Studies were conducted to assess the percutaneous absorption of the triacyglycerols (TAGs), tocols and carotenoids present in crude and refined palm oil. In vitro experiments using upright Franz diffusion cells were employed to investigate the permeability of these compounds across full thickness human skin and into the receptor solution. Cetrimide, a cationic surfactant was chosen to be used as a solubilising agent in the receptor phase with an optimum concentration of 3.0 mg/mL and was able to provide sink conditions throughout the permeation. TAGs, tocols and carotenoids all permeated human skin from crude palm oil (CPO), whereas only TAGs permeated when refined palm oil (RPO) was used. Of the TAGs, oleic acid-containing TAGs was preferentially absorbed despite palmitic acid being the most prevalent fatty acid (FA) in TAGs. Tocols in the form of α-T3 showed the highest permeation followed by γ-T3, α-T and the lowest permeation was observed for δ-T3. Carotenoids (α-carotene and β-carotene) also showed an appreciable amount of permeation from CPO.
DNA is widely used in plant genetic and molecular biology studies. In this chapter, we describe how to extract DNA from wheat tissues. The tissue samples are ground to disrupt the cell wall. Then cetyltrimethylammonium bromide (CTAB) or sodium dodecyl sulfate (SDS) is used to disrupt the cell and nuclear membranes to release the DNA into solution. A reducing agent, β-mercaptoethanol, is added to break the disulfide bonds between the cysteine residues and to help remove the tanins and polyphenols. A high concentration of salt is employed to remove polysaccharides. Ethylenediaminetetraacetic acid (EDTA) stops DNase activity by chelating the magnesium ions. The nucleic acid solution is extracted with chloroform-isoamyl alcohol (24:1) or 6 M ammonium acetate. The DNA in aqueous phase is precipated with ethanol or isopropanol, which makes DNA less hydrophilic in the presence of sodium ions (Na+).
Channa striatus, a fresh water snakehead fish, is reported to enhance dermal wound healing. Biochemical components such as amino acids and fatty acids are important for the synthesis of collagen fibers during wound healing. Arachidonic acid, a precursor of prostaglandin plays a vital role in healing the wounds. Haruan (C. striatus) contains all the essential amino acids for wound healing particularly glycine as well as high contents of arachidonic acid and polyunsaturated fatty acids that can promote prostaglandin synthesis. In the present work we have studied the wound healing effect of C. striatus in Sprague-Dawley rats. Cream formulations having different haruan fish extract concentrations as the active ingredient were prepared and stabilized, and they were applied to the wounds. The healing of wounds was characterized by an increase in the tensile strength of the skin, determined on the 7th post-operative day in each case. Haruan treatment of wounds promotes remodeling of collagen, by the synthesis of inter- and intra-molecular protein crosslinking and thus produces a marked increase (P<0.05) in tensile strength as compared to the cetrimide treated group. On the basis of our experiment we conclude that C. striatus helps in wound healing as indicated by the increase in tensile strength. We hypothesise that this effect may be due to its high content of arachidonic acid, glycine and polyunsaturated fatty acids. The mechanism of wound healing will be investigated in future studies.
Keratins are a group of important proteins in skin and hair and as biomaterials they can provide desirable properties such as strength, biocompatibility, and moisture regaining and retaining. The aim of this work is to develop water-soluble keratin polypeptides from sheep wool and then explore how their surface adsorption behaves with and without surfactants. Successful preparation of keratin samples was demonstrated by identification of the key components from gel electrophoresis and the reproducible production of gram scale samples with and without SDS (sodium dodecylsulphate) during wool fibre dissolution. SDS micelles could reduce the formation of disulphide bonds between keratins during extraction, reducing inter-molecular crosslinking and improving keratin polypeptide solubility. However, Zeta potential measurements of the two polypeptide batches demonstrated almost identical pH dependent surface charge distributions with isoelectric points around pH 3.5, showing complete removal of SDS during purification by dialysis. In spite of different solubility from the two batches of keratin samples prepared, very similar adsorption and aggregation behavior was revealed from surface tension measurements and dynamic light scattering. Mixing of keratin polypeptides with SDS and C12TAB (dodecyltrimethylammonium bromide) led to the formation of keratin-surfactant complexes that were substantially more effective at reducing surface tension than the polypeptides alone, showing great promise in the delivery of keratin polypeptides via the surface active complexes. Neutron reflection measurements revealed the coexistence of surfactant and keratin polypeptides at the interface, thus providing the structural support to the observed surface tension changes associated with the formation of the surface active complexes.
Abstract Water quality in the dental unit waterlines (DUWLs) is important to the patients and dental health care personnel as they are at risk of being infected with opportunistic pathogens such as Pseudomonas or Legionella species. In this study, a total of 86 samples were collected from DUWLs of 19 dental units in 11 Malaysian Armed Forces dental centres (MAFDC). 350 ml water sample was collected in sterile thiosulphite bags from the outlets of 3–way syringe, high speed handpiece, scaler, cup filler, independent water reservoir or the tap of the same surgery respectively. Samples were transported to the laboratory within 24 hours and kept in the refrigerator at 40C. 100ml of each sample was filtered through a 0.45 μm polycarbonate membrane filter. The filter was then inoculated onto plate count agar and incubated at 370 C for 24 hours, after which the formed colonies were enumerated. Another separate 100ml of water sample was poured onto buffered charcoal yeast extract agar and cetrimide agar to culture Legionnella and Pseudomonas respectively. Identification of these bacteria were confirmed by polymerase chain reaction and sequencing. Pseudomonas aeruginosa was detected in 9.5% of the samples but Legionnella was not detected in any of the samples. 77% of the samples met American Dental Association (ADA) recommendation of less than 200 cfu/ml. The result of this study showed that it is difficult if not impossible to eliminate biofilm from the DUWLs. Regular monitor of water quality from DUWL is required to maximise the health of the dental patients and dental health care personnel.