Molecular Dipole Modulation of Porphyrins to Enhance Photocatalytic Oxidation Activity for Inactivation of Intracellular Bacteria

Abstract

The regulation of molecular structures of porphyrin-based photosensitizers is crucial for yielding the effective singlet oxygen as one of the efficient photocatalytic reactive oxidation species. Here, we select methoxy substitution as an electron donor to decorate the porphyrin rings. Introducing a series of metal ions into porphyrin centers further prepares the methoxysubstituted metalloporphyrins (MPs, M = Co, Ni, Cu, Zn), with the hope of modulating their molecular dipole moments and photocatalytic activity. The theoretical calculation analyses show that the metal-free porphyrin center possesses a higher transition dipole and more delocalized orbitals, leading to efficient charge transfer and improved photocatalytic activity. The metalloporphyrin samples are then polymerized by poly(D, L-lactide-co-glycolide) to be applied to in vitro sterilization experiments. As expected, metal-free porphyrin has good antibacterial ability and good biocompatibility. Moreover, the highly effective bacteriostatic metal-free porphyrin achieves satisfactory photodynamic therapeutic outcomes against intracellular pathogens in cancer cells. This work demonstrates that the molecular dipole modulation of porphyrins is critical for their photocatalytic oxidation and antibacterial ability.

Laser‐Guided Self‐Assembly of Thin Films into Micro‐Rolls

“…Although there is little PTFE residue attached on the micro-rolls (as the XPS spectrum shows), there should be no potential issue since PTFE is generally considered to be a biocompatible material and has been used in medical applications such as a coating for medical devices [33] and as a component of artificial joints and other implants. [34] After controlling the laser parameters and substrate influence, we created Au stents that matched the vascular sample from a pig heart. As illustrated in Figure 6a, we placed the Au stents within a clinical syringe and injected them into the vessel.…”

Optical properties of meso-tetra(sulphonatophenyl) porphyrins (TPPS 4) and their Fe 3+, Mn 3+, Zn 2+ complexes with different pH values studied using by picosecond pulse trains

“…Materials with large organic ring structures of conjugated π-electrons [1,2], such as porphyrins and their derivatives, are of great interest and got fast advanced for photonic applications like optical limiters [3][4][5], chemical sensors [6,7], molecular switches [8][9][10], and for medical applications like photomedicine [11][12][13], therapy [12,14] and diagnostics and others [11,15,16]. Until now, many works reported excellent features of porphyrins, for instance, broad visible absorption region [17,18], strong transition dipole moments [19], and high triplet state quantum yield [20].…”