Superelastic and pH-Responsive Degradable Dendrimer Cryogels Prepared by Cryo-aza-Michael Addition Reaction

Abstract

Dendrimers exhibit super atomistic features by virtue of their well-defined discrete quantized nanoscale structures. Here, we show that hyperbranched amine-terminated polyamidoamine (PAMAM) dendrimer G4.0 reacts with linear polyethylene glycol (PEG) diacrylate (575 g/mol) via the aza-Michael addition reaction at a subzero temperature (−20 °C), namely cryo-aza-Michael addition, to form a macroporous superelastic network, i.e., dendrimer cryogel. Dendrimer cryogels exhibit biologically relevant Young’s modulus, high compression elasticity and super resilience at ambient temperature. Furthermore, the dendrimer cryogels exhibit excellent rebound performance and do not show significant stress relaxation under cyclic deformation over a wide temperature range (−80 to 100 °C). The obtained dendrimer cryogels are stable at acidic pH but degrade quickly at physiological pH through self-triggered degradation. Taken together, dendrimer cryogels represent a new class of scaffolds with properties suitable for biomedical applications.

Nanodrug Delivery Systems for the Treatment of Ovarian Cancer

“…Polymer-drug conjugates and dendrimers have covalently bonded drug molecules to the polymeric carriers. This consecutively necessitates the association of the complex with specific biochemical processes, shielding the complex from in vivo catalytic enzymatic destruction and protonic acid-hydrolytic reactions [48][49][50]. Furthermore, the minute-size of these carriers (normally 10 nm), enables perforation through plasma membranes of the glomeruli [17].…”

Recent Progress and Advances of Multi-Stimuli-Responsive Dendrimers in Drug Delivery for Cancer Treatment

“…Another study by Wang et al also evaluated the application of stimuli-responsive dendrimers in the delivery of drugs [35]. The main highlights of this study included the recent advancement and opportunities for developing stimuli-responsive dendrimers for treating several diseases, especially cancer.…”

“…Light can act as an external source of change when designing stimuli-sensitive materials because it is non-invasive and can be controlled remotely [123]. In addition to UV, other light triggers include near and visible infrared depending on their wavelengths [35]. An example of dendrimer conjugate that is sensitive to UV light is ortho-nitrobenzyl (ONB), which is mainly utilized in the manufacture of light-responsive materials [51,84].…”

“…An example of dendrimer conjugate that is sensitive to UV light is ortho-nitrobenzyl (ONB), which is mainly utilized in the manufacture of light-responsive materials [51,84]. The dendrimer is quickly cleaved by UV lights between the wavelengths of 254 and 365 nm [35]. There is also a possibility of conjugating anti-cancer medications such as doxorubicin to dendrimers using ONB linkers.…”

Platelet-Derived Growth Factor Stimulated Migration of Bone Marrow Mesenchymal Stem Cells into an Injectable Gelatin-Hydroxyphenyl Propionic Acid Matrix

“…In recent years, several types of injectable polymers have undergone investigation, including: photo-polymerizable polymers [ 1 ]; self-assembling peptides [ 2 ]; shear-thinning (thixotropic) polymers [ 3 ]; and cryo gels [ 4 , 5 ]. Another class of injectable polymers is capable of undergoing enzyme-mediated covalent cross-linking (e.g., horseradish peroxidase, tyrosinase, laccase, transglutaminase) In the horseradish peroxidase (HRP)-induced polymerization, the enzyme catalyzes the di-phenolic formation of phenol-conjugated polymer backbones (e.g., gelatin, hyaluronic acid) with hydrogen peroxide (H 2 O 2 ) [ 6 , 7 , 8 , 9 ].…”