Detection And Treatment Of Bacte-Rial Infection By Peptide-Chlorphyll Molecule Family

Disease caused by drug-resistant infection is one of the harsh problem for human health.The problem of curing drug-resistant bacterial infectious diseases has been in-creaing urgent problem for antibiotics abuse and drug-resistant bacterial increasing in recent years.Thus,it is of vital pressing to develop a new probe and anti-bacterial agent as the arrival of“post-antibiotic”era.Therefore,we demand new methods to detect and treat the remained bacterial for avoiding infection relapse.Staphylococcus aureus,which is host bacteria in immune cells,could escape an-tibiotic treatment by the shelter of immune cells,like macrophage.With the concen-tration of antibiotics fade or transported to other parts of body,Staphylococcus aureus would make waves again and cause infection relapse.In our study,peptide-chlorophyll molecules possessing good biocompatibility was applied to effective kill Staphylococcus aureus under the shelter of macrophage.In addition,we designed the sequence of peptide chain to detect the host bacterial and residual bacterial after antibiotic treatment.And the peptide chain could be cut and followed self-assemble when it active targeting to infected macrophages.First of all,we synthesized peptide-chlorophyll photodynamic agent and probe,both possessing good biocompatibility,by a coupled method of solid phase synthesis and click reaction.Afterwards,we evaluated the active oxygen production capacity of peptide-chlorophyll photodynamic agent.The result showed peptide-chlorophyll photodynamic agent chelated with Cu²⁺exceeded the others and effectively killed Staphylococcus aureus.The same result also emerged through in vitro and in vivo ex-periments.In addition,we assessed the performance of peptide-chlorophyll molecules to detect immune cell host bacterial.Chlorophyll derivative could be monodispersed in DMSO,while assembled in water driven by?-?stacking.By photoacoustic meas-urement,assembled aggregation and dimer peptide-chlorophyll molecules showed a good signal ratio.We also verified the enzyme cleavage effect and followed self-assembled property through macrophage infection model,obtaining a good pho-toacoustic signal.Furtherly,we modeled host bacterial infection in mice legs.The photoacoustic image result indicated the infected macrophages possessed much higher signal,suggesting that our peptide-chlorophyll molecules effectively detect immune cell host bacterial.In summary,we developed new peptide-chlorophyll molecules for efficiently eliminating immune cell host bacterial through photodynamic technology and effec-tively detect the immune cell host bacterial with minimally invasive through photoa-coustic image.We believe our work do have broader impacts on detect and eliminat-ing host bacterial.