TABLE 2.

The drug-loading ways and relevant drug release behaviors of NG-DDS.

The drug-loading way	The loaded drug	The encapsulation technique	The encapsulation efficiency (%)	Stimuli-responsive drug release	References
Physical encapsulation	Chlorin e6	The dialysis method	61.9 ± 0.15	Hyaluronidase	Yoon et al. (2012)
	Curcumin	The sonication method	With 114% loading of curcumin over the solution	Temperature	Luckanagul et al. (2018b)
	Doxorubicin	Hydrogen-bonded complexes	82 ± 4	Glutathione	Senthilkumar et al. (2019)
Chemical coupling	Chlorin e6	Amidation reaction	96.23 ± 4.8	—	Lee et al. (2011)
	Doxorubicin	Schiff base formation	32.66	pH	Su et al. (2018)
	Camptothecin	Esterification reaction	95.4 ± 0.9 (grafting rate)	pH/redox	Qu et al. (2019)