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Global Translational Medicine Eco-friendly biomedical materials: A review

structures with dimensions in the nanometer scale 2. Metallic nanomaterials
(generally with at least one dimension between 1 and
100 nm). Nanomaterials have been useful for applications Metallic nanomaterial synthesis involves both top-down
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in dentistry, water treatment, drug delivery, and food and bottom-up methods. Researchers more commonly
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science. The characteristics of these materials such as shape use bottom-up chemical and biological techniques for
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and size can be controlled by changing the conditions in biomedical applications. These methods typically utilize
which they are synthesized. In addition, these parameters a metal precursor and a stabilizing agent to prevent
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have an impact on the physical and chemical properties nanoparticle agglomeration in an aqueous medium.
of the material. For instance, Suchomel et al. proposed a However, bottom-up methods often require high
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size-controlled synthesis of Au nanoparticles and evaluated temperatures or toxic solvents to produce the desired
the effect of this characteristic on the catalytic activity of nanomaterial. To address this issue, researchers have
the material. On the other hand, Zhang et al. presented proposed green approaches using bioactive components,
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a size-tunable synthesis of rhodium nanostructures and such as fungi, microorganisms, and plant materials as
subsequently studied their plasmonic properties. precursors and natural substances or solvents as stabilizing
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agents. Figure 1 illustrates the key aspects of these
Nanomaterials are generally synthesized through top- green approaches and some applications of the resulting
down (e.g., milling, laser ablation, etching) and bottom-up nanomaterials. The most prominent examples of these
(e.g., chemical vapor deposition [CVD], hydrothermal nanomaterials for biomedical applications include silver,
method) approaches with varying conditions of temperature copper, titanium zinc, and gold nanoparticles (AuNPs).
and pressure. However, many of these approaches require
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the usage of excessive amounts of energy and temperature 2.1. Silver nanoparticles (AgNPs)
along with the usage of solvents that are harmful to AgNPs have garnered significant attention in the
the environment. Because of this, green synthesis of biomedical field for their potent antibacterial and
nanomaterials has been proposed as an alternative to antimicrobial properties coupled with low toxicity. As
reduce the impact of producing these materials. Green depicted in Figure 2, AgNPs find diverse applications
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synthesis of materials and nanomaterials is defined as the in the biomedical realm, including cancer therapy,
usage of methods and procedures that intend to reduce wound dressings, antibacterial scaffolds, and protective
or eliminate toxic waste, energy consumption, secondary clothing. Green synthesis of these nanomaterials
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products, and chemical accidents and, on the other hand, involves the biological reduction of Ag to Ag using
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utilize catalysts, renewable resources, and more ecological species or compounds derived from plants or organisms,
solvents and precursors. 13-15 Nanomaterials synthesized
through green methods exhibit improved antimicrobial
activity and improved reducing and stabilizing properties.
For instance, Saratale et al. demonstrated that varying the
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amount of bio-reducing agents affects these characteristics
in metallic nanoparticles. The main advantages of
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green synthesis methods over traditional top-down and
bottom-up approaches can be seen in the environmental
impact they have as they generally do not require toxic
solvents (or they can be replaced by less toxic alternatives),
use lower synthesis temperatures and pressures (although
some of them require specific equipment such as
microwave-assisted and laser ablation methods, which
require increased amounts of energy) and have a lower
carbon footprint overall, as presented by the 12 principles
of green chemistry. 17
In this review, we examine nanomaterials employed for
biomedical applications and investigate green approaches
to their fabrication. These approaches offer the potential
to create sustainable materials while simultaneously
controlling biological, chemical, and physical properties Figure 1. A schematic showing the list of metallic and metallic oxide
by altering their morphology, shape, and size. Finally, we nanomaterials and their wide range of applications. The figure was created
discuss future perspectives and summarize key conclusions. using BioRender (https://www.biorender.com/).

Volume 3 Issue 4 (2024) 2 doi: 10.36922/gtm.4698