JAN 27, 2022 7:00 AM PST

Hemp-Mediated Synthesis of Gold & Silver Nanoparticles for Bacterial Biofilm Inhibition

WRITTEN BY: Nadine Husami

For many years, antibiotic resistance has been urgently rising as a globally-significant public health concern. More recently, increasing knowledge on the conferral of enhanced antibiotic resistance by biofilm microenvironments has highlighted the role of biofilm formation and maturation in antibiotic-resistant infections.

Gold and silver nanoparticles have emerged as encouraging antimicrobial alternatives to the currently available antibiotics that are in widespread use across the globe (those of which have been rendered ineffective against multidrug-resistant bacterial strains). Notably, previous studies have shown that these metallic nanoparticles are capable of biofilm inhibition.

With ‘green synthesis’ methodologies (i.e., the use of plants or microorganisms as reducing agents in nanoparticle production) continuing to gain favor among the nano-biotechnology community, there have been increased efforts made by researchers to identify efficient, cost-effective, and environmentally-friendly sources for nanoparticle production.

In a recent study published in the International Journal of Nanomedicine, researchers from Sweden and Denmark explored Cannabis sativa (industrial hemp) for its potential to efficiently produce metallic nanoparticles via green synthesis in hopes of developing a more effective treatment for infections caused by antibiotic-resistant, biofilm-forming bacteria.

By combining the slew of naturally-occurring, biologically active compounds within C. sativa extracts (and subsequently their presumptive medicinal properties) with the antibacterial activity of metallic nanoparticles, the research team intended to establish an improved bacterial biofilm therapeutic.  

Aqueous C. sativa stem extract was separated into two fractions:

  1. Cortex – a bast fiber-enriched outer layer of the plant stem.
  2. Xylem – part of the inner layer of the stem’s core, a predominant source of hemp’s well-known phenolic compounds (i.e., alkaloids and cannabinoids).

To synthesize the nanoparticles, each of these fractions was incubated with metal salt solutions containing either gold (HAuCl4⋅3H2O) or silver (AgNO3). From these reactions, a variety of different nanoparticle types were successfully yielded (fiber-gold nanoparticles, F-AuNPs; core-gold nanoparticles, C-AuNPs; and core-silver nanoparticles, C-AgNPs). Each type of nanoparticle was vigorously characterized using a variety of complementary chemical methods and analyses.

The silver nanoparticles (C-AgNPs) were further assessed for their potential to inhibit Pseudomonas aeruginosa and Escherichia coli biofilms using minimum inhibitory concentration (MIC; indicative of bacteriostatic potential), minimum bactericidal concentration (MBC; indicative of bactericidal potential), and biofilm formation assays.

AgNPs exhibited a potent inhibitory effect against biofilm formation by all bacterial strains assessed (P. aeruginosa, E. coli, and Staphylococcus epidermis). Notably, the inhibition sensitivity appeared to be dependent on the strain’s presence/absence of a peptidoglycan cellular envelope: gram-positive strains (i.e., S. epidermis) required higher nanoparticle concentrations for inhibition as compared to gram-negative strains (i.e., P. aeruginosa and E. coli).

The authors concluded that although further studies are needed to ensure consistency in nanoparticle size and shape within designated ranges, the results of this study provide encouraging evidence in support of employing C. sativa-mediated green synthesis of metallic nanoparticles towards the inhibition and disruption of bacterial biofilm formation and maturation.  

 

Sources: G. Pal, P. Rai, & A. Pandey’s Chapter 1 in Micro and Nano Technologies, Green Synthesis, Characterization and Applications of NanoparticlesInternational Journal of Nanomedicine

About the Author
Biochemistry Graduate Student
Nadine (She/Her) is a Cannabis Sciences category writer at Labroots. She received her BSc in Biotechnology from Niagara University, where she investigated the use of bacterial glycoside hydrolases for the production of universal blood via hydrolytic ABO antigen cleavage. She also performed cannabis research during her undergraduate career as a laboratory associate for a plant genetics biotechnology company. She is currently a biochemistry graduate student at the University at Buffalo; her current thesis work investigates the role of long noncoding RNAs in ocular pathologies.
You May Also Like
NOV 04, 2021
Cannabis Sciences
Can Cannabidiol Be Used to Treat a Wide Variety of Seizure Disorders?
NOV 04, 2021
Can Cannabidiol Be Used to Treat a Wide Variety of Seizure Disorders?
In 2015, it was estimated that nearly half a million children had active epilepsy, otherwise known as a seizure disorder ...
DEC 09, 2021
Cannabis Sciences
Considering Cannabinoids as a COVID-19 Treatment
DEC 09, 2021
Considering Cannabinoids as a COVID-19 Treatment
Research suggests that Cannabis sativa-derived cannabinoids – such as cannabidiol (CBD), Δ9tetrahydrocannabi ...
DEC 15, 2021
Health & Medicine
Limonene: The Terpene to Deploy against Cancer
DEC 15, 2021
Limonene: The Terpene to Deploy against Cancer
Limonene is one of the most well-known cannabis terpenes, and it’s getting increased attention in the medical prof ...
JAN 01, 2022
Cannabis Sciences
Pharmacological Effects of Cannabis: To Be or Not To Be... Carboxylated?
JAN 01, 2022
Pharmacological Effects of Cannabis: To Be or Not To Be... Carboxylated?
Results from a new study published in Nature’s Scientific Reports suggest that the carboxylated (i.e., acidic) for ...
MAR 02, 2022
Cannabis Sciences
How Science is Protecting Cannabis Consumers from Harmful Chemicals
MAR 02, 2022
How Science is Protecting Cannabis Consumers from Harmful Chemicals
The legalization of cannabis also comes with many tight laws and regulations to protect the consumers. This is done with ...
APR 22, 2022
Cannabis Sciences
Cannabis and Cravings:  Why you have the munchies when you're high
APR 22, 2022
Cannabis and Cravings: Why you have the munchies when you're high
Smoking weed sometimes leads to eating crazy combinations of foods, or even everything in sight. But why is that? There' ...
Loading Comments...