Table 4.

Overview of mesoporous silica NPs: structure, pH sensitization method, tumor type, and delivered drug.

First Author	Publication Year	Structure of NPs	pH Sensitization Method	Tumor Type	Drug
Chen [24]	2020	MSN-citraconic-poly-L-lisine	acid-labile disulfide linkers	4T1 breast carcinoma cell line	Doxorubicin
Cheng [27]	2017	Polydopamine-FA-PEG-MSN	pH-labile polydopamine coating	HeLa cervival cancer	Doxorubicin
Ding [34]	2020	MSN-carboxymethyl chitin-GRP78 peptide	pH-labile thioketal linkers	H22 hepatocellular carcinoma	Doxorubicin
Ding [35]	2020	MSN-lipidbilayer-TLS11a aptamer	pH-labile TAT peptide	4T1 breast carcinoma cell line	Doxorubicin
Kundu [65]	2020	MSN-FA	pH-labile PAA linker	MCF-7 breast carcinoma cell line	Umbelliferone
Li [73]	2020	Gal-P123-MSN	pH-triggered structural changes (DC lipid)	Huh-7 hepatocellular carcinoma	Irinotecan
Li [68]	2017	DM1-MSN-PDA	pH-labile PDA coating	SW480 colorectal cancer cell line	EpCAM
Liao [76]	2021	Chitosan-MSN	pH-labile imidazole linkers	4T1 breast carcinoma cell line	Doxorubicin
Liu [80]	2019	MSN	pH-labile calcium carbonate	LNCaP-AI prostate carcinoma	Doxorubicin
Mu [94]	2017	MSN-PLH-PEG	hydrophobic to hydrophilic transition	H22 hepatocellular carcinoma	Sorafenib
Saroj [104]	2018	MSN	pH-labile PAA linker	PC3 prostate cancer	Bicalutamide
Zhang [130]	2017	MSN-pH-responsive peptide	pH-responsive peptide	MCF-7 breast carcinoma cell line	Doxorubicin
Zhao [136]	2018	MSN-TPGS	pH-labile ester linkers	MCF-7 breast carcinoma cell line	Doxorubicin

Legend: MSN, mesoporous silica nanoparticles; FA, folic acid; PEG, polyethylene glycol; GRP78P, glucose regulated protein 78 peptide; TAT, tumor-associated antigens; Gal, gala tosyl; DM1, maytansinoid conjugate; PDA, hydrochloride dopamine; PLH, D-alpha-tocopherol polyethylene glycol 1000-succinate; PAA, polyacrylic acid.