Preparation Of Silicon Phthalocyanine Self-assembled Nanomaterials And Study On The Antibacterial Activity Of PDT/PTT

Phthalocyanine is a planar conjugated heterocyclic compound with 18π electron.Due to its excellent photophysical properties,good stability and the structure that is easy to modify,it has a broad application prospect in the field of phototherapy.However,the application of phthalocyanine is limited due to its easy aggregation and sedimentation,poor biocompatibility and poor dispersion.Therefore,the introduction of hydrophilic groups on phthalocyanine molecules can help to increase water solubility,inhibit molecular aggregation,and promote the formation of self-assembled nanoparticles,which is conducive to the application of phototherapy.In this paper,the structure of silicon phthalocyanine with axial substituents was designed,and its PDT/PTT antibacterial properties were studied by self-assembly into nanomaterials.The main contents are as follows:(1)Design and synthesis of di-[4-(2-methylaminoethyl)phenoxyl] silicon phthalocyanine and study on the antibacterial properties of PDT/PTT self-assembled nanoparticles.Axially substituted Di-[4-(2-dimethylaminoethyl)phenoxy] silicon phthalocyanine molecules were designed and synthesized,and self-assembled in aqueous solution containing CEL to obtain 20 nm nanoparticles(Si Pc@CEL).Photophysical test showed that Si Pc@CEL can produce abundant superoxide anion radical and singlet oxygen,and had good PDT properties of Type I and Type II.The photothermal performance test showed that Si Pc@CEL had good PTT performance with photothermal conversion efficiency of 16.1% under 660 nm illumination.The results of in vitro antibacterial experiments showed that Si Pc@CEL had higher phototoxicity and lower dark toxicity to Staphylococcus aureus and Escherichia coli under 660 nm light.Under the synergistic effect of Si Pc@CEL PDT/PTT,Staphylococcus aureus was effectively inhibited in wound infection of mice.In addition,Si Pc@CEL promoted wound healing as effectively as streptomycin did in mice.(2)Design and synthesis of di-[N-(methyl iodomorpholine)hydroxypropyl] silicon phthalocyanine and its self-assembly of nanoparticles PDT/PTT antibacterial study.The axially substituted Di-[N-(morpholinyl)hydroxypropyl] silphthalocyanine(1)was designed and synthesized,and its axial substituents were cationized to obtain bis-[N-(methyliodomorpholinyl)hydroxypropyl] silphthalocyanine(2).Due to the increase of water solubility,compound 2 can self-assemble in water to obtain stable dispersed spherical nanoparticles NP2,while the nanoparticles NP1 formed by compound 1 in water will polymerize.Under 660 nm light,NP2 had a high release rate of superoxide anion radical,and its singlet oxygen yield was 18.3%,indicating that NP2 had good PDT performance of both Type I and Type II.In addition,NP2 had good PTT performance and its photothermal conversion efficiency was 17.3%.Due to the PDT/PTT combined therapeutic effect of NP2,the inhibition rate of Staphylococcus aureus and Escherichia coli under 660 nm light was 99.8% and 93.9%,respectively.In vivo antibacterial experiments showed that NP2 had a good inhibitory effect on Staphylococcus aureus infected by wound in mice,and its ability to promote wound healing in mice was comparable to streptomycin.