Synthetic vs. natural antimicrobial agents for safer textiles: a comparative review

Abstract

Textiles in all forms act as carriers in transmitting pathogens and provide a medium of microbial growth, especially in those fabrics which are used in sports, medical and innerwear clothing. More attention towards hygiene and personal healthcare made it a necessity to develop pathogen-free textiles. Synthetic and natural antimicrobial compositions are used to control and reduce microbial activity by killing or inhibiting microbial growth on textiles. Synthetic metallic nanoparticles of Ag, Zn, Cu Ti and Ga are the most commonly and recently used advanced nanocomposites. Synthetic organic materials such as triclosan, quaternary ammonium compounds, polyhexamethylene biguanide, and N-halamines have proven antimicrobial activity. Carbon quantum dots are one of the advanced nanomaterials prepared from different kinds of organic carbon material with photoluminescence efficiency also work efficiently in antimicrobial textiles. A greener approach for producing natural antimicrobial textiles has gained significant importance and demand for personal care due to their less toxic effects on health and the environment In comparison to synthetic. The naturally existing materials including extracts and essential oils of plants have significant applications for antimicrobial textiles. Additionally, a number of animal extracts are also used as antimicrobial agents include chitosan, alginate, collagen hydrolysate to prepare naturally treated antimicrobial textiles. This review focuses on the comparative performance of antimicrobial fabrics between synthetic and natural materials. Textiles with synthetic substances cause health and environmental concerns whereas textiles treated with natural compositions are more safe and eco-friendly. Finally, it is concluded that textiles modified with natural antimicrobial compositions may be a better alternative and option as functional textiles.

Fig. 1. Classification of antimicrobial and antiviral agents.

Fig. 2. Mechanism of action of metal nanoparticles as antimicrobial agents. Metal nanoparticles inactivate the virus by destroying the spikes and kill the bacteria and fungi by rupturing the cellular structures.

Fig. 3. Mechanism of action of organic materials as antimicrobial agents for textiles. QACs inactivate bacteria or yeast by interacting with their cell membranes. PHMB damages membrane proteins. N-Halamines disrupt electron transport functioning. Triclosan damages intracellular proteins and stops lipid synthesis.

Fig. 4. (a and b) Reproduced with permission from https://creativecommons.org/licenses/by-nc-sa/4.0/(a) Ag ions concentration measured by ICP-MS in washing liquids of the PAEMA-co-Ag fabric in accelerated laundering test; (b) the cytotoxicity of washing liquid on human HaCaT cells. The cells were exposed to different concentrations of PAEMA-co-Ag washing liquid at 5th. Accelerated laundering cycle and WOB detergent for 48 h ref. copyright (2014) https://nature.com. (c) Reproduced with permission from https://creativecommons.org/licenses/by/4.0/quantity of silver released from the seven textiles at the time of washing as well as rinsing. The inset presents an expanded outlook of the lower concentration range ref. copyright (2020) MDPI. (d)“TEM” image of colloidal material from sock wash water. Inset: EDX confirmation that the dark particles within the circle are predominantly silver. Reproduced with permission from “Reprinted with permission from {ref. }. Copyright {2008} American Chemical Society”.

Fig. 5. Mechanism of action of natural antimicrobial agents showing different natural antimicrobials target different cell functions.