(C) (10% wt.) into polylactic acid (PLA) to produce PLA-10T, PLA-10K, and PLA10-C packaging films via solvent casting method. The morphology, functional chemistry, thermal stability, permeability, and antimicrobial properties were evaluated for PLA films. Functional chemical analysis confirmed the presence of interfacial bonding between aromatic groups of active agents and PLA carbonyl group. PLA-10K exhibited the highest thermal resistance comparing to PLA-10T and PLA-10C while water vapor barrier was enhanced after incorporation of active agents. Qualitative observation had indicated that chicken meat could be preserved in the active films until 15 days, while odourless and firm texture properties retained in food sample. For disc diffusion assay (in vitro), it showed positive results against Gram-positive bacteria (Staphylococcus aureus) whereas with negative results against Gram-negative bacteria (Escherichia coli) and Aspergillus Brasiliensis due to embedded active agents within PLA matrix. We concluded that produced active agents filled PLA films potential to use in food packaging application to enhance the shelf life of meats, fruits and vegetables product.
    Matched MeSH terms: Polyesters/chemistry*
  15. Abudula T, Gauthaman K, Mostafavi A, Alshahrie A, Salah N, Morganti P, et al.
    Sci Rep, 2020 11 24;10(1):20428.
    PMID: 33235239 DOI: 10.1038/s41598-020-76971-w
    Non-healing wounds have placed an enormous stress on both patients and healthcare systems worldwide. Severe complications induced by these wounds can lead to limb amputation or even death and urgently require more effective treatments. Electrospun scaffolds have great potential for improving wound healing treatments by providing controlled drug delivery. Previously, we developed fibrous scaffolds from complex carbohydrate polymers [i.e. chitin-lignin (CL) gels]. However, their application was limited by solubility and undesirable burst drug release. Here, a coaxial electrospinning is applied to encapsulate the CL gels with polycaprolactone (PCL). Presence of a PCL shell layer thus provides longer shelf-life for the CL gels in a wet environment and sustainable drug release. Antibiotics loaded into core-shell fibrous platform effectively inhibit both gram-positive and -negative bacteria without inducting observable cytotoxicity. Therefore, PCL coated CL fibrous gel platforms appear to be good candidates for controlled drug release based wound dressing applications.
    Matched MeSH terms: Polyesters/chemistry*
  16. Samrot AV, Sean TC, Kudaiyappan T, Bisyarah U, Mirarmandi A, Faradjeva E, et al.
    Int J Biol Macromol, 2020 Dec 15;165(Pt B):3088-3105.
    PMID: 33098896 DOI: 10.1016/j.ijbiomac.2020.10.104
    Chitosan, collagen, gelatin, polylactic acid and polyhydroxyalkanoates are notable examples of biopolymers, which are essentially bio-derived polymers produced by living cells. With the right techniques, these biological macromolecules can be exploited for nanotechnological advents, including for the fabrication of nanocarriers. In the world of nanotechnology, it is highly essential (and optimal) for nanocarriers to be biocompatible, biodegradable and non-toxic for safe in vivo applications, including for drug delivery, cancer immunotherapy, tissue engineering, gene delivery, photodynamic therapy and many more. The recent advancements in understanding nanotechnology and the physicochemical properties of biopolymers allows us to modify biological macromolecules and use them in a multitude of fields, most notably for clinical and therapeutic applications. By utilizing chitosan, collagen, gelatin, polylactic acid, polyhydroxyalkanoates and various other biopolymers as synthesis ingredients, the 'optimal' properties of a nanocarrier can easily be attained. With emphasis on the aforementioned biological macromolecules, this review presents the various biopolymers utilized for nanocarrier synthesis along with their specific synthetization methods. We further discussed on the characterization techniques and related applications for the synthesized nanocarriers.
    Matched MeSH terms: Polyesters/chemistry*
  17. Sayyed RZ, Wani SJ, Alarfaj AA, Syed A, El-Enshasy HA
    PLoS One, 2020;15(1):e0220095.
    PMID: 31910206 DOI: 10.1371/journal.pone.0220095
    There are numerous reports on poly-β-hydroxybutyrate (PHB) depolymerases produced by various microorganisms isolated from various habitats, however, reports on PHB depolymerase production by an isolate from plastic rich sites scares. Although PHB has attracted commercial significance, the inefficient production and recovery methods, inefficient purification of PHB depolymerase and lack of ample knowledge on PHB degradation by PHB depolymerase have hampered its large scale commercialization. Therefore, to ensure the biodegradability of biopolymers, it becomes imperative to study the purification of the biodegrading enzyme system. We report the production, purification, and characterization of extracellular PHB depolymerase from Stenotrophomonas sp. RZS7 isolated from a dumping yard rich in plastic waste. The isolate produced extracellular PHB depolymerase in the mineral salt medium (MSM) at 30°C during 4 days of incubation under shaking. The enzyme was purified by three methods namely ammonium salt precipitation, column chromatography, and solvent purification. Among these purification methods, the enzyme was best purified by column chromatography on the Octyl-Sepharose CL-4B column giving optimum yield (0.7993 Umg-1mL-1). The molecular weight of purified PHB depolymerase was 40 kDa. Studies on the assessment of biodegradation of PHB in liquid culture medium and under natural soil conditions confirmed PHB biodegradation potential of Stenotrophomonas sp. RZS7. The results obtained in Fourier-Transform Infrared (FTIR) analysis, High-Performance Liquid Chromatography (HPLC) study and Gas Chromatography Mass-Spectrometry (GC-MS) analysis confirmed the biodegradation of PHB in liquid medium by Stenotrophomonas sp. RZS7. Changes in surface morphology of PHB film in soil burial as observed in Field Emission Scanning Electron Microscopy (FESEM) analysis confirmed the biodegradation of PHB under natural soil environment. The isolate was capable of degrading PHB and it resulted in 87.74% biodegradation. A higher rate of degradation under the natural soil condition is the result of the activity of soil microbes that complemented the biodegradation of PHB by Stenotrophomonas sp. RZS7.
    Matched MeSH terms: Polyesters/chemistry*
  18. Trakunjae C, Boondaeng A, Apiwatanapiwat W, Kosugi A, Arai T, Sudesh K, et al.
    Sci Rep, 2021 01 21;11(1):1896.
    PMID: 33479335 DOI: 10.1038/s41598-021-81386-2
    Poly-β-hydroxybutyrate (PHB) is a biodegradable polymer, synthesized as carbon and energy reserve by bacteria and archaea. To the best of our knowledge, this is the first report on PHB production by a rare actinomycete species, Rhodococcus pyridinivorans BSRT1-1. Response surface methodology (RSM) employing central composite design, was applied to enhance PHB production in a flask scale. A maximum yield of 3.6 ± 0.5 g/L in biomass and 43.1 ± 0.5 wt% of dry cell weight (DCW) of PHB were obtained when using RSM optimized medium, which was improved the production of biomass and PHB content by 2.5 and 2.3-fold, respectively. The optimized medium was applied to upscale PHB production in a 10 L stirred-tank bioreactor, maximum biomass of 5.2 ± 0.5 g/L, and PHB content of 46.8 ± 2 wt% DCW were achieved. Furthermore, the FTIR and 1H NMR results confirmed the polymer as PHB. DSC and TGA analysis results revealed the melting, glass transition, and thermal decomposition temperature of 171.8, 4.03, and 288 °C, respectively. In conclusion, RSM can be a promising technique to improve PHB production by a newly isolated strain of R. pyridinivorans BSRT1-1 and the properties of produced PHB possessed similar properties compared to commercial PHB.
    Matched MeSH terms: Polyesters/chemistry*
  19. Rizal S, Saharudin NI, Olaiya NG, Khalil HPSA, Haafiz MKM, Ikramullah I, et al.
    Molecules, 2021 Apr 01;26(7).
    PMID: 33916094 DOI: 10.3390/molecules26072008
    The degradation and mechanical properties of potential polymeric materials used for green manufacturing are significant determinants. In this study, cellulose nanofibre was prepared from Schizostachyum brachycladum bamboo and used as reinforcement in the PLA/chitosan matrix using melt extrusion and compression moulding method. The cellulose nanofibre(CNF) was isolated using supercritical carbon dioxide and high-pressure homogenisation. The isolated CNF was characterised with transmission electron microscopy (TEM), FT-IR, zeta potential and particle size analysis. The mechanical, physical, and degradation properties of the resulting biocomposite were studied with moisture content, density, thickness swelling, tensile, flexural, scanning electron microscopy, thermogravimetry, and biodegradability analysis. The TEM, FT-IR, and particle size results showed successful isolation of cellulose nanofibre using this method. The result showed that the physical, mechanical, and degradation properties of PLA/chitosan/CNF biocomposite were significantly enhanced with cellulose nanofibre. The density, thickness swelling, and moisture content increased with the addition of CNF. Also, tensile strength and modulus; flexural strength and modulus increased; while the elongation reduced. The carbon residue from the thermal degradation and the glass transition temperature of the PLA/chitosan/CNF biocomposite was observed to increase with the addition of CNF. The result showed that the biocomposite has potential for green and sustainable industrial application.
    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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