Table 2. Examples of pH-sensitive polymeric materials which can be applied for RA therapy.
| Polymeric material | Size of nanoparticles (nm) | Stimulus | Response
pH value |
Reference |
| Poly(2-tetrahydropyranyl methacrylate) | 314 | pH (acetal bone) | 5.1 | Jung et al. 2007 |
| Poly(ethylene oxide)–poly(β-amino ester) | 150–200 | pH (dissolution mechanism) | < 6.5 | Shenoy et al. 2005 |
| Poly(ethylenimine)–poly(methacryloyl sulfadimethoxine) (PSD)-block-PEG | 300 | pH (sulfonamide group) | 6.6 | Sethuraman et al. 2006 |
| Poly(ethylene glycol)-poly (L-histidine)-poly(L-lactide) | 803 | pH (imidazole group) | 5.0 | Liu et al. 2011 |
| Chitosan–histidine–arginine | 105 | pH (imidazole group) | 6–5 | Gaspar et al. 2013 |
| (5-methyl-2-(2,4,6-trimethoxyphenyl)-[1,3]-5-dioxanylmethyl methacrylate) and (1,4-O-methacryloylhydroquinone) | 20–100 | pH (acetal bone) | 5 | Zubris et al. 2013 |
| PEG–aldehyde functionalized dextran–DOX | 100 | pH (imine bonds) | 5.5 | Sagnella et al. 2014 |
| Poly(oligoethylene glycol) methyl ether acrylate | 10–20 | pH (imine bonds) | 5.5 | Liu et al. 2012 |
| Poly(oligoethylene methoxy acrylate) modified with NO donor molecules | 32 | pH | < 7.0 | Duong et al. 2014 |
| Poly(lactic-co-glycolic acid) and eudragit S-100 | 250 | pH (dissolution mechanism) | > 7.57 | Zhang et al. 2011 |