Opportunities and Challenges of Switchable Materials for Pharmaceutical Use

Abstract

Switchable polymeric materials, which can respond to triggering signals through changes in their properties, have become a major research focus for parenteral controlled delivery systems. They may enable externally induced drug release or delivery that is adaptive to in vivo stimuli. Despite the promise of new functionalities using switchable materials, several of these concepts may need to face challenges associated with clinical use. Accordingly, this review provides an overview of various types of switchable polymers responsive to different types of stimuli and addresses opportunities and challenges that may arise from their application in biomedicine.

Multi-tunable thermoresponsive behaviors of poly(amido thioether)s

“…Thermoresponsive polymers (TRPs) have attracted increasing attention due to their promising applications in distinct fields such as sensors, drug delivery, tissue engineering, and pharmacology. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] As a class of smart polymers with temperature-dependent solubility, TRPs can undergo intriguing phase transition at the lower critical solution temperature (LCST) and/or upper critical solution temperature (UCST). [7][8][9][10][11][12][13][14][15][16][17][18] Owing to variations of the hydrophilic/hydrophobic ratio and mutual interactions (e.g., hydrogen bonding (HB) and electrostatic/ dipole-dipole interactions), the thermoresponsivity can be affected by some factors involving the chemical composition, molar mass, molecular weight distribution, branching structure, and topology.…”

“…Thermoresponsive polymers (TRPs) have attracted increasing attention due to their promising applications in distinct fields such as sensors, drug delivery, tissue engineering, and pharmacology. 1–15 As a class of smart polymers with temperature-dependent solubility, TRPs can undergo intriguing phase transition at the lower critical solution temperature (LCST) and/or upper critical solution temperature (UCST). 7–18 Owing to variations of the hydrophilic/hydrophobic ratio and mutual interactions ( e.g.…”

Tailoring thermoresponsiveness of biocompatible polyethers: copolymers of linear glycerol and ethyl glycidyl ether

“…5,6 Thermodynamically, the cloud point phase separation is driven by unfavorable entropy of mixing. 2,4,5 The most intensely studied thermoresponsive polymer is poly(N-isopropylacrylamide) (PNIPAAm), which exhibits LCST behavior with T cp = 32 °C. 7 However, there is a controversial discussion regarding the toxicity of PNIPAAm.…”

“…Polymers showing responsive behavior to external stimuli, especially thermoresponsive behavior, are promising materials for many applications, e.g. drug delivery 1,2 or tissue engineering. 3,4 Thermoresponsive polymers with a lower critical solution temperature (LCST) are water soluble due to strong hydration of the polymer molecules below a critical temperature, the cloud point temperature T cp .…”

“…5,6 Thermodynamically, the cloud point phase separation is driven by unfavorable entropy of mixing. 2,4,5…”