Nanotechnology is a branch of science that deals with nanomaterials with a size of less than 100nm. These nanoparticles have a wide variety of applications in the field of bioimaging, biosensors, drug delivery, gene therapy, etc. The main advantage of using nanoparticles is that they may be fabricated as desired depending upon the area of application. The size, surface chemistry and physiochemical properties may be changed as required by following the parameters of synthesis. Nanoparticles may also help in RNAi therapy that delivers siRNA, shRNA and miRNAs to the target site. The major drawback of using these RNA molecules in their bare form is the fragile nature that makes them degradable by the enzymes in the blood vascular system. In this regard, nanoparticles protect them from degradation as they may encapsulate the RNA molecules within their structure. There are mainly three types of nanoparticles such as inorganic, organic and polymeric nanoparticles. In this book, we are intended to discuss the wide variety of nanoparticles that are used in biosensing, bioimaging, drug delivery, gene therapy, immunotherapy and vaccination.

The ongoing research in nanotechnology has developed a number of different synthesis techniques of nanoparticles from a diverse range of materials such as metals, biological, metal oxides, ceramics, polymers, etc. Nanoparticles have a range of morphological, physical, chemical properties depending upon their synthesis and precursors that are important for their wide variety of applications such as biosensors, drug delivery, gene delivery, diagnostics and theragnostics. This study is intended to give a broader view of various synthesis methods available nowadays in the field of medicinal applications of nanoparticles. It also contains the advantages and shortfalls of the synthesis methods.

Nanoparticles used in the detection of biomolecules are being possibly used due to their physical and chemical properties that optimize them with unique characteristics. These properties enable the diagnosis of several disease conditions to make them available for treatment. This study is intended to discuss the emergence of this area and help the researchers in further progress in this field.

This study discusses the disadvantages of the use of currently available methods for diagnostic purposes. It also examines the advantages of the use of nanoparticles in this field of study. This study reviews the properties of metallic nanoparticles including gold and silver, and also quantum dot, silica nanoparticles, etc.

Nanotechnology has extended the limitation of the current diagnostic procedures. The potential of using nanoparticles in the diagnosis of diseases is unlimited. Safety study is needed for in vivo uses. Nanobiotechnology in clinical uses will play a valuable role in the future development of nanomedicines also.

The study of nanocarriers for drug delivery opens a novel platform for the development of delivery vehicles that can transport and control release the payload in the target disease tissue by the smart application of biotechnology and nanotechnology. This study highlights the parameters that can be fabricated to make the nanocarrier optimum for specific disease condition and their current clinical application areas. Moreover, this study also reports about the several organic and inorganic nanoparticles and their properties that make them unique as a drug delivery vehicle. Despite remarkable development in this area of application, nanocarriers demonstrate a significant amount of unwanted side effects, such as, cytotoxicity or off-target side effects that diminish their efficiency in the biotechnology and biomedical applications. A complex biological environment makes this field more complicated, so, deep knowledge of the biological condition is the most important before developing an optimum therapeutic solution.

Integrated DNA in nanoparticles show unique and augmented properties due to their synergistic activity on the biological system. Their capabilities are attracting the attention of researchers for their wide variety of applications in diagnostics, therapeutics, theranostics, biosensing, labeling, imaging, etc. In this study, we discuss these nanohybrids and their area of application. DNA incorporated within these nanoparticles helps in gene delivery to the targeted tissue. Sometimes, DNA aptamers can recognize specific target sequence by complementarity. They can target specific cell/tissue/organ to deliver their payload to that target site. However, it is clear that there are more things to be revealed in the application of nanoparticles in the biological system. The unique properties of nanomaterial have more to offer in this field of nanotechnology.

Gene silencing is a mechanism by which several protein expressions may be controlled in eukaryotes. Since its invention, many studies have been performed for its diagnostic and therapeutic intervention. siRNAs have created special attention for the treatment of incurable and difficult disease conditions. However, there are many challenges regarding their systemic administration and stability in the blood vascular system. In this regard, nanoparticles are demonstrating unique properties that may make this tool applicable as an advanced delivery vehicle. In this study, we have discussed various challenges for the use of bare siRNAs in the human body. We have also discussed the methods that may be used to fabricate the nanoparticles in order to deliver siRNAs. Moreover, we have included several nanoparticle conjugates with their advantages and disadvantages while using them as a delivery vehicle.

The recent trend of gene therapy includes the RNAi therapeutic approach. RNAi therapy comprises the delivery of siRNA, shRNA and miRNA molecules to the cells for gene silencing. Among these types, shRNA is a more stable knockdown method. However, bare shRNA molecules are large and they can not penetrate the cell membrane due to their negative charge and also they are fragile and degradable by RNase enzymes in the body. To overcome these problems, nanoparticles play a vital role. They encapsulate the shRNA within their structure and protect them from degradation. The nanoparticles are sometimes positively charged so they readily penetrate the cell membrane and are internalized by the cell. These features of the nanoconjugate made them a potential therapeutic agent. In this study, we intended to discuss the wide variety of nanoconjugates and their applications in diseases.

Micro RNAs are naturally occurring RNA molecules that help in the degradation of mRNA molecules sequence specifically. They degrade the mRNA molecules and thus inhibit the formation of protein after translation. miRNA expression varies from tissue to tissue and from one disease condition to other. Thus this molecule becomes a target of therapy in various types of disease conditions. But, the use of bare miRNAs has several drawbacks as they may degrade in the body fluid due to their fragile nature. So, in this regard nanoparticles have a very vital role to overcome these disadvantages. In this study, we intended to discuss the various forms of miRNA therapeutic approaches, along with various types of nanoparticles that may carry the miRNA and its antagomirs to the target site.

Immunostimulatory agents such as adjuvants, cytokines, and antibodies have a great potential for the treatment of disease conditions. However, their direct administration may lead to suboptimal pharmacokinetics, compromised targeting and vulnerability to biodegradation. To overcome these drawbacks, nanoparticles play a vital role and they improve the delivery mechanism of these therapeutic agents. The nanoparticle in conjugation elevates the bioavailability of the encapsulated payloads. In this study, we intended to discuss these immunostimulants when delivered by nanoparticles.

As a result of new emerging pathological conditions, new microorganisms have set a challenge in front of the researchers for the development of treatment and vaccination strategies. In the area of vaccine development, new effects have been made to invent new vaccines and also to improve the efficacy of the currently available vaccines. A wide variety of vaccines have been developed from killed whole organisms, subunits and RNA or DNA fractions. To overcome the side effects of these vaccines, nanoparticles may carry the payload and deliver them on the target site. The nanoparticles have the potential to improve the efficacy of these antigens and reduce the side effects to a large extent . These nanoparticles should have the ability of safe delivery of the antigens, protect them from degradation, control release and biocompatible. In this study, we intended to discuss different characteristics of the nanoparticles along with their properties and the variety of payloads for immunstimulation.

From the last half of the century, scientists are developing nanoparticles for a wide variety of applications. Novel synthesis methods are explored to make them ideal for medical applications. They may be used for the detection of biological or chemical substances for the diagnosis of many disease conditions. Moreover, drugs are also delivered through nanoparticles to the target organ. Further, RNAi therapy is also supported by nanoparticles that help in the delivery of siRNA/shRNA/miRNA to the target site. DNA molecules are also conjugated with nanoparticles for gene therapy. Other than drug or gene therapy, antigens and other immunomodulators are also delivered through nanoparticles to enhance the immune response. Different vaccination strategies are also followed through nanoparticles for increased immunostimulation.