Table 5.

Summary of researches on responsive polymeric LAs delivery system

Reference number	Polymer	LAs	Diameter	Stimuli	Release profile	Toxicity
[138]	HGNPs@P(MEO2MA-co-OEGMA500)	Bupivacaine	206.5 ± 49.3 nm	Heat	After 12 sequential heat pulses, the cumulative diffusive release reached a 40% in less than 8 h compared to more than 160 h at 37 °C	At 2 mg/mL, the viability percentages obtained were between 31% (mMSCs) and 42% (U251MG)
[139]	Poly (N-isopropylacrylamide)	Bupivacaine	100–1000 nm	Heat	Thermally triggered aggregation happens from 32.4 to 37.5 °C	Nanogels had minimal impact on cell viability and large (> 500 nm diameter) nanogels typically remained as liquid-like residues in vivo and induced more severe inflammatory reactions
[140]	Methacrylicacid–ethyl acrylate (MAA-EA)	Procaine hydrochloride	30.9–141.1 nm	pH	The percentage of procaine released at pH of 8 was ∼ 90% compared to ∼ 30% at pH of 5	None

HGNP Hollow gold nanoparticle