Antifungal Encapsulated into Ligand-Functionalized Nanoparticles with High Specificity for Macrophages

Abstract

Infectious diseases caused by intracellular microorganisms such as Histoplasma capsulatum represent a significant challenge worldwide. Drug encapsulation into functionalized nanoparticles (NPs) is a valuable alternative to improving drug solubility and bioavailability, preventing undesirable interactions and drug degradation, and reaching the specific therapeutic target with lower doses. This work reports on Itraconazole (ITZ) encapsulated into core-shell-like polymeric NPs and functionalized with anti-F4/80 antibodies for their targeted and controlled release into macrophages. Uptake assay on co-culture showed significant differences between the uptake of functionalized and bare NPs, higher with functionalized NPs. In vitro assays showed that F4/80-NPs with 0.007 µg/mL of encapsulated ITZ eliminated the H. capsulatum fungus in co-culture with macrophages effectively compared to the bare NPs, without any cytotoxic effect on macrophages after 24 h interaction. Furthermore, encapsulated ITZ modulated the gene expression of anti and pro-inflammatory cytokines (IL-1, INF-Y, IL-6 and IL-10) on macrophages. Additionally, the anti-F4/80 antibody-coating enhanced natural and adequate antifungal response in the cells, exerting a synergistic effect that prevented the growth of the fungus at the intracellular level. Functionalized NPs can potentially improve macrophage-targeted therapy, increasing NPs endocytosis and intracellular drug concentration.

Is Micro and Nanotechnology Helping Us Fight Histoplasmosis?

“…In addition, the treatment with these nanoformulations also significantly reduced IL-6 and IL-10 expression compared to free itraconazole. All in all, this research supports the idea that the encapsulation of itraconazole into NP allows a controlled and targeted drug release into macrophages, along with enhanced efficacy and efficiency in battling the fungal intracellular infection [8,23,25,40].…”

“…The infection is caused by inhaling aerosols that contain the infecting particles of the dimorphic fungus, Histoplasma capsulatum and it affects most frequently the lung [8]. Nevertheless, it can also affect the skin [9][10][11], and the central nervous system (CNS) causing meningitis [12] or even evolve into a progressive disseminated infection that may trigger an inflammatory response and bring rheumatological and heart complications (pericarditis), with high morbidity rates [13,14].…”

“…Considering the hepatoxicity, limited efficacy due to deficient absorption, low bioavailability, drug degradation, long treatment duration, and frequent drug interactions of the traditional antifungal drugs, it is imperative to develop more efficient strategies for this disease, which would be able to overcome these hurdles [8].…”

“…The functionalization of nanocarriers for drug delivery has been ceaselessly disclosing its potential as an alternative and versatile technological platform for the management and treatment of intracellular infections caused by fungi from the H. capsulatum species [23,25]. Indeed, the encapsulation of antifungal agents into nanoparticles to selectively target pathogens has shed light on improving treatment's efficacy and efficiency [8]. Some of these novel drug delivery approaches, such as AmBisome® and Visudyne®, are already commercialized and now serve as benchmark treatments and proof-of-concept of the usefulness of nanotechnology in antifungal drug delivery [26][27][28].…”

Effect of Protein Corona on the Specificity and Efficacy of Nanobioconjugates to Treat Intracellular Infections

“…The macroscopic turbidity method (data not shown) and a 4,5‐dimethylthiazol‐2‐yl) 2,5‐diphenyltetrazolium bromide (MTT) assay ( Figure 3 A) showed that encapsulated ITZ into both PEGylated NPs presented a higher antifungal effect (0.0037 µg mL −1 , PEG‐NPs and COOH‐PEG‐NPs, p < 0.0001 and p < 0.01, respectively) compared with free ITZ (0.0015 µg mL −1 , p < 0.0001) and with the MIC of unPEGylated NPs (0.007 µg mL −1 ) reported in previous works. [ 42 ] Empty NPs presented the inhibition of fungal growth in high concentration with an MIC of 0.062 µg mL −1 ( p < 0.0001), indicating that the NPs composition may be inhibiting the fungal growth favoring the effect of the drug.…”