Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus), 381 Royal Parade, Parkville, VIC 3052, Australia.
Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus), 381 Royal Parade, Parkville, VIC 3052, Australia; ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus), 381 Royal Parade, Parkville, VIC 3052, Australia.
J Colloid Interface Sci. 2020 Nov 1;579:379-390. doi: 10.1016/j.jcis.2020.06.006. Epub 2020 Jun 9.
Hexaarylbiimidazoles (HABIs) are a promising class of photoswitchable molecule that have received little attention in the literature. Among them, (2,2'-dimethoxydiphenylimidazole)-1,1'-binaphthyl (HABI1) displays unusual negative photochromism and is responsive to green light. This study investigates the potential of HABIs to serve as photo-responsive actuators controlling the structure of lyotropic liquid crystalline (LLC) materials. HABI1 with four methyl chains and HABI2 with four dodecyl chains were synthesized. Time resolved small angle X-ray scattering was used to characterize the potential disruptive effects of HABIs on the nanostructure of LLC systems. HABIs underwent rapid isomerization under irradiation, with a very slow reversion in the dark in toluene and in the LLC matrix, demonstrating excellent stability and photo-fatigue resistant. HABIs completely triggered phase transitions in the phytantriol-based materials, and HABI2 generated a greater disruption than HABI1 on the lipid packing due to the enhanced steric influence. Tuning the lipid composition yielded systems that transitioned from a "slow release" lamellar phase to a "burst release" bicontinuous cubic phase upon light irradiation. Such systems therefore may exhibit a triggered release behavior upon a short time of irradiation, showing great potential in "on demand" drug delivery.
六芳基双咪唑（HABI）是一类很有前途的光致变色分子，但在文献中却很少受到关注。其中，（2,2'-二甲氧基二苯并咪唑）-1,1'-联萘（HABI1）显示出异常的负光致变色性，并对绿光有响应。本研究探讨了 HABI 作为光响应致动器控制溶致液晶（LLC）材料结构的潜力。合成了带有四个甲基链的 HABI1 和带有四个十二烷基链的 HABI2。利用时间分辨小角 X 射线散射来表征 HABI 对 LLC 体系纳米结构的潜在破坏作用。HABI 在照射下迅速发生异构化，在甲苯和 LLC 基质中黑暗中则非常缓慢地反转，表现出极好的稳定性和光疲劳抗性。HABI 完全触发了以植物三醇为基础的材料的相转变，并且由于空间位阻影响增强，HABI2 对脂质堆积的破坏作用大于 HABI1。通过调整脂质组成，可以得到从层状相到光照下“快速释放”的双连续立方相的转变。因此，这类系统在短时间的照射下可能会表现出触发释放的行为，在“按需”药物输送方面具有很大的潜力。
