Molecular Communication and Nanonetwork for Targeted Drug Delivery: A Survey

Molecular communication (MC) and molecular network (MN) are communication paradigms that use biochemical signaling to achieve information exchange among naturally and artificially synthesized nanosystems. Among the envisaged application areas of MC and MN is the field of nanomedicine, where the subject of targeted drug delivery (TDD) is at the forefront. Typically, when someone gets sick, therapeutic drugs are administered to the person for healing purposes. Since no therapeutic drug can be effective until it is delivered to the target site in the body, different modalities to improve the delivery of drugs to the targeted sites are being explored in contemporary research. The most promising of these modalities is TDD. TDD modality promises a smart localization of appropriate dose of therapeutic drugs to the targeted part of the body at reduced system toxicity. Research in TDD has been going on for many years in the field of medical science; however, the translation of expectations and promises to clinical reality has not been satisfactorily achieved because of several challenges. The exploration of TDD ideas under the MC and MN paradigms is considered as an option to addressing these challenges and to facilitate the translation of TDD from the bench to the patients' bedsides. Over the past decade, there have been some research efforts made in exploring the ideas of TDD on the MC and MN platforms. While the number of research output in terms of scientific articles is few at the moment, the desire in the scientific community to participate in realizing the goal of TDD is quite high as is evidence from the rise in research output over the last few years. To increase awareness and provide the multidisciplinary research community with the necessary background information on TDD, this paper presents a visionary survey of this subject within the domain of MC and MN. We start by introducing in an elaborate manner, the motivation behind the application of MC and MN paradigms to the study and implementation of TDD. Specifically, an explanation on how MC-based TDD concepts differ from traditional TDD being explored under the field of medical science is provided. We also summarize the taxonomy of the different perspectives through which MC-based TDD research can be viewed. System models and design challenges/requirements for developing MC-based TDD are discussed. Various metrics that can be used to evaluate the performance of MC-based TDD systems are highlighted. We also provide a discussion on the envisaged path from contemporary research activities to clinical implementation of the MC-based TDD. Finally, we discuss issues such as informatics and software tools, as well as issues that border on the requirement for standards and regulatory policies in MC-based TDD research and practice.

I. Introduction

In the field of science and technology, novel ideas that address our seemingly unending real-life challenges are constantly being sought from the macro-engineering perspective, and recently from the micro-engineering perspective. A paradigm shift from the vastly explored macro-engineering approach of problem solving to the micro-engineering approach has become a focal point for many research and development industries in the recent time, where concepts such as nanoscience and nanotechnology have become hot topics. While nanoscience is concern with the study of the properties and characteristics of things at the nano scale level, nanotechnology is concern with the engineering of nano scale-size things using different techniques and knowledge from nanoscience [1]. Nanoscale in this work refers to structures with a length scale of between 1–100 nanometers. An application domain that brings together concepts from nanotechnology and nanoscience is the field of nanomedicine, which is of concern in this paper.