Alghalayini, A, Jiang, L, Gu, X, Yeoh, GH, Cranfield, CG, Timchenko, V, Cornell, BA & Valenzuela, SM 2020, 'Real-time monitoring of heat transfer between gold nanoparticles and tethered bilayer lipid membranes.', Biochimica et biophysica acta. Biomembranes, vol. 1862, no. 9, p. 183334.View/Download from: Publisher's site
Plasmon resonance frequency irradiated gold nanoparticles (GNPs) have gained interest as a laser-targeted treatment for infections, tumors and for the controlled release of drugs in situ. Questions still remain, however, as to the efficiency of heat delivery within biological tissues and how this can be reliably determined. Here, we demonstrate how a nanomaterial-electrode interface that mimics cell membranes can detect the localized heat transfer characteristics arising from plasmon resonance frequency-matched laser excitation of GNPs. We demonstrate that the lipid bilayer membrane can be affected by conjugated GNP induced hyperthermia when irradiated with a laser power output as low as 135 nW/μm2. This is four orders of magnitude lower power than previously reported. By restricting the lateral movement of the lipids in the bilayer membrane, it was shown that the change in membrane conductance as a result of the heat transfer was due to the creation of transient lipidic toroidal pores within the membrane. We further demonstrate that the heat transfer from the GNPs alters diffusion rates of monomers of the gramicidin-A peptide within the lipid leaflets. This work highlights how targeted low laser power GNP hyperthermia treatments, in vivo, could play a dual role of interfering with both cell membrane morphology and dynamics, along with membrane protein function.
Liu, P & Separovic, F 2019, 'Membrane biophysics session', Biophysical Reviews, vol. 11, no. 3, pp. 283-284.View/Download from: Publisher's site
Alghalayini, A, Garcia, A, Berry, T & Cranfield, CG 2019, 'The Use of Tethered Bilayer Lipid Membranes to Identify the Mechanisms of Antimicrobial Peptide Interactions with Lipid Bilayers.', Antibiotics (Basel, Switzerland), vol. 8, no. 1.View/Download from: Publisher's site
This review identifies the ways in which tethered bilayer lipid membranes (tBLMs) can be used for the identification of the actions of antimicrobials against lipid bilayers. Much of the new research in this area has originated, or included researchers from, the southern hemisphere, Australia and New Zealand in particular. More and more, tBLMs are replacing liposome release assays, black lipid membranes and patch-clamp electrophysiological techniques because they use fewer reagents, are able to obtain results far more quickly and can provide a uniformity of responses with fewer artefacts. In this work, we describe how tBLM technology can and has been used to identify the actions of numerous antimicrobial agents.
Sameer, A-EI, Amany, GM, Abdela, AA & Fadel, SA 2009, 'CYP2C19 genotypes in a population of healthy volunteers and in children with hematological malignancies in Gaza Strip.', The Canadian journal of clinical pharmacology = Journal canadien de pharmacologie clinique, vol. 16, no. 1, pp. e156-e162.
Cytochrome P450 2C19 (CYP2C19) participates in the metabolism of many clinically important drugs and xenobiotic compounds. Genetic polymorphisms of the CYP2C19 gene are described to have possible effect on drug treatment and increasing susceptibility to carcinogenic substances. The aim of this study was to determine the frequencies of the common polymorphic CYP2C19 alleles (CYP2C19*2 and CYP2C19*3) in Gaza Strip population and to investigate their association with occurrence of childhood hematological malignancies as compared to healthy subjects.The polymorphism of CYP2C19 was analyzed by PCR-RFLP. DNA was extracted from blood samples obtained from 52 previously diagnosed hematological malignancy children and 200 normal subjects.In the patient group the frequencies of CYP2C19*2 and CYP2C19*3 were 9.62% and 0.96%, respectively; while in the control group the respective frequencies were 5.75% and 3%. There is no significant difference between the healthy and the patient groups in terms of the frequencies of CYP2C19*2 and CYP2C19*3. The genotyping analysis showed the following results: 15.39% (1*/2*), 1.92% (1*/3*), 1.92% (2*/2*) and 80.77% (1*/1*) in the patients, while in the normal subjects the distribution of CYP2C19*1/*1, *1/*2, *1/*3, *2/*2, *2/*3 and *3/*3 genotypes were 86.5, 6.5, 3, 1.5, 2, and 0.5 %, respectively.There is no significant association between the CYP2C19 polymorphism and the occurrence of the childhood hematological malignancies. The distribution of CYP2C19*2 in the Gaza Strip population is lower than that in Caucasians, Africans and the Asian populations. The CYP2C19*3 allele, which was not reported in the Caucasian populations, is present in 3% of the Gaza Strip population. Further studies are needed to investigate the role of other CYPs' polymorphisms in our patient group.