Safe ablation of the anal mucosa and perianal skin in rats using Photodynamic Therapy--a promising approach for treating Anal Intraepithelial Neoplasia

Photodynamic Therapy for the Treatment of Complex Anal Fistula

BACKGROUND AND OBJECTIVES

To validate and analyze the results of intralesional photodynamic therapy in the treatment of complex anal fistula.

STUDY DESIGN/MATERIALS AND METHODS

This prospective multicentric observational study enrolled patients treated for complex anal fistula who underwent intralesional photodynamic therapy (i-PDT). The included patients were treated from January 2016 to December 2018 with a minimum follow-up of 1 year to evaluate recurrence, continence and postoperative morbidity. Intralesional 5-aminolevulinic acid (ALA) gel (2%) was injected directly into the fistula. The internal and external orifices were closed. After an incubation period of 2 hours, the fistula was irradiated using an optical fiber connected to a red laser (Multidiode 630 PDT) operating at 1 W/cm for 3 minutes (180 J).

RESULTS

In total, 49 patients were included (61.2% male). The mean age was 48 years, and the mean duration of fistula was 13 months. Of the fistulas included, 75.5% were medium transphincteric, and 24.5% were high transphincteric. The median fistula length was 4 ± 1,14 cm (range: 3-5). A total of 41 patients (83.7%) had a previous history of fistula surgery. Preoperatively, some degree of anal incontinence was found in 5 patients (10.2%). No center reported any other procedure-related complications intraoperatively. Phototoxicity was found in one patient. In the first 48 hours after the procedure, fever was reported in 2 patients (4%). At the end of follow-up, total healing was observed in 32/49 patients (65.3%). No patient reported new incontinence postoperatively.

CONCLUSION

i-PDT could be considered a good choice in patients with complex anal fistulas to avoid surgery and its complications. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Semaphoring mAb: a new guide in RIT in inhibiting the proliferation of human skin carcinoma

Semaphoring is a transmembrane receptor which participates in many cytokine-mediated signal pathways that are closely related to the angiogenesis, occurrence and development of carcinoma. The present study was designed to access the effect of mono-antibody (mAb) guided radioimmunotherapy (RIT) on skin carcinoma and investigate the potential mechanisms. Semaphoring mAb was acquired from mice (Balb/c), purified with rProtein A column; purity, concentration and activity were tested with SDS-PAGE and indirect ELISA; specificity and expression on the cutanuem carcinoma line and tissue were tested by Western blotting; morphology change was assessed by microscopy. MTT assay and colony inhibition tests were carried out to test the influence on the proliferation of tumor cells; Western blotting was also carried out for expression of apoptosis-associated (caspase-3, Bax, Bcl-2) and proliferation-related (PI3K, p-Akt, Akt, p-ERK1/2, ERK1/2) proteins and analyse the change in signal pathways (PI3K/Akt and MEK/ERK). The purity of purified semaphorin mAb was 96.5% and the titer is about 1?106. Western blotting showed semaphoring mAb to have specifically binding stripes with semaphoring b1b2 protein, B16F10, and A431 cells at 39KDa, 100KDa and 130KDa, respectively. Positive expression was detected both in cutanuem carcinoma line and tissue and it mostly located in cell membranes. MMT assay revealed dose-relate and time-relate inhibitory effect of semaphorin mAb on A431 and B16F10. Colony inhibition tests also showed dose-relate inhibitory effects. Western blotting demonstrated the expression of apoptosis and proliferation-related protein and changes in signal pathway. In conclusion, we demonstrated that semaphorin is highly expressed on the tumor cell-surfaces and RIT with semaphorin mAb has effect in inhibiting proliferation and accelerating apoptosis of tumor cells.