Table 3.

Characteristics and observations from the systematic reviews.

Author	Year	Objective of Study	Summary Finding
Yun’an Qing et al. [36]	2018	To determine the potential antibacterial mechanisms of Ag-NPs. To elaborate methods to enhance the biocompatibility of Ag-NPs.	To avoid implant-related infection and show how Ag-NPs with high antibacterial efficacy are commonly used in implant surface modification.
Ferdous [51]	2020	To elucidate the factors such as the size, shape scale, surface chemistry, and stability. To examine how Ag-NPs’ antibacterial activities are influenced by structural factors, which could aid in the development of more effective Ag-NPs.	How the defined structural factors such as size, shape scale, surface chemistry, and stability affect the antibacterial mechanism of Ag-NPs.
Yin et al. [52]	2020	To gather the most up-to-date information on the biomedical applications of Ag-NP-based nanostructures.	It is centered on the recent data on Ag-NP-based nanostructures’ biomedical applications, and parameters such as toxicity, physiochemical, and bio-functional properties,
Ahmad et al. [53]	2019	To assess the green synthesis, characterization, and biological activities of Ag-NPs using a variety of biological sources.	In the field of nanotechnology, green synthesized Ag-NPs have unrivaled significance. Ag-NPs have a broad range of pharmacological operations, and their cost-effectiveness makes them a viable alternative to local medicines.
Hamelian et al. [57]	2018	To focus on Thymus-based green silver nanoparticle synthesis. To investigate an antibacterial, antioxidant, and cytotoxic effects of synthesized nanoparticles.	Thymus Kotschyanus extract was used in this study to synthesize Ag-NPs in an environmentally friendly, healthy, and practical way. There were no chemical substances involved. Silver nanoparticles with a diameter of 50 nm in this herb have a strong antibacterial and antioxidant impact.
Gumel et al. [26]	2019	To learn more about silver nanoparticle biogenesis and the mechanisms that underpin their antimicrobial efficacy.	The antimicrobial properties of silver nanoparticles and plant extracts, such as antibacterial and antifungal properties, are demonstrated in this report.
Escárcega-González et al. [54]	2018	To develop a green one-pot synthesis process for Ag-NP production that incorporates the Acacia rigidula extract as a therapeutic agent to treat pathogens.	The results show that the Ag-NPs used in this study can destroy pathogenic bacteria.
Nagar et al. [55]	2018	To investigate whether a leaf broth of A. indica can be used as a reducing and capping agent to synthesize Ag-NPs.	The biosynthesized Ag-NPs is classified using a variety of instrumental techniques. The particles were described as crystalline average size cubical particles with a high level of stability.
Ahmad et al. [40]	2019	This analysis focuses on the synthesis of biological MNPs by plants and microbes, as well as their cellular uptake, biocompatibility, cytotoxicity, and biomedical applications.	The synthesis of MNPs is influenced by temperature, incubation time, and pH. This study found that biologically synthesized MNPs had higher biocompatibility than MNPs synthesized using different physicochemical methods.
Mishra et al. [41]	2019	The aim of this research was to look into current Ag-NP biosynthesis trends; and To find out if they have antimicrobial activity and any biotechnological potential as well.	Ag-NPs are regarded as a crucial expansion in the continuum of nanomaterials due to the versatile qualities it offers in terms of application in various fields of study. It is likely that NP synthesis will be used in the future to make antimicrobial compounds in biomedical nanotechnology.
Mikhailov et al. [56]	2018	To synthesize Ag-NP using different physicochemical methods. To look at a certain synthetic method that use biological objects to make elemental silver nanoparticles.	At this time, experimentally determining the scale, form, etc. and feasibility of biosynthesized Ag-NP dispersion. Implementing silver nanoparticles NP biosynthesis and predefined parameters will eventually necessitate the development of new concepts and methods.
Roy et al. [42]	2019	To address recent developments in green synthesis of silver nanoparticles, while the mechanism of antimicrobial action underpins their use as antimicrobial agents.	Nanoparticles appear to be able to cross the membrane and cause damage. Loading drugs on the nanoparticle surface can increase the efficiency of biocidal motion in addition to disrupting the membrane.
Zulfiqar et al. [58]	2019	To determine if plant extract Fagonia cretica could be used as a reducing and stabilizing agent in the synthesis of Ag-NPs and to see how effective the extract is against bacteria.	According to morphological and structural characteristics, the study found Ag-NPs as hugely crystalline, averaging 16 nm size, and the presence of active bio-reducing and stabilizing agents in the Fagonia cretica extract. Ag-NPs revealed antibacterial activity against a few other plant extracts
Nasrollahzadeh et al. [43]	2019	To examine whether by reducing Ag+ ions (plant extracts) and controlling the size of the NPs, the Ag-based nanoparticles can be produced.	This research looked into the green synthesis of Ag-based nano catalysts such as Ag-NPs, AgPD NPs, and AU Ag-NPs.
Zafar et al. [44]	2019	To emphasize the importance of plant extracts in the bio-fabrication of nanoparticles as a renewable, non-toxic, and environmentally friendly process.	Ag-NPs have been shown to be effective in treating M. Incognita. Silver nanoparticles are used in food packaging to increase the shelf life of the product.
Nisar et al. [45]	2019	To assess the antimicrobial properties of various biosynthesized metal nanoparticles, as well as the mechanisms by which they work.	Several antimicrobial green-base nanoparticles have been successfully developed from a variety of biological sources, the most prominent of which are plants. These bio-nanomaterials have proved to be effective against bacterial and fungi that cause disease (both plant and human).
Some et al. [46]	2019	The goal of this work is to look into the synthesis and characterization of biomolecule-capped Ag-NPs; and To evaluate antimicrobial properties in the presence of human and plant pathogens.	Biomolecules act as both reducing and stabilizing agents in the green pathway, resulting in biocompatible NPs. In the literature, promising findings on Ag-NPs’ antimicrobial activity against a variety of pathogenic microorganisms have been recorded.
Haqq et al. [59]	2018	To examine the biological activities of Ag-NP and plant-mediated green synthesis.	The potential of Ag-NPs to perform in a number of bioassays has also been lauded. This study would help researchers create new Ag-NP-based drugs using green technology.
Ishak et al. 2019 [60]	2019	To share the latest research on metal and metal oxide nanoparticles, including silver and gold nanoparticles; and to issue directions and implementations for green synthesis methods based on plant extracts.	Plant extracts have attracted a lot of interest because of their ability to minimize and stabilize metal nanoparticles in a single phase using their unique natural properties.
El Shafey [48]	2020	To focus on MNP and Monps biosynthesis procedures, including a comparison of green synthesis and conventional chemistry methods, as well as several new directions for green synthesis of nanoparticles from various plant parts, particularly plant leaf extract.	The environmentally sustainable and general approach can be extended to a number of therapeutic and scientific uses, as well as other noble metals such as Ag and Pd. The low cost and ease of synthesis of antimicrobial nanoparticles using local plant extracts without the use of a toxic chemical reducer are the main advantages of the greener preparation methods.
de Aragao et al. [61]	2019	To make silver nanoparticles, researchers use a natural polysaccharide derived from red marine algae (Gracilaria birdiae). To monitor the antimicrobial activity of the synthesized NPs against representative strains of Staphylococcus aureus and Escherichia coli.	Ag-NPs were tested for antimicrobial activity against Gram-negative and Gram-positive Escherichia coli and Staphylococcus aureus, and both samples showed antimicrobial activity against E. coli. The Ag-NPs were made using natural sources such as red algae, which have favorable properties, in a simple, fast, and one-step process.
Hasnain et al. 2019 [62]	2019	Synthesis of stability in silver nanoparticles from extract of purple heart plant leaves using a biological reduction technique. To see if it is successful against bacteria.	According to antibacterial activity testing, purple heart plant extracts primarily resulted in the removal of silver ions and the stabilization of silver nanoparticles. These purple heart plant leaves extract-mediated synthesized silver nanoparticles have antibacterial activity against E. coli and S. aureus at a concentration of 100 µg/mL, which is much better than the extract concentration.
Khan et al. [39]	2018	To provide basic information about medicinal plants and silver nanoparticles and show whether they have antiviral, bactericidal, and fungicidal properties. To demonstrate how medicinal plants can be used in a wide range of applications.	Promising non-chemicals have no effect on adult bees (plant extracts). This study attempted to determine the current state of medicinal plant science worldwide.
Kumar et al. [49]	2019	The aim of this study was to plan, classify, and evaluate the potential of G-Ag-NPs as a wound treatment against human pathogenic bacteria.	According to the current study, the novel G-Ag-NPs demonstrated strong antibacterial properties against both Gram-negative and Gram-positive bacterial strains, suggesting that they have a lot of potential for treating pathogen-infected wounds.
Fahimirad et al. [47]		To gain a thorough understanding of the Ag-NPs synthesis process as it is mediated by plants. To evaluate antimicrobial and cytotoxic properties, as well as their implementations.	These nanoparticles were found to be non-toxic to normal human cells at therapeutic concentrations.
Singh et al. [36]	2020	To research into the green synthesis of different metal NPs that have been verified. To assess the antibacterial properties’ different modes and mechanisms.	Nanoparticles interact with DNA, enzymes, ribosomes, and lysosomes, influencing cell membrane permeability, oxidative stress, gene expression, protein activation, and enzyme activation.
Das et al. [63]	2020	To discuss the synthesis of Ag-NPs by plants and algae, as well as their use as an antimicrobial agent.	Ag-NP biosynthesis has been investigated using a number of plants and algae, as well as Ag-NP reduction using biological components.
Salleh et al. [50]	2020	To learn more about the mechanisms that cause Ag-NPs to have antiviral and antibacterial effects on microorganisms.	Ag-NPs’ specific physicochemical properties are influenced by a variety of factors, including scale, surfactant, and structure morphology.