Drug Delivery Nanosystems for Biomedical Applications

Chandra P. Sharma, Chandra P Sharma

• Publisher: Elsevier
• Year: 2018
• Print ISBN: 9780323509220
• eBook ISBN: 9780323509237
• Topic: Technology & Engineering
• Subtopic: Pharmacology
• Index: Technology & Engineering

Drug Delivery Nanosystems for Biomedical Application reviews some of the most challenging nanosystems with different routes of delivery that are useful for specific drugs, from both efficacy and bioavailability points-of-view. The chapters explore how this area is developing, the present state of the field, and future developments, in particular, inorganic, metallic, polymeric, composite and lipid nanosystems and their possible evolution to clinical applications. The book is a valuable research reference for both researchers and industrial partners who are not only interested in learning about this area, but also want to gain insights on how to move towards translational research. - Focuses on applications, including tissue engineering and regenerative technologies, showing how nanosystems are used in practice - Explores how nanosystems are used to deliver a variety of drugs, including peptides, hormone growth factors and genes - Assesses the safety and nanotoxicity aspects of drug delivery nanosystems

Chapter 1

Drug delivery nanosystems—An introduction

Hindumathi R. Dhanasekaran^⁎; Chandra Prakash Sharma^†; Prathap Haridoss^{⁎ ⁎} Indian Institute of Technology Madras, Chennai, India
^† Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, India

Abstract

Nanosystems mainly help in safe delivery of drug molecules to the target site, by minimizing the side effects. A wide range of drugs, genes, and other therapeutic molecules can be loaded onto the nanosystems, targeting various sites of action and various diseases. The use of nanosystems has facilitated the growth of drug delivery systems with multimodal functionality, which involve a combination of therapeutic molecules, therapy techniques or site of action, etc. This short review is aimed at giving a brief introduction to the different forms of nanosystems, their classification, and their future scope when applied for drug delivery systems aimed at treating cancer and other diseases.

Keywords

Nanosystems; Colloidal nanoparticles; Inorganic nanoparticles; Nanoemulsions; Nanocapsules; Multifunctional nanosystems; Self-assembly; Self-degradation

Chapter Outline

• 1.1 Foreword
• 1.2 Different Forms of Drug Delivery Vehicles
  • 1.2.1 Colloidal Nanoparticles and Nanocapsules
  • 1.2.2 Nonspherical and Inorganic Nanoparticles
  • 1.2.3 Polymeric Micelles and Other Nanoparticles
• 1.3 Classification of Drug Delivery Nanosystems
• 1.4 Versatality to the Target Site
• 1.5 Perspectives
• References

1.1 Foreword

Numerous microscale and nanoscale systems have been developed as part of the efforts to find efficient carrier systems for the delivery of drugs, genes, and antigens to specific sites in the human body, with minimal side effects. The biocompatible nanosuspensions in aqueous base as a drug carrier mainly increase the dispersibility of the hydrophobic drug, transport it safely to the target site, and are able to release the drug in a controlled manner depending on the various stimuli.

Spherical and nonspherical nanosystems of hydrodynamic diameter 10–200 nm are preferred for drug delivery [1]. Interestingly, most of the recently reported nanosystems fall in this range. Metal nanoparticles can be designed with size less than 100 nm, while liposomes and polymeric nanoparticles are generally above 100 nm. In the last decade, several nanoparticles including carbon nanotubes and other nonspherical inorganic nanoparticles were vigorously tested for their biocompatibility, with contradictory results on their toxicity reported by various researchers. Ignoring the physicochemical properties of the nanoparticles was the reason for inconsistent results. The focus was then on the surface chemistry and the ability for functionalization, and it was learned that functionalization with biocompatible materials could largely reduce the toxicity of these materials. Subsequently, importance of the particle dimension was also recognized, and the physical aspects of the nanoparticles started showing up in publications. Advancements in microscopy techniques for characterizing nanomaterials have made this possible. The advantages of nanosystems are largely preserved in composite nanostructures which are in present focus. They provide additional versatility in developing multicomponent and multifunctional drug delivery systems involving multiple drugs, antibodies, and gene delivery.

External stimuli such as the electromagnetic force, temperature, light, radiation, and ultrasound have proven to be clinically beneficial both in triggering drug release and by synergistically improving the therapeutic property of the drug. Nanosystems are also being designed to respond to internal stimuli such as pH, redox potential, enzymatic activity, and temperature [2–6]. Because of the acidic microenvironment of solid tumors, pH-stimulated delivery is the most used strategy among various stimuli [2]. Biomolecule-based nanosystems and polymers could protect the SiRNA and DNA from in vivo degradation till they are safely transported to the target site [7]. Hence, nanosystems are also widely explored for gene delivery.

1.2 Different Forms of Drug Delivery Vehicles

The different types of drug-loaded nanoparticles depending on their form or structure are shown in Fig. 1.1. Drug and other therapeutic molecules could be either embedded or attached to the surface of the colloidal nanoparticles as shown in Fig. 1.1A and B. Both the core and the shell component of the nanocapsule-type nanoparticle can be embedded with drug molecules as in Fig. 1.1C. Drugs can be attached to the surface of the nonspherical nanoparticles either with or without the help of functionalizing groups (Fig. 1.1D). Amphiphilic block co-polymers with both hydrophilic and hydrophobic reactive components can form micelle-like arrangement with hydrophobic drugs and aqueous solution (Fig. 1.1E). Emulsion-type drug delivery systems mostly contain oils and surfactants, which could enhance the intestinal absorption of poorly water-soluble drugs, and hence is being used in developing oral drug delivery systems [8].

Fig. 1.1 Various forms of drug-loaded nanoparticles: (A) drug-embedded solid colloidal nanoparticle, (B) drug-adhered solid colloidal nanoparticle, (C) drug-embedded nanocapsules, (D) inorganic nanoparticles, and (E) micelle-type nanoassembly.

1.2.1 Colloidal Nanoparticles and Nanocapsules

Drug-loaded biocompatible nanoparticles with a wide range of materials and size can be formed as colloids. For example, curcumin-loaded PLGA-PEG nanoparticles of size less than 200 nm were obtained using a single emulsion solvent evaporation technique, with an encapsulation efficiency of more than 70% [9]. Curcumin could also be loaded onto PLGA particles alone, and the carrier also contributes to the enhanced anticancer activity of the formulation [10,11]. Protein-loaded PLGA nanoparticles were formed using PEG 400 as a solvent, maintaining the integrity of the protein [12]. High-pressure homogenization helps in the formation of pluronic nanosuspensions of particle size of about 300 nm, with a novel anticancer drug Q39 (3-(4-bromopheny l)-2-(ethyl-sulfonyl)-6-methylquinoxaline1, 4-dioxide) [13]. PLGA nanoparticles of about 200 nm size showed colloidal stability when tested in different biological fluids [14]. Unique core-shell-type silica nanostructures with drug-carrying small mesopores in the core and gene-carrying medium-sized mesopores in the shell is intended for combination therapy, where the genes are first released from the shell and downregulate the cancer-progressing genes and the drug in the core is released next for effective killing of cancer cells [15].

1.2.2 Nonspherical and Inorganic Nanoparticles

Inorganic nanoparticles have a wide range of physical and chemical properties suitable for various drug delivery applications [16]. In addition to drug loading and release, they could also serve as imaging agents and therapeutic molecules responding to external stimuli such as light, temperature, and electromagnetic radiation. Toxicity is the main issue with these nanoparticles but with considerable research, the physical property requirements of nontoxic, inorganic nanoparticles have been identified and suitable modifications have been made in terms of functionalization for the attachment of hydrophobic drug molecules and for controlled release at the target site. For example, the highest entrapment effi...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Contributors
• Chapter 1: Drug delivery nanosystems—An introduction
• Chapter 2: Blood compatibility of nanomaterials
• Chapter 3: Safety and toxicity concerns of nanosystems
• Chapter 4: Pharmaceutical perspectives of selection criteria and toxicity profiling of nanotheranostic agents
• Chapter 5: Nanosystems and antibacterial applications
• Chapter 6: Exosomes: Cellular capsules for drug delivery in Parkinson’s disease
• Chapter 7: Advances in tissue regeneration through nanomaterials
• Chapter 8: Calcium phosphate nanoplatforms for drug delivery and theranostic applications
• Chapter 9: Nanocomposites used for drug delivery applications
• Chapter 10: Role of advanced nanomaterials in biosensing
• Chapter 11: Hydrogel-nanoparticle composites for drug delivery
• Chapter 12: Polymeric micelles: Smart nanocarriers for anticancer drug delivery
• Chapter 13: Principles and applications of medical nanotechnology devices
• Chapter 14: Drug delivery in nano-dimensions: A focus on oro-dental infections
• Chapter 15: Nanodiamonds as “magic bullets” for prostate cancer theranostics
• Chapter 16: Nanodrug delivery system using medicinal plants
• Chapter 17: Inorganic nanotheranostics: Strategy development and applications
• Index