forces, including hydrophobic effect of the hollow cavity and ion-dipole interaction
of the carboxylic acid or amino groups. The interplay of multiple driving forces
renders WPs to be high-affinity host molecules for suitable guests. For example, the
value of K a for complex formed between WP7 and methyl viologen is up to
(2.96 Æ 0.31) Â 10
9 M
À1 in water [15].
One interesting aspect of WP is its intrinsic pH responsiveness. As shown in
Fig. 5, Li et al. used WP6 with carboxylic acid groups to targeted deliver antitumor drug oxaliplatin to acidic microenvironment of tumor [16]. Carboxylic
acid groups are deprotonated under neutral condition and protonated at acidic
pH. Therefore, oxaliplatin could be encapsulated by WP6 and controlled
released when reached tumor tissues. This WP6-based nano-container was
used to deliver oxaliplatin in vivo and was discovered to enhance the efficacy
of oxaliplatin. Targeted delivery of chemotherapeutic agents is generally
achieved by nanomedicine, which could encapsulate and controlled release
cargo in target tissues. By comparison, this targeted delivery by nano-container
Fig. 4 The uptake of analytes into cells preloaded with the macrocycle-dye complex results in
displacement of the dye from the macrocycle and an associated fluorescence increase. (Adapted
with permission from Ref. [14]. Copyright 2014 John Wiley and Sons)
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W. Mao and D. Ma
of the carboxylic acid or amino groups. The interplay of multiple driving forces
renders WPs to be high-affinity host molecules for suitable guests. For example, the
value of K a for complex formed between WP7 and methyl viologen is up to
(2.96 Æ 0.31) Â 10
9 M
À1 in water [15].
One interesting aspect of WP is its intrinsic pH responsiveness. As shown in
Fig. 5, Li et al. used WP6 with carboxylic acid groups to targeted deliver antitumor drug oxaliplatin to acidic microenvironment of tumor [16]. Carboxylic
acid groups are deprotonated under neutral condition and protonated at acidic
pH. Therefore, oxaliplatin could be encapsulated by WP6 and controlled
released when reached tumor tissues. This WP6-based nano-container was
used to deliver oxaliplatin in vivo and was discovered to enhance the efficacy
of oxaliplatin. Targeted delivery of chemotherapeutic agents is generally
achieved by nanomedicine, which could encapsulate and controlled release
cargo in target tissues. By comparison, this targeted delivery by nano-container
Fig. 4 The uptake of analytes into cells preloaded with the macrocycle-dye complex results in
displacement of the dye from the macrocycle and an associated fluorescence increase. (Adapted
with permission from Ref. [14]. Copyright 2014 John Wiley and Sons)
610
W. Mao and D. Ma