Chapter 17. Overview of Antimicrobial Resistance and Nanoparticulate Drug Delivery Approach to Combat Antimicrobial Resistance

Although high numbers of novel antibiotics are available in the market currently, it is still a challenge to treat intracellular pathogens. These therapeutic agents always need to be used in high doses, as their antibiotic concentrations are often sub-therapeutic. This is expensive and results in adverse systemic and localized side effects. The current rising threat of antibiotic resistance further complicates the treatment of intracellular pathogenic diseases. As a result, there is a crucial need for methods and systems that enable physicians to attain therapeutically effective intracellular concentrations of those antibiotics. In this scenario, the use of drug delivery systems carrying antibiotics showing targeted and effective antibacterial activity in vitro need to be considered and given due attention. Incorporating or encapsulating antibacterial drugs within these unique drug delivery systems offers better control of pharmacokinetic behavior of the active bactericidal molecule. Such new and advanced methods will replace old conventional antibiotics, which are becoming unusable due to resistance or toxicity. They are vital in rescuing the last-line therapeutic antibiotics through advancing the therapeutic index, broadening the antibiotic antimicrobial spectrum and avoiding failure due to membrane permeability problems, and thus shortening the current time required by classical treatments and reducing the extent of drug resistance. Hence, new and improved drug carriers have been established for treating intracellular pathogens, including antibiotics loaded into hydrogels, liposomes, micelles, polymeric carriers, and metal nanoparticles. This chapter focuses on the role of a drug delivery system as a potential tool against intracellular bacterial pathogens.