Background: Aerosol delivery of chemotherapeutic nanocarriers represents a promising alternative for lung cancer therapy. This study optimized gemcitabine (Gem)-loaded gelatin nanocarriers (GNCs) cross-linked with genipin (Gem-GNCs) to evaluate their potential for nebulized lung cancer treatment. Methods: Gem-GNCs were prepared by two-step desolvation and optimized through Taguchi design and characterized for physicochemical properties. Particle size and morphology were confirmed by scanning and transmission electron microscopy. In vitro release of Gem from Gem-GNCs performed in Dulbecco's phosphate-buffered saline and simulated lung fluid was evaluated to determine release mechanisms. Particle size stability was assessed under varying pH. Differential scanning calorimetry and powder X-ray diffraction were used to determine the presence and stability of Gem-GNC components and amorphization of Gem, respectively. Gem-GNC efficacy within A549 and H460 cells was evaluated using MTT assays. Mucus rheology upon treatment with Gem-GNCs, lactose, and normal saline control was measured. Andersen cascade impaction identified the aerodynamic particle size distribution of the nebulized formulation. Results: Gem-GNCs had particle size, zeta potential, entrapment efficiency, and loading efficiency of 178 ± 7.1 nm, −18.9 mV, 92.5%, and 9.1%, respectively. The Gem and formulation excipients where molecularly dispersed and configured amorphously. Gem-GNCs were stable at pH 5.4–7.4 for 72 hours. Gem release from Gem-GNCs was governed by non-Fickian controlled release due to diffusion/erosion from a matrix-based nanocarrier. Gem-GNCs elicited a 40% reduction of the complex viscosity η*(1 Hz) of human bronchial epithelial cell mucus containing 3 wt% solids to mimic mild airway disease. The nebulized Gem-GNCs had a mass median aerodynamic diameter (MMAD) of 2.0 ± 0.16 μm, geometric standard deviation (GSD) of 2.7 ± 0.16, and fine particle fraction (FPF) of 75.2% ± 2.4%. The Gem-GNC formulation did not outperform the Gem solution in A549 cells. However, in H460, Gem-GNCs outperformed the Gem IC50 reduction by ∼5-fold at 48 and 10-fold 72 hours. Conclusion: Stable, effective, and sustained-release Gem-GNCs were developed. The nebulized Gem-GNCs had satisfactory MMAD, GSD, and FPF and the formulation reduced the dynamic complex viscosity of mucus consistent with increased mobility of nanoparticles.

NLC is a next-generation lipid nanocarrier, which holds many advantages over other colloidal lipid carrier systems like higher drug loading, better and controlled release and enhanced stability. Owing to the unique structural composition, i.e. crystallized solid and liquid lipid blend, it offers excellent biocompatibility and higher permeation across physiological membranes like BBB. Moreover, the surface of NLC can easily be modified with target-specific ligands, proteins, peptides, etc. which makes it a potential candidate for brain targeting of CNS acting drugs. NLC has found various applications for the treatment of various CNS disorders including Alzheimer’s disease, Parkinson’s disease, schizophrenia, epilepsy, migraine, cerebral ischemia, etc. Among these, the application of NLC towards the treatment of AD has been well-explored in the past two decades. In this piece of work, we have discussed the types of NLC, its composition, fabrication techniques, characterization, stability profile and application in the treatment of AD.