Awad Muhammed, Barnes Timothy J, Prestidge Clive A
Centre for Pharmaceutical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide 5000, Australia.
Basil Hetzel Institute for Translational Health Research, Woodville South 5011, Australia.
Antibiotics (Basel). 2023 Sep 4;12(9):1405. doi: 10.3390/antibiotics12091405.
Lipid liquid crystalline nanoparticles (LCNPs) are unique nanocarriers that efficiently deliver antimicrobials through biological barriers. Yet, their wide application as an antimicrobial delivery system is hindered by their poor stability in aqueous dispersions. The production of dried LCNP powder via lyophilization is a promising approach to promote the stability of LCNPs. However, the impact of the process on the functionality of the loaded hydrophobic cargoes has not been reported yet. Herein, we investigated the potential of lyophilization to produce dispersible dry LCNPs loaded with a hydrophobic antimicrobial compound, gallium protoporphyrin (GaPP). The effect of lyophilization on the physicochemical characteristics and the antimicrobial activity of rehydrated GaPP-LCNPs was studied. The rehydrated GaPP-LCNPs retained the liquid crystalline structure and were monodisperse (PDI: 0.27 ± 0.02), with no significant change in nanoparticle concentration despite the minor increase in hydrodynamic diameter (193 ± 6.5 compared to 173 ± 4.2 prior to freeze-drying). Most importantly, the efficacy of the loaded GaPP as an antimicrobial agent and a photosensitizer was not affected as similar MIC values were obtained against (0.125 µg/mL), with a singlet oxygen quantum yield of 0.72. These findings indicate the suitability of lyophilization to produce a dry form of LCNPs and pave the way for future studies to promote the application of LCNPs as an antimicrobial delivery system.
脂质液晶纳米颗粒（LCNPs）是一种独特的纳米载体，能够有效地通过生物屏障递送抗菌剂。然而，它们在水性分散体中的稳定性较差，这阻碍了其作为抗菌递送系统的广泛应用。通过冻干生产LCNP粉末是提高LCNPs稳定性的一种有前景的方法。然而，该过程对负载的疏水性货物功能的影响尚未见报道。在此，我们研究了冻干法制备负载疏水性抗菌化合物原卟啉镓（GaPP）的可分散干燥LCNPs的潜力。研究了冻干对复水后的GaPP-LCNPs理化特性和抗菌活性的影响。复水后的GaPP-LCNPs保留了液晶结构且呈单分散状态（PDI：0.27±0.02），尽管流体动力学直径略有增加（冻干前为173±4.2，冻干后为193±6.5），但纳米颗粒浓度没有显著变化。最重要的是，负载的GaPP作为抗菌剂和光敏剂的功效没有受到影响，因为对[具体对象未给出]的最低抑菌浓度（MIC）值相似（0.125 µg/mL），单线态氧量子产率为0.72。这些发现表明冻干法适合制备LCNPs的干燥形式，并为未来促进LCNPs作为抗菌递送系统应用的研究铺平了道路。
