CONSPECTUS:　Immune　checkpoint　blockade　(ICB)　therapy　elicits　antitumor　response　by　inhibiting　immune　suppressor　components,　including　programmed　cell　death　protein　1　and　its　ligand　(PD-1/PD-L1)　and　cytotoxic　T-lymphocyte-associated　antigen　4　(CTLA-4).　Despite　improved　therapeutic　efficacy,　the　clinical　response　rate　is　still　unsatisfactory　as　revealed　by　the　fact　that　only　a　minority　of　patients　experience　durable　benefits.　Additionally,　＂off-target＂　effects　after　systemic　administration　remain　challenging　for　ICB　treatment.　To　this　end,　the　local　and　targeted　delivery　of　ICB　agents　instead　could　be　a　potential　solution　to　maximize　the　therapeutic　outcomes　while　minimizing　the　side　effects.　In　this　Account,　our　recent　studies　directed　at　the　development　of　different　strategies　for　the　local　and　targeted　delivery　of　ICB　agents　are　discussed.　For　example,　transdermal　microneedle　patches　loaded　with　anti-programmed　death-1　antibody　(aPD1)　and　anti-CTLA4　were　developed　to　facilitate　sustained　release　of　ICB　agents　at　the　diseased　sites.　Triggered　release　could　also　be　achieved　by　various　stimuli　within　the　tumor　microenvironment,　including　low　pH　and　abnormally　expressed　enzymes.　Recently,　the　combination　of　an　anti-programmed　death-ligand　1　antibody　(aPD-L1)　loaded　hollow-structured　microneedle　patch　with　cold　atmospheric　plasma　(CAP)　therapy　was　also　reported.　Microneedles　provided　microchannels　to　facilitate　the　transdermal　transport　of　CAP　and　further　induce　immunogenic　tumor　cell　death,　which　could　be　synergized　by　the　local　release　of　aPD-L1.　In　addition,　in　situ　formed　injectable　or　sprayable　hydrogels　were　tailored　to　deliver　immunomodulatory　antibodies　to　the　surgical　bed　to　inhibit　tumor　recurrence　after　primary　tumor　resection.　In　paralell,　inspired　by　the　unique　targeting　ability　of　platelets　toward　the　inflammatory　sites,　we　engineered　natural　platelets　decorated　with　aPD-L1　for　targeted　delivery　after　tumor　resection　to　inhibit　tumor　recurrence.　We　further　constructed　a　cell-cell　combination　delivery　platform　based　on　conjugates　of　platelets　and　hematopoietic　stem　cells　(HSCs)　for　leukemia　treatment.　With　the　homing　ability　of　HSCs　to　the　bone　marrow,　the　HSC-platelet-aPD1　assembly　could　effectively　deliver　aPD1　in　an　acute　myeloid　leukemia　mouse　model.　Besides　living　cells,　we　also　leveraged　HEK293T-derived　vesicles　with　PD1　receptors　on　their　surfaces　to　disrupt　the　PD-1/PD-L1　immune　inhibitory　pathway.　Moreover,　the　inner　space　of　the　vesicles　allowed　the　packaging　of　an　indoleamine　2,3-dioxygenase　inhibitor,　further　reinforcing　the　therapeutic　efficacy.　A　similar　approach　has　also　been　demonstrated　by　genetically　engineering　platelets　overexpressing　PD1　receptor　for　postsurgical　treatment.　We　hope　the　local　and　targeted　ICB　agent　delivery　methods　introduced　in　this　collection　would　further　inspire　the　development　of　advanced　drug　delivery　strategies　to　improve　the　efficiency　of　cancer　treatment　while　alleviating　side　effects.