Emerging strategies in nanotechnology to treat respiratory tract infections: realizing current trends for future clinical perspectives

Abstract

A boom in respiratory tract infection cases has inflicted a socio-economic burden on the healthcare system worldwide, especially in developing countries. Limited alternative therapeutic options have posed a major threat to human health. Nanotechnology has brought an immense breakthrough in the pharmaceutical industry in a jiffy. The vast applications of nanotechnology ranging from early diagnosis to treatment strategies are employed for respiratory tract infections. The research avenues explored a multitude of nanosystems for effective drug delivery to the target site and combating the issues laid through multidrug resistance and protective niches of the bacteria. In this review a brief introduction to respiratory diseases and multifaceted barriers imposed by bacterial infections are enlightened. The manuscript reviewed different nanosystems, i.e. liposomes, solid lipid nanoparticles, polymeric nanoparticles, dendrimers, nanogels, and metallic (gold and silver) which enhanced bactericidal effects, prevented biofilm formation, improved mucus penetration, and site-specific delivery. Moreover, most of the nanotechnology-based recent research is in a preclinical and clinical experimental stage and safety assessment is still challenging.

Keywords: Respiratory tract infections; bacterial infections; nanodiagnostics; smart nanosystems.

Figure 1.

Anatomy of the respiratory tract and its bacterial infection.

Figure 2.

Bacterial respiratory infectious diseases. i. Pathophysiology of pneumonia: Pathogens enter via inhalation and reach lower airways. Alveoli releases cytokines and inflammatory mediators which lead to alveolar fluid accumulation. ii. Pathogenesis of TB: M. tuberculosis enters the respiratory tract through inhalation and infects alveoli. In the first step, alveolar macrophages recognize, engulf, and try to destroy bacilli. In the second step, bacilli start to grow within the infected alveolar macrophages which ultimately transform into granuloma. Most human with infected TB don’t exhibit a progression of the disease and remains in a latent state. However, some infected persons progress to the final stage where cavities are filled with free-floating bacteria and spread in the lungs causing pulmonary TB. iii. Comparison of normal and Cystic fibrosis patient airways- Illustration showing normal and highly viscous mucus airways in lungs and respiratory tubes.

Figure 3.

Steps involved in biofilm formation.

Figure 4.

Schematic representation of smart nano delivery carriers.

Figure 5.

Hybridization-based nano diagnostics for pathogens. (Upon hybridization of target DNA AACGTACATGA with the probe containing nanoparticles the nanoparticles will change their color thus helps in detection of the target DNA sequence).

Figure 6.

Overview of nano systems for respiratory tract infections.