Supramolecular Soft Biomaterials for Biomedical Applications - In-Situ Gelling Polymers: For Biomedical Applications - page 115

Fig. 7 Controlled release of bioactive substances by supramolecular hydrogel 1 (as a logic-gate
barrier) and photogel 2 (as a holding matrix) and fine-tuning of the release function through a
combination of AND logic gate operation and UV light stimulation. a Photographs displaying
a supramolecular hydrogel gate composed of AND logic gate gel 1 and photogel 2 containing
vitamin B12 in a 1 cm cell before and after the AND input; the logic scheme is also shown.
b Corresponding time courses for the release of the bioactive substances (vitamin B12, FITC-
insulin, and FITC-BSA). c Photographs showing the supramolecular hydrogel gate holding vita-
min B12 before and after application of UV light and the AND input and then after application
of UV light subsequently; the combinatorial logic scheme is also shown. d Corresponding time
courses of the vitamin B12 release. e Truth table for the combinational logic circuit. ( a - e ) are
reproduced with permission from Ref. [ 43 ]
Anions which are bonded on the supramolecular hydrogel surface can also
act as the growth center for biomineralization. Low molecular weight hydrogels
have also found applicability in aiding bone repair, a burgeoning area of medi-
cal science given significant increases in average lifespan. The significance of
bone repair has encouraged Shi et al. to study the technique of promoting growth
of biominerals, which can be used as artificial bone material [ 44 ]. In the study,