Hydrogen sulfide activatable metal-organic frameworks for Fluorescence Imaging-Guided Photodynamic Therapy of colorectal cancer

Abstract

Photodynamic therapy (PDT) is a promising alternative and palliative therapeutic strategy for colorectal cancer (CRC). A novel photosensitizer with higher selectivity for CRC and fewer side effects is vital for clinical application. Given that the overexpression of hydrogen sulfide (H2S) in CRC, it is expected to provide a selective stimulus for activatable photosensitizers that in respond to the specific microenvironment. Herein, we report a novel development of metal-organic frameworks (MOFs) composed of meso-Tetra (4-carboxyphenyl) porphine (TCPP) and ferric ion (Fe3+) through a facile one-pot process. Experiments both in vitro and in vivo reveal that the MOF is capable of depredating in response to the high content of H2S in tumor microenvironment of CRC. Accompanying with the degradation and release of TCPP, the fluorescence and photosensitivity effect is switched from “off” to “on”, enabling the MOF to serve as a H2S activatable nano-photosensitizer for real-time fluorescence imaging-guided and targeted PDT of CRC.

Advancements and Challenges in the Application of Metal-Organic Framework (MOF) Nanocomposites for Tumor Diagnosis and Treatment

“…Fluorescence bioimaging stands as a distinguished technique, predicated on the excitation of fluorophores through photon absorption at discrete wavelengths, followed by photon emission at longer, higher-energy wavelengths. 102 However, the method grapples with challenges in quantifying fluorescence intensity within biological entities, encumbered by auto-fluorescence, tissue signal attenuation, and inadequate light penetration in superficial tissues. Such challenges have spurred intense research into fluorescent materials to bolster optical imaging, particularly for deep tissue and intracellular applications.…”

“…Fluorescence bioimaging stands as a distinguished technique, predicated on the excitation of fluorophores through photon absorption at discrete wavelengths, followed by photon emission at longer, higher-energy wavelengths. 102 However, the 103 Advancements in this domain have been notably marked by the advent of luminescent MOFs, lauded over the past two decades for attributes including substantial payload capacities, tunable surface chemistries for enhanced pharmacokinetics, and variable sizes and structures. 104 Research has yielded a plethora of MOF constructs with luminescent capabilities, ranging from those incorporating fluorescent dyes or drugs to those intrinsically luminescent.…”

Liposome encapsulated polydopamine nanoparticles: Enhancing ferroptosis and activating hypoxia prodrug activity

“…The Fe ions (ferrous (Fe 2+ ) or ferric (Fe 3+ ))-mediated Fenton reaction converts endogenous H 2 O 2 into strong cytotoxicity hydroxyl radicals (•OH). The high level of •OH in the cell leads to an excess of lipid peroxide (LPO) on the cell membranes, then triggers and completes ferroptosis in tumor cells [ [7] , [8] , [9] , [10] ]. Recently, tumor therapy based on ferroptosis has a good prospect in inducing cancer cell death due to its characteristics of high tumor specificity and low systemic side effects [ [11] , [12] , [13] ].…”

Amphiphilic Dendrimer Doping Enhanced pH‐Sensitivity of Liposomal Vesicle for Effective Co‐delivery toward Synergistic Ferroptosis–Apoptosis Therapy of Hepatocellular Carcinoma

“…Ideal drug delivery systems should respond to the tumor microenvironment (TME) to allow for specific and effective drug release within tumor tissue. [ 20 ] Among various drug delivery systems developed against cancer, liposomes are the most advanced with the unique ability to load both hydrophobic and hydrophilic drugs. However, liposomes are, in general, relatively insensitive to pH variation, and hence remain stable in the acidic TME.…”