Photoswitchable polyurethane based nanoaggregates for on-command release of noncovalent guest molecules

Abstract

The monomer 3 is commercially available. Monomer 1 and 2 were synthesized in laboratory and is outlined below.Monomer 1 (M1): 4,4'-Dihydroxyazobenzene (0.5 g, 2.33 mmol) and 3-bromo-1-propanol (1.94 g, 14 mmol) were taken in around bottomed flask along with activated potassium carbonate (1.93 g, 14 mmol) and catalytic amount of potassium iodide. All reactants were dissolved in 10 mL dry DMF and the reaction mixture was placed in preheated oil bath 60°C and stirred for 24 hours. Then the reaction was stopped and the reaction mixture was diluted with 20 mL Ethylacetate and washed with water for 3 times. The organic layer was collected and dried over anh. Na 2 SO 4 and evaporated to get the crude product as yellow solid in 72% yield.

Synthetic copolymers with natural product side‐chain pendents

“…Thus, D h increases with increasing alanine unit content, confirming the formation of particles in aqueous solution 44 . Also, an FESEM study was performed to explain and visualize the morphologies originating from the self‐aggregated copolymers in water 45 . The FESEM images (Figs 6(C) and S25B) displayed spherical micellar morphology with an average size varying between 60 and 90 nm.…”

“…44 Also, an FESEM study was performed to explain and visualize the morphologies originating from the self-aggregated copolymers in water. 45 The FESEM images (Figs 6(C) and S25B) displayed spherical micellar morphology with an average size varying between 60 and 90 nm. It should be noted that sizes appraised from SEM are marginally less than those predicted from DLS as described elsewhere.…”

Degradable Polymer-Based Nanoassemblies for Precise Targeting and Drug Delivery to Breast Cancer Cells without Affecting Normal Healthy Cells

“…Polymeric material-based nanoassemblies such as micelles, − vesicles, − and liposomes − are widely used as drug carriers due to their enhanced kinetic and thermodynamic stability compared to small-molecule-based assemblies. They hold the promise to keep the sequestered drug molecules safe under one set of conditions and release them under another in response to physiological stimuli such as pH, − light, − hypoxia, − redox, − temperature, − enzymes, , etc. The stimuli-responsive functionality has been installed on the polymeric structure for location-specific triggered guest release, thus overcoming the poor selectivity and severe side effects of chemotherapeutic treatments.…”

Enzyme-Triggered Degradation of Supramolecularly Cross-Linked Polymersomes of Azobenzene-Based Polyurethane: Cell-Selective Anticancer Drug Release

“…For enhancing delivery precision, regulation of the ability of the nanocarrier to escape from the endo/lysosome compartment is crucial to increase the availability of payloads in the cytosol. Prof. Kataoka and Prof. Cabral’s group recently reported the targeted delivery of antibodies by utilizing dysregulated endo/lysosomal acidification in cancer cells or the differential activity of overexpressed enzyme cathepsin B (CTSB) in endo/lysosome of particular cancer cells. , For targeted delivery, polymer-based stimuli-responsive nanoassemblies are widely used because of their enhanced kinetic and thermodynamic stability compared to small-molecule systems. − There are different types of biodegradable polymers, including polyamide, polyester, polyimide, and polyurethane, in commercial use, but we are aiming for polyurethane-based systems because of the following reasons: (i) ease of synthesis, which is well documented in the literature, − (ii) formation of stable nanoaggregates due to the H-bonding nature of the backbone, and (iii) outstanding biocompatibility and biodegradability. , The most common stimuli used in designing these materials are chemical (pH or redox variation) − and physical stimuli (temperature, light, magnetic field, and ionic strength), − but lately, the field of biological stimuli (protein or enzyme) for targeted delivery have attracted some attention. The inherent imbalances of pH or redox conditions in certain disease tissues can be considered to be secondary imbalances in biology, as the primary imbalances are often anomalous protein concentrations or enzymatic activity in disease locations. , Therefore, there is a growing interest in developing polymer-based stimuli-responsive smart nanocarriers that respond to these primary factors in biology .…”