Plant Gum Based Drug Carriers

Abstract

Recently, there have been various chemical carriers and routines for treatment of infections. Plant gum nanoparticles are being used greatly for this purpose. They have several advantages over chemical drug carriers including being biodegradable, biocompatible, nontoxic, providing better tolerance to the patient, and having fewer side effects. They also do not cause allergies in humans, do not irritate the skin or eyes, and have low production costs. The use of plant gums as drug carriers is limited due to a series of disadvantages. They may have microbial contamination because of the moisture in their content. Also, in storage, their viscosity decreases due to contact with water. By green nanoparticle synthesis of these plant gums as drug carriers, the disadvantages can be limited. There are several studies showing that plant gum drug carriers can have a great combination with various drugs and nanoparticles, thus they could be extremely effective against multi-resistant bacteria and even systemic illness like cancer. These days, the need for green synthesis of medicine and drug carriers has become quite popular and it will be even more essential in the future because of emerging antibiotic-resistant bacteria and climate change.

1. Introduction

The use of Synthetic polymers as drug carriers is common nowadays. They do have several advantages, yet there are noticeable disadvantages, including poor adaptation to the patient’s body, high cost, and also causing acute and chronic side effects, for example poly-(methyl methacrylate) (PMMA) can cause skin and eye irritation. Other disadvantages of synthetic polymers utilized in tissue engineering include low biocompatibility, the release of acidic products during degradation that may cause systemic and native reactions, and rapid loss of mechanical strength [1].

The use of plant gum nanoparticles as drug carriers is one of the several ways that is employed greatly for the treatment of infections and various illnesses like cancer and this has been stated in various researches [2].

Plant gums are the native gum-producing trees, growing freely within the country’s forests, and represent abundantly available materials. Plant-derived gums consist of polysaccharides and a few of them are applied medicinally for several years, including gum Tragacanth which has been used since third century B.C. Various studies have shown the advantage of using Green chemistry-based drug carriers for various purposes compared with using synthetic and chemical substances. Plant gum drug carriers can have advantages in the pharmaceutical industry including being biodegradable, biocompatible, nontoxic, providing better tolerance to the patient, and having fewer side effects. They also do not cause allergies in humans, do not irritate the skin or eyes, and have low production costs [3]. The extensive use of antibiotics has led to serious issues including resistance toward multiple antibiotics. Now there are articles showing that the use of plant gum nanoparticles loaded with drugs was successful in the treatment of multi-drug resistant bacteria including MRSA,¹ VRE,² and MDR-GNB³ [4, 5].

Natural gums constitute a structurally diverse class of biological macromolecules with a broad range of physicochemical properties, therefore they can be loaded with various drugs and can have a multi-target therapeutic effect. In this case, there will not be the need for consuming several drugs for the treatment of systemic disease.

That being said, the use of plant gums is limited due to a series of disadvantages. They may have microbial contamination because of the moisture in their content. Also, in storage, their viscosity decreases due to contact with water. This situation can be handled by creating nanoparticles from these plant gums and then using them as drug carriers. Green chemistry-based NPs⁴ are often applied for designing and manufacturing products by applying sustainable materials which may eliminate or reduce the appliance and formation of unsafe and toxic substances. In this regard, plant gum polysaccharides and their nanostructures are often applied as drug carriers. Natural nanoparticles, improve the stability and bioavailability, as well as the biological distribution of natural products, and also significantly reduce the adverse effects of drug uptake. That’s why gum-based nano formulations for creating drug carriers have attracted a lot of attention [6].

The important tree exudate gums available on the market are as follows: gum Arabic (GA), gum Karaya (GK), gum Tragacanth (GT), Kondagogu gum (KG), gum Ghatti (GG), and gum Guar. Figure 1 demonstrates the images related to the four of these famous plant gums. There also are several ways within which plant gum nanoparticles are created including mixing and agitation in a controlled environment, Microwave (MW)-assisted technique, ultrasonic irradiation, etc. The biosynthesis of nanoparticles, nanofibers, and composites for supported tree gums would be very beneficial within the pursuit of relevance to medication for various health issues.

Figure 1.

The images related to the four famous plant gums: gum Tragacanth, gum Arabic, Gum Ghatti, gum Karaya.

The purpose of this chapter is to review the beneficial medical aspects of these plant gum-based drug carriers. There are several researches that have been done in order to show the advantages of these substances in infection and illness treatment. Various plant gums and routines have been used in order to create nanoparticles with minimum side effects which will be discussed in this chapter.

2. Chemical character and chemical composition of plant gums

Toxic reagents are used in the synthesis and stabilization of commercially generated metal/metal oxide nanoparticles, raising the danger of chemical contamination and acute toxicity, which should be considered in clinical applications. As a result of the rising need for environmentally acceptable technology for the synthesis of antimicrobial fillers, safer approaches with reduced toxicity have gotten a lot of attention. As eco-friendly production of metal/metal oxide nanostructures for purposes like drug delivery, diagnosis, bioengineering, bioremediation, catalysis, antibacterial and antifungal agents, etc. is anticipated in the future. Also, greener strategies for nanomaterials synthesis are still being explored [7].

Green chemistry is related to the practices that promote the development of medicine and processes that decrease or eliminate the usage and creation of hazardous compounds. Biopolymers including cellulose, chitosan, dextran, and tree gums, for example, are frequently utilized as reducing and stabilizing agents in metal NP production. Plant-based ingredients (extracts, stems, gums, seeds, and fruits), among other biological sources, have been shown to be an efficient constituent for synthesizing nanoparticles while maintaining other important factors such as material cost, large-scale production capacity, and potential uses in a variety of applications. The pressure, temperature, solvent, and pH of the medium all play a role in the plant-based biogenic production of nanomaterials [8].

Gum Arabic, gum Karaya, gum Kondagogu, gum Tragacanth, gum Ghatti, Cashew gum, Guar gum, Olibanum gum, and Neem gum, are some examples of greener alternatives with useful chemical properties that have been successfully used for the production and stabilization of NPs.

3. Natural gum characteristics and sources and ways to create green nanofibers

Natural gums, which belong to the polysaccharide family, are often used to increase the viscosity of solutions, even at low concentrations. Natural gums are hydrophobic substances mostly obtained from plants or bacteria. Because the gum molecules are biological, they have a wide range of linear chain lengths, branching features, molecular weight, and other characteristics. Gums are divided into four categories based on their source of origin: (a) plant exudate gum (such as gum Karaya, Salai gum, and gum Arabic), (b) seed gum (such as Guar gum, Locust bean gum, and Tamarind gum), (c) microbial gum (such as Xanthan gum, Gellan gum, and Dextran gum), and (d) marine gums (such as alginic acids) [9].

Various techniques are used in the green synthesis of nanofibers. The plant extracts will be used in: (a) mixing and agitation in a controlled environment, (b) autoclaving, (c) microwave (MW)-assisted technique, (d) ultrasonic irradiation, and (e) UV/visible light irradiation.

3.1 Gum Arabic

3.1.1 Chemical composition

Gum Arabic (GA) is a polysaccharide having branching chains of [1, 2, 3] connected β-D-galactopyranosyl units comprising α-L-arabinofuranosy, α-L-rhamnopyranosyl, β-D-glucuronopyranosyl, and 4-O-methyl-β-D-glucuronopyranosyl units. It is a water-soluble dietary fiber. Ca²⁺, K⁺, and Mg²⁺ are abundant in GA. GA is made from the dried gummy exudates of Acacia senegal’s stems and branches. Microorganisms in the colon break down GA into short-chain fatty acids [10].

3.1.2 Manufacturing and application

GA is one of the safest dietary fibers, according to the US Food and Drug Administration. GA is used to treat individuals with chronic kidney disease and end-stage renal disease in Middle Eastern nations [10].

Using a simple and practical approach for making Au nano-architectures with branching forms of GA is considered critical for the intriguing anisotropic. Au structures are beneficial in a variety of research domains. Using gold nanoparticles, reducing agents, and assembling them on gum Arabic under sonication for around 20 minutes at room temperature is described as a natural drug delivery agent [11].

Through a chemical reduction, with the help of gum Arabic, Au particles with a variety of morphologies (e.g., flower-shaped and confieto-shaped) are effectively created. Au nano-flower shapes can have high biocompatibility with human bladder cancer cells (T-24), which might be used in biomedical applications. Sonicating a combination of gum Arabic solution with KAuBr₄ and ascorbic acid for around five seconds at room temperature can result in a well-organized approach for manufacturing gold nano-flowers [12].

Gum Arabic can also be used as a drug carrier in order to increase the solubility and stability of curcumin under physiological pH conditions. The compound may demonstrate anticancer activity in human hepatocellular carcinoma (Hep G2) cells, which is claimed to be higher than in human breast carcinoma (MCF-7) cells. Hep G2 cells show a faster accumulation of gum Arabic/curcumin NPs due to the high effectiveness of targeting the galactose groups present in gum Arabic, bypassing the prior hurdles and making it appropriate for drug delivery systems [13].

Biocompatible gold NPs can be created by continuously mixing an aqueous gum Arabic solution (0.2 percent), phosphine amino acid, and NaAuCl₄ together. The produced NPs can be used as molecular imaging contrast agents and can exhibit in vitro and in vivo endurance for months in aqueous, salt, and buffered solutions using an X-ray computed tomography scan [14].

In a study, using gum Arabic as a bio-template, a cost-effective and simple one-step technique for the manufacture of extremely stable molybdenum trioxide (MoO₃) nanoparticles was devised. The cytotoxic effects of the NP were measured using 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide assays in Hep G2 (human liver cancer) and HEK293 (human embryonic kidney) cell lines. MoO₃ nanoparticles are benign to Hep G2 cell lines and have low toxicity even at extremely high concentrations (1000 ppm), but have significant toxicity to HEK293 cells, according to the findings of this study [15].

Antibacterial activities of gum Arabic as drug carriers are stated in Table 2.

3.2 Gum Karaya

3.2.1 Chemical composition

Natural polysaccharide gum Karaya (GK, Sterculiaurens) is a plant exudates widely available and relatively cheap biomaterial, which is used in food and medical industry. However, GK is insoluble in water and it limits subsequent processing and broader utilization in medicine. That’s why it’s necessary to use nanoparticles in order to limit this situation [16].

One of the key challenges with inorganic nanoparticles as a medicine delivery technology is their biocompatibility. Sugars, hydrocolloids, and plant extracts have all been proven to have the potential to be used in the green production of biocompatible gold nanoparticles.

3.2.2 Manufacturing and application

The manufacture of gum Karaya (GK) stabilized gold nanoparticles (GKNP)⁵ and their application in the delivery of anticancer medicines is described in Ref. [17]. GKNP showed great biocompatibility toward CHO,⁶ normal ovary cells, and A549 human non-small cell lung cancer cells. The anti-cancer medication gemcitabine hydrochloride (GEM) was loaded on the surface of gum Karaya with a drug loading efficiency of 19.2%. In anti-proliferation and various experiments, GEM-loaded nanoparticles (GEM-GNP) inhibited cancer cell growth more than regular GEM. This impact was linked to GEM-GNP producing more reactive oxygen species in A549 cells than GEM alone. In conclusion, GK offers tremendous promise for the manufacture of biocompatible gold nanoparticles that might be exploited as a possible anticancer drug delivery carrier. This study also stated that gum Karaya loaded with gold nanoparticles has a longer shelf life and is extremely resistant to factors such as pH and salt. The GK-Au NP combination demonstrated effectiveness as a drug carrier and improved colloidal stability for Au NPs in human lung cancer cells, outperforming the drug gemcitabine hydrochloride in anticancer activity, colony formation suppression, and ROS generation.

Gum Karaya can also be used as a drug carrier for copper oxide (CuO) nanoparticles which have gained a lot of interest because of their catalytic, electric, optical, photonic, textile, Nanofluid, and antibacterial properties, which is based on their size, shape, and surrounding medium. Green technology can be used to make CuO nanoparticles put on the surface of the gum Karaya, which is a harmless natural hydrocolloid. In a study, a colloid-thermal synthesis technique was used to make the CuO nanoparticles. The mixture was kept at 75°C at 250 rpm for 1 h in an orbital shaker with varied concentrations of CuCl₂·2H₂O (1 mM, 2 mM, and 3 mM) and gum Karaya (10 mg/mL). CuO nanoparticles of various sizes were obtained by purifying and drying the CuO nanoparticles that had been produced [18].

3.3 Kondagogu gum

3.3.1 Chemical composition

Gum Kondagogu (Cochlospermumgossypium) maybe a tree exudate gum that belongs to the family Bixaceae. Compositional analysis of the gum by HPLC and LC-MS revealed uronic acids to be the key component of the polymer (∼26 mol%). Furthermore, analysis of the gum by GC-MS indicated the presence of sugars like arabinose (2.52 mol%), mannose (8.30 mol%), α-d-glucose (2.48 mol%), β-d-glucose (2.52 mol%), rhamnose (12.85 mol%), galactose (18.95 mol%), d-glucuronic acid (19.26 mol%), β-d-galactouronic acid (13.22 mol%), and α-d-galacturonic acid (11.22 mol%). The viscoelastic behavior of gum Kondagogu solutions (1 and 2%) in aqueous as well as in 100 mM NaCl solution shows a unique gel-like system, making it suitable for being used as a drug carrier [19].

3.3.2 Manufacturing and application

Gum Kondagogu (GK) has been used to reduce and cap gold nanoparticle constructions in recent investigations [20].

Antibacterial activity of Kondagogu gum loaded with AuNPs against Escherichia coli and Bacillus subtilis is reported to be excellent [21].

Using gum Kondagogu, a natural biopolymer, as a reducing and stabilizing agent, for delivering silver nanoparticles has shown to be beneficial. The effect of several factors on the production of nanoparticles was investigated, including gum particle size, gum concentration, silver nitrate concentration, and reaction time. The silver nanoparticles are easily incorporated for diverse applications since they have the best functional properties [22].

A study used sodium borohydride as a reductant and gum Kondagogu as a stabilizer to create selenium nanoparticles (Se NPs). Plant gum is a biopolymer-based feedstock that is sustainable, non-toxic, and non-immunogenic. Using ultraviolet-visible spectroscopy and dynamic light scattering, the role of gum on synthesis and mean particle size was investigated. In comparison to ionic Se, the current work shows that tree gum stabilized Se NPs may be used as a strong antioxidant nutrition supplement at a significantly lower dose [23].

Another study employed a two-stage chemical reduction approach to make copper nanoparticles (CuNPs), with a distinct reducing agent Hydrazine Hydrate (HH), and a separate stabilizing agent Gum Kondagogu extract. The anti-biofilm impact of gum Kondagogu extract stabilized copper NPs against clinical isolate Klebsiella pneumoniae was investigated, and the results revealed that the copper NPs film had an efficient anti-biofilm effect [24].

3.4 Gum Ghatti

3.4.1 Chemical composition

Gum Ghatti is a proteinaceous exudate tree gum. It is utilized in traditional medicine. The exudate gum has a glass-like appearance and the color is from dark red to white based on the shape of it which can be either a nodule or spiro [25].

3.4.2 Manufacturing and application

A simple and environmentally acceptable green approach for producing silver nanoparticles from silver nitrate has been devised, utilizing gum Ghatti (Anogeissuslatifolia) as a reducing and stabilizing agent. This approach can have various benefits including better treatment of bacterial illnesses.

The non-toxic, renewable plant polymer gum Ghatti was used as both the reducing and stabilizing agent in a simple and green way to make palladium nanoparticles from palladium chloride. The development of deep brown color and wide continuous absorption spectra in the UV-visible range verified the synthesis of palladium nanoparticles. At a considerably lower nanoparticle dosage, the nanoparticles demonstrated improved antioxidant activity. To evaluate the homogeneous catalytic activity of palladium nanoparticles, dyes such as coomassie brilliant blue G-250, methyl orange, methylene blue, and a nitro compound, 4-nitrophenol, were reduced using sodium borohydride. The nanoparticles showed high catalytic activity in dye degradation, and the findings suggest that biogenic palladium nanoparticles might be used as a nanocatalyst in environmental remediation [26].

Because of the unique intrinsic catalytic properties of diverse size, shape, and surface-functionalized gold nanoparticles, their prospective applications in disciplines such as drug transport, diagnostics and biosensor are being investigated. However, the traditional method of production of these metallic nanoparticles employs hazardous chemicals as reducing agents, an extra capping agent for stability, and surface functionalization for drug delivery objectives. Gum Ghatti can be a great drug delivery option for stabilizing this nanoparticle [27].

3.5 Gum tragacanth

3.5.1 Chemical composition, manufacturing and application

The aqueous extract of gum Tragacanth (Astragalusgummifer), a renewable, nontoxic natural phyto-exudate, can be used to develop a simple and environmentally acceptable technique for the green production of silver nanoparticles. Reductants and stabilizers are provided by the gum’s water-soluble components. The probable functional groups involved in nanoparticle reduction and capping have also been identified [28].

The sol-gel technique can be used to make Ni_0.35Cu_0.25Zn_0.4Fe₂O₄ nanoparticles utilizing Tragacanth gum as a bio-template and Metals nitrate as a metal supply. The advantages of this approach include a simple set-up, moderate reaction conditions, quick reaction periods, the use of a cost-effective catalyst, and good product yields. The catalyst may be easily recycled and reused several times without losing its catalytic activity [29].

Nano-particles that can be loaded on plant gums are stated briefly in Table 1.

Plant gums	NPs
Gum Arabic	Magnetite, Cu, Ag, Se, Au, Zn, Zein-curcumin, Chitosan/GA, Fe3O4
Gum Karaya	Ag, Cu, Au, Magnetite, Pt, Fe3O4
Gum Kondagogu	Ag, Au, Cu, Pd, Pt, Ti, Fe3O4, Ag2S
Gum Tragacanth	Ag, ZnO, TiO2, Carbon dots, Au
Gum Ghatti	Pd, Magnetite, Ag, Au
Guar gum	Ag, Au, Pd, Pt Magnetite, Zn, Palmshell extract/chitosan
Cashew gum	Ag, ZnO
Gellan gum	TiO2, Ag
Xanthan gum	Au
Gum Olibanum	Ag

Table 1.

Greener synthesis of NPs using plant gums.

4. Using plant gums loaded with NPs as antibacterial agents

Different studies have illustrated the benefits of using Plant gums loaded with NPs as antibacterial agents. Metallic NPs and other components can have various antibacterial effects based on the type of plant gum drug carriers and their way of production.

4.1 Silver nanoparticles

These NPs can be loaded on different plant gum drug carriers for various anti-bacterial purposes. AgNPs have a strong bactericidal and catalytic effect according to various studies and they are extremely beneficial for preventing drug-resistant bacteria.

In a study, Gum acacia was loaded with silver NPs mixed with structures of HDN (fruit flavonoid). In this essay, after the preparation of GA-AgNPs (Gum acacia silver NPs loaded with NP structures of HDN), a Bactericidal assay was performed by incubating 108 colony-forming units per mL of MRSA and E. coli K1 with various concentrations of GA-AgNPs-HDN and respective controls in 1.5 mL centrifuge tubes at 37°C for 2 h. For negative controls, untreated bacterial cultures were incubated with PBS,⁷ while 100 μg/mL gentamicin-treated bacteria were used as positive control. The result for this essay is stated in Table 2.

Plant gums loaded with NPs	Result	Antibacterial activity against	Reference
GA-AgNPs	Bactericidal effect of this nanoparticle was more significant on E. coli K1 infections than MRSA infections, indicating that this component is more effective on Gram-negative bacteria than Gram-positive but overall these NPs have more bactericidal effects than chemicals	MRSA and E. coli K1	[30]
Gum Tragacanth loaded with Silver Nanoparticles	The inhibition zone of about 1 1. 5 ± 0 mm was observed around the Gram-positive bacteria. For Gram-negative bacterial strains E. coli and P. aeruginosa the inhibition zone was reported 9. 5 ± 0. 4 and 1 0. 5 ± 0, respectively. In the case of positive control plates loaded with erythromycin discs, growth inhibition was noted much less than the loaded NPs	Gram-positive bacterial strain S. aureus and Gram-negative bacterial strains E. coli and P. aeruginosa	[28]
P. domestica gum loaded Silver NPs	P. domestica gum-loaded silver nanoparticles can have a potential antibacterial effect against S. aureus (19.7 ± 0.4 mm) and E. coli (14.4 ± 0.7 mm), and P. aeruginosa (13.1 ± 0.2 mm). although this study suggests that streptomycin has an antibacterial effect of higher magnitude as compared to P. domestica gum-loaded silver nanoparticles against the tested bacterial strains (23.6 ± 0.8 mm, 21.8 ± 0.2 mm, and 18.6 ± 0.3 mm)	Gram-positive (Staphylococcus aureus), Gram-negative (E. coli), and P. aeruginosa	[2]
P. domestica gum loaded Gold NPs	Gum-loaded gold nanoparticles had the least effect on foregoing bacteria (S. aureus (10.5 ± 0.6 mm), E. coli (10 ± 0.4) mm, and P. aeruginosa (8.2 ± 0.3 mm)) compared to P. domestica gum loaded silver NPs and streptomycin	Gram-positive (S. aureus), Gram-negative (Escherichia coli), and P. aeruginosa	[2]
CS/PVA/GG	SEM results showed that surface morphology was more affected by mixing and bonding ratios. Also, The FTIR and XRD confirmed the strong intermolecular bonding between polymers. The study suggests that these blends have great potential to be used against Pasteurella multocida, S. aureus, E. coli, and B. subtilis bacterial agents since they managed to have a great bactericidal effect on these organisms	P. multocida, S. aureus, E. coli, and B. subtilis	[31]
Gum Karaya loaded with Copper oxide (CuO)	Bactericidal effect on both Gram-negative and positive cultures, especially, smaller NPs (4.8 ± 1.6 nm), which are highly stable and have maximum zone of inhibition compared to the larger size of synthesized CuO nanoparticles (7.8 ± 2.3 nm)	Gram-negative and positive cultures	[18]
Kondagogu gum loaded with Gold nanoparticles	The AuNPs showed good antibacterial activity against E. coli and Bacillus subtilis.	E. coli and B. subtilis	[21]
Kondagogu gum loaded with Silver nanoparticles	The minimum inhibitory concentration values were lower by 3.2- and 16-folds for Gram-positive S. aureus and Gram-negative E. coli strains, respectively. The minimum bactericidal concentration values were lower by 4 and 50-folds. Thus, the biogenic silver nanoparticles were found to be more potent bactericidal agents in terms of concentration. The study implies that this NP has strong effects on biofilms, indicating that it can have great effect on drug-resistant bacterial infections caused by biofilms. Also, the growth curve stated a faster inhibition in Gram-negative bacteria as compared to Gram-positive	Gram-positive S. aureus and Gram-negative E. coli	[32]
Gum Kondagogu loaded with; Selenium nanoparticles	In this study, NPs exhibited growth inhibition activity against Gram-positive bacteria only. B. subtilis and Micrococcus luteus showed respective inhibition zones of 6.3 and 8.6 mm at 12 μg. This study implies that the tree gum stabilized Se NPs have more applicability as a potent antioxidant nutrition supplement at a much lower dose, in comparison with ionic Se.	B. subtilis and M. luteus	[23]
Gum Kondagogu loaded with Copper nanoparticles	Anti-biofilm effect of gum Kondagogu extract stabilized copper NPs against clinical isolate Klebsiella Pneumoniae was demonstrated in this study	Klebsiella Pneumoniae	[24]

Table 2.

Plant gums loaded with NPs as antibacterial agents.

In another study, gum Tragacanth was used as a drug carrier for Ag NPs. The well-diffusion method was used to study the antibacterial activity of the synthesized silver nanoparticles. Bacterial suspension was prepared by growing a single colony of Gram-positive bacterial strain S. aureus and Gram-negative bacterial strains E. coli and P. aeruginosa overnight in nutrient broth and by adjusting the turbidity to 0.5 McFarland standard. Mueller Hinton agar plates were inoculated with this bacterial suspension, and 5 μg of Gum Tragacanth loaded with silver nanoparticles were added to the center well with a diameter of 6 mm. Culture plates loaded with discs of antibiotic, erythromycin (15 μg/disc) were included as positive controls. The result of this research is stated in Table 2.

Silver NPs can also be loaded on P. domestica plant gum according to research performed in 2017, which showed an antibacterial effect on both Gram-positive (Staphylococcus aureus) and Gram-negative (E. coli and P. aeruginosa) bacteria. Disc diffusion method was used for Antibacterial assay using Gram-positive (S. aureus), Gram-negative (Escherichia coli), and Pseudomonas aeruginosa, three independent experiments were carried out for each bacterial strain with streptomycin as the positive control. Au/Ag-NPs (5 μg) were dissolved in DMSO⁸ and incubated at 30°C for 24 h. the result and reference for this article are stated in the table down below.

Kondagogu gum loaded with silver nanoparticles also demonstrated antibacterial effect against Gram-positive S. aureus and Gram-negative E. coli. Variety of susceptibility assays was done in this study in order to demonstrate the antibacterial effects including micro-broth dilution, anti-biofilm activity, growth kinetics, cytoplasmic content leakage, membrane permeabilization, etc. The production of reactive oxygen species (ROS) and cell surface damage during bacterial nanoparticle interaction were also demonstrated using dichlorodihydrofluorescein diacetate, N-acetylcysteine; and scanning electron microscopy and energy-dispersive X-ray spectra.

4.2 Gold nanoparticles

Gold nanoparticles (AuNPs) can also be loaded on various plant gum drug carriers and be used as antibacterial agents. Gold nanoparticles (AuNPs) have exceptional stability against oxidation and therefore may play a significant role in the advancement of clinically useful diagnostic and therapeutic Nanomedicines. That being said, conventional process for synthesis of these metallic nanoparticles utilizes toxic reagents as reducing agents, additional capping agents for stability as well as surface functionalization for drug delivery purposes.

Just like silver NPs, P. domestica gum can also be loaded with AuNPs. Preparation and assessment in this study were performed like P. domestica gum-loaded silver NPs and the antibacterial effect was studied on Gram-positive (S. aureus), Gram-negative (E. coli and P. aeruginosa) bacteria.

Kondagogu gum is also one of the drug carriers that was used in a study for AuNPs in order to demonstrate their effects on E. coli and Bacillus subtilis. After the preparation of these NPs, their concentration, and reaction time on the synthesis of AuNPs were investigated by using techniques like UV-visible spectroscopy, FTIR, and XRD.

4.3 Copper nanoparticles

These nanoparticles may have great antibacterial effects if they are loaded on suitable plant gum drug carriers.

In a study, copper oxide (CuO) was used as a NP and was loaded on gum Karaya. The CuO nanoparticles were synthesized by a colloid-thermal synthesis process. The synthesized CuO was purified and dried to obtain different sizes of CuO nanoparticles. The well diffusion method was used to study the antibacterial activity of the synthesized CuO nanoparticles on gram-negative and positive cultures. The zone of inhibition, minimum inhibitory concentration, and minimum bactericidal concentration were determined by the broth microdilution method.

Gum Kondagogu loaded with Copper is another example of using plant gums as drug carriers for copper nanoparticles. The synthesized CuNPs were characterized by using Transmission Electron Microscopy (TEM), SEM, UV-visible spectroscopy, XRD, and FTIR experimental methods and then were tested on Klebsiella Pneumoniae.

4.4 Other nanoparticles

Various chemicals and drugs can be loaded on plant gums which can have a great antibacterial effects. For instance, in a study, chitosan and polyvinyl alcohol were loaded on Guar gum (CS/PVA/GG), then their effects were studied on Pasteurella multocida, S. aureus, E. coli, and B. subtilis. After the preparation of a mixture of chitosan/poly (vinyl alcohol)/guar gum (CS/PVA/GG), the ratio of swelling, together with antimicrobial properties, was studied. These components were characterized by scanning electron microscopy (SEM), Fourier Transform Infra-red (FTIR), and X-ray powder diffraction (XRD).

In another stud, selenium nanoparticles (Se NPs) were loaded on Gum Kondagogu. Role of gum on synthesis and mean particle size was studied using ultraviolet-visible spectroscopy and dynamic light scattering. Size of the NPs was determined (from 44.4 to 200 nm) and mean particle size was 105.6 nm. Antibacterial potential of these NPs on B. subtilis and Micrococcus luteus were checked with well diffusion assay.

It should be stated that the results for these studies and their related references are stated in the table down below.

5. Conclusion

Plant-based synthesis and stabilization of metal/metal oxide NPs have been successfully implemented by many researchers worldwide. These techniques have various advantages including being more affordable physically and financially, having better drug distribution, and having easier production. The major drawbacks of this method include the use of imprecise evaluation tools for the stability, aggregation behavior, size, shape of the NPs, and the subsequent systematic description of the application of the NPs as a result of their physical and chemical characteristics.

Based on these articles, using plant gums alone is less effective than being loaded with NPs substances and on some occasions, they even may have side effects on human body. For an instant, guar gum can lead to infection because of its high moisture if it’s not loaded with NPs.

Various metallic or non-metallic NPs can be created and added to these plant gums. Most frequent of them in these studies are AgNPs and AuNPs. Gold nanoparticles (AuNPs) have exceptional stability against oxidation, and therefore, may play a significant role in the advancement of clinically useful diagnostic and therapeutic Nanomedicines. That being said, conventional process for synthesis of these metallic nanoparticles utilizes toxic reagents as reducing agents, additional capping agents for stability as well as surface functionalization for drug delivery purposes. Also, according to various studies, they are less effective against microorganisms than AgNPs. AgNPs have a strong bactericidal and catalytic effect according to various studies. They are extremely beneficial for preventing drug-resistant bacteria which will be a huge issue in the future.

The influence of different parameters such as gum particle size, concentration of gum, concentration of silver nitrate, and reaction time on the synthesis of nanoparticles is quite significant in various studies. For instants, smaller NPs can have more bactericidal effects compared to their bigger counterparts. Thus, using the right concentration and technique for making these NPs are very important and should be considered.

The future use of tree gums also relies on the development of ultralightweight, high, strength, bio-based, biodegradable, porous, and tunable, two-dimensional (2D) membranes, and three-dimensional (3D) sponges with facile and easy to implement synthetic schemes. Each year scientists are getting more keen on researching about these green NPs because of various reasons including the significant growth in the number of antibiotic-resistant bacteria or climate change. Also, these NPs can be afforded and produced easily.

Acknowledgments

This study was supported by Isfahan University of Medical Sciences, Isfahan, Iran.

DM: designed the study. Supervised, conceptualized the paper, and edited the manuscript, MM and AT Conducted research and performed writing the manuscript.

Abbreviations

PMMA	poly-methyl methacrylate
MDR-GNB	multidrug-resistant Gram-negative bacteria
VRE	Vancomycin-Resistant Enterococci
MRSA	methicillin-resistant S. aureus
NPs	Nano-particles
GA	gum Arabic
GK	gum Karaya
GT	gum Tragacanth
KG	Kondagogu gum
GG	gum Ghatti
Hep G2	hepatocellular carcinoma cells
MCF-7	human breast carcinoma cells
GKNP	gum Karaya stabilized gold nanoparticles
CHO	chinese hamster ovary cells
GEM	gemcitabine hydrochloride
GEM-GNP	gemcitabine hydrochloride loaded nanoparticles
HH	hydrazine hydrate
CuNPs	copper nanoparticles
SGG	selenium-infused guar gum nanoparticles
PBS	phosphate buffer saline
DMSO	D-methyl-sulfoxide
CS/PVA/GG	chitosan/poly(vinyl alcohol)/guar gum
GA-AgNPs	gum acacia silver NPs
HDN	fruit flavonoid
SEM	scanning electron microscopy
FTIR	Fourier Transform Infra-red
XRD	X-ray powder diffraction
AuNPs	gold nanoparticles
AgNPs	silver nanoparticles
CuNPs	copper nanoparticles
Se NPs	selenium nanoparticles
ROS	reactive oxygen species