Tissue optical clearing enhances efficacy of vascular targeted photodynamic therapy of mouse dorsal skin

Vascular-targeted photodynamic therapy(V-PDT)is an effective treatment for port wine stains(PWS).However,repeated treatment is usually needed to achieve optimal treatment outcomes,possibly due to the limited treatment light penetration depth in the PWS lesion.The optical clearing technique can increase light penetration in depth by reducing light scattering.This study aimed to investigate the V-PDT in combination with an optical clearing agent(OCA)for the therapeutic enhancement of V-PDT in the rodent skinfold window chamber model.Vascular responses were closely monitored with laser speckle contrast imaging(LSCI),optical coherence tomography angiography,and stereo microscope before,during,and after the treatment.We further quantitatively demonstrated the effects of V-PDT in combination with OCA on the blood flow and blood vessel size of skin microvasculature.The combination of OCA and V-PDT resulted in significant vascular damage,including vasoconstriction and the reduction of blood flow.Our results indicate the promising potential of OCA for enhancing V-PDT for treating vascular-related diseases,including PWS.

Antitumor effects of a novel photosensitizer-mediated photodynamic therapy and its influence on the cell transcriptome

Photodynamic therapy(PDT)is a promising cancer treatment.This study investigated the antitumor effects and mechanisms of a novel photosensitizer meso-5-[ρ-diethylene triamine pentaacetic acid-aminophenyl]−10,15,20-triphenyl-porphyrin(DTP)mediated PDT(DTP-PDT).Cell viability,reactive oxygen species(ROS),and apoptosis were measured with a Cell Counting Kit-8 assay,DCFH-DA fluorescent probe,and Hoechst staining,respectively.Cell apoptosis-and autophagy-related proteins were examined using western blotting.RNA sequencing was used to screen differentially expressed mRNAs(DERs),and bioinformatic analysis was performed to identify the major biological events after DTP-PDT.Our results show that DTP-PDT inhibited cell growth and induced ROS generation in MCF-7 and SGC7901 cells.The ROS scavenger N-acetyl-L-cysteine(NAC)and the P38 MAPK inhibitor SB203580 alleviated DTP-PDT-induced cytotoxicity.DTP-PDT induced cell apoptosis together with upregulated Bax and downregulated Bcl-2,which could also be inhibited by NAC or SB203580.The level of LC3B-Ⅱ,a marker of autophagy,was increased by DTP-PDT.A total of 3496 DERs were obtained after DTP-PDT.Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses indicated that DERs included those involved in cytosolic ribosomes,the nuclear lumen,protein binding,cell cycle,protein targeting to the endoplasmic reticulum,and ribosomal DNA replication.Disease Ontology and Reactome enrichment analyses indicated that DERs were associated with a variety of cancers and cell cycle checkpoints.Protein-protein interaction results demonstrated that cdk1 and rps27a ranked in the top 10 interacting genes.Therefore,DTP-PDT could inhibit cell growth and induce cell apoptosis and autophagy,partly through ROS and the P38 MAPK signaling pathway.Genes associated with the cell cycle,ribosomes,DNA replication,and protein binding may be the key changes in DTP-PDT-mediated cytotoxicity.

Enhancing the Photosensitivity of Hypocrellin A by Perylene Diimide Metallacage‑Based Host–Guest Complexation for Photodynamic Therapy

The development of supramolecular hosts which can efficiently encapsulate photosensitizers to improve the photodynamic efficacy holds great promise for cancer therapy.Here,we report two perylene diimide-based metallacages that can form stable host–guest complexes with planar conjugated molecules including polycyclic aromatic hydrocarbons and photosensitizers(hypocrellin A).Such host–guest complexation not only prevents the aggregation of photosensitizers in aqueous environments,but also offers fluorescence resonance energy transfer(FRET)from the metallacage to the photosensitizers to further improve the singlet oxygen generation(Φ_(Δ)=0.66).The complexes are further assembled with amphiphilic polymers,forming nanoparticles with improved stability for anticancer study.Both in vitro and in vivo studies indicate that the nanoparticles display excellent anticancer activities upon light irradiation,showing great potential for cancer photodynamic therapy.This study provides a straightforward and effective approach for enhancing the photosensitivity of conventional photosensitizers via host–guest complexation-based FRET,which will open a new avenue for host–guest chemistry-based supramolecular theranostics.

Anti-PD1 antibody and not anti-LAG-3 antibody improves the antitumor effect of photodynamic therapy for treating metastatic breast cancer

Photodynamic therapy(PDT)has limited effects in treating metastatic breast cancer.Immune checkpoints can deplete the function of immune cells;however,the expression of immune checkpoints after PDT is unclear.This study investigates whether the limited e±cacy of PDT is due to upregulated immune checkpoints and tries to combine the PDT and immune checkpoint inhibitor to observe the e±cacy.A metastatic breast cancer model was treated by PDT mediated by hematoporphyrin derivatives(HpD-PDT).The anti-tumor effect of HpD-PDT was observed,as well as CD4þT,CD8þT and calreticulin(CRT)by immunohistochemistry and immunofluorescence.Immune checkpoints on T cells were analyzed byflow cytometry after HpD-PDT.When combining PDT with immune checkpoint inhibitors,the antitumor effect and immune effect were assessed.For HpD-PDT at 100 mW/cm2 and 40,60 and 80 J/cm2,primary tumors were suppressed and CD4þT,CD8þT and CRT were elevated;however,distant tumors couldn't be inhibited and survival could not be prolonged.Immune checkpoints on T cells,especially PD1 and LAG-3 after HpD-PDT,were upregulated,which may explain the reason for the limited HpD-PDT effect.After PDT combined with anti-PD1 antibody,but not with anti-LAG-3 antibody,both the primary and distant tumors were signi-cantly inhibited and the survival time was prolonged,additionally,CD4þT,CD8þT,IFN-þCD4þT and TNF-þCD4þT cells were signi-cantly increased compared with HpD-PDT.HpD-PDT could not combat metastatic breast cancer.PD1 and LAG-3 were upregulated after HpD-PDT.Anti-PD1 antibody,but not anti-LAG-3 antibody,could augment the antitumor effect of HpD-PDT for treating metastatic breast cancer.

Potential of photodynamic therapy in the management of infectious oral diseases

Photodynamic therapy(PDT)can take place in the presence of three elements:Light with an appropriate wavelength;a photosensitizer;and the presence of oxygen.This type of treatment is very effective overall against bacterial,viral and mycotic cells.In the last 10 years many papers have been published on PDT with different types of photosensitizers(e.g.,methylene blue,toluidine blue,indocyanine green,curcumin-based photosensitizers),different wavelengths(e.g.,460 nm,630 nm,660 nm,810 nm)and various parameters(e.g.,power of the light,time of illumination,number of sessions).In the scientific literature all types of PDT seem very effective,even if it is difficult to find a standard protocol for each oral pathology.PDT could be an interesting way to treat some dangerous oral infections refractory to common pharmacological therapies,such as candidiasis from multidrug-resistant Candida spp.

Clinical Study of Photodynamic Therapy for Upper Gastrointestinal Tract Cancers

Objective： To evaluate the clinical effectiveness and adverse effects of photodynamic therapy （PDT） for the upper gastrointestinal tract cancers. Methods： 56 patients with upper gastrointestinal cancers in different clinical stages were treated with PDT. Diode laser （630 nm） was used as the light source and the parameters were as follows： power density 200 to 400 mW/cm, energy density 100 to 300 J/cm. PHOTOFRIN was used as photosensitizer, which was given in a dose of 2 mg/kg intravenously 12-24 h before irradiation. Results： Evaluation of the 56 patients＇ therapeutic effectiveness showed that 6 patients （10.7%） had a complete response （CR）, 33 patients （58.9%） partial response （PR）, 12 patients （21.4%） mild response （MR）, and 5 patients （8.9%） no response （NR）. The total response rate （CR＋PR） was 69.6%. No patients had severe adverse effects in this group. Conclusion： PDT is an effective and safe palliative modality for upper gastrointestinal tract cancers.

Study on the Synthesis and in vitro Photodynamic Anti-cancer Activity of Tetra(trifluoroethoxy) Germanium Phthalocyanine

The synthesis and in vitro photodynamic anticancer activity of a new photosen- sitizer, tetra（trifluoroethoxy） germanium phthalocyanine （GePcF）, were studied. GePcF was characterized by UV-Vis, IR, MS and elemental analysis. The in vitro photodynamic activity of GePcF was studied by MTT. IC50 of GePcF for SW480 cells of human colonic adenocarcinoma and HeLa cells of cervical cancer were 36.53 and 45.78 μmol/L, respectively. GePcF as a photosensitizer may be used to treat cancers due to its photodyrmmic anticancer activity.

Long term outcomes for patients treated with half-fluence photodynamic therapy for chronic central serous chorioretinopathy: a case series

A case series was used to evaluate the efficacy of halffluence photodynamic therapy（PDT） for chronic central serous chorioretinopathy（CSCR）. Patients were treated with standard-dose verteporfin and half-fluence PDT. Totally 13 eyes from 11 patients were included. The mean patient age was 52.0 y. There was a mean reduction in central retinal thickness of 107.0 microns. Totally 7/13 eyes（53.8%） achieved resolution of subretinal fluid（SRF） on optical coherence tomography（OCT） scan after 1 treatment with PDT. Four eyes had further treatment with PDT; of these 1 eye achieved resolution of SRF. Seven of the 13 eyes（53.8%） achieved an improvement of more than 5 ETDRS letters. One patient experienced acute macula oedema 1 d post PDT treatment. These results support the hypothesis that half-fluence PDT can have a positive effect in chronic CSCR for a gain in visual acuity and reduction in sub-retinal fluid. Acute macula oedema is a rare but potential adverse effect of half-fluence PDT.

Ultrasmall pH-responsive silicon phthalocyanine micelle for selective photodynamic therapy against tumo

Targeted photodynamic therapy(TPDT)based on the photosensitizers responsive for tumor micr oenvironment is promising because of the better anti-tumor effect and less phototoxicity against normal tissue than the traditional PDT.Nanoparticle based stimuli responsive photo-sensitizers have been widely explored for TPDT.Based on the acidic microenvironments in solid tumors,an ultrasmall pH-responsive silicon phthalocyanine nanomicelle(PSN)(smaller than 10 nm)was designed for selective PDT of tumor.PSN had high drug loading efficacy(more than 28%)and exhibited morphological transitions,enhanced fuorescence and improved singlet∞x-ygen yield under acidic environments.PSN was renal dlearable and could rapidly accumulate and be retained at tumor sites,achieving a tumor-inhibiting ffect better than phthalocyanine micelle without pH response.Tumors of mice treated with PSN for PDT were completely ablated without recurrence.Thus,we have developed a phthalocyanine-based pH responsive micelle with excellent tumor targeting ability,which is expected to realize the selective PDT of tumor.

Meso-substituted cationic 3-and 4-N-Pyridylporphyrins and their Zn(II)derivatives for antibacterial photodynamic therapy

Photodynamic inactivation of microorganisms known as antibacterial photodynamic therapy(APDT)is one of the most promising and innovative approaches for the destruction of pathogenic microorganisms.Among the photosensitizers(PSs),compounds based on cationic porphyrins/metalloporphyrins are most successfully used to inactivate microorganisms.Series of meso-substituted cationic pyridylporphyrins and metalloporphyrins with various peripheral groups in the third and fourth positions of the pyrrole ring have been synthesized in Armenia.The aim of this work was to determine and test the most e®ective cationic porphyrins and metalloporphyrins with high photoactivity against Gram negative and Gram positive microorganisms.It was shown that the synthesized cationic pyridylporphyrins/metalloporphyrins exhibit a high degree of phototoxicity towards both types of bacteria,including the methicillinresistant S.aureus strain.Zinc complexes of porphyrins are more phototoxic than metal-free porphyrin analogs.The e®ectiveness of these Zn–metalloporphyrins on bacteria is consistent with the level of singlet oxygen generation.It was found that the high antibacterial activity of the studied cationic porphyrins/metalloporphyrins depends on four factors:the presence in the porphyrin macrocycle of a positive charge(+4),a central metal atom(Zn2þÞand hydrophobic peripheral functional groups as well as high values of quantum yields of singlet oxygen.The results indicate that meso-substituted cationic pyridylporphyrins/metalloporphyrins cannd wider application in photoinactivation of bacteria than anionic or neutral PSs usually used in APDT.

Effect of antibacterial photodynamic therapy on Streptococcus mutans plaque biofilm in vitro

The main objective of this study is to evaluate the antibacterial effect of antibacterial pho-todynamic therapy(aPDT)on Streptococcus mutans(S.mutans)biofilm model in vitro.The selection of photosensitizers is the key step for the efficacy of photodynamic therapy(PDT).However,no studies have been conducted in the oral field to compare the functional char-acteristics and application effects of PDT mediated by various photosensitizers.In this re-search,the antibacterial effect of Methylene blue(MB)/650 nm laser and Hematoporphyrin monomethyl ether(HMME)/532 nm laser on S.mutans biofilm was compared under different energy densities to provide experimental reference for the clinical application of the two PDT.The yield of lactic acid was analyzed by Colony forming unit(CFU)and spectrophotometry,and the complete biofilm activity was measured by Confocal Laser Scanning Microscopy(CLSM)to evaluate the bactericidal effect on each group.Based on the results of CFU,the bacterial colonies formed by 30.4J/cm^(2)532nm MB-aPDT group and 30.4J/cm^(2)532nm HMME-aPDT group were significantly less than those in other groups,and the bacterial colonies in HMME-aPDT group were less than those in HMME-aPDT group.Lactic acid production in all treatment groups except the photosensitizer group was statistically lower than that in the normal saline control group.The activity of bacterial plaque biofilm was significantly decreased in the two groups treated with 30.4 J/cm^(2) aPDT.Therefore,aPDT suitable for energy measurement can kill S.mutans plaque biofilm,and MB-aPDT is better than HMME-aPDT.

Combined photodynamic therapy and ranibizumab for polypoidal choroidal vasculopathy：a 2-year result and systematic review

AIM：To report a cohort of patients with polypoidal choroidal vasculopathy（PCV）treated with photodynamic therapy（PDT）followed by intravitreal ranibizumab injection 24-48 h later,and to compare the results between eyes with PCV treated by PDT followed by intravitreal anti-vascular endothelial growth factor（VEGF）injection and intravitreal anti-VEGF injection followed by PDT by Meta-analysis.METHODS：Retrospective study and systematic literature review. Medical records of patients with PCV who were initially treated using PDT followed by intravitreal ranibizumab injection 24-48 h after PDT and had completed at least 2y follow-up were reviewed and analyzed. Clinical data,including age,sex,best-corrected visual acuity（BCVA）,fundus photograph,fluorescein angiography,indocyanine green angiography and optical coherence tomography were investigated. A systematic literature review was also conducted,and a visual outcome of studies over 1y was compared using Meta-analysis. RESULTS：A total of 52 patients were included in the study. Mean BCVA at baseline and follow-up at 1 or 2y were 0.71± 0.61,0.51±0.36 and 0.68±0.51 log MAR,respectively. The cumulative hazard rate for recurrence at 1 and 2y followup was 15.4% and 30.3% respectively. The percentage of eyes with polyps regression at 3,12 and 24 mo follow-up was 88.5%,84.6% and 67.3% respectively. A Meta-analysis based on 22 independent studies showed the overall vision improvements at 1,2 and 3y follow-up were 0.13±0.04（P〈0.001）,0.12±0.03（P〈0.001）,0.16±0.06（P〈0.001）,respectively. The proportion of polyps regression at 1y follow-up was 64.6%（95%CI：51.5%,77.7%,P〈0.001）in 434 eyes treated by intravitreal anti-VEGF agents beforePDT and 76.0%（95%CI：64.8%,87.3%,P=0.001）in 199 eyes treated by intravitreal anti-VEGF agents after PDT. CONCLUSION：Intravitreal ranibizumab injection 24-48 h following PDT effectively stabilizes visual acuity in the eye with PCV. PDT followed by intravitreal anti-VEGF agents may contribute to a relatively higher proportion of polyps＇ regression as compared to that of intravitreal anti-VEGF before PDT.

Low-fluence photodynamic therapy combinations in the treatment of exudative age-related macular degeneration

AIM:To compare the efficacy of low-fluence photodynamic therapy(PDT) combinations in the treatment of age-related macular degeneration(AMD).· METHODS:Forty-five previously untreated eyes of 45 patients with exudative AMD whose best-corrected visual acuity(BCVA) was ≥0.3(Snellen) were enrolled.15 patients in Group I underwent low-fluence PDT(25J/cm2-300mW/cm2-83sec) and intravitreal pegaptanib combination,15 patients in Group II underwent PDT(50J/cm2-600mW/cm2-83sec) and intravitreal pegaptanib combination while,15 patients in Group III underwent intravitreal pegaptanib monotherapy.Complete ophthalmologic examinations were performed in pre and post treatment visits,and the results were statistically analised.A clinical activity score(CAS) was calculated by using changes in lesion size,amount of hemorrhage,staining pattern in FA and OCT measurement of intra/subretinal fluid.≤3 logMAR lines of decrease in BCVA and decrease in CAS were considered as successful treatment.· RESULTS:The mean age of 19 female(42.2%) and 26 male(57.8%) patients was(72.82±8.02) years.Mean follow-up was(13.93±5.87) months.Lesion type was occult in 28 eyes(62.2%).Treatment success rates according to BCVA assessments were 86.7%,80%,60% and mean BCVA decrease were 0.3,1.0,2.2 logMAR lines in Group I,II and III,respectively(P >0.05).According to the changes in central macular thickness and CAS,no difference was found among the study groups(P =0.850 and P =0.811,respectively).Patients treated with combination regimens had lower intravitreal injection frequencies(P =0.015).· CONCLUSION:Combination regimen with intravitreal pegaptanib and low-fluence PDT seems to be safe and effective in stabilizing the clinical activity and BCVA in exudative AMD.·

Silicon quantum dots delivered phthalocyanine for fluorescence guided photodynamic therapy of tumor

Imaging-guided cancer therapy provides a simultaneous tumor imaging and treatment, which helps to eliminate the excessive toxicity to the healthy tissues. For this purpose, multifunctional probes capable of both imaging and curing are needed. In this work, we synthesize water-soluble silicon quantum dots（Si QDs） smaller than 5 nm. Such Si QDs are used for delivering the hydrophobic drug phthalocyanine（Pc）. The as-prepared Si/Pc nanocomposite particles show efficient transmembrane delivery into cells and feasible biocompatibility. Moreover, these composite particles emit dualchannel fluorescence signals even after cellular internalization and demonstrate robust photostability in the Si channel.More interestingly, the Si/Pc composite particles show efficient photodynamic therapy effects against tumors both in vitro and in vivo.

Recent Advances in Tumor Microenvironment Hydrogen Peroxide-Responsive Materials for Cancer Photodynamic Therapy

Photodynamic therapy(PDT),as one of the noninvasive clinical cancer phototherapies,suffers from the key drawback associated with hypoxia at the tumor microenvironment(TME),which plays an important role in protecting tumor cells from damage caused by common treatments.High concentration of hydrogen peroxide(H2O2),one of the hallmarks of TME,has been recognized as a double-edged sword,posing both challenges,and opportunities for cancer therapy.The promising perspectives,strategies,and approaches for enhanced tumor therapies,including PDT,have been developed based on the fast advances in H2O2-enabled theranostic nanomedicine.In this review,we outline the latest advances in H2O2-responsive materials,including organic and inorganic materials for enhanced PDT.Finally,the challenges and opportunities for further research on H2O2-responsive anticancer agents are envisioned.

Influence of Photodynamic Therapy on Apoptosis and Invasion of Human Cholangiocarcinoma QBC939 Cell Line

Objective To investigate the effect of photodynamic therapy(PDT) mediated by hematoporphyrin derivative(HPD) on apoptosis and invasion of cholangiocarcinoma QBC939 cell lines. Methods In vitro cultured cholangiocarcinoma QBC939 cell line was exposed to 2, 4, 6, 8, 10, 12, and 14 μg/ml HPD with 5, 10, and 15 J/cm2 light intensity, respectively. The optical density at 450 nm of the QBC939 cells was measured by CCK8 assay and its growth inhibition ratio was calculated. Flow cytometry and transwell migration assay were applied to detect cell apoptosis and invasion respectively. RT-PCR and immunocytochemistry analyses were used to detect expressions of vascular endothelial growth factor-C(VEGF-C), cyclooxygenase-2(COX-2), and proliferating cell nuclear antigen(PCNA). Enzyme-linked immunosorbent assay(ELISA) was carried out to examine the secretion of VEGF-C and COX-2 in QBC939 cells. Results Exposure to HPD-PDT can significantly suppress the growth of QBC939 cells(all P<0.05). HPD-PDT can promote apoptosis of QBC939 cells at the early stage. When the concentration of HPD was 2 μg/ml and light irradiation was 5 J/cm2, HPD-PDT had no obvious inhibitory effect on QBC939 cell growth, but can obviously inhibit cell invasion, and significant difference was observed between the HPD-PDT and control groups(P<0.01). The HPD-PDT can reduce the m RNA and protein expressions of VEGF-C, COX-2, and PCNA, and decrease the secretion of VEGF-C and COX-2 in QBC939 cells. Conclusion PDT could promote apoptosis and inhibit growth and invasion of cholangiocarcinoma cells QBC939 in vitro.

Success of photodynamic therapy in palliating patients with nonresectable cholangiocarcinoma: A systematic review and meta-analysis

To perform a systematic review and meta-analysis on clinical outcomes of photodynamic therapy (PDT) in non-resectable cholangiocarcinoma.METHODSIncluded studies compared outcomes with photodynamic therapy and biliary stenting (PDT group) vs biliary stenting only (BS group) in palliation of non-resectable cholangiocarcinoma. Articles were searched in MEDLINE, PubMed, and EMBASE. Pooled proportions were calculated using fixed and random effects model. Heterogeneity among studies was assessed using the I2 statistic.RESULTSTen studies (n = 402) that met inclusion criteria were included in this analysis. The P for χ2 heterogeneity for all the pooled accuracy estimates was > 0.10. Pooled odds ratio for successful biliary drainage (decrease in bilirubin level > 50% within 7days after stenting) in PDT vs BS group was 4.39 (95%CI: 2.35-8.19). Survival period in PDT and BS groups were 413.04 d (95%CI: 349.54-476.54) and 183.41 (95%CI: 136.81-230.02) respectively. The change in Karnofsky performance scores after intervention in PDT and BS groups were +6.99 (95%CI: 4.15-9.82) and -3.93 (95%CI: -8.63-0.77) respectively. Odds ratio for post-intervention cholangitis in PDT vs BS group was 0.57 (95%CI: 0.35-0.94). In PDT group, 10.51% (95%CI: 6.94-14.72) had photosensitivity reactions that were self-limiting. Subgroup analysis of prospective studies showed similar results, except the incidence of cholangitis was comparable in both groups.CONCLUSIONIn palliation of unresectable cholangiocarcinoma, PDT seems to be significantly superior to BS alone. PDT should be used as an adjunct to biliary stenting in these patients.

Combined therapy with bevacizumab and photodynamic therapy for myopic choroidal neovascularization: A oneyear follow-up controlled study

AIMTo evaluate the efficacy and safety of a combined treatment for myopic choroidal neovascularization (CNV) using photodynamic therapy (PDT) and intravitreal bevacizumab and to compare it with intravitreal bevacizumab monotherapy.

Effects of integrin-targeted photodynamic therapy on pancreatic carcinoma cell

AIM:To investigate the effects of photodynamic therapy with quantum dots-arginine-glycine-aspartic acid(RGD)probe as photosensitizer on the proliferation and apoptosis of pancreatic carcinoma cells.METHODS:Construction of quantum dots-RGD probe as photosensitizer for integrin-targeted photodynamic therapy was accomplished.After cells were treated with photodynamic therapy(PDT),the proliferation of SW1990 cells were measured by methyl thiazolyl tetrazolium assay.Morphologic changes,cell cycle retardance and apoptosis were observed under fluoroscope and flow cytometry.The expression of myeloid cell leukemia-1(Mcl-1),protein kinase B(Akt)and tumor necrosis factor-related apoptosis-inducing ligand(TRAIL)mRNA were detected by reverse transcriptionpolymerase chain reaction.The amount of reactive oxygen species were also evaluated by fluorescence probe.RESULTS:The photodynamic therapy with quantum dots-RGD probe as photosensitizer significantly inhibited cell proliferation(P<0.01).Apoptotic cells and morphologic changes could be found under optical microscope.The FCM revealed PDT group had more significant cell apoptosis rate compared to control cells(F=130.617,P<0.01)and cell cycle G0/G1and S retardance(P<0.05)compared to control cells.The expression of Mcl-1 and Akt mRNA were down-regulated,while expression of TRAIL mRNA was up-regulated after cells treated with PDT.PDT group had more significant number of cells producing reactive oxygen species compared to control cells(F=3262.559,P<0.01).CONCLUSION:The photodynamic therapy with quantum dots-RGD probe as photosensitizer significantly inhibits cell proliferation and increases apoptosis in SW1990 cells.