Poster W14 - Development of Manganese porphyrin-containing polymeric micelles for catalytic generation of per/polysulfide species and their proangiogenic activity
Assistant Professor Penn State University Park, Pennsylvania, United States
Introduction: Hydrogen sulfide (H2S) and related sulfur species have emerged as essential signal mediators that regulate many cellular processes including angiogenesis, cell proliferation and neurotransmission in the human body. Among them, per/polysulfide species (RSnH, RSn+1R’, H2Sn, n>2) have attracted attention since these molecules can readily react with protein cysteine residues (-SH) via S-sulfhydration of cysteine residues (i.e., cysteine-SSH). Recent mechanistic investigations revealed that this post-translational modification is involved in a wide range of signal transductions. With the discovery of the interesting biological activities of per/polysulfide species, their therapeutic use has attracted growing attention. However, due to their low stability in biological systems, the controlled delivery of these molecules remains a challenge. In this report, we report a novel per/polysulfide delivery system using polymeric micelles containing manganese porphyrin (MnPMCs) in combination with a H2S donor that enable sustained per/polysulfide generation in cells via catalytic oxidation of H2S.1 We also evaluated the effects of this delivery system in human umbilical vein endothelial cells (HUVECs).
Materials and
Methods: MnPMCs was synthesized by conjugating porphyrin amine to polymeric micelles containing pentafluorophenyl acrylate groups in a core. The catalytic activity to generate pre/polysulfide species from H2S was evaluated using fluorescent sulfane sulfur detection dye (SSP4). HUVECs were treated with MnPMCs and the H2S donor anethole dithiolone (ADT) and the tube formation and morphological change were investigated.
Results, Conclusions, and Discussions: Results and Discussion We first synthesized an amphiphilic diblock copolymer consisting of hydrophilic poly(acryloyl morpholine) and hydrophobic and amine-reactive poly(pentafluorophenyl acrylate) segments.2 This diblock copolymer was used to prepare micelles in water and the pentafluorophenyl ester groups within the micelle core were reacted with porphyrin bearing four amino groups (porphyrin amine) to yield porphyrin-conjugated micelles (PMC). Then, PMCs were complexed with manganese ions to obtain MnPMC. Both PMCs and MnPMCs have an average diameter of ca. 35 nm. The catalytic activity of MnPMCs to convert H2S to per/polysulfide species was investigated in aerobic phosphate buffer saline (PBS). Mixing MnPMCs with Na2S (sodium salt of H2S) results in per/polysulfide formation as confirmed by the increase of the fluorescence intensity of the SPP4 dye. In addition, the formed species were further analyzed using HPLC-MS/MS techniques showing the formation of H2S2 and H2S3. Co-treatment of MnPMCs and the H2S donor ADT increased the intracellular per/polysulfide levels in HUVECs. Furthermore, we observed the tubulogenic activity in HUVECs cultured on fibrin gel after the treatment with the combination of MnPMCs and ADT for 2 days. Further investigation revealed that per/polysulfide species generated in cells induce cell migration and alignment.
Conclusion A novel approach for intracellular delivery of polysulfide species by combining a H2S donor and MnPMC was developed. This delivery system generate per/polysulfide species intracellularly via catalytic oxidation of H2S. MnPMCs in combination with a H2S donor ADT efficiently deliver per/polysulfide species in HUVECs and induced proangiogenic response. The developed per/polysulfide delivery system has the potential to be applied for therapeutic delivery of polysulfides for facilitating wound healing and tissue repair.
References; 1. Young et al. Adv Healthc Mater 2024, 13 (4), e2302429. 2. van der Vlies et al. Biomacromolecules 2022, 23 (1), 77-88.
Acknowledgements (Optional): This work was supported by the U.S. National Science Foundation (NSF), CBET, 2102848. S.Y. acknowledges financial support from the National Institute of Technology Faculty Research Abroad Program, Japan.
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