Displaying publications 1 - 20 of 83 in total

  1. Abdolmohammadi S, Siyamak S, Ibrahim NA, Yunus WM, Rahman MZ, Azizi S, et al.
    Int J Mol Sci, 2012;13(4):4508-22.
    PMID: 22605993 DOI: 10.3390/ijms13044508
    This study investigates the effects of calcium carbonate (CaCO(3)) nanoparticles on the mechanical and thermal properties and surface morphology of polycaprolactone (PCL)/chitosan nanocomposites. The nanocomposites of PCL/chitosan/CaCO(3) were prepared using a melt blending technique. Transmission electron microscopy (TEM) results indicate the average size of nanoparticles to be approximately 62 nm. Tensile measurement results show an increase in the tensile modulus with CaCO(3) nanoparticle loading. Tensile strength and elongation at break show gradual improvement with the addition of up to 1 wt% of nano-sized CaCO(3). Decreasing performance of these properties is observed for loading of more than 1 wt% of nano-sized CaCO(3). The thermal stability was best enhanced at 1 wt% of CaCO(3) nanoparticle loading. The fractured surface morphology of the PCL/chitosan blend becomes more stretched and homogeneous in PCL/chitosan/CaCO(3) nanocomposite. TEM micrograph displays good dispersion of CaCO(3) at lower nanoparticle loading within the matrix.
    Matched MeSH terms: Polyesters/chemistry*
  2. Abdullah BM, Zubairi SI, Huri HZ, Hairunisa N, Yousif E, Basu RC
    PLoS One, 2016;11(3):e0151603.
    PMID: 27008312 DOI: 10.1371/journal.pone.0151603
    Presently, plant oils which contain high percentage of linoleic acid 1 are perceived to be a viable alternative to mineral oil for biolubricant applications due to their biodegradability and technical properties. In order to get biodegradable lubricant, triester derivatives compounds (1-5) were synthesized and characterized. The processes involved were monoepoxidation of linoleic acid 2, oxirane ring opening 3, esterification 4 and acylation 5. The structures of the products were confirmed by FTIR, 1H and 13C-NMR and LC-MS. The results that showed lowest temperature properties were obtained for triester 5, with a pour point value (PP) of -73°C, highest onset temperature (260°C) and lowest volatility at 0.30%. Viscosity index (VI) increased for the ester's synthetic compounds (2, 3, 4, 5), while the PP decreased. This behavior is the result of the increase of the chain length of the branching agents. Triester based linoleic acid has improved properties such as low-temperature and tribological properties. These results will make it feasible for plant oil to be used for biolubricants, fuels in chain saws, transmission oil and brake fluid.
    Matched MeSH terms: Polyesters/chemistry*
  3. 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*
  4. Ahmad AF, Abbas Z, Obaiys SJ, Ibrahim N, Hashim M, Khaleel H
    PLoS One, 2015;10(10):e0140505.
    PMID: 26474301 DOI: 10.1371/journal.pone.0140505
    Bio-composites of oil palm empty fruit bunch (OPEFB) fibres and polycaprolactones (PCL) with a thickness of 1 mm were prepared and characterized. The composites produced from these materials are low in density, inexpensive, environmentally friendly, and possess good dielectric characteristics. The magnitudes of the reflection and transmission coefficients of OPEFB fibre-reinforced PCL composites with different percentages of filler were measured using a rectangular waveguide in conjunction with a microwave vector network analyzer (VNA) in the X-band frequency range. In contrast to the effective medium theory, which states that polymer-based composites with a high dielectric constant can be obtained by doping a filler with a high dielectric constant into a host material with a low dielectric constant, this paper demonstrates that the use of a low filler percentage (12.2%OPEFB) and a high matrix percentage (87.8%PCL) provides excellent results for the dielectric constant and loss factor, whereas 63.8% filler material with 36.2% host material results in lower values for both the dielectric constant and loss factor. The open-ended probe technique (OEC), connected with the Agilent vector network analyzer (VNA), is used to determine the dielectric properties of the materials under investigation. The comparative approach indicates that the mean relative error of FEM is smaller than that of NRW in terms of the corresponding S21 magnitude. The present calculation of the matrix/filler percentages endorses the exact amounts of substrate utilized in various physics applications.
    Matched MeSH terms: Polyesters/chemistry*
  5. Al-Namnam NM, Kutty MG, Chai WL, Ha KO, Kim KH, Siar CH, et al.
    Mater Sci Eng C Mater Biol Appl, 2017 Mar 01;72:332-340.
    PMID: 28024594 DOI: 10.1016/j.msec.2016.11.086
    Recently, a modified form of a three-dimension (3D) porous poly(caprolactone-trifumarate) (PCLTF) scaffold has been produced using a fabrication technique that involves gelatin microparticles porogen leaching. This poly(caprolactone trifumarate-gelatin microparticles) (PCLTF-GMPs) scaffold has been shown to be biocompatible, more flowable clinically, and has a shorter degradation time as compared to its existing predecessors. In this report, a detailed characterization of this new scaffold was performed by testing its cytocompatibility, analyzing the surface topography, and understanding its thermal, physical and mechanical properties. The result showed that the PCLTF-GMPs has no critical cytotoxic effect. To confirm improvement, the surface properties were compared against the older version of PCLTF fabricated using salt porogen leaching. This PCLTF-GMPs scaffold showed no significant difference (unpaired t-test; p>0.05) in mechanical properties before and after gelatin leaching. However, it is mechanically weaker when compared to its predecessors. It has a high biodegradability rate of 16weeks. The pore size produced ranges from 40 to 300μm, and the RMS roughness is 613.7±236.9nm. These characteristics are condusive for osteoblast in-growth, as observed by the extension of filopodia across the macropores. Overall, this newly produced material has good thermal, physical and mechanical properties that complements its biocompatibility and ease of use.
    Matched MeSH terms: Polyesters/chemistry*
  6. Ali Akbari Ghavimi S, Ebrahimzadeh MH, Solati-Hashjin M, Abu Osman NA
    J Biomed Mater Res A, 2015 Jul;103(7):2482-98.
    PMID: 25407786 DOI: 10.1002/jbm.a.35371
    Interests in the use of biodegradable polymers as biomaterials have grown. Among the different polymeric composites currently available, the blend of starch and polycaprolactone (PCL) has received the most attention since the 1980s. Novamont is the first company that manufactured a PCL/starch (SPCL) composite under the trademark Mater-Bi®. The properties of PCL (a synthetic, hydrophobic, flexible, expensive polymer with a low degradation rate) and starch (a natural, hydrophilic, stiff, abundant polymer with a high degradation rate) blends are interesting because of the composite components have completely different structures and characteristics. PCL can adjust humidity sensitivity of starch as a biomaterial; while starch can enhance the low biodegradation rate of PCL. Thus, by appropriate blending, SPCL can overcome important limitations of both PCL and starch components and promote controllable behavior in terms of mechanical properties and degradation which make it suitable for many biomedical applications. This article reviewed the different fabrication and modification methods of the SPCL composite; different properties such as structural, physical, and chemical as well as degradation behavior; and different applications as biomaterials.
    Matched MeSH terms: Polyesters/chemistry
  7. Almoustafa HA, Alshawsh MA, Chik Z
    Int J Pharm, 2017 Nov 25;533(1):275-284.
    PMID: 28943210 DOI: 10.1016/j.ijpharm.2017.09.054
    Nanoprecipitation is a simple and increasingly trending method for nanoparticles preparation. The self-assembly feature of poly (ethylene glycol)-poly (lactide-co-glycolic acid) (PEG-PLGA) amphiphilic copolymer into a nanoparticle and its versatile structure makes nanoprecipitation one of the best methods for its preparation. The aim of this study is to review currently available literature for standard preparation of PEG-PLGA nanoparticles using nanoprecipitation technique in order to draw conclusive evidenceto draw conclusive evidence that can guide researchers during formulation development. To achieve this, three databases (Web of Science, Scopus and PubMed) were searched using relevant keywords and the extracted articles were reviewed based on defined inclusion and exclusion criteria. Data extraction and narrative analysis of the obtained literature was performed when appropriate, along with our laboratory observations to support those claims wherever necessary. As a result of this analysis, reports that matched our criteria conformed to the general facts about nanoprecipitation techniques such as simplicity in procedure, low surfactants requirement, narrow size distribution, and low resulting concentrations. However, these reports showed interesting advantages for using PEG-PLGA as they are frequently reported to be freeze-dried and active pharmaceutical ingredients (APIs) with low hydrophobicity were reported to successfully be encapsulated in the particles.
    Matched MeSH terms: Polyesters/chemistry*
  8. 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*
  9. Ansari NF, Amirul AA
    Appl Biochem Biotechnol, 2013 Jun;170(3):690-709.
    PMID: 23604967 DOI: 10.1007/s12010-013-0216-0
    Polyhydroxyalkanoates (PHAs) are hydrophobic biodegradable thermoplastics that have received considerable attention in biomedical applications due to their biocompatibility, mechanical properties, and biodegradability. In this study, the degradation rate was regulated by optimizing the interaction of parameters that influence the enzymatic degradation of P(3HB) film using response surface methodology (RSM). The RSM model was experimentally validated yielding a maximum 21 % weight loss, which represents onefold increment in percentage weight loss in comparison with the conventional method. By using the optimized condition, the enzymatic degradation by an extracellular PHA depolymerase from Acidovorax sp. DP5 was studied at 37 °C and pH 9.0 on different types of PHA films with various monomer compositions. Surface modification of scaffold was employed using enzymatic technique to create highly porous scaffold with a large surface to volume ratio, which makes them attractive as potential tissue scaffold in biomedical field. Scanning electron microscopy revealed that the surface of salt-leached films was more porous compared with the solvent-cast films, and hence, increased the degradation rate of salt-leached films. Apparently, enzymatic degradation behaviors of PHA films were determined by several factors such as monomer composition, crystallinity, molecular weight, porosity, and roughness of the surface. The hydrophilicity and water uptake of degraded salt-leached film of P(3HB-co-70%4HB) were enhanced by incorporating chitosan or alginate. Salt-leached technique followed by partial enzymatic degradation would enhance the cell attachment and suitable for biomedical as a scaffold.
    Matched MeSH terms: Polyesters/chemistry
  10. Ariffin H, Nishida H, Hassan MA, Shirai Y
    Biotechnol J, 2010 May;5(5):484-92.
    PMID: 20408140 DOI: 10.1002/biot.200900293
    Chemical recycling of bio-based polymers polyhydroxyalkanoates (PHAs) by thermal degradation was investigated from the viewpoint of biorefinery. The thermal degradation resulted in successful transformation of PHAs into vinyl monomers using alkali earth compound (AEC) catalysts. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)s (PHBVs) were smoothly and selectively depolymerized into crotonic (CA) and 2-pentenoic (2-PA) acids at lower degradation temperatures in the presence of CaO and Mg(OH)(2) as catalysts. Obtained CA from 3-hydroxybutyrate sequences in PHBV was copolymerized with acrylic acid to produce useful water-soluble copolymers, poly(crotonic acid-co-acrylic acid) that have high glass-transition temperatures. The copolymerization of CA derived from PHA pyrolysis is an example of cascade utilization of PHAs, which meets the idea of sustainable development.
    Matched MeSH terms: Polyesters/chemistry*
  11. Baba Ismail YM, Ferreira AM, Bretcanu O, Dalgarno K, El Haj AJ
    Colloids Surf B Biointerfaces, 2017 Nov 01;159:445-453.
    PMID: 28837894 DOI: 10.1016/j.colsurfb.2017.07.086
    This paper presents a new approach in assembling bone extracellular matrix components onto PLA films, and investigates the most favourable environment which can be created using the technique for cell-material interactions. Poly (lactic acid) (PLA) films were chemically modified by covalently binding the poly(ethylene imine) (PEI) as to prepare the substrate for immobilization of polyelectrolyte multilayers (PEMs) coating. Negatively charged polyelectrolyte consists of well-dispersed silicon-carbonated hydroxyapatite (SiCHA) nanopowders in hyaluronic acid (Hya) was deposited onto the modified PLA films followed by SiCHA in collagen type I as the positively charged polyelectrolyte. The outermost layer was finally cross-linked by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrocholoride and N-hydroxysulfosuccinimide sodium salt (EDC/NHS) solutions. The physicochemical features of the coated PLA films were monitored via X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscope (AFM). The amounts of calcium and collagen deposited on the surface were qualitatively and quantitatively determined. The surface characterizations suggested that 5-BL has the optimum surface roughness and highest amounts of calcium and collagen depositions among tested films. In vitro human mesenchymal stem cells (hMSCs) cultured on the coated PLA films confirmed that the coating materials greatly improved cell attachment and survival compared to unmodified PLA films. The cell viability, cell proliferation and Alkaline Phosphatase (ALP) expression on 5-BL were found to be the most favourable of the tested films. Hence, this newly developed coating materials assembly could contribute to the improvement of the bioactivity of polymeric materials and structures aimed to bone tissue engineering applications.
    Matched MeSH terms: Polyesters/chemistry*
  12. 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*
  13. Bakhsheshi-Rad HR, Hamzah E, Kasiri-Asgarani M, Jabbarzare S, Iqbal N, Abdul Kadir MR
    Mater Sci Eng C Mater Biol Appl, 2016 Mar;60:526-537.
    PMID: 26706560 DOI: 10.1016/j.msec.2015.11.057
    The present study addressed the synthesis of a bi-layered nanostructured fluorine-doped hydroxyapatite (nFHA)/polycaprolactone (PCL) coating on Mg-2Zn-3Ce alloy via a combination of electrodeposition (ED) and dip-coating methods. The nFHA/PCL composite coating is composed of a thick (70-80 μm) and porous layer of PCL that uniformly covered the thin nFHA film (8-10 μm) with nanoneedle-like microstructure and crystallite size of around 70-90 nm. Electrochemical measurements showed that the nFHA/PCL composite coating presented a high corrosion resistance (R(p)=2.9×10(3) kΩ cm(2)) and provided sufficient protection for a Mg substrate against galvanic corrosion. The mechanical integrity of the nFHA/PCL composite coatings immersed in SBF for 10 days showed higher compressive strength (34% higher) compared with the uncoated samples, indicating that composite coatings can delay the loss of compressive strength of the Mg alloy. The nFHA/PCL coating indicted better bonding strength (6.9 MPa) compared to PCL coating (2.2 MPa). Immersion tests showed that nFHA/PCL composite-coated alloy experienced much milder corrosion attack and more nucleation sites for apatite compared with the PCL coated and uncoated samples. The bi-layered nFHA/PCL coating can be a good alternative method for the control of corrosion degradation of biodegradable Mg alloy for implant applications.
    Matched MeSH terms: Polyesters/chemistry*
  14. Bang LT, Ramesh S, Purbolaksono J, Long BD, Chandran H, Ramesh S, et al.
    Biomed Mater, 2015 Aug;10(4):045011.
    PMID: 26225725 DOI: 10.1088/1748-6041/10/4/045011
    Interconnected porous tricalcium phosphate ceramics are considered to be potential bone substitutes. However, insufficient mechanical properties when using tricalcium phosphate powders remain a challenge. To mitigate these issues, we have developed a new approach to produce an interconnected alpha-tricalcium phosphate (α-TCP) scaffold and to perform surface modification on the scaffold with a composite layer, which consists of hybrid carbonate apatite / poly-epsilon-caprolactone (CO3Ap/PCL) with enhanced mechanical properties and biological performance. Different CO3Ap combinations were tested to evaluate the optimal mechanical strength and in vitro cell response of the scaffold. The α-TCP scaffold coated with CO3Ap/PCL maintained a fully interconnected structure with a porosity of 80% to 86% and achieved an improved compressive strength mimicking that of cancellous bone. The addition of CO3Ap coupled with the fully interconnected microstructure of the α-TCP scaffolds coated with CO3Ap/PCL increased cell attachment, accelerated proliferation and resulted in greater alkaline phosphatase (ALP) activity. Hence, our bone substitute exhibited promising potential for applications in cancellous bone-type replacement.
    Matched MeSH terms: Polyesters/chemistry*
  15. Castro-Aguirre E, Iñiguez-Franco F, Samsudin H, Fang X, Auras R
    Adv Drug Deliv Rev, 2016 12 15;107:333-366.
    PMID: 27046295 DOI: 10.1016/j.addr.2016.03.010
    Global awareness of material sustainability has increased the demand for bio-based polymers like poly(lactic acid) (PLA), which are seen as a desirable alternative to fossil-based polymers because they have less environmental impact. PLA is an aliphatic polyester, primarily produced by industrial polycondensation of lactic acid and/or ring-opening polymerization of lactide. Melt processing is the main technique used for mass production of PLA products for the medical, textile, plasticulture, and packaging industries. To fulfill additional desirable product properties and extend product use, PLA has been blended with other resins or compounded with different fillers such as fibers, and micro- and nanoparticles. This paper presents a review of the current status of PLA mass production, processing techniques and current applications, and also covers the methods to tailor PLA properties, the main PLA degradation reactions, PLA products' end-of-life scenarios and the environmental footprint of this unique polymer.
    Matched MeSH terms: Polyesters/chemistry*
  16. Chang HC, Sun T, Sultana N, Lim MM, Khan TH, Ismail AF
    Mater Sci Eng C Mater Biol Appl, 2016 Apr 1;61:396-410.
    PMID: 26838866 DOI: 10.1016/j.msec.2015.12.074
    In the current study, electrospinning technique was used to fabricate composite membranes by blending of a synthetic polymer, polylactic acid (PLA) and a natural polymer, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), PHBV. Conductive membranes were prepared by dipping PLA/PHBV electrospun membranes into poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (
    Matched MeSH terms: Polyesters/chemistry*
  17. Chee JW, Amirul AA, Majid MI, Mansor SM
    Int J Pharm, 2008 Sep 1;361(1-2):1-6.
    PMID: 18584978 DOI: 10.1016/j.ijpharm.2008.05.007
    Copolyesters of 3-hydroxybutyrate (3HB) and 4-hydroxybutyrate (4HB) were produced by Cupriavidus sp. (USMAA2-4) (DSM 19379) from carbon sources of 1,4-butanediol and gamma-butyrolactone. The composition of copolyesters produced varied from 0 to 45 mol% 4HB, depending on the combination of carbon sources supplied. The P(3HB-co-4HB) films containing Mitragyna speciosa crude extract were prepared with the ratio varying from 10 to 40% (w/w). The in vitro crude extract release of the films was studied in 0.1M phosphate buffer (pH 7.4) at 37 degrees C. Although the release rate was slow, it was maintained at a constant rate. This suggests that the crude extract release was due to the polymer degradation because the amount of crude extract released was consistent. The amount of degradation was based on the films' dry weight loss, decrease in molecular weight and surface morphology changes. The degradation rate increased with the 4HB content. This showed that the polymer degradation is dependant on the molecular weight, crystallinity, thermal properties and water permeability. The different drug loading ratio which led to surface morphology changes also gave an effect on polymer degradation.
    Matched MeSH terms: Polyesters/chemistry*
  18. Dasan YK, Bhat AH, Ahmad F
    Carbohydr Polym, 2017 Feb 10;157:1323-1332.
    PMID: 27987839 DOI: 10.1016/j.carbpol.2016.11.012
    The current research discusses the development of poly (lactic acid) (PLA) and poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) reinforced nanocrystalline cellulose bionanocomposites. The nanocrystalline cellulose was derived from waste oil palm empty fruit bunch fiber by acid hydrolysis process. The resulting nanocrystalline cellulose suspension was then surface functionalized by TEMPO-mediated oxidation and solvent exchange process. Furthermore, the PLA/PHBV/nanocrystalline cellulose bionanocomposites were produced by solvent casting method. The effect of the addition of nanocrystalline cellulose on structural, morphology, mechanical and barrier properties of bionanocomposites was investigated. The results revealed that the developed bionanocomposites showed improved mechanical properties and decrease in oxygen permeability rate. Therefore, the developed bio-based composite incorporated with an optimal composition of nanocrystalline cellulose exhibits properties as compared to the polymer blend.
    Matched MeSH terms: Polyesters/chemistry*
  19. Eng CC, Ibrahim NA, Zainuddin N, Ariffin H, Yunus WM
    ScientificWorldJournal, 2014;2014:213180.
    PMID: 25254230 DOI: 10.1155/2014/213180
    Natural fiber as reinforcement filler in polymer composites is an attractive approach due to being fully biodegradable and cheap. However, incompatibility between hydrophilic natural fiber and hydrophobic polymer matrix restricts the application. The current studies focus on the effects of incorporation of silane treated OPMF into polylactic acid (PLA)/polycaprolactone (PCL)/nanoclay/OPMF hybrid composites. The composites were prepared by melt blending technique and characterize the composites with Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). FTIR spectra indicated that peak shifting occurs when silane treated OPMF was incorporated into hybrid composites. Based on mechanical properties results, incorporation of silane treated OPMF enhances the mechanical properties of unmodified OPMF hybrid composites with the enhancement of flexural and impact strength being 17.60% and 48.43%, respectively, at 10% fiber loading. TGA thermogram shows that incorporation of silane treated OPMF did not show increment in thermal properties of hybrid composites. SEM micrographs revealed that silane treated OPMF hybrid composites show good fiber/matrix adhesion as fiber is still embedded in the matrix and no cavity is present on the surface. Water absorption test shows that addition of less hydrophilic silane treated OPMF successfully reduces the water uptake of hybrid composites.
    Matched MeSH terms: Polyesters/chemistry
  20. 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
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