Synthesis of Plant Nanoparticles

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1		Ehsanul Hoque Apu	--	1703	2022-05-18 16:45:16	\|
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This entry is adapted from the peer-reviewed paper 10.3390/challe13010018

Silver nanoparticles (AgNPs) are toxic to microorganisms and can potentially kill multidrug-resistant bacteria. Nanoparticles can be synthesized in many ways, such as physical or chemical methods. Plant-based nanoparticles are considered eco-friendly as their production methods can effectively replace chemical reduction processes.

silver nanoparticles plant extracts antimicrobial activity green chemistry

1. Background

Particles having a diameter of less than 100 nm are termed nanoparticles. Nanoparticles exhibit novel and improved properties based on specific features such as better size, distribution, and morphology compared to their constituent larger particles of the bulk materials. Due to their small size, nanoparticles have a more excellent surface-to-volume ratio. The specific surface area of silver nanoparticles (AgNPs) is essential for their catalytic activity and other associated features such as antibacterial properties ^[1]^[2]. Nanoparticles can be synthesized in several ways, such as physical and various other chemical methods. These methods are expensive and use many different toxic substances, which makes them difficult to scale these methods for mass production. In recent years it has been found that plant molecules can perform the same reduction reactions necessary for the production of nanoparticles but in a much more efficient way. Here, green chemistry was employed to synthesize AgNPs using leaf extracts of Cymbopogon citratus.

The synthesis of AgNPs is of much interest to the scientific community because of their wide applications. For almost 2000 years, the medicinal benefits of silver have been recognized. Since the nineteenth century, silver compounds have been employed in several antibacterial applications ^[3]. Silver ions and silver-based compounds are widely acknowledged as lethal to microbes, including some of the most common bacterial strains ^[4]. These properties make it ideal for various purposes in the medical sector ^[4]. Topical lotions and creams containing silver reduce burn infection and sores ^[5]. Medical equipment and implants made from silver embedded polymers are another prominent application. Furthermore, silver-containing consumer products such as colloidal silver cream and silver-integrated fibers are being utilized in sports and athletic equipment ^[6]. Due to their enhanced antimicrobial activity and their potential application in treating cancers, many researchers are now focusing on developing an effective way to synthesize AgNPs ^[7]. These AgNPs are also being successfully used in cancer diagnosis and treatment ^[8]^[9].

The exact mechanism responsible for the antimicrobial effect of AgNPs is still not clear. Several theories have been put forward to explain the antimicrobial effect of AgNPs. They can attach to the cell wall of bacteria and penetrate it, which subsequently leads to structural damage in the cell wall and membrane with altered permeability of the cell membrane ^[10]. The nanoparticles are accumulated on the cell surface by forming ‘pits.’ Additionally, the formation of free radicals by the AgNPs may also be responsible for cell death ^[11]. Numerous studies suggest that they can form free radicals when in contact with the bacteria and damage the bacterial cell membrane by forming pores that result in cell death ^[12]. It was also suggested that nanoparticles might produce silver ions ^[13]. These ions can interact and inactivate the thiol groups of many important enzymes ^[11]. Moreover, the inactivation of the respiratory enzymes by silver ions can also generate reactive oxygen species, attacking the bacterial cell ^[14].

There are many physical, chemical, and biological methods depicted in various literature on synthesizing AgNPs. The chemical processes include numerous ways that use toxic substances or are expensive and therefore are the ‘not so favored’ synthesis methods ^[15]. The physical methods include many pieces of high-end equipment, which are expensive and occupy a considerable amount of space. The synthesis of AgNPs with a tube furnace possesses several disadvantages as a tube furnace is very large, requires much energy (more than several kilowatts) while increasing the temperature around the source material, and also needs a great deal of time (more than 10 min) to be thermally stable ^[16]. The chemical methods include many toxic components that are harmful to humans when consumed, and they also require harsh physical and chemical conditions, which can be hazardous to human health. In addition, the toxic residues produced along with the nanoparticles during a chemical reduction process make the AgNPs unusable for any kind of biomedical application ^[17].

2. Synthesis of Plant Nanoparticles

There has been a significant interest in developing a new strategy to successfully synthesize AgNPs eliminating the drawbacks of chemical and physical production methods. Considering this, the idea of green chemistry has attained considerable recognition, particularity the concepts that are mainly focused on replacing the use of harmful chemicals. Scientists are also focused on developing methods and technologies to reduce and eliminate the compounds harmful to human health and the environment ^[18]. Among several biological methods, plant extracts for synthesizing AgNPs have gained immense popularity. Owing to its directness in procedures, ease of monitoring, easy sampling, and lower costs, this plant-based technique can be adopted to replace the regularly utilized chemical techniques to facilitate the widespread production of AgNPs ^[18]. Plant-based nanoparticles are considered eco-friendly as their production methods can effectively replace chemical reduction processes ^[19]. The metabolites present in plant extracts may aid in the reduction process ^[19]. Moreover, plants are readily available, easy to grow, and safe to handle.

Fourier transforms infrared spectroscopy (FTIR) spectroscopy of biosynthesized AgNPs has revealed that the biomolecules present in plant extracts are responsible for synthesizing nanoparticles ^[20]. Terpenoids are one of the biomolecules involved in this process. Terpenoids are commonly referred to as isoprene, an organic molecule that contains five-carbon isoprene compounds. Some studies have suggested that the Geranium leaf extract contains terpenoids which contribute the most to AgNPs biosynthesis ^[20]. Another major plant metabolite is flavonoids, a polyphenolic compound that consists of 15 carbon atoms and is water-soluble ^[21]. That is why it is imperative that while synthesizing the nanoparticles from the plant extract, the plant must have a high amount of terpenoids and flavonoids and exhibit some medicinal properties of its own. In addition, genetic variations in environmental and ecological factors have made plants chemically very diverse, which further facilitates their application in synthesizing AgNPs ^[22].

3. Selection of Plant Extract

C. citratus, also known as lemongrass, belongs to the Gramineae family. This herb is very rich in essential oil content. The Cymbopogon genus is commonly available in the tropical and subtropical areas of Asia, America, and Africa. People have been using C. citratus as an everyday tea, insecticide, insect repellant, and a medicinal supplement to treat anti-inflammatory and analgesic diseases worldwide. Medical application of this herb also includes cures for malaria and stomachache due to its antioxidant properties ^[23]. This plant species was selected in the current research since it has phytochemicals such as flavonoids, alkaloids, tannins, carbohydrates, steroids, and phytosteriods in relatively high concentrations ^[24]. Medicinal plants have shown their efficiency in treating infectious diseases, diabetes and cancer due to the presence of flavonoids, terpenoids, alkaloids, and phytosteriods ^[25]. An aqueous extract prepared from the leaves of C. citratus was used as both a bioreductant and capping agent for the green synthesis of AgNPs to study the effect of volume of plant extract, reaction temperature, and reaction pH on the AgNPs stability, synthesis rate, and particle size. The AgNPs were prepared using different volumes of C. citratus extract, and the response was conducted under different physiological conditions and checked for quality using UV-Vis spectroscopy. Antibacterial effects of the synthesized nanoparticles were also examined by testing them against selected pathogens such as enterotoxigenic Escherichia coli (ETEC), Salmonella paratyphi, Bacillus cereus, Vibrio cholera, Shigella flexneri. However, the potentiality of C. citratus derived materials obtained from the forests in Bangladesh has not been studied in detail.

4. Naturally Derived Materials and Plant Extracts Provide Solutions for Global Challenges

Tissue engineering has significantly developed naturally derived materials that are used for plant-derived and biodegradable products ^[26]^[27]. While routing for more options for developing widely available options, researchers have also explored self-healing materials as delivery systems for drugs, biomolecules, and tissue regeneration ^[27]^[28]. One of the most prevalent naturally derived materials is polymers. Because of their availability and biocompatibility, the most commonly used polymers are collagen, gelatin, chitosan, alginate, etc. Some contain peptides that are ideal for biomedical research applications for wound healing and drug development studies. They help in cellular adhesion, movement, and normal functioning. Silk is also a newly popular option due to its high availability, bulk processability, and elastic properties ^[26]. Natural extracellular matrices (ECM) have been used in many tissue engineering applications for drug development research ^[26]. It has been found that patient-derived cancer tissue matrices provide handy options for more realistic results than animal models, which are highly expensive. Even scientists have explored the potential usage of patient-derived ECM products for anti-cancer drug development ^[29]^[30]. These approaches save both time and costs because the patient-derived materials are recycled as natural ECM or cancer-tissue mimicking models for studies. Furthermore, discarding this huge amount of diseased tissue is expensive and often creates biohazard risks to the global environment if not properly followed by the standard protocols, which is difficult to maintain in underdeveloped countries due to a lack of proper funding and infrastructures. Genetically engineered rat, mouse, zebrafish, and patient-derived tumor xenografts in animal models are commonly used in vivo models in cancer research ^[31]. However, they do not replicate the human clinical cancer condition. The closest match to human cancer can be studied by using non-human primates, such as monkeys and chimpanzees ^[32]. Experts had been trying to convince the National Institute of Health (NIH) to scale back chimpanzee usage in biomedical research, and the NIH announced in 2013 to significantly reduce these procedures ^[33]^[34]. The Food and Drug Administration (FDA) delayed clinical trials due to a lack of reliable non-human primates. Unrealistic data often results in the failure of drug trials. The success rate of drugs entering clinical trials and approved by the FDA is only 5.1% in cancer research ^[35]. These complexities increase the duration and price of drug development and hospital care and create significant obstructions for medication supplies in lower-income countries where people cannot afford expensive treatment options. Usage of plants such as Cymbopogon citratus and green synthesis may bridge the gap of the increased need for healthcare products, time, and expenses to combat the planetary health challenges. The herb is widely available and distributed in Asia, Africa, South, and North America. In low-income and underdeveloped communities, its derived materials can provide pharmacological solutions for many pathological diseases due to amazing advantages such as their anti-microbial, anti-obesity, anti-bacterial, anti-oxidants, anti-diarrheal, and anti-inflammatory properties which could enhance immunity ^[36].

References

Sharma, G.; Jasuja, N.D.; Kumar, M.; Ali, M.I. Biological Synthesis of Silver Nanoparticles by Cell-Free Extract of Spirulina Platensis. J. Nanotechnol. 2015, 2015, 1–6.
Ivanova, N.; Gugleva, V.; Dobreva, M.; Pehlivanov, I.; Stefanov, S.; Andonova, V. Silver Nanoparticles as Multi-Functional Drug Delivery Systems. In Nanomedicines; Akhyar Farrukh, M., Ed.; IntechOpen: London, UK, 2019; ISBN 978-1-78985-283-7.
Prabhu, S.; Poulose, E.K. Silver Nanoparticles: Mechanism of Antimicrobial Action, Synthesis, Medical Applications, and Toxicity Effects. Int. Nano Lett. 2012, 2, 32.
Venkataramana, B.; Sankar, S.S.; Kumar, A.S.; Naidu, B.V.K. Synthesis of Silver Nanoparticles Using Setaria Italica (Foxtail Millets) Husk and Its Antimicrobial Activity. Res. J. Nanosci. Nanotechnol. 2015, 5, 6–15.
Munteanu, A.; Florescu, I.P.; Nitescu, C. A Modern Method of Treatment: The Role of Silver Dressings in Promoting Healing and Preventing Pathological Scarring in Patients with Burn Wounds. J. Med. Life 2016, 9, 306–315.
Sim, W.; Barnard, R.T.; Blaskovich, M.A.T.; Ziora, Z.M. Antimicrobial Silver in Medicinal and Consumer Applications: A Patent Review of the Past Decade (2007–2017). Antibiotics 2018, 7, e93.
Jain, S.; Mehata, M.S. Medicinal Plant Leaf Extract and Pure Flavonoid Mediated Green Synthesis of Silver Nanoparticles and Their Enhanced Antibacterial Property. Sci. Rep. 2017, 7, 15867.
Popescu, M.; Velea, A. Biogenic Production of Nanoparticles. Dig. J. Nanomater. Biostruct. 2010, 6, 1035–1040.
Baruwati, B.; Polshettiwar, V.; Varma, R.S. Glutathione Promoted Expeditious Green Synthesis of Silver Nanoparticles in Water Using Microwaves. Green Chem. 2009, 11, 926.
Yin, I.X.; Zhang, J.; Zhao, I.S.; Mei, M.L.; Li, Q.; Chu, C.H. The Antibacterial Mechanism of Silver Nanoparticles and Its Application in Dentistry. Int. J. Nanomed. 2020, 15, 2555–2562.
Mikhailova, E.O. Silver Nanoparticles: Mechanism of Action and Probable Bio-Application. J. Funct. Biomater. 2020, 11, e84.
Goswami, G.; Boruah, H.; Gautom, T.; Hazarika, D.J.; Barooah, M.; Boro, R.C. Chemically Synthesized Silver Nanoparticles as Cell Lysis Agent for Bacterial Genomic DNA Isolation. Adv. Nat. Sci. Nanosci. Nanotechnol. 2017, 8, 045015.
Feng, Q.L.; Wu, J.; Chen, G.Q.; Cui, F.Z.; Kim, T.N.; Kim, J.O. A Mechanistic Study of the Antibacterial Effect of Silver Ions on Escherichia Coli and Staphylococcus Aureus. J. Biomed. Mater. Res. 2000, 52, 662–668.
Xu, H.; Qu, F.; Xu, H.; Lai, W.; Andrew Wang, Y.; Aguilar, Z.P.; Wei, H. Role of Reactive Oxygen Species in the Antibacterial Mechanism of Silver Nanoparticles on Escherichia Coli O157:H7. Biometals 2012, 25, 45–53.
Gudikandula, K.; Charya Maringanti, S. Synthesis of Silver Nanoparticles by Chemical and Biological Methods and Their Antimicrobial Properties. J. Exp. Nanosci. 2016, 11, 714–721.
Natsuki, J.; Natsuki, T.; Hashimoto, Y. A Review of Silver Nanoparticles: Synthesis Methods, Properties and Applications. Int. J. Mater. Sci. Appl. 2015, 4, 325.
Ebrahiminezhad, A.; Bagheri, M.; Taghizadeh, S.-M.; Berenjian, A.; Ghasemi, Y. Biomimetic Synthesis of Silver Nanoparticles Using Microalgal Secretory Carbohydrates as a Novel Anticancer and Antimicrobial. Adv. Nat. Sci. Nanosci. Nanotechnol. 2016, 7, 015018.
Shaik, M.; Khan, M.; Kuniyil, M.; Al-Warthan, A.; Alkhathlan, H.; Siddiqui, M.; Shaik, J.; Ahamed, A.; Mahmood, A.; Khan, M.; et al. Plant-Extract-Assisted Green Synthesis of Silver Nanoparticles Using Origanum Vulgare L. Extract and Their Microbicidal Activities. Sustainability 2018, 10, 913.
Gavade, S.J.M.; Nikam, G.H.; Dhabbe, R.S.; Sabale, S.R.; Tamhankar, B.V.; Mulik, G.N. Green Synthesis of Silver Nanoparticles by Using Carambola Fruit Extract and Their Antibacterial Activity. Adv. Nat. Sci. 2015, 6, 045015.
Khatoon, N.; Mazumder, J.A.; Sardar, M. Biotechnological Applications of Green Synthesized Silver Nanoparticles. J. Nanosci. Curr. Res. 2017, 2, 107.
Jain, D.; Daima, H.K.; Kachhwaha, S.; Kothari, S.L. Synthesis of Plant-Mediated Silver Nanoparticles Using Papaya Fruit Extract and Evaluation of their Anti Microbial Activities. Dig. J. Nanomater. Biostruct. 2009, 7, 557–563.
Vokou, D.; Kokkini, S.; Bessiere, J.-M. Geographic Variation of Greek Oregano (Origanum Vulgare Ssp. Hirtum) Essential Oils. Biochem. Syst. Ecol. 1993, 21, 287–295.
Chukwuocha, U.M.; Fernández-Rivera, O.; Legorreta-Herrera, M. Exploring the Antimalarial Potential of Whole Cymbopogon Citratus Plant Therapy. J. Ethnopharmacol. 2016, 193, 517–523.
Umar, M.; Mohammed, I.; Oko, J.; Tafinta, I.; Aliko, A.; Jobbi, D. Phytochemical Analysis and Antimicrobial Effect of Lemon Grass (Cymbopogon Citratus) Obtained from Zaria, Kaduna State, Nigeria. J. Complementary Altern. Med. Res. 2016, 1, 1–8.
Rakib-Uz-Zaman, S.M.; Iqbal, A.; Mowna, S.A.; Khanom, M.G.; Al Amin, M.M.; Khan, K. Ethnobotanical Study and Phytochemical Profiling of Heptapleurum Hypoleucum Leaf Extract and Evaluation of Its Antimicrobial Activities against Diarrhea-Causing Bacteria. J. Genet. Eng. Biotechnol. 2020, 18, 18.
Ashammakhi, N.; GhavamiNejad, A.; Tutar, R.; Fricker, A.; Roy, I.; Chatzistavrou, X.; Apu, E.H.; Nguyen, K.-L.; Ahsan, T.; Pountos, I.; et al. Highlights on Advancing Frontiers in Tissue Engineering. Tissue Eng. Part B Rev. 2021.
Ashammakhi, N.; Hernandez, A.L.; Unluturk, B.D.; Quintero, S.A.; de Barros, N.R.; Hoque Apu, E.; Bin Shams, A.; Ostrovidov, S.; Li, J.; Contag, C.; et al. Biodegradable Implantable Sensors: Materials Design, Fabrication, and Applications. Adv. Funct. Mater. 2021, 31, 2104149.
Ashammakhi, N.; Hoque Apu, E.; Caterson, E.J. Self-Healing Biomaterials to Heal Tissues. J. Craniofacial Surg. 2021, 32, 819–820.
Hoque Apu, E.; Akram, S.U.; Rissanen, J.; Wan, H.; Salo, T. Desmoglein 3–Influence on Oral Carcinoma Cell Migration and Invasion. Exp. Cell Res. 2018, 370, 353–364.
Salo, T.; Sutinen, M.; Hoque Apu, E.; Sundquist, E.; Cervigne, N.K.; de Oliveira, C.E.; Akram, S.U.; Ohlmeier, S.; Suomi, F.; Eklund, L.; et al. A Novel Human Leiomyoma Tissue Derived Matrix for Cell Culture Studies. BMC Cancer 2015, 15, 981.
Yee, N.S.; Ignatenko, N.; Finnberg, N.; Lee, N.; Stairs, D. ANIMAL MODELS OF CANCER BIOLOGY. Cancer Growth Metastasis 2015, 8, 115–118.
Devaux, C.A.; Mediannikov, O.; Medkour, H.; Raoult, D. Infectious Disease Risk Across the Growing Human-Non Human Primate Interface: A Review of the Evidence. Front. Public Health 2019, 7, 305.
Kaiser, J. Animal Models. Advisers Urge NIH to Scale Back Chimpanzee Research. Science 2013, 339, 501.
National Institutes of Health (NIH). NIH to Reduce Significantly the Use of Chimpanzees in Research. Available online: https://www.nih.gov/news-events/news-releases/nih-reduce-significantly-use-chimpanzees-research (accessed on 31 March 2022).
Smietana, K.; Siatkowski, M.; Møller, M. Trends in Clinical Success Rates. Nat. Rev. Drug Discov. 2016, 15, 379–380.
Oladeji, O.S.; Adelowo, F.E.; Ayodele, D.T.; Odelade, K.A. Phytochemistry and Pharmacological Activities of Cymbopogon Citratus: A Review. Sci. Afr. 2019, 6, e00137.

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Subjects: Plant Sciences

Contributors MDPI registered users' name will be linked to their SciProfiles pages. To register with us, please refer to https://encyclopedia.pub/register :

Ehsanul Hoque Apu

S M Rakib-Uz-Zaman

Mohammed Muntasir

Sadrina Afrin Mowna

Sha Saif Jahan

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Update Date: 20 May 2022

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