Inhalable Microparticles Embedding Biocompatible Magnetic Iron-Doped Hydroxyapatite Nanoparticles

Area of Science:

• Biomaterials Science
• Nanotechnology
• Pulmonary Drug Delivery

Background:

• Increasing interest in biocompatible inhalable nanoparticles for lung disease treatment and diagnosis.
• Superparamagnetic iron-doped calcium phosphate nanoparticles (FeCaP NPs) show promise for MRI, drug delivery, and hyperthermia.
• Need for safe and effective delivery systems for nanoparticles to the lungs.

Purpose of the Study:

• To develop and characterize inhalable microparticle formulations of FeCaP NPs for lung delivery.
• To assess the safety and efficacy of FeCaP NPs for inhalation administration.
• To demonstrate the utility of spray drying for creating a dry powder platform for lung delivery.

Main Methods:

• Synthesis and characterization of superparamagnetic iron-doped calcium phosphate nanoparticles (FeCaP NPs).
• Cytotoxicity assessment of FeCaP NPs on human lung alveolar epithelial type 1 (AT1) cells.
• Formulation of D-mannitol spray-dried microparticles embedding FeCaP NPs.
• Evaluation of aerodynamic particle size distribution and nanoparticle release upon microparticle dissolution.

Main Results:

• FeCaP NPs were found to be non-cytotoxic to human lung AT1 cells, even at high doses.
• Respirable dry powders of D-mannitol microparticles embedding FeCaP NPs were successfully formulated using spray drying.
• The nanoparticle-in-microparticle approach protected FeCaP NPs, enabling their release with preserved characteristics.
• The microparticles achieved optimal aerodynamic properties for effective lung deposition.

Conclusions:

• FeCaP NPs are safe for inhalation administration and suitable for lung delivery applications.
• Spray-dried D-mannitol microparticles provide an effective platform for delivering FeCaP NPs to the lungs.
• This approach facilitates magnetically driven applications in the lung, including diagnostics and therapeutics.