An L-arginine-functionalized pillar[5]arene-based supramolecular photosensitizer for synergistically enhanced cancer therapeutic effectiveness

Supramolecular palladium complexes based on guanidinium pillar[5]arene for cancer therapy

The supramolecular palladium complex G-Pd, formed via self-assembly of the Pd-complex of guanidinium pillar[5]arene with Pd2+, was used to encapsulate doxorubicin to form G-Pd@DOX. The nanoparticles exhibit responsiveness to glutathione, controlled drug release, the ability to damage mitochondria, and potent anticancer activity while maintaining low toxicity towards normal cells. This work provides a good example for the application of pillararene-based palladium complexes in cancer therapy and is significant for the discovery of new medicines from supramolecular coordination complexes.

Pillararene-Based Stimuli-Responsive Supramolecular Delivery Systems for Cancer Therapy

Cancer poses a significant challenge to global public health, seriously threatening human health and life. Although various therapeutic strategies, such as chemotherapy (CT), radiotherapy, phototherapy, and starvation therapy, are applied to cancer treatment, their limited therapeutic effect, severe side effects, and unsatisfactory drug release behavior need to be carefully considered. Thus, there is an urgent need to develop efficient drug delivery strategies for improving cancer treatment efficacy and realizing on-demand drug delivery. Notably, pillararenes, as an emerging class of supramolecular macrocycles, possess unique properties of highly tunable structures, superior host-guest chemistry, facile modification, and good biocompatibility, which are widely used in cancer therapy to achieve controllable drug release and reduce the toxic side effects on normal tissues under various internal/external stimuli conditions. This review summarizes the recent advance of stimuli-responsive supramolecular delivery systems (SDSs) based on pillararenes for tumor therapy from the perspectives of different assembly methods and hybrid materials, including molecular-scale SDSs, supramolecular nano self-assembly delivery systems, and nanohybrid SDSs. Moreover, the prospects and critical challenges of stimuli-responsive SDSs based on pillararenes for cancer therapy are also discussed.

The design strategy for pillararene based active targeted drug delivery systems

Pillararenes have columnar architectures with electron-rich cavities to endow themselves with unique host-guest complexation capability. Easy structural modifiability facilitates them to be used in many applications. Currently, pillararene based drug delivery systems (DDSs) have been developed as a powerful tool for precise diagnosis and treatment of cancer. Various functional guest molecules could be integrated with pillararenes to construct nanomaterials for cancer chemotherapy, phototherapy and chemodynamic therapy. In order to improve cancer therapy efficacy, active targeted DDSs have become particularly important. Benefiting from the good host-guest properties and structural variability of pillararenes, tumor targeting groups could be easily introduced into pillararene based DDSs to realize precise drug delivery at tumor sites. In this feature article, we provide a comprehensive summary of the present design strategy for pillararene based active targeted DDSs, which can be classified into three types namely host-guest complexation, charge reversal and targeted group modified pillararenes. Some important examples are selected to for a detailed discussion on their respective strengths and weaknesses.

Acyclic cucurbit[n]uril-based nanosponges significantly enhance the photodynamic therapeutic efficacy of temoporfin in vitro and in vivo

Acyclic cucurbit[n]uril-based nanosponges are prepared based on supramolecular vesicle-templated cross-linking. The nanosponges are capable of encapsulating the clinically approved photodynamic therapeutic (PDT) drug temoporfin. When loaded with nanosponges, the PDT bioactivity of temoporfin is enhanced 7.5-fold for HeLa cancer cells and 20.8 fold for B16-F10 cancer cells, respectively. The reason for the significant improvement in PDT efficacy is confirmed to be an enhanced cell uptake by confocal laser scanning microscopy and flow cytometry. Animal studies show that nanosponges could dramatically increase the tumor suppression effect of temoporfin. In vitro and in vivo experiments demonstrate that nanosponges are nontoxic and biocompatible.