Fabrication of methylene blue-loaded ovalbumin/polypyrrole nanoparticles for enhanced phototherapy-triggered antitumour immune activation

Abstract

Background Phototherapy-triggered immunogenic cell death (ICD) rarely elicits a robust antitumour immune response, partially due to low antigen exposure and inefficient antigen presentation. To address these issues, we developed novel methylene blue-loaded ovalbumin/polypyrrole nanoparticles (MB@OVA/PPY NPs) via oxidative polymerization and π–π stacking interactions. Results The as-prepared MB@OVA/PPY NPs with outstanding photothermal conversion efficiency (38%) and photodynamic properties were readily internalized into the cytoplasm and accumulated in the lysosomes and mitochondria. Upon 808 nm and 660 nm laser irradiation, the MB@OVA/PPY NPs not only ablated tumour cells by inducing local hyperthermia but also damaged residual tumour cells by generating a large amount of reactive oxygen species (ROS), finally triggering the release of many damage-associated molecular patterns (DAMPs). Moreover, the MB@OVA/PPY NPs synergized with DAMPs to promote the maturation and improve the antigen presentation ability of DCs in vitro and in vivo. Conclusions This work reported a PPY NPs-based nanoplatform to encapsulate the therepeutic proteins and absorb the functional molecules for combination therapy of tumours. The results demonstrated that the prepared MB@OVA/PPY NPs could be used as effective nanotherapeutic agents to eliminate solid tumours and trigger a powerful antitumour immune response.

PpIX/IR-820 Dual-Modal Therapeutic Agents for Enhanced PDT/PTT Synergistic Therapy in Cervical Cancer

“…The photothermal conversion efficiency (η) of PpIX-IR-820@Lipo NPs (IR-820 concentration: 250 μg/mL) was measured as follows: PpIX-IR-820@Lipo NPs were dispersed in DIW and irradiated under a 793 nm NIR laser (250 mW/ cm 2 , 12 min). The temperature curve when the laser was on and off was recorded, and η could be calculated by the following equation: 53,54…”

“…The photothermal conversion efficiency (η) of PpIX-IR-820@Lipo NPs (IR-820 concentration: 250 μg/mL) was measured as follows: PpIX-IR-820@Lipo NPs were dispersed in DIW and irradiated under a 793 nm NIR laser (250 mW/cm 2 , 12 min). The temperature curve when the laser was on and off was recorded, and η could be calculated by the following equation: 53 , 54 where T Max and T Max,water represent the maximum equilibrium temperature for PpIX-IR-820@Lipo NPs solution and water, respectively. I is the NIR laser power density, and A 793 is the absorption of dispersion at 793 nm, measured using the time constant τ s of the system with the help of the mass ( M D ) and the heat capacity ( C D ) of DIW.…”

Immunoinducible Carbon Dot-Incorporated Hydrogels as a Photothermal-Derived Antigen Depot to Trigger a Robust Antitumor Immune Response

“…7 The introduction of immune adjuvants in cancer therapy is an effective strategy to amplify the PTTmediated antitumor immune response. 8 It demonstrated that immune adjuvants synergized with PTT could activate the APCs to trigger intense innate and adaptive immune responses. 9,10 Cytosine−phosphate−guanine oligodeoxynucleotide (CpG ODN) is a TLR9 receptor agonist located on the inner membrane of lysosome 11 and could activate DCs to induce specific cellular immunity.…”

“…These DAMPs facilitate the recruitment and activation of antigen-presenting cells (APCs) to activate T cell-mediated antitumor immune responses strongly. − However, PTT-triggered ICD cannot inspire an intense immune response because of the intrinsic immunosuppressive microenvironment and poor antigen presentation . The introduction of immune adjuvants in cancer therapy is an effective strategy to amplify the PTT-mediated antitumor immune response …”

NIR responsive nanoenzymes via photothermal ablation and hypoxia reversal to potentiate the STING-dependent innate antitumor immunity

“…Compared with traditional treatments (surgery [ 5 ], chemotherapy [ 6 ], and radiation [ 7 ]), PTT had unique advantages of minimal invasion, less pain for patients, precise temporal and spatial controllability [ 4 , 8 , 9 ]. We [ 3 , 10 ] and other research groups have found that PTT was capable of inducing immunogenic cell death (ICD) of tumor cells and triggering the release of danger associated molecular patterns (DAMPs) and tumor-associated antigens (TAA), which were taken up by DC cells to activate anti-tumor immune responses [ [11] , [12] , [13] , [14] ]. Nevertheless, PPT is almost impossible to elicit robust antitumor immune response mainly due to the hypoxic tumor microenvironment as well as inefficient recognition and presentation of antigens [ 15 ].…”