Introduction: Pulmonary arterial hypertension (PAH) is a progressive disease characterized by remodeling of small pulmonary arteries leading to increased pulmonary arterial pressure. Existing treatments acts to normalize vascular tone via three signaling pathways: the prostacyclin, the endothelin-1, and the nitric oxide. Although over the past 20 years, there has been considerable progress in terms of treatments for PAH, the disease still remains incurable with a disappointing prognosis. Areas covered: This review summarizes the pathophysiology of PAH, the advantages and disadvantages of the inhalation route, and assess the relative advantages various inhaled therapies for PAH. The recent studies concerning the development of controlled-release drug delivery systems loaded with available anti-PAH drugs have also been summarized. Expert opinion: The main obstacles of current pharmacotherapies of PAH are their short half-life, stability, and formulations, resulting in reducing the efficacy and increasing systemic side effects and unknown pathogenesis of PAH. The pulmonary route has been proposed for delivering anti-PAH drugs to overcome the shortcomings. However, the application of approved inhaled anti-PAH drugs is limited. Inhalational delivery of controlled-release nanoformulations can overcome these restrictions. Extensive studies are required to develop safe and effective drug delivery systems for PAH patients.

New antibiotics are seen as ‘drugs of last resort’ against virulent bacteria. However, development of resistance towards new antibiotics with time is a universal fact. Delafloxacin (DFX) is a new fluoroquinolone antibiotic that differs from existing fluoroquinolones by the lack of a protonatable substituent, which gives the molecule a weakly acidic nature, affording it higher antibacterial activity under an acidic environment. Furthermore, antibiotic-functionalized metallic nanoparticles have been recently emerged as a feasible platform for conquering bacterial resistance. In the present study, therefore, we aimed at preparing DFX-gold nano-formulations to increase the antibacterial potential of DFX. To synthesize DFX-capped gold nanoparticles (DFX-AuNPs), DFX was used as a reducing and stabilizing/encapsulating agent. Various analytical techniques such as UV-visible spectroscopy, TEM, DLS, FTIR and zeta potential analysis were applied to determine the properties of the synthesized DFX-AuNPs. The synthesized DFX-AuNPs revealed a distinct surface plasmon resonance (SPR) band at 530 nm and an average size of 16 nm as manifested by TEM analysis. In addition, Zeta potential results (−19 mV) confirmed the stability of the synthesized DFX-AuNPs. Furthermore, FTIR analysis demonstrated that DFX was adsorbed onto the surface of AuNPs via strong interaction between AuNPs and DFX. Most importantly, comparative antibacterial analysis of DFX alone and DFX-AuNPs against Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus and Bacillus subtilis) verified the superior antibacterial activity of DFX-AuNPs against the tested microorganisms. To sum up, DFX gold nano-formulations can offer a promising possible solution, even at a lower antibiotic dose, to combat pathogenic bacteria.

Ceftriaxone has been a part of therapeutic regime for combating some of the most aggressive bacterial infections in the last few decades. However, increasing bacterial resistance towards ceftriaxone and other third generation cephalosporin antibiotics has raised serious clinical concerns especially due to their misuse in the COVID-19 era. Advancement in nanotechnology has converted nano-therapeutic vision into a plausible reality with better targeting and reduced drug consumption. Thus, in the present study, gold nanoparticles (GNPs) were synthesized by using ceftriaxone antibiotic that acts as a reducing as well as capping agent. Ceftriaxone-loaded GNPs (CGNPs) were initially characterized by UV-visible spectroscopy, DLS, Zeta potential, Electron microscopy and FT-IR. However, a TEM micrograph showed a uniform size of 21 ± 1 nm for the synthesized CGNPs. Further, both (CGNPs) and pure ceftriaxone were examined for their efficacy against Escherichia coli, Staphylococcus aureus, Salmonella abony and Klebsiella pneumoniae. CGNPs showed MIC₅₀ as 1.39, 1.6, 1.1 and 0.9 µg/mL against E. coli, S. aureus, S. abony and K. pneumoniae, respectively. Interestingly, CGNPs showed two times better efficacy when compared with pure ceftriaxone against the tested bacterial strains. Restoring the potential of unresponsive or less efficient ceftriaxone via gold nanoformulations is the most alluring concept of the whole study. Moreover, applicability of the findings from bench to bedside needs further validation.