Antimicrobial Photosensitizing Material Based on Conjugated Zn(II) Porphyrins

SANTAMARINA, SOFÍA C.; HEREDIA, DANIEL A.; DURANTINI, ANDRÉS M.; DURANTINI, EDGARDO N.

Antibiotics

MDPI - Publisher of Open Access Journals

Año: 2022

2079-6382

The widespread use of antibiotics has led to a considerable increase in the resistance ofmicroorganisms to these agents. Consequently, it is imminent to establish new strategies to combatpathogens. An alternative involves the development of photoactive polymers that represent aninteresting strategy to kill microbes and maintain aseptic surfaces. In this sense, a conjugated polymer(PZnTEP) based on Zn(II) 5,10,15,20-tetrakis-[4-(ethynyl)phenyl]porphyrin (ZnTEP) was obtained bythe homocoupling reaction of terminal alkyne groups. PZnTEP exhibits a microporous structure withhigh surface areas allowing better interaction with bacteria. The UV-visible absorption spectra showthe Soret and Q bands of PZnTEP red-shifted by about 18 nm compared to those of the monomer.Also, the conjugate presents the two red emission bands, characteristic of porphyrins. This polymerwas able to produce singlet molecular oxygen and superoxide radical anion in the presence ofNADH. Photocytotoxic activity sensitized by PZnTEP was investigated in bacterial suspensions.No viable Staphylococcus aureus cells were detected using 0.5 M PZnTEP and 15 min irradiation.Under these conditions, complete photoinactivation of Escherichia coli was observed in the presence of100 mM KI. Likewise, no survival was detected for E. coli incubated with 1.0 M PZnTEP after 30 minirradiation. Furthermore, polylactic acid surfaces coated with PZnTEP were able to kill efficientlythese bacteria. This surface can be reused for at least three photoinactivation cycles. Therefore, thisconjugated photodynamic polymer is an interesting antimicrobial photoactive material for designingand developing self-sterilizing surfaces.