In recent years, nanotechnology has emerged as one of the most advanced and attractive scientific fields, drawing significant attention from researchers in various disciplines such as pharmacy, materials engineering, biology, and physics. One of the most promising branches of this technology is the application of nanoparticles in advanced drug delivery systems and targeted therapy. Nanoparticles are extremely small particles, typically ranging from 1 to 100 nanometers in size, and they exhibit unique physical and chemical properties. These characteristics have enabled the widespread use of nanoparticles in medicine, modern pharmaceutical sciences, biotechnology, electronics, materials science, and environmental applications.
The term “nano” originates from ancient Greek, meaning “dwarf,” and later entered Latin to denote extreme smallness. In the International System of Units (SI), the prefix nano represents one-billionth (10⁻⁹) of a unit and serves as the basis of the nanoscale. At the nanoscale, materials exhibit behaviors that differ significantly from their bulk counterparts. These behaviors include distinct mechanical, electrical, thermal, and chemical properties of nanomaterials, which arise from quantum effects and the high surface-to-volume ratio of nanoparticles.
Definition of Nanoparticles and Their Importance in Pharmacy
Pharmaceutical nanoparticles are solid, submicron drug carriers that encapsulate therapeutic agents and enable controlled drug release, improved drug solubility, and targeted delivery to specific tissues or cells. Researchers generally classify these nanoparticles into two main types: nanospheres, which uniformly disperse the drug within a polymeric matrix, and nanocapsules, which confine the drug inside a cavity surrounded by a polymeric shell. The unique design of these structures allows the incorporation of both hydrophilic and hydrophobic drugs, making them highly suitable for pharmaceutical applications and targeted drug delivery systems.
Classification of Nanoparticles
Based on their dimensions and structure, nanoparticles are classified into three major categories. One-dimensional (1D) nanostructures include thin films and nanosurfaces that have found extensive applications in electronics, chemistry, and materials engineering.These thin films, with thicknesses ranging from 1 to 100 nanometers, play a key role in solar cells, chemical and biological sensors, and optical systems. Carbon nanotubes (CNTs) best represent two-dimensional (2D) nanostructures; they consist of hexagonal networks of carbon atoms with diameters of approximately 1 nanometer and lengths that can reach up to 100 nanometers.
Carbon nanotubes are further classified into single-walled and multi-walled types. Their exceptional mechanical strength and high electrical conductivity have made them valuable in nanoelectronics and advanced electronic applications. Three-dimensional (3D) nanoparticles include fullerenes and dendrimers. Fullerenes form spherical carbon structures that resemble a soccer ball and exhibit remarkable physical properties, whereas dendrimers form highly branched polymers with precisely controlled nanoscale architectures and serve widely in targeted drug delivery and medical imaging.
In addition, quantum dots constitute an important class of nanoparticles. These semiconductor particles, typically 2 to 10 nanometers in size, possess unique optical and electronic properties and find widespread application in rapid DNA assays, medical imaging, and tissue engineering.
Methods for Nanoparticle Preparation
Researchers have developed various techniques to prepare pharmaceutical nanoparticles, and they choose the appropriate method based on the chemical properties of the polymer and the nature of the drug.Commonly used methods include the emulsion–solvent evaporation method, double emulsion technique, salting-out method, solvent diffusion method, and solvent displacement (precipitation) method. Researchers extensively employ these approaches to synthesize polymeric and drug-loaded nanoparticles.
Characteristics and Characterization
Commonly characterized in terms of size, shape, and surface charge. The primary analytical techniques include scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM). The size of nanoparticles plays a crucial role in determining their physical stability, drug release kinetics, and biodistribution within the body.
Advantages of Nanoparticles in Drug Delivery
The use of nanoparticles in nano drug delivery systems offers numerous advantages, including enhanced drug bioavailability, reduced dosage requirements, controlled drug release, targeted delivery to specific tissues or cells, integration of diagnosis and therapy (theranostics), and improved stability of drugs sensitive to environmental conditions.
Disadvantages and Risks
Despite their significant potential, nanoparticles may pose certain risks. For instance, titanium dioxide nanoparticles and carbon nanotubes have been reported to induce pulmonary inflammation or cellular toxicity. Additionally, some dendrimers may damage cell membranes due to their surface charge, highlighting the importance of evaluating nanoparticle safety and biocompatibility.
Applications of Nanoparticles in Various Scientific Fields
Widely utilized across diverse scientific and industrial fields, including medicine, pharmacy, cosmetic industries, materials science, food technology, environmental protection, energy production, electronics, and agricultural sciences.
Future Perspectives of Nanoparticles
Nanotechnology and nanoparticle-based systems hold great promise for the future of pharmaceutical sciences. They are expected to play a critical role in personalized medicine and targeted therapies by improving therapeutic efficacy while minimizing side effects.
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