is a simple and effective design, which ensures complete cargo release in tumor
tissues.
23.3 Stimuli Types for Biomedical Applications
The purpose of introducing stimuli responsiveness to self-assembly systems for biomedical applications depends on the specific motive. Generally speaking, for drug delivery
applications, the purpose is to overcome biological barriers [17]. The existence of
multiple biological barriers makes drug delivery by systemic administration challenging.
Among these barriers, stable encapsulation during circulation and efficient cell internalization are two of the most challenging tasks. On the other side, stimuli responsiveness is
often used to trigger spectroscopic change for bioimaging applications.
23.3.1 pH Responsiveness
Acidic pH is a common pathological indication in tumor and inflammatory tissues
[18]. Endosomal compartment is also known to be acidic. Selective pathological and
Fig. 5 Schematic illustration of the DDS effect expected to be operative in the case of a 1:1 mixture
of OX and CP6A. (Adapted with permission from Ref. [16]. Copyright 2017 Royal Society of
Chemistry)
23 Stimuli-Responsive Self-Assembly Based on Macrocyclic Hosts and Biomedical. . .
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