Poly(N-isopropylacrylamide) and Copolymers: A Review on Recent Progresses in Biomedical Applications

Abstract

Abstract:The innate ability of poly(N-isopropylacrylamide) (PNIPAAm) thermo-responsive hydrogel to copolymerize and to graft synthetic polymers and biomolecules, in conjunction with the highly controlled methods of radical polymerization which are now available, have expedited the widespread number of papers published in the last decade-especially in the biomedical field. Therefore, PNIPAAm-based hydrogels are extensively investigated for applications on the controlled delivery of active molecules, in self-healing materials, tissue engineering, regenerative medicine, or in the smart encapsulation of cells. The most promising polymers for biodegradability enhancement of PNIPAAm hydrogels are probably poly(ethylene glycol) (PEG) and/or poly(ε-caprolactone) (PCL), whereas the biocompatibility is mostly achieved with biopolymers. Ultimately, advances in three-dimensional bioprinting technology would contribute to the design of new devices and medical tools with thermal stimuli response needs, fabricated with PNIPAAm hydrogels.

Polypropylene mesh for hernia repair with controllable cell adhesion/de-adhesion properties

“…In a previous study, 11 we successfully prepared a novel surgical mesh, composed by a commercial light-weight PP substrate and a thermoresponsive hydrogel, poly(N-isopropylacrylamide-co-N,N 0methylene bis(acrylamide) (PNIPAAm-co-MBA). 12 The new hardsoft bilayer system was designed to reduce the problems of organ adhesion, discussed above, after mesh implantation. In particular, the hydrogel microstructure resembles natural tissue and due to its stimuli responsive properties, it has been reported to be applied for various biomedical purposes, such as smart actuators for chemical valves, 13 scaffolds for tissue engineering, 14,15 ''on/off'' switches for chemical reactions, 16,17 vehicles for drug delivery, 14,18 matrices for bioseparations, 15,19 and ''artificial'' muscles and soft biomimetic machines.…”

Multifunctional temperature‐responsive polymers as advanced biomaterials and beyond

“…One attractive quality that PNIPAAm possesses is the ease in which the functionality of the polymer can be designed and modified through the addition of comonomers or addition of nanoparticles, as shown in Figure . The resulting copolymers and nanocomposites are relatively easy to synthesize through various polymerization strategies . Incorporation of cofunctionality will often shift the polymer LCST and can produce enhanced materials with tunable attributes, depending on the desired application …”

“…Since its debut around 50 years ago, an astonishing amount of articles have reported on PNIPAAm polymers and their applicability in sectors such as environmental science, energy, physics, astronomy, and, most notably, biomedicine . This review intends to highlight some recent progress in the area of multifunctional thermoresponsive polymers as well as their unique applications.…”

“…The resulting copolymers and nanocomposites are relatively easy to synthesize through various polymerization strategies. 13 Incorporation of cofunctionality will often shift the polymer LCST and can produce enhanced materials with tunable attributes, depending on the desired application. 14 Since its debut around 50 years ago, an astonishing amount of articles have reported on PNIPAAm polymers and their applicability in sectors such as environmental science, energy, physics, astronomy, and, most notably, biomedicine.…”

“…14 Since its debut around 50 years ago, an astonishing amount of articles have reported on PNIPAAm polymers and their applicability in sectors such as environmental science, energy, physics, astronomy, and, most notably, biomedicine. 13,15 This review intends to highlight some recent progress in the area of multifunctional thermoresponsive polymers as well as their unique applications. Since these multifunctional PNIPAAm systems have revolutionized several biomedical fields such as controlled drug delivery, tissue engineering, self-healing materials, and beyond (e.g., environmental treatment applications), it is important to review the most recent technologies to assess their pertinent contributions.…”