## 3 Description of the State of Knowledge  
### Antifungal Activity of Silver Nanoparticles against Candida Species  
Silver nanoparticles are regarded to have antifungal properties, but the number of studies confirming this feature is currently insufficient. Although fungal infections are not as widespread as bacterial infections, the incidence of fungal infections has been increasing in recent years. An especially alarming phenomenon is the increasing drug resistance, which is an even more serious problem due to the small arsenal of antifungal agents available on the market. Currently, the most commonly used systemic drugs are amphoteric B, nystain, fluconazole, and itraconazole, but their solubility and bioavailability are not satisfactory [19; 20; 21]. In addition, their use is associated with the risk of side effects, such as allergic and severe skin reactions. Fungal infections often affect and pose a serious threat to immunocompromised patients [22; 23; 24]. Yeasts of the genus _Candida_ are considered to be the most common cause of invasive fungal disease in such individuals. They can lead to bloodstream infections, which are associated with high mortality despite treatment [25]. The most common representative of this species is _Candida_ albicans. It is part of the healthy human microflora, where it exists as a harmless commensal. However, if the natural balance in the microbiome is disturbed, e.g., in subjects with reduced immunity, it can become the cause of life-threatening infections. In addition, _C. albicans_ has the ability to form a biofilm. It is a tightly packed community of cells that can grow on biotic and abiotic surfaces. This form is very difficult to combat with the use of traditional drugs [26]. Studies have shown that AgNPs have good activity against _Candida_ spp. They can both inhibit the growth of yeast cells and influence various virulence factors, e.g., biofilm formation. The antifungal activity of AgNPs against _C. albicans_ was investigated by [PERSON] et al. [27]. AgNPs were coated with polyvinylpyrrolidone (PVP) for water dispersion. Five isolates of _C. albicans_ were used in the study and the minimum inhibitory concentration (MIC) was determined. The MIC values of AgNPs against _C. albicans_ isolates ranged between 24 and 12 \(\upmu\)g/mL. They were compared to fluconazole, which had an MIC value of 20 \(\upmu\)g/mL. In this study, AgNPs were even more potent than fluconazole against some strains of _C. albicans_. In another study, AgNPs were synthesized using ribose sugars as reducing agents and sodium dodecyl sulfate (SDS) as a blocking agent. The antifungal activity of these nanoparticles was evaluated against 30 strains of _Candida_ spp. (14 _C. albicans_ and 16 _C. tropicalis_) isolated from blood samples from hospitalized patients. The tested strains showed a strong sensitivity to the nanoparticles used [28]. It was shown that silver nanoparticles are also effective against _C. albicans_ biofilm with the half maximal inhibitory concentration (IC\({}_{50}\)) of 0.089 ppm [29]. Recent studies conducted using an iturin-AgNPs complex also showed excellent antifungal activity of the synthesized  
Figure 3: Diagram illustrating the approach to collecting and analyzing information. molecules (MIC = 1.25-5 \(\upmu\)g/mL) against _C. albicans_. Moreover, the mechanism of the antifungal activity of the tested complex was revealed. Iturin-AgNPs caused damage to the integrity of the cell membrane, which in turn increased its permeability and the leakage of intracellular proteins and nucleic acids outside the cell [30]. In a study conducted by [PERSON] et al. [31], silver nanoparticles were synthesized using the sugarcane process by-product (molasses) and named Mo-capped AgNPs. The synthesized molecules showed promising activity against _C. albicans_ DAY185 with an MIC of 16 \(\upmu\)g/mL.