The role of nanotechnology is increasingly important in our society. Through it, scientists are acquiring the ability to understand the structure and properties of materials and manipulate them at the scale of atoms and molecules. Nanomaterials are at the forefront of the rapidly growing field of nanotechnology. The synthesis of nanostructured materials, especially metallic nanoparticles, has attracted tremendous interest over the past decade due to their unique properties, making these materials excellent and indispensable in many areas of human activity. These special properties can be attributed to the small size and large specific surface area of nanoparticles, which are very different from those of bulk materials. Nanoparticles of different sizes and shapes are needed for many applications, so a variety of protocols are required to produce monodisperse nanoparticles with controlled morphology. The purpose of this review is firstly to introduce the reader to the basic aspects related to the field of nanotechnology and, secondly, to discuss metallic nanoparticles in greater detail. This article explains the basic concepts of nanotechnology, introduces methods for synthesizing nanoparticles, and describes their types, properties, and possible applications. Of many methods proposed for the synthesis of metal nanoparticles, a chemical reduction is usually preferred because it is easy to perform, cost-effective, efficient, and also allows control of the structural parameters through optimization of the synthesis conditions. Therefore, a chemical reduction method is discussed in more detail—each factor needed for the synthesis of nanoparticles by chemical reduction is described in detail, i.e., metal precursors, solvents, reducing agents, and stabilizers. The methods that are used to characterize nanomaterials are described. Finally, based on the available literature collection, it is shown how changing the synthesis parameters/methods affects the final characteristics of nanoparticles.

Vegetable oils are obtained by mechanical extraction or cold pressing of various parts of plants, most often: seeds, fruits, and drupels. Chemically, these oils are compounds of the ester-linked glycerol and higher fatty acids with long aliphatic chain hydrocarbons (min. C14:0). Vegetable oils have a variety of properties, depending on their percentage of saturation. This article describes sea-buckthorn oil, which is extracted from the well characterized fruit and seeds of sea buckthorn. The plant has a large number of active ingredients the properties of which are successfully used in the cosmetic industry and in medicine. Valuable substances contained in sea-buckthorn oil play an important role in the proper functioning of the human body and give skin a beautiful and healthy appearance. A balanced composition of fatty acids give the number of vitamins or their range in this oil and explains its frequent use in cosmetic products for the care of dry, flaky or rapidly aging skin. Moreover, its unique unsaturated fatty acids, such as palmitooleic acid (omega-7) and gamma-linolenic acid (omega-6), give sea-buckthorn oil skin regeneration and repair properties. Sea-buckthorn oil also improves blood circulation, facilitates oxygenation of the skin, removes excess toxins from the body and easily penetrates through the epidermis. Because inside the skin the gamma-linolenic acid is converted to prostaglandins, sea-buckthorn oil protects against infections, prevents allergies, eliminates inflammation and inhibits the aging process. With close to 200 properties, sea-buckthorn oil is a valuable addition to health and beauty products.

Currently, carriers of active ingredients in the form of particles of a size measured in nanometers are the focus of interest of research centers worldwide. So far, submicrometer emulsions, liposomes, as well as microspheres, and nanospheres made of biodegradable polymers have been used in medicine. Recent studies show particular interest in nanoparticles based on lipids, and at the present time, are even referred to as the “era of lipid carriers”. With the passage of time, lipid nanoparticles of the so-called first and second generation, SLN (Solid Lipid Nanoparticles) and nanostructured lipid carriers and NLC (Nanostructured Lipid Carriers), respectively, turned out to be an alternative for all imperfections of earlier carriers. These carriers are characterized by a number of beneficial functional properties, including, among others, structure based on lipids well tolerated by the human body, high stability, and ability to carry hydro- and lipophilic compounds. Additionally, these carriers can enhance the distribution of the drug in the target organ and alter the pharmacokinetic properties of the drug carriers to enhance the medical effect and minimize adverse side effects. This work is focused on the current review of the state-of-the-art related to the synthesis and applications of popular nanoparticles in medicine, with a focus on their use, e.g., in COVID-19 vaccines.