MyMedR

Displaying all 5 publications

Abstract:

Sort:

Fulltext Preparation of Temozolomide-Loaded Nanoparticles for Glioblastoma Multiforme Targeting-Ideal Versus Reality

Lee CY, Ooi IH

Pharmaceuticals (Basel), 2016;9(3).
PMID: 27618068 DOI: 10.3390/ph9030054

Temozolomide (TMZ) is one of the most effective chemotherapeutic agents for glioblastoma multiforme, but the required high administration dose is accompanied by side effects. To overcome this problem and to further improve TMZ's efficacy, targeted delivery of TMZ by using polymeric nanoparticles has been explored. We synthesised the PLGA-PEG-FOL copolymer and attempted encapsulation of TMZ into PLGA-PEG-FOL nanoparticles using the emulsion solvent evaporation method and the nanoprecipitation method. Conjugation of PEG and FOL to PLGA has been reported to be able to increase the delivery of TMZ to the brain as well as targeting the glioma cells. However, despite making numerous modifications to these methods, the loading of TMZ in the nanoparticles only ranged between 0.2% and 2%, and the nanoparticles were between 400 nm and 600 nm in size after freeze-drying. We proceed with determining the release profile of TMZ in phosphate buffered saline (PBS). Our initial data indicated that TMZ was slowly released from the nanoparticles. The metabolite of TMZ rather than the parent compound was detected in PBS. Our study suggests that while PLGA-PEG-FOL can be used as a polymeric or encapsulation material for central delivery of TMZ, a practical and cost effective formulation method is still far from reach.
Fulltext A new Haniffia species (Zingiberaceae) and a new generic record from Sarawak, Malaysian Borneo

Wong SY, Ooi IH, Boyce PC

Bot Stud, 2014 Dec;55(1):51.
PMID: 28510939 DOI: 10.1186/s40529-014-0051-9

BACKGROUND: Haniffia Holttum is a genus of three described species of terrestrial gingers hitherto restricted to Peninsular Thailand and various localities in Peninsular Malaysia.
RESULTS: With generic placement confirmed using nrITS, trn K and mat K plastid sequence data, Haniffia santubongensis S.Y. Wong & P.C. Boyce is described as a taxonomically novel species representing a new generic record for Borneo, to where it is endemic to Mount Santubong, Kuching Division, NW Sarawak, Malaysian Borneo. An identification key to all species is given and H. santubongensis is illustrated from living plants.
CONCLUSION: Haniffia santubongensis is the fourth species of Haniffia so far described, and the first occurring on sandstone.
Floral diversity and pollination strategies of three rheophytic Schismatoglottideae (Araceae)

Low SL, Wong SY, Ooi IH, Hesse M, Städler Y, Schönenberger J, et al.

Plant Biol (Stuttg), 2016 Jan;18(1):84-97.
PMID: 25688576 DOI: 10.1111/plb.12320

Homoplastic evolution of 'unique' morphological characteristics in the Schismatoglottideae - many previously used to define genera - prompted this study to compare morphology and function in connection with pollination biology for Aridarum nicolsonii, Phymatarum borneense and Schottarum sarikeense. Aridarum nicolsonii and P. borneense extrude pollen through a pair of horned thecae while S. sarikeense sheds pollen through a pair of pores on the thecae. Floral traits of spathe constriction, presence and movement of sterile structures on the spadix, the comparable role of horned thecae and thecae pores, the presence of stamen-associated calcium oxalate packages, and the timing of odour emission are discussed in the context of their roles in pollinator management. Pollinators for all investigated species were determined to be species of Colocasiomyia (Diptera: Drosophilidae).
Enantiomeric pair of copper(II) polypyridyl-alanine complexes: Effect of chirality on their interaction with biomolecules

Ng CH, Chan CW, Lai JW, Ooi IH, Chong KV, Maah MJ, et al.

J Inorg Biochem, 2016 07;160:1-11.
PMID: 27105312 DOI: 10.1016/j.jinorgbio.2016.04.003

Like chiral organic drugs, the chemical and biological properties of metal complexes can be dependent on chirality. Two pairs of [Cu(phen)(ala)(H2O)]X·xH2O (phen=1.10-phenanthroline: X=NO3(-); ala: l-alanine (l-ala), 1 and d-alanine (d-ala) 2; and (X=Cl(-); ala: l-ala, 3 and d-ala, 4) complex salts (x=number of lattice water molecules) have been synthesized and characterized. The crystal structure of 3 has been determined. The same pair of enantiomeric species, viz. [Cu(phen)(l-ala)(H2O)](+) and [Cu(phen)(d-ala)(H2O)](+), have been identified to be present in the aqueous solutions of both 1 and 3, and in those of both 2 and 4 respectively. Both 3 and 4 bind more strongly to ds(AT)6 than ds(CG)6. There is no or insignificant effect of the chirality of 3 and 4 on the production of hydroxyl radicals, binding to deoxyribonucleic acid from calf thymus (CT-DNA), ds(CG)6, G-quadruplex and 17-base pair duplex, and inhibition of both topoisomerase I and proteasome. Among the three proteasome proteolytic sites, the trypsin-like site is inhibited most strongly by these complexes. However, the chirality of 3 and 4 does affect the number of restriction enzymes inhibited, and their binding constants towards ds(AT)6 and serum albumin.
Sunitinib DDI with paracetamol, diclofenac, mefenamic acid and ibuprofen shows sex-divergent effects on the tissue uptake and distribution pattern of sunitinib in mice

Tan SY, Wong MM, Tiew AL, Choo YW, Lim SH, Ooi IH, et al.

Cancer Chemother Pharmacol, 2016 10;78(4):709-18.
PMID: 27495788 DOI: 10.1007/s00280-016-3120-9

PURPOSE: Pharmacokinetic interaction of sunitinib with diclofenac, paracetamol, mefenamic acid and ibuprofen was evaluated due to their P450 mediated metabolism and OATP1B1, OATP1B3, ABCB1, ABCG2 transporters overlapping features.
METHODS: Male and female mice were administered 6 sunitinib doses (60 mg/kg) PO every 12 h and 30 min before the last dose were administered vehicle (control groups), 250 mg/kg paracetamol, 30 mg/kg diclofenac, 50 mg/kg mefenamic acid or 30 mg/kg ibuprofen (study groups), euthanized 6 h post last administration and sunitinib plasma, liver, kidney, brain concentrations analyzed.
RESULTS: Ibuprofen halved sunitinib plasma concentration in female mice (p