**7. Charactrisation of AgNP's**

#### **7.1 Visual and UV: Visible study**

To ascertain either AgNPs are developed or not visual and calorimetric appearance of samples checked by UV–Visible spectrophotometer before and after formulation of AgNPs at different time intervals. Before synthesis of AgNPs silver nitrate is colorless and herbal extract has definite color. Once AgNPs synthesized silver nitrate solution develop yellowish brown color after interacting with herbal extract which is confirmed by surface Plasmon resonance SPR and UV visible absorption in the specific range of 400–475 nm [75].

#### **7.2 FTIR analysis**

FTIR spectroscopy is an investigational tool to determine/conform functional groups priesnt in the moiety which is characteristic of that compound. Major

*Silver Micro-Nanoparticles - Properties, Synthesis, Characterization, and Applications*

When AgNP reaches toward cell they release Ag+ ions. These released ion then interact with sulfur and phosphorus containing compound present in cell wall. This lead to disarranged cell wall formation and small pits forms in the cell wall. Formed pit gives access to entry of ions and other foreign material to entry into cell. This increase intracellular osmotic pressure. As pressure built up in the cell, it begins to swell. Finally all these event lead to bursting of cell wall and cell lysis take place. This type of antimicrobial activity is more in gram −ve cell than gram +ve cell. As gram +ve cell have more cross linked peptidoglycan layer and teichic acid in their cell wall. The gram −ve cell have less or no peptidoglycane layer and have more lipopolysaccharide in their cell wall. So the AgNP's easily interact with gram −ve

As described in above when pit formation takes place in the cell wall, the Ag+ ions released by AgNP's get entered into cell. Then they reaches to mitochondria where they interact with thiolgoups and bind to NADPH dehydrogenase enzyme and liberates ROS. These formed ROS in mitochondria interacted with respiratory enzymes damage ATP formation and respiratory cycle of cell. Formed ROS also interact with protein, sulfur and phosphorus containing cell constituent. Also these formed ROS also bind to phosphorus elements of DNA and RNA which lead to inhibit cell replication and protein synthesis. Due to binding with DNA aggregation of damage protein sysnthesis which lead to cell death. Another possible action is by autophagy. AgNP's have ability to induce autophagy by accumulation of autophagolysosmes in human ovarian cancer cell. This autophagy work by mainly 2 ways; at lower level they increases cell life i.e. surviving rate, but when its level increase it

**5. Mechanism of action of silver nanoparticles**

**5.1 AgNP's antimicrobial MOA**

cell due less barrier [72].

**5.2 AgNP's anticancer MOA**

lead to cell death (**Figure 2**) [73].

*Anticancer mechanism of action of silver nano particles.*

**66**

**Figure 2.**

functional moieties present in AgNPs and herbal extract were identified by scanning the samples in the range of 4000 to 400 cm−1 [76].

#### **7.3 SEM/TEM analysis**

Scanning electron microscopy/Transmission electron microscopy mainly used to study surface morphology of synthesized AgNPs. SEM/TEM plates were prepared by addition of silver nitrate to develop smear of solution on slides. Conductivity was incorporated in system by making thin film of platinum which was coated on slides. Once the slides were ready they were scanned at 20 KV accelerating voltage and high quality images were captured [77].

#### **7.4 X-ray diffraction (XRD) analysis**

X-ray diffraction is a modern technique mainly utilized to identify state of matter either it is crystalline or amorphous in nature at different radiation angles. X-ray diffraction determines phases either crystalline/amorphous and cell dimension [78].

## **8. Application of silver nanoparticles**

#### **8.1 Antimicrobial activity**

Products prepared with silver nanoparticles have been permitted by no. of accredited bodies including USFDA, USEPA, Korea's testing body and SIAA of japan institute of research. Antimicrobial and antimicrobial potential potential of AgNPs containing silver sulfadiazine is incorporated in to medicines and used in burns to avoid infections. Nowadays AgNPs involved in extending field of nanotechnology and appears in many consumer products that include acne vulgaris cream and for deodorizing sprays. The antimicrobial properties of silver nanoparticles depend on size, environmental conditions (size, Ph, tonic strength) and capping agent. Recently an improvement in antimicrobial activity synergistic effect has been reported when silver naqnoparticles combined with ampicillin, amoxicillin and chloramphenicol on the contrary reports showed antagonistic interaction between silver nanoparticles and amoxicillin or oxacillin antibiotic combined with silver nanoparticles have suggested improve therapeutic activity (**Figure 4**) [79, 80].

#### **8.2 Antiviral activity**

Antiviral activity of silver nanoparticles have proven to exert antiviral activity against HIV-1 at non cytotoxic concentration but the mechanism underlying their HIV inhibitory activity has not been fully elucidated. The study from intranasal silver nano particles administration in mice increased survical, lower lung viral titer levels, minor pathologic lesions in lung disease, and remarkable survival benefit after infection with the H3N2 influenza virus, suggesting that AgNPs had significant role in mice survival. Biologically prepared silver nano particles inhibited the viability in herpes simplex virus (HSV) types 1 and 2 and human para influenza virus type 3 based on size and zeta potential. The treatment of vero cells with non-cytotoxic concentrations of silver nanoparticles significantly inhibited by the replication of paste des petits ruminants virus (PPRV). The mechanisms of viral replication are due to the interaction of silver

**69**

*Silver Nanoparticles: Properties, Synthesis, Characterization, Applications and Future Trends*

nanoparticles with the virion core. Tannic acid mediated synthesis of various various sizes of silver nanoparticles capable of reducing HSV-2 infectivity both in in-vitro and in-vivo through direct interaction, blocked virus attachment,

Silver nano particles are one of the most attractive nonmaterial's for commercialization applications. As antibacterial agents silver nanoparticles were used for wide range of applications from disinfecting medical devices and home appliances to water treatment. AgNPs promisingly used in drastic fields such as healthcare products, food storage, textile and medicinal devices. In antibacterial potential AgNPs free silver ions are released at slower rate along with higher surface area which produces noxious environment and this is the main reason for broad spec-

AgNPs has prominent anticancer potential as it discourage mitochondrial respiratory chain, increase reactive oxygen species (ROS) rate of synthesis which finally leads to DNA damage and cancerous cell death. Yu-Guo Yuan in 2018 revealed that the combination of camptothecin and silver nanoparticles treatment significantly increases the levels of cancer cells. It increases oxidative stress markers and decrease ant oxidative stress markers compared to single treatment. Overall these results suggested that camptothecin and silver nanoparticles cause cell death by inducing the mitochondrial membrane permeability change and activation of caspase. The synergistic cytotoxicity and apoptosis effect seems to be associated with enhanced ROS formation and depletion of antioxidant. Certainly a combination of CPT and silver nano particles provide advantageous effect in treatment of cervical cancer

*DOI: http://dx.doi.org/10.5772/intechopen.99173*

penetration and further spread [81, 82].

trum antibacterial potential of AgNPs [83].

**8.3 Antibacterial activity**

*Applications of silver nanoparticles.*

**Figure 4.**

**8.4 AgNP's in cancer control**

compared to immunotherapy [84].

*Silver Nanoparticles: Properties, Synthesis, Characterization, Applications and Future Trends DOI: http://dx.doi.org/10.5772/intechopen.99173*

**Figure 4.** *Applications of silver nanoparticles.*

*Silver Micro-Nanoparticles - Properties, Synthesis, Characterization, and Applications*

ning the samples in the range of 4000 to 400 cm−1 [76].

erating voltage and high quality images were captured [77].

**7.4 X-ray diffraction (XRD) analysis**

**8. Application of silver nanoparticles**

**7.3 SEM/TEM analysis**

cell dimension [78].

(**Figure 4**) [79, 80].

**8.2 Antiviral activity**

**8.1 Antimicrobial activity**

functional moieties present in AgNPs and herbal extract were identified by scan-

Scanning electron microscopy/Transmission electron microscopy mainly used to study surface morphology of synthesized AgNPs. SEM/TEM plates were prepared by addition of silver nitrate to develop smear of solution on slides. Conductivity was incorporated in system by making thin film of platinum which was coated on slides. Once the slides were ready they were scanned at 20 KV accel-

X-ray diffraction is a modern technique mainly utilized to identify state of matter either it is crystalline or amorphous in nature at different radiation angles. X-ray diffraction determines phases either crystalline/amorphous and

Products prepared with silver nanoparticles have been permitted by no. of accredited bodies including USFDA, USEPA, Korea's testing body and SIAA of japan institute of research. Antimicrobial and antimicrobial potential potential of AgNPs containing silver sulfadiazine is incorporated in to medicines and used in burns to avoid infections. Nowadays AgNPs involved in extending field of nanotechnology and appears in many consumer products that include acne vulgaris cream and for deodorizing sprays. The antimicrobial properties of silver nanoparticles depend on size, environmental conditions (size, Ph, tonic strength) and capping agent. Recently an improvement in antimicrobial activity synergistic effect has been reported when silver naqnoparticles combined with ampicillin, amoxicillin and chloramphenicol on the contrary reports showed antagonistic interaction between silver nanoparticles and amoxicillin or oxacillin antibiotic combined with silver nanoparticles have suggested improve therapeutic activity

Antiviral activity of silver nanoparticles have proven to exert antiviral activity against HIV-1 at non cytotoxic concentration but the mechanism underlying their HIV inhibitory activity has not been fully elucidated. The study from intranasal silver nano particles administration in mice increased survical, lower lung viral titer levels, minor pathologic lesions in lung disease, and remarkable survival benefit after infection with the H3N2 influenza virus, suggesting that AgNPs had significant role in mice survival. Biologically prepared silver nano particles inhibited the viability in herpes simplex virus (HSV) types 1 and 2 and human para influenza virus type 3 based on size and zeta potential. The treatment of vero cells with non-cytotoxic concentrations of silver nanoparticles significantly inhibited by the replication of paste des petits ruminants virus (PPRV). The mechanisms of viral replication are due to the interaction of silver

**68**

nanoparticles with the virion core. Tannic acid mediated synthesis of various various sizes of silver nanoparticles capable of reducing HSV-2 infectivity both in in-vitro and in-vivo through direct interaction, blocked virus attachment, penetration and further spread [81, 82].

#### **8.3 Antibacterial activity**

Silver nano particles are one of the most attractive nonmaterial's for commercialization applications. As antibacterial agents silver nanoparticles were used for wide range of applications from disinfecting medical devices and home appliances to water treatment. AgNPs promisingly used in drastic fields such as healthcare products, food storage, textile and medicinal devices. In antibacterial potential AgNPs free silver ions are released at slower rate along with higher surface area which produces noxious environment and this is the main reason for broad spectrum antibacterial potential of AgNPs [83].

#### **8.4 AgNP's in cancer control**

AgNPs has prominent anticancer potential as it discourage mitochondrial respiratory chain, increase reactive oxygen species (ROS) rate of synthesis which finally leads to DNA damage and cancerous cell death. Yu-Guo Yuan in 2018 revealed that the combination of camptothecin and silver nanoparticles treatment significantly increases the levels of cancer cells. It increases oxidative stress markers and decrease ant oxidative stress markers compared to single treatment. Overall these results suggested that camptothecin and silver nanoparticles cause cell death by inducing the mitochondrial membrane permeability change and activation of caspase. The synergistic cytotoxicity and apoptosis effect seems to be associated with enhanced ROS formation and depletion of antioxidant. Certainly a combination of CPT and silver nano particles provide advantageous effect in treatment of cervical cancer compared to immunotherapy [84].

#### **8.5 Antidiabetic activity of AgNP's**

Tephrosiatinctoria stem extracts mediated silver nano particle synthesis was evaluated for control of blood suger levels. AgNP's scavenged free radicals, reduced the levels of enzymes that bring about hydrolysis of complex carbohydrates (α α − − *glucosidase amylase* ) and as a result of which there is an increase in consumption ratr of glucose. The promising antidiabetic activity of shown by *Ananascomosus* (L.) silver nanoparticles. In dose dependent manner. AC-AgNP's inhibit α-glucosidase enzyme in stomach. Which is helpful in non-insulin diabetic patient. Also the silvernanoparticles synthesized with *Argyreia nervosa*leaf extract shown great antidiabetic activity. They inhibit mainly enzymes that digest the carbohydrates into monosaccharide and reduce blood glucose level [85, 86].

#### **8.6 Different field application of AgNp's**

Studies can contracting on the therapeutic applications of AgNP's in the gastrointestinal tract have displayed that gastric cells can be sensitized to radiation by the use of AgNP's and they may bypass the stomach and instead release the drug in small intestine. Apart from the health related applications; Silver Nanoparticles are act as a brilliant heterogeneous catalyst used for reduction of halogenated organic pollutants. Also it increases the bleaching power of organic dyes. The tubular shaped silver Nanoparticles have a very potent catalytic activity so they can used as a catalyst. In case of water treatment when the biosynthesized Silver Nanoparticles which are biologically synthesized on nitrocellulose membrane filters, can used for the promising inhibition and inactivation of microbes like *E. coli* and *Enterococcus faecalis*, etc. Rather as the silver Nanoparticles are the very good antimicrobial agents so they are used as the preservatives in various food and agricultural products [87].

#### **8.7 Antifungal activity of AgNPs**

AgNP's play important role as antifungal agents against various diseases caused by fungi. Biologically synthesized AgNP's shows enhanced antifungal activity with fluconazole against *phomaglomerata*, *Candida albicans* species. AgNP's stabilized by sodium dodecyl sulphate showed greater antifungal activity against *Candida albicans* compared to conventional antifungal agents. The AgNP's synthesized by bacillus species exhibit strong antifungal activity against the plant pathogenic fungus *fusariumoxysporum* at concentration of 8 μg/ml. AgNP's shown promising antifungal activity on *T. asahii* with MIC of 0.5ug/ml by damaging cell wall and components of cell. Due to size of nanoparticles they easily penetrate into cell. Where it binds to different cell components and inhibits cell functions. In combination with antimicrobial agents like ketoconazole shown great antifungal activity with MIC less than 0.5 mg/ml against the Malassezia where they give synergistic effect with ketoconazole it form pores in cell to show antifungal activity [88, 89].

#### **8.8 Anti angiogenic activity of AgNP's**

Antiangiogenic potential of green synthesized AgNP's in retinal endothelial cells model mainly produced by inhibition, proliferation and migration of BRECs at 500 nM concentration. In CAM model (chicken embryo chorioallantoic membrane) the silver nanoparticles inhibit angiogenesis approximately up to 73%. In comparison to other antiangiogenic molecules. They give dose dependent cytototoxic action on endothelial cell present in blood vessels to inhibit formation of new blood vessel in tumor region. Also the by using the same model i.e. by CAM

**71**

docking methods [93].

**9. Future prospects**

*Silver Nanoparticles: Properties, Synthesis, Characterization, Applications and Future Trends*

assay the silver nanoparticle synthesized by *Rubinatinctorum* shown antigiogenic activity. Ru-AgNP's shown inhibitory action on blood vessels. In CAM model, there is decrease in length of embryo resulted out due to the antiangiogenic action of

Nanoparticles have advantage over today's therapies because they can be engineered to have certain properties or to in certain way. They are helpful in cellular imaging. Silver plays an important role in imaging systems due to its stronger and sharper Plasmon resonance. Currently biosensor made with silver used as powerful tool to detect cytochrome P53 of squamous cell cancer of head and neck. Due to the colorimetric sensing property the silver Nanoparticles are applicable to detect the heavy metal ions of nickel, cobalt and mercury along with the sulfide traces. Among all the types of silver Nanoparticles, especially the triangular shaped silver Nanoparticles have higher anisotropy and lightening rod effect which leads to its wide use in manufacturing of Plasmon sensors or Plasmon detectors which are used to detect the mercurial ions in the solution. Also the silver Nanoparticles are used to develop the electrochemical sensor which is used to detect common herbicide atrazine. On the other hand the in situ growth and development of silver Nanoparticles on polydopamine traced filter paper is responsible for the quick collection and

AgNPs have been known for its antimicrobial but the anti-inflammatory response is still limited. Rats treated intra colonic ally with 4 mg/kg or orally with 40 mg/kg of nanocrystalline silver (NP32101) showed significantly reduced colonic inflammation. AgNPs showed rapid healing and improved cosmetic appreance occurring in dose dependent manner. Silver Nanoparticles made by using the extraction method with petroleum ether and some small amount of ethyl acetate are having potent cyclooxigenase-2 inhibition property. So, as one can add the natural extract of anti-inflammatory activity to this silver Nanoparticles extracted with petroleum ether, the anti-inflammatory activity of the resulted silver Nanoparticles get increased. Recently some scientists were done the extraction of soft coral named nephthea sp. Which already possessing the anti-inflammatory activity and extracted the silver Nanoparticles with petroleum ethers then the produced silver Nanoparticles of nephthea sp. having very potent anti-inflammatory activity which were estimated by analysis and molecular

AgNPs has potential applications in healthcare system and treating infectious diseases and it is emerging as remedies for large no of resistant bacteria infections along with it is known for its anti-inflammatory potential. Apart from it has numerous application in biological and research fields such as electrochemistry, biochemistry, nanoprism synthesis, garments, detergents and soap industry, involved in devising water purification system, and surgical instrument. Nowadays Ag-NPs opened new era as it has used in artificial implants which decreeing dependency on antibiotics. Studies have been revealed that Ag-NPs have novel potential in development of new pharmaceutical dosage forms and AgNPs cures inflammation

**8.9 Diagnostic, biosensor and gene therapy applications of AgNP's**

detection of green colored residue of malachite [92].

**8.10 Anti-inflammatory activity of AgNP's**

*DOI: http://dx.doi.org/10.5772/intechopen.99173*

Ru-AgNP's [90, 91].

assay the silver nanoparticle synthesized by *Rubinatinctorum* shown antigiogenic activity. Ru-AgNP's shown inhibitory action on blood vessels. In CAM model, there is decrease in length of embryo resulted out due to the antiangiogenic action of Ru-AgNP's [90, 91].

### **8.9 Diagnostic, biosensor and gene therapy applications of AgNP's**

Nanoparticles have advantage over today's therapies because they can be engineered to have certain properties or to in certain way. They are helpful in cellular imaging. Silver plays an important role in imaging systems due to its stronger and sharper Plasmon resonance. Currently biosensor made with silver used as powerful tool to detect cytochrome P53 of squamous cell cancer of head and neck. Due to the colorimetric sensing property the silver Nanoparticles are applicable to detect the heavy metal ions of nickel, cobalt and mercury along with the sulfide traces. Among all the types of silver Nanoparticles, especially the triangular shaped silver Nanoparticles have higher anisotropy and lightening rod effect which leads to its wide use in manufacturing of Plasmon sensors or Plasmon detectors which are used to detect the mercurial ions in the solution. Also the silver Nanoparticles are used to develop the electrochemical sensor which is used to detect common herbicide atrazine. On the other hand the in situ growth and development of silver Nanoparticles on polydopamine traced filter paper is responsible for the quick collection and detection of green colored residue of malachite [92].

#### **8.10 Anti-inflammatory activity of AgNP's**

AgNPs have been known for its antimicrobial but the anti-inflammatory response is still limited. Rats treated intra colonic ally with 4 mg/kg or orally with 40 mg/kg of nanocrystalline silver (NP32101) showed significantly reduced colonic inflammation. AgNPs showed rapid healing and improved cosmetic appreance occurring in dose dependent manner. Silver Nanoparticles made by using the extraction method with petroleum ether and some small amount of ethyl acetate are having potent cyclooxigenase-2 inhibition property. So, as one can add the natural extract of anti-inflammatory activity to this silver Nanoparticles extracted with petroleum ether, the anti-inflammatory activity of the resulted silver Nanoparticles get increased. Recently some scientists were done the extraction of soft coral named nephthea sp. Which already possessing the anti-inflammatory activity and extracted the silver Nanoparticles with petroleum ethers then the produced silver Nanoparticles of nephthea sp. having very potent anti-inflammatory activity which were estimated by analysis and molecular docking methods [93].

### **9. Future prospects**

AgNPs has potential applications in healthcare system and treating infectious diseases and it is emerging as remedies for large no of resistant bacteria infections along with it is known for its anti-inflammatory potential. Apart from it has numerous application in biological and research fields such as electrochemistry, biochemistry, nanoprism synthesis, garments, detergents and soap industry, involved in devising water purification system, and surgical instrument. Nowadays Ag-NPs opened new era as it has used in artificial implants which decreeing dependency on antibiotics. Studies have been revealed that Ag-NPs have novel potential in development of new pharmaceutical dosage forms and AgNPs cures inflammation

*Silver Micro-Nanoparticles - Properties, Synthesis, Characterization, and Applications*

Tephrosiatinctoria stem extracts mediated silver nano particle synthesis was evaluated for control of blood suger levels. AgNP's scavenged free radicals, reduced

− − *glucosidase amylase* ) and as a result of which there is an increase in con-

Studies can contracting on the therapeutic applications of AgNP's in the gastrointestinal tract have displayed that gastric cells can be sensitized to radiation by the use of AgNP's and they may bypass the stomach and instead release the drug in small intestine. Apart from the health related applications; Silver Nanoparticles are act as a brilliant heterogeneous catalyst used for reduction of halogenated organic pollutants. Also it increases the bleaching power of organic dyes. The tubular shaped silver Nanoparticles have a very potent catalytic activity so they can used as a catalyst. In case of water treatment when the biosynthesized Silver Nanoparticles which are biologically synthesized on nitrocellulose membrane filters, can used for the promising inhibition and inactivation of microbes like *E. coli* and *Enterococcus faecalis*, etc. Rather as the silver Nanoparticles are the very good antimicrobial agents so they are

AgNP's play important role as antifungal agents against various diseases caused by fungi. Biologically synthesized AgNP's shows enhanced antifungal activity with fluconazole against *phomaglomerata*, *Candida albicans* species. AgNP's stabilized by sodium dodecyl sulphate showed greater antifungal activity against *Candida albicans* compared to conventional antifungal agents. The AgNP's synthesized by bacillus species exhibit strong antifungal activity against the plant pathogenic fungus *fusariumoxysporum* at concentration of 8 μg/ml. AgNP's shown promising antifungal activity on *T. asahii* with MIC of 0.5ug/ml by damaging cell wall and components of cell. Due to size of nanoparticles they easily penetrate into cell. Where it binds to different cell components and inhibits cell functions. In combination with antimicrobial agents like ketoconazole shown great antifungal activity with MIC less than 0.5 mg/ml against the Malassezia where they give synergistic effect with ketoconazole it form pores in cell to show antifungal activity [88, 89].

Antiangiogenic potential of green synthesized AgNP's in retinal endothelial cells model mainly produced by inhibition, proliferation and migration of BRECs at 500 nM concentration. In CAM model (chicken embryo chorioallantoic membrane) the silver nanoparticles inhibit angiogenesis approximately up to 73%. In comparison to other antiangiogenic molecules. They give dose dependent cytototoxic action on endothelial cell present in blood vessels to inhibit formation of new blood vessel in tumor region. Also the by using the same model i.e. by CAM

the levels of enzymes that bring about hydrolysis of complex carbohydrates

sumption ratr of glucose. The promising antidiabetic activity of shown by *Ananascomosus* (L.) silver nanoparticles. In dose dependent manner. AC-AgNP's inhibit α-glucosidase enzyme in stomach. Which is helpful in non-insulin diabetic patient. Also the silvernanoparticles synthesized with *Argyreia nervosa*leaf extract shown great antidiabetic activity. They inhibit mainly enzymes that digest the carbohydrates into monosaccharide and reduce blood glucose level [85, 86].

used as the preservatives in various food and agricultural products [87].

**8.5 Antidiabetic activity of AgNP's**

 α

**8.6 Different field application of AgNp's**

**8.7 Antifungal activity of AgNPs**

**8.8 Anti angiogenic activity of AgNP's**

(α

**70**

of bladder which tremendous application in healthcare systems. AgNPs useful in animal models for detection of biosensors [94]. A reliable mechanism responsible for the impressive biological activity of AgNPs is considered to be a key factor in future research. Wide scope to aware control the release of silver and improving the stability of AgNPs used in medical and mechanical devices.
