PH Responsive Polyurethane for the Advancement of Biomedical and Drug Delivery

Abstract

Due to the specific physiological pH throughout the human body, pH-responsive polymers have been considered for aiding drug delivery systems. Depending on the surrounding pH conditions, the polymers can undergo swelling or contraction behaviors, and a degradation mechanism can release incorporated substances. Additionally, polyurethane, a highly versatile polymer, has been reported for its biocompatibility properties, in which it demonstrates good biological response and sustainability in biomedical applications. In this review, we focus on summarizing the applications of pH-responsive polyurethane in the biomedical and drug delivery fields in recent years. In recent studies, there have been great developments in pH-responsive polyurethanes used as controlled drug delivery systems for oral administration, intravaginal administration, and targeted drug delivery systems for chemotherapy treatment. Other applications such as surface biomaterials, sensors, and optical imaging probes are also discussed in this review.

Recent strategies to develop pH-sensitive injectable hydrogels

“…41,42 The solubility and chain conformation of pHresponsive polymers can also be modulated using solvents and electrolytes. 43 In addition, changes in colloidal properties such…”

“…41,42 The solubility and chain conformation of pH-responsive polymers can also be modulated using solvents and electrolytes. 43 In addition, changes in colloidal properties such as chain extension or collapse of polymer chains, flocculation and the precipitation of copolymers occur in response to environmental pH changes. 44 The pH-responsive properties can also contribute to the self-assembly of the copolymers, which leads to the formation of micelles, vesicles, and nanogels.…”

Recent advances of bioresponsive polymeric nanomedicine for cancer therapy

“…This variance is determined by the volume, histology, and detection location of tumors [33]. Nanoparticles can partly accumulate in tumor sites via blood circulation by the enhanced permeability and retention (EPR) effect [34]. And depending on their physical and physiochemical properties, they can either release the drug directly in the TME or be taken up by the tumor cells.…”

Polymeric Gel Systems Cytotoxicity and Drug Release as Key Features for their Effective Application in Various Fields of Addressed Pharmaceuticals Delivery

“…Therefore, the range of polymers used for the manufacture of hydrogels is limited. These include natural and synthetic polymers, in particular, poly-N-vinylpyrrolidone [ 36 ], polyoxazolines and copolymers of oxazolines [ 37 , 38 , 39 ], polysaccharides [ 40 ], polyurethanes [ 41 ], poly-N-isopropylacrylamide [ 42 ], polyacrylic acid [ 43 ] and others.…”