Highly ordered ring-like structures are formed via the directed assembly of lipid domains in supported bilayers, using the extracellular matrix protein fibronectin. The ability of biological molecules to guide nanoscale assembly suggests potential biomimetic approaches to nanoscale structures.
Zerumbone (ZER), a compound derived from the rhizome of Zingiber Zerumbet (L.) Smith, has demonstrated anti-inflammatory properties but suffers from poor water solubility, limiting its clinical application. While ZER's effects on lung inflammation are known, its role in lung fibrosis remains unexplored. Herein, ZER was encapsulated in pH-sensitive liposomes formulated with oleic acid, dipalmitoylphosphatidylcholine, and cholesterol to enhance ZER solubility and delivery to the acidic environment of lung fibrosis. The liposomes were optimized using Box-Behnken design, resulting in an average diameter of 87.8 ± 3.5 nm, a polydispersity index of 0.16 ± 0.2, and a zeta potential of -24 ± 0.32 mV. ZER release from the carrier followed zero-order kinetics and showed higher release in acidic settings. Cascade impactor and HPLC analyses confirmed that ZER liposome powder produced by freeze-drying reached stage 7, indicating effective delivery to deep lung regions. The uptake of ZER liposomes was concentration and pH-dependent, being higher in acidic conditions and greater in MRC-5 cells compared to A549 cells. Notably, ZER liposomes reduced cell migration and downregulated fibrotic markers such as fibronectin, MMP-2, and α-SMA in MRC-5 and A549 cells. This study suggests that ZER liposomes hold promise for treating lung fibrosis and merit further investigation.
Unilamellar liposomes composed of dipalmitoylphosphatidylcholine (DPPC) were prepared by the reverse-phase
evaporation method and extrusion through a polycarbonate membrane filter. Liposomes at 0.7 mg/mL lipid concentration
in deionized water were exposed to gamma irradiation at a dose in the range 0.5 to 25 kGy. Gamma irradiation of
liposomes resulted in the degradation of DPPC lipids into free fatty acids, lysophosphatidylcholine and 1,2-palmitoylphosphatidic
acid (DPPA). The effect of gamma irradiation towards the physical stability of liposomes was investigated
by means of dynamic light scattering (DLS), transmission electron microscopy (TEM) and zeta potential analysis. From
the DLS analysis, no significant changes were observed in the hydrodynamic size of liposomes. TEM images indicate that
the liposomes surface became smoother and rounder as higher irradiation doses were applied. Zeta potential analysis
showed that gamma irradiation of DPPC liposomes at radiation doses as low as 0.5 kGy resulted in a drastic rise in the
magnitude of the zeta potential. The results also demonstrate that gamma irradiation of liposomes suspension enhanced
the overall stability of liposomes. Hence, it can be concluded that gamma irradiation on DPPC liposomes may potentially
produce liposomes with higher stability.