Preface

Traditional drug administration faces numerous challenges, such as full dosage absorption and efficient targeting, undesirable secondary effects and damage to the liver and kidneys, and inflammation and immune response. Drug carriers can combat these challenges by promoting drug absorption, enhancing targeting, and avoiding or decreasing secondary effects. Some drug carriers can even camouflage the drug from the immune system. Moreover, carriers can permit controlled release, which provides prolonged delivery of a drug while maintaining its blood concentration within therapeutic limits. This book discusses different novel and traditional strategies to create and characterize drug carrier systems using nanotechnology, microfluidics devices, and more.

This book is divided into two sections. The first section describes several drug carrier systems, and the second section focuses on nanotechnology. The book includes nine chapters.

Chapter 1 presents, describes, and discusses some examples of drug carriers such as electrospun nanofibers, aptamers, micelles, and liposomes, unfolding the properties and polymers used in each system. It is observed that fast dissolving administration is the most recommended strategy for a drug carrier system. Drug carriers have numerous advantageous properties such as biocompatibility, biodegradability, good mechanical properties, and high surface area, among others. Drug carriers are becoming crucial to avoid or diminish secondary effects and improve the targeting of administered drugs to enhance their effectiveness.

Chapter 2 discusses the selection and role of polymers in designing a drug carrier. It describes the main characteristics and properties of polymers in order of their importance in a drug carrier approach. Depending on the polymer's characteristics, the drug carrier system will regulate the delivery of bioactive molecules in reproducible dosages in a certain period of time. The nature of the polymer governs the kind of drug-loaded and the strategy of delivery. The hydrophobicity and hydrophilicity of the polymer surface determines the bioactive molecule that will be selected for each drug carrier. It is intended that polymers became inert systems with their only function being to carry the drug to the target in the best way.

Chapter 3 discusses thin films and their potential properties as drug carriers. Thin films have attracted interest due to their capacity to safely load bioactive molecules and deliver them in a regulated manner thus improving their efficiency. The chapter proposes oral, buccal, sublingual, ocular, and transdermal administrations of thin films for local and systemic effects.

Chapter 4 explains metal-organic frameworks (MOFs) as drug carriers and their physicochemical properties. These systems offer a high drug loading capacity and controlled release at the target site.

Graphene is an allotrope of carbon consisting of a single layer of atoms arranged in a two-dimensional honeycomb lattice nanostructure. Its specific and unique properties make it an ideal cancer drug carrier. Chapter 5 discusses examines how graphene quantum dots (GQDs) are used for cancer drug delivery due to their unique surface, which allows a diverse set of molecules to interact. In addition, their photothermal properties can be used to improve the efficiency of the drug-releasing activity by enhancing their specificity to the target zone. Another important application of GQDs permit is the monitoring of cellular responses thanks to the high-quality images that can be obtained using this drug carrier's platforms. This chapter addresses the advances in the use of GQD platforms for drug delivery and the biocompatibility studies reported so far.

Chapter 6 discusses microfluidics technology as drug carriers. Microfluidics use nano- and micro-scale manufacturing technologies to develop controlled and reproducible liquid microenvironments. Lead compounds with controlled physicochemical properties can be obtained using microfluidics characterized by high productivity and evaluated by biomimetic methods. Microfluidics produce nanoparticles in a wellcontrolled, reproducible, and high-throughput manner and create three-dimensional environments to mimic physiological and/or pathological processes.

Nanotechnology has been widely used for more effective drug carriers. Because of their size, they can reach difficult areas that pharmaceutical drugs or other drug carriers cannot. Chapter 7 reviews a lipid nanoparticle drug carrier, discussing the use of hybrid lipid polymers that provides a platform for the encapsulation and delivery of lipophilic biomolecules. These lipophilic systems are proposed for dermal, transdermal, mucosal, intramuscular, and ocular administration. They have also proved useful for cancer therapy, delivery of nucleic acids such as DNA and RNA, and as diagnostic imaging agents. The chapter explains that the nanostructure lipidic carriers can decrease the undesired secondary effects of certain drugs. As such, the chapter presents a general discussion of synthetic and natural lipid polymers with the use of surfactants.

Chapter 8 also discusses the potential characteristics of lipid and polymeric nanoparticles. These drug carriers promote stability and are disponible and provide sustained delivery. The chapter describes systems based on natural macromolecules, lipids, or polymeric/polyelectrolyte nanocapsules and their principal chemical and functional characteristics. Special focus is given to nano-vesicular systems that possess coreshell structures in which bioactive molecules can be loaded into the inner area of the particle. Moreover, the chapter examines diverse methodologies in the preparation of these nanosystems and reviews applications of lipid and polymeric nanocapsules, focusing on the encapsulation of drugs.

Chapter 9 discusses plant gum-based drug carriers. These carriers have a diverse set of advantages over chemical drug carriers including being biodegradable, biocompatible, nontoxic, more tolerable to the patient with few side effects, nonallergenic, and non-irritable to the skin or eyes. They have low production costs as well. Despite these favorable characteristics, the use of plant gums as drug carriers is limited due to a series of disadvantages such as microbial contamination because of the moisture in their content. In addition, their viscosity decreases in storage due to contact with water. In the case of green nanoparticle synthesis of these plant gums as drug carriers, the disadvantages can be limited. There are several studies showing that plant gum drug carriers can have a great combination with various drugs and nanoparticles, thus they could be extremely effective against multi-resistant bacteria and even systemic illnesses like cancer. Today, the green synthesis of drug carriers has been gaining importance because of emerging antibiotic-resistant bacteria and climate change.
