1：Experimental Design and Method Selection:

The study involved synthesizing polydopamine nanoparticles (PDA) and modifying them with beclin 1 peptide, PEG, and RGD peptides to create PPBR nanoparticles. Methods included chemical conjugation, characterization, and in vitro and in vivo assays to evaluate autophagy induction, cellular uptake, photothermal effects, and therapeutic efficacy.

2：Sample Selection and Data Sources:

Cancer cell lines (MDA-MB-231, HeLa, NIH3T3) and BALB/c nude mice with MDA-MB-231 tumors were used. Data were obtained from cell culture experiments, animal models, and various imaging and analytical techniques.

3：List of Experimental Equipment and Materials:

Equipment included transmission electron microscope (HT7700, HITACHI), UV-Vis spectrophotometer (Cary 60, Agilent Technologies), Zetasizer Nano ZS90 (Malvern), confocal laser scanning microscope (Leica SP5), NIR laser (808 nm, Changchun New Industries Optoelectronics Technology Co., Ltd), infrared thermal camera (Magnity Electronics), ICP-MS (Neptune MC-ICP-MS, Thermo), MRI (ClinScan, BRUKER), and PAI instrument (Endra Life Sciences Nexus128). Materials included dopamine hydrochloride, various peptides, PEG derivatives, and chemicals from Sigma-Aldrich, Ponsure Biotech, GL Biochem, Aladdin Reagent, Sinopharm Chemical Reagent, J&K Scientific, Sango Biotech, Tiangen Biotech, Gene Pharma, and others.

4：8). Materials included dopamine hydrochloride, various peptides, PEG derivatives, and chemicals from Sigma-Aldrich, Ponsure Biotech, GL Biochem, Aladdin Reagent, Sinopharm Chemical Reagent, J&K Scientific, Sango Biotech, Tiangen Biotech, Gene Pharma, and others. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: Synthesis of nanoparticles involved step-wise conjugation and purification. In vitro assays included GFP-LC3 dot formation, cytotoxicity (MTT), AO staining, western blot, cellular uptake, and photothermal killing. In vivo procedures involved biodistribution studies, PAI, MRI, photothermal therapy, and analysis of apoptosis and autophagy in tumors.

5：Data Analysis Methods:

Statistical analysis used Student's t-test. Data from UV-Vis, flow cytometry, microscopy, and other instruments were quantified and compared.