We examined the potential of virgin coconut oil (VCO) incorporated in gellan gum (GG) films as a dressing material. Pure GG film is extremely brittle and inclusion of 0.3% (w/w) VCO in the GG film (GG-VCO3) improved the toughness (?J?g?1) of the composite films. Swelling properties and water vapor transmission rates of GG-VCO composite films decreased, whereas thermal behavior values increased upon the addition of higher concentrations of VCO. Cell studies exhibit that the VCO is noncytotoxic to human skin fibroblast cells (CRL2522) with limited cell growth observed on GG-VCO3 films at 1,650 cells/well after incubation for 72?h which could be due to hydrophobic influence of the material surface. The qualitative and in vitro quantitative antibacterial results revealed that VCO does not possess strong bacterial resistance against all four tested bacteria, that is, two Gram-positive (Staphylococcus aureus and Staphylococcus epidermidis) and two Gram-negative bacteria (Pseudomonas aeruginosa and Proteus mirabilis). 1. Introduction The development of wound care materials continues to cater to the various different needs of damaged skin problems. Biopolymers such as gellan gum (GG) have received great attention, particularly in the field of biomedicine, due to their biocompatibility and biodegradability properties. Gellan gum is produced by Pseudomonas elodea and consists of a repeating unit of tetrasaccharide: 1,3-linked -D-glucose, 1,4-linked -D-glucuronic acid, 1,4-linked -D-glucose, and 1,4-linked -L-rhamnose. Gellan gum has been approved by the United States Food and Drug Administration (US FDA) and the European Union (EU) labels it as E 415 in EU regulation for the use in food industry. It is currently popular in the development of tissue engineering. Studies on medical and pharmaceutical applications of gellan gum have also been reported which include “dual layer films” [1], bioink substrates for printing living cells [2], use for dressing material [3], and use as a vehicle for ophthalmic drugs [4]. Besides that, gellan gum demonstrates good compatibility with live cells such as mouse fibroblast (L929 cell line), human dermal fibroblasts (HDFs), human fetal osteoblasts (hFOBs 1.19), human nasal cartilage, and rat bone marrow cells (rBMC) [1, 5–7]. On the other hand, virgin coconut oil (VCO) is one of the recent promising candidates in promoting healing process due to its biocompatibility property and antibacterial activities. Previous studies reported that pure VCO examined through in vivo test could enhance the healing process. Nevin and Rajamohan
References
[1]
K. A. Mat Amin, K. J. Gilmore, J. Matic et al., “Polyelectrolyte complex materials consisting of antibacterial and cell-supporting layers,” Macromolecular Bioscience, vol. 12, no. 3, pp. 374–382, 2012.
[2]
C. J. Ferris, K. J. Gilmore, S. Beirne, D. McCallum, G. G. Wallace, and M. In Het Panhuis, “Bio-ink for on-demand printing of living cells,” Biomaterials Science, vol. 1, no. 2, pp. 224–230, 2013.
[3]
M.-W. Lee, H.-J. Chen, and S.-W. Tsao, “Preparation, characterization and biological properties of Gellan gum films with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide cross-linker,” Carbohydrate Polymers, vol. 82, no. 3, pp. 920–926, 2010.
[4]
B. N. Singh and K. H. Kim, “Effects of divalent cations on drug encapsulation efficiency of deacylated gellan gum,” Journal of Microencapsulation, vol. 22, no. 7, pp. 761–771, 2005.
[5]
C. Wang, Y. Gong, Y. Lin, J. Shen, and D.-A. Wang, “A novel gellan gel-based microcarrier for anchorage-dependent cell delivery,” Acta Biomaterialia, vol. 4, no. 5, pp. 1226–1234, 2008.
[6]
J. T. Oliveira, T. C. Santos, L. Martins et al., “Gellan gum injectable hydrogels for cartilage tissue engineering applications: in vitro studies and preliminary in vivo evaluation,” Tissue Engineering—Part A, vol. 16, no. 1, pp. 343–353, 2010.
[7]
A. M. Smith, R. M. Shelton, Y. Perrie, and J. J. Harris, “An initial evaluation of gellan gum as a material for tissue engineering applications,” Journal of Biomaterials Applications, vol. 22, no. 3, pp. 241–254, 2007.
[8]
K. G. Nevin and T. Rajamohan, “Effect of topical application of virgin coconut oil on skin components and antioxidant status during dermal wound healing in young rats,” Skin Pharmacology and Physiology, vol. 23, no. 6, pp. 290–297, 2010.
[9]
S. Intahphuak, P. Khonsung, and A. Panthong, “Anti-inflammatory, analgesic, and antipyretic activities of virgin coconut oil,” Pharmaceutical Biology, vol. 48, no. 2, pp. 151–157, 2010.
[10]
Z. A. Zakaria, M. N. Somchit, A. M. Mat Jais, L. K. Teh, M. Z. Salleh, and K. Long, “In vivo antinociceptive and anti-inflammatory activities of dried and fermented processed virgin coconut oil,” Medical Principles and Practice, vol. 20, no. 3, pp. 231–236, 2011.
[11]
M. Shilling, L. Matt, E. Rubin et al., “Antimicrobial effects of virgin coconut oil and its medium-chain fatty acids on clostridium difficile,” Journal of Medicinal Food, vol. 16, no. 12, pp. 1079–1085, 2013.
[12]
C. L. Hawkins and M. J. Davies, “Degradation of hyaluronic acid, poly- and monosaccharides, and model compounds by hypochlorite: evidence for radical intermediates and fragmentation,” Free Radical Biology and Medicine, vol. 24, no. 9, pp. 1396–1410, 1998.
[13]
U. N. Wanasundara, F. Shahidi, and C. R. Jablonski, “Comparison of standard and NMR methodologies for assessment of oxidative stability of canola and soybean oils,” Food Chemistry, vol. 52, no. 3, pp. 249–253, 1995.
[14]
A. Rohman, Y. B. Che Man, A. Ismail, and P. Hashim, “Application of FTIR spectroscopy for the determination of virgin coconut oil in binary mixtures with olive oil and palm oil,” JAOCS, Journal of the American Oil Chemists' Society, vol. 87, no. 6, pp. 601–606, 2010.
[15]
X. Xu, B. Li, J. F. Kennedy, B. J. Xie, and M. Huang, “Characterization of konjac glucomannan-gellan gum blend films and their suitability for release of nisin incorporated therein,” Carbohydrate Polymers, vol. 70, no. 2, pp. 192–197, 2007.
[16]
P. K. Binsi, C. N. Ravishankar, and T. K. Srinivasa Gopal, “Development and characterization of an edible composite film based on chitosan and virgin coconut oil with improved moisture sorption properties,” Journal of Food Science, vol. 78, no. 4, pp. E526–E534, 2013.
[17]
S. R. Sudhamani, M. S. Prasad, and K. Udaya Sankar, “DSC and FTIR studies on Gellan and polyvinyl alcohol (PVA) blend films,” Food Hydrocolloids, vol. 17, no. 3, pp. 245–250, 2003.
[18]
M. Milas, X. Shi, and M. Rinaudo, “On the physicochemical properties of gellan gum,” Biopolymers, vol. 30, no. 3-4, pp. 451–464, 1990.
[19]
R. Chandrasekaran and A. Radha, “Molecular architectures and functional properties of gellan gum and related polysaccharides,” Trends in Food Science and Technology, vol. 6, no. 5, pp. 143–148, 1995.
[20]
Z. Z. E. Sikorski and A. Kolakowska, Chemical and Functional Properties of Food Lipids, CRC Press, Boca Raton, Fla, USA, 2003.
[21]
C. L. Silva, J. C. Pereira, A. Ramalho, A. A. C. C. Pais, and J. J. S. Sousa, “Films based on chitosan polyelectrolyte complexes for skin drug delivery: development and characterization,” Journal of Membrane Science, vol. 320, no. 1-2, pp. 268–279, 2008.
[22]
J. T. Oliveira, L. Martins, R. Picciochi et al., “Gellan gum: a new biomaterial for cartilage tissue engineering applications,” Journal of Biomedical Materials Research Part A, vol. 93, no. 3, pp. 852–863, 2010.
[23]
P. Wu, A. C. Fisher, P. P. Foo, D. Queen, and J. D. S. Gaylor, “In vitro assessment of water vapour transmission of synthetic wound dressings,” Biomaterials, vol. 16, no. 3, pp. 171–175, 1995.
[24]
C. G. T. Neto, J. A. Giacometti, A. E. Job, F. C. Ferreira, J. L. C. Fonseca, and M. R. Pereira, “Thermal analysis of chitosan based networks,” Carbohydrate Polymers, vol. 62, no. 2, pp. 97–103, 2005.
[25]
J. Ostrowska-Czubenko and M. Gierszewska-Druzyńska, “Effect of ionic crosslinking on the water state in hydrogel chitosan membranes,” Carbohydrate Polymers, vol. 77, no. 3, pp. 590–598, 2009.
[26]
F. Freitas, V. D. Alves, J. Pais et al., “Characterization of an extracellular polysaccharide produced by a Pseudomonas strain grown on glycerol,” Bioresource Technology, vol. 100, no. 2, pp. 859–865, 2009.
[27]
F. Lina, Z. Yue, Z. Jin, and Y. Guang, “Bacterial cellulose for skin repair materials,” in Biomedical Engineering—Frontiers and Challenges, pp. 249–274, 2011.
[28]
Y.-W. Wang, Q. Wu, and G.-Q. Chen, “Reduced mouse fibroblast cell growth by increased hydrophilicity of microbial polyhydroxyalkanoates via hyaluronan coating,” Biomaterials, vol. 24, no. 25, pp. 4621–4629, 2003.
[29]
D. E. Discher, P. Janmey, and Y.-L. Wang, “Tissue cells feel and respond to the stiffness of their substrate,” Science, vol. 310, no. 5751, pp. 1139–1143, 2005.
[30]
K. Hatano, H. Inoue, T. Kojo et al., “Effect of surface roughness on proliferation and alkaline phosphatase expression of rat calvarial cells cultured on polystyrene,” Bone, vol. 25, no. 4, pp. 439–445, 1999.
[31]
D. Campoccia, C. R. Arciola, M. Cervellati, M. C. Maltarello, and L. Montanaro, “In vitro behaviour of bone marrow-derived mesenchymal cells cultured on fluorohydroxyapatite-coated substrata with different roughness,” Biomaterials, vol. 24, no. 4, pp. 587–596, 2003.
[32]
A. N. Z. Limited, “New Zealand datasheet: arrow-norfloxacin,” A. N. Z. Limited, Ed., 2013.
[33]
D. O. Ogbolu, A. A. Oni, O. A. Daini, and A. P. Oloko, “In vitro antimicrobial properties of coconut oil on Candida species in Ibadan, Nigeria,” Journal of Medicinal Food, vol. 10, no. 2, pp. 384–387, 2007.
[34]
G. Bergsson, J. Arnfinnsson, ó. Steingrímsson, and H. Thormar, “In vitro killing of Candida albicans by fatty acids and monoglycerides,” Antimicrobial Agents and Chemotherapy, vol. 45, no. 11, pp. 3209–3212, 2001.
[35]
M. K. M. Nair, P. Vasudevan, T. Hoagland, and K. Venkitanarayanan, “Inactivation of Escherichia coli O157:H7 and Listeria monocytogenes in milk by caprylic acid and monocaprylin,” Food Microbiology, vol. 21, no. 5, pp. 611–616, 2004.
[36]
D. Altiok, E. Altiok, and F. Tihminlioglu, “Physical, antibacterial and antioxidant properties of chitosan films incorporated with thyme oil for potential wound healing applications,” Journal of Materials Science: Materials in Medicine, vol. 21, no. 7, pp. 2227–2236, 2010.
[37]
R. J. W. Lambert, P. N. Skandamis, P. J. Coote, and G.-J. E. Nychas, “A study of the minimum inhibitory concentration and mode of action of oregano essential oil, thymol and carvacrol,” Journal of Applied Microbiology, vol. 91, no. 3, pp. 453–462, 2001.