Table 1

Summary of TME-responsive polymeric nanoparticles enhancing cancer immunotherapy

Response typePolymer formulationLoaded medicationTherapeutic modelTherapeutic outcomesRef.
pH responsePBA modified poly(ethylene glycol)-b-poly(ε-caprolactone) (PBA-PEG-b-PCL); poly(ε-caprolactone)-b-poly(β-amino ester) (PCL-b-P(D)AE)Interleukin (IL)-12Mouse melanoma: large advanced tumors, primary and distant model, lung metastasis modelThis system demonstrated significant inhibitory effects on melanoma, produced a distant effect, and suppressed postoperative tumor recurrence and metastasis.10
COOH-PEG-b-PCL; PCL-b-PAEChemokine (CXCL)-9; BRD4-PROTAC (dBET6)Mouse breast cancer modelCXCL9 and dBET6 synergistically enhanced T-cell-dependent antitumor immunity by promoting CD8+ T-cell infiltration and inducing programmed cell death.11
Enzyme responseDual-sensitive nanoparticle (Dual-NP) system composed of VPLSLYSG-modified dendrimer and dextran nanoparticlesDOXMouse glioblastoma modelWithin the glioblastoma model, the dual-NPs exhibited exceptional deep tumor penetration and a retention period extending to 6 days.12
Photosensitizer was conjugated with methoxy poly(ethylene glycol) via GALGLPG (mPEG-GALGLPG-PPa)Indoleamine 2,3-dioxygenase 1 (IDO-1) inhibitorCT26 colorectal and 4T1 breast mouse modelsCompared with photodynamic therapy alone, this combined immunotherapy regimen demonstrated significantly enhanced antitumor efficacy.13
ROS responsePPCD, CpG/PAMAM-TK-Ad, mPEG-TK-AdPt (IV), CpGMouse colorectal modelThis system promoted antigen-presenting cell activation, antigen presentation, and robust antitumor immune responses.14
GSH responsePhosphorus dendrimer-copper(II) complexes (1G3-Cu), PCL-SS-PEGToyocamycin (Toy)Mouse melanoma modelThis nanoparticle eradicated tumors and suppressed recurrence and metastasis by synergistically inducing ICD through dual mitochondrial/endoplasmic reticulum pathway.15
Hypoxia responsePNBJQImmunomodulating agent JQ1Mouse colorectal modelPNBJQ responded to tumor hypoxia to overcome innate and adaptive immune resistance by triggering ICD and downregulating PD-L1 under near-infrared light irradiation.16
ATP responseALG-Aapt/CpGOxaliplatin, CpGCT26 colorectal modelSmart hydrogels released immune adjuvants concurrently with low-dose repeated chemo/radiotherapies to enhance antitumor immune responses.17
E. coli@PDMC-PEGMn2+Mouse subcutaneous melanoma, rabbit in situ liver cancerThis system was degraded in an ATP-excessive TME, synergistically activating the cGAS-STING pathway by releasing Mn2⁺ and exposing bacteria, thereby effectively inhibiting tumor growth.18
Multiple responsesmPEG-b-P(MTE-co-PDA)NiclosamideMurine triple-negative breast cancer and syngeneic oral cancer modelsROS/pH dual-responsive MPNPs combined with oncolytic viruses enhanced tumor penetration, induced pyroptosis, and stimulated antitumor immunity.19
COOH-PEG-PAEMAFe2O3, DOX4T1 breast mouse modelThis triple-responsive nanoplatform accumulated in tumor tissue, enhanced ICD, and promoted T-cell proliferation.20