Design and Application of pH-Responsive Liposomes for Site-Specific Delivery of Cytotoxin from Cobra Venom.

Background: Current immunotherapies with unexpected severe side effects and treatment resistance have not resulted in the desired outcomes for patients with melanoma, and there is a need to discover more effective medications. Cytotoxin (CTX) from Cobra Venom has been established to have favorable cytolytic activity and antitumor efficacy and is regarded as a promising novel anticancer agent. However, amphiphilic CTX with excellent anionic phosphatidylserine lipid-binding ability may also damage normal cells. Methods: We developed pH-responsive liposomes with a high CTX load (CTX@PSL) for targeted acidic-stimuli release of drugs in the tumor microenvironment. The morphology, size, zeta potential, drug-release kinetics, and preservation stability were characterized. Cell uptake, apoptosis-promoting effects, and cytotoxicity were assessed using MTT assay and flow cytometry. Finally, the tissue distribution and antitumor effects of CTX@PSL were systematically assessed using an in vivo imaging system. Results: CTX@PSL exhibited high drug entrapment efficiency, drug loading, stability, and a rapid release profile under acidic conditions. These nanoparticles, irregularly spherical in shape and small in size, can effectively accumulate at tumor sites (six times higher than free CTX) and are rapidly internalized into cancer cells (2.5-fold higher cell uptake efficiency). CTX@PSL displayed significantly stronger cytotoxicity (IC50 0.25 µg/mL) and increased apoptosis in than the other formulations (apoptosis rate 71.78±1.70%). CTX@PSL showed considerably better tumor inhibition efficacy than free CTX or conventional liposomes (tumor inhibition rate 79.78±5.93%). Conclusion: Our results suggest that CTX@PSL improves tumor-site accumulation and intracellular uptake for sustained and targeted CTX release. By combining the advantages of CTX and stimuli-responsive nanotechnology, the novel CTX@PSL nanoformulation is a promising therapeutic candidate for cancer treatment.

Cervical Cancer Screening via Visual Inspection With Acetic Acid and Lugol Iodine for Triage of HPV-Positive Women.

Importance: Limited evidence supports the performance of human papillomavirus (HPV) DNA testing as a primary screening method, followed by triage with visual inspection with acetic acid, in areas with limited health care resources, as suggested by the 2021 World Health Organization guidelines. Objective: To evaluate the performance of visual inspection with acetic acid and Lugol iodine as a triage method for detecting cervical precancerous lesions among HPV-positive women in 1 visit. Design, Setting, and Participants: This cohort study examined the implementation of a government-led cervical cancer screening program conducted from January 1, 2016, to December 31, 2020, in Ordos City, China. Female residents, aged 35 to 64 years, who understood the screening procedures and voluntarily participated were included in the study. Women were excluded if they reported never having had sexual intercourse, were pregnant, had a hysterectomy, or had ever undergone treatment for cervical lesions. Statistical analysis was conducted from December 2022 to December 2023. Exposures: The program used the careHPV DNA assay as the primary screening method, and immediate triage was performed by visual inspection if HPV screening results were positive, with a 5-year screening interval. A colposcopy was performed for the women who had suspected cancer on visual inspection results or who were HPV positive and had abnormal visual inspection results, all in 1 visit. Main Outcomes and Measures: The rate of compliance with colposcopy and the detection rate of cervical intraepithelial neoplasia grade 2 or higher (CIN2+). Results: The study included 187 863 women (median age, 46 years [IQR, 40-52 years]) who participated in the program and had valid HPV test results. The overall prevalence of HPV positivity was 12.8% (24 070 of 187 863), and the adherence to triage with visual inspection among HPV-positive women was 93.9% (22 592 of 24 070). Among HPV-positive women, the rate of compliance with colposcopy was 65.6% (2714 of 4137), and the CIN2+ detection rate was 2.8% (643 of 22 592). Conclusions and Relevance: The findings of this cohort study suggest that the implementation of HPV testing, visual inspection, and colposcopy within 1 visit may mitigate losses to follow-up, detect precancerous lesions, and hold significant implications for screening in comparable areas with limited health care resources.