Next Article in Journal
VCGIDB: A Database and Web Resource for the Genomic Islands from Vibrio cholerae
Next Article in Special Issue
Isolation of Naegleria spp. from a Brazilian Water Source
Previous Article in Journal
Entry of Scotophilus Bat Coronavirus-512 and Severe Acute Respiratory Syndrome Coronavirus in Human and Multiple Animal Cells
Previous Article in Special Issue
Antioxidant and Leishmanicidal Evaluation of Pulicaria Inuloides Root Extracts: A Bioguided Fractionation
Open AccessArticle

Effects of Shape and Size of Cobalt Phosphate Nanoparticles against Acanthamoeba castellanii

Department of Biological Sciences, School of Science and Technology, Sunway University, Subang Jaya 47500, Selangor, Malaysia
Graphene and Advanced 2D Materials Research Group, School of Science and Technology, Sunway University, Subang Jaya 47500, Selangor, Malaysia
State Key Laboratory of ASIC and System, SIST, Fudan University, Shanghai 200433, China
Research Centre for Nano-Materials and Energy Technology, School of Science and Technology, Sunway University, Subang Jaya 47500, Selangor, Malaysia
Department of Biology, Chemistry and Environmental Sciences, College of Arts and Sciences, American University of Sharjah, University City, Sharjah 26666, UAE
Authors to whom correspondence should be addressed.
Pathogens 2019, 8(4), 260;
Received: 22 August 2019 / Revised: 5 October 2019 / Accepted: 6 October 2019 / Published: 22 November 2019
(This article belongs to the Special Issue Emerging Parasitic Protozoa)
T4 genotype Acanthamoeba are opportunistic pathogens that cause two types of infections, including vision-threatening Acanthamoeba keratitis (AK) and a fatal brain infection known as granulomatous amoebic encephalitis (GAE). Due to the existence of ineffective treatments against Acanthamoeba, it has become a potential threat to all contact lens users and immunocompromised patients. Metal nanoparticles have been proven to have various antimicrobial properties against bacteria, fungi, and parasites. Previously, different types of cobalt nanoparticles showed some promise as anti-acanthamoebic agents. In this study, the objectives were to synthesize and characterize the size, morphology, and crystalline structure of cobalt phosphate nanoparticles, as well as to determine the effects of different sizes of cobalt metal-based nanoparticles against A. castellanii. Cobalt phosphate octahydrate (CHP), Co3(PO4)2•8H2O, was synthesized by ultrasonication using a horn sonicator, then three different sizes of cobalt phosphates Co3(PO4)2 were produced through calcination of Co3(PO4)2•8H2O at 200 °C, 400 °C and 600 °C (CP2, CP4, CP6). These three types of cobalt phosphate nanoparticles were characterized using a field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) analysis. Next, the synthesized nanoparticles were subjected to biological assays to investigate their amoebicidal, amoebistatic, anti-encystation, and anti-excystation effects against A. castellanii, as well as cell cytotoxicity. The overall results showed that 1.30 ± 0.70 µm of CHP microflakes demonstrated the best anti-acanthemoebic effects at 100 µg/mL, followed by 612.50 ± 165.94 nm large CP6 nanograins. However, amongst the three tested cobalt phosphates, Co3(PO4)2, the smaller nanoparticles had stronger antiamoebic effects against A. castellanii. During cell cytotoxicity analysis, CHP exhibited only 15% cytotoxicity against HeLa cells, whereas CP6 caused 46% (the highest) cell cytotoxicity at the highest concentration, respectively. Moreover, the composition and morphology of nanoparticles is suggested to be important in determining their anti-acathamoebic effects. However, the molecular mechanisms of cobalt phosphate nanoparticles are still unidentified. Nevertheless, the results suggested that cobalt phosphate nanoparticles hold potential for development of nanodrugs against Acanthamoeba. View Full-Text
Keywords: cobalt phosphate nanoparticles; size selectivity; antiamoebic; Acanthamoeba cobalt phosphate nanoparticles; size selectivity; antiamoebic; Acanthamoeba
Show Figures

Graphical abstract

MDPI and ACS Style

Anwar, A.; Chi Fung, L.; Anwar, A.; Jagadish, P.; Numan, A.; Khalid, M.; Shahabuddin, S.; Siddiqui, R.; Khan, N.A. Effects of Shape and Size of Cobalt Phosphate Nanoparticles against Acanthamoeba castellanii. Pathogens 2019, 8, 260.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

Back to TopTop