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Poly(N-isopropylacrylamide) and copolymers: a review on recent progresses in biomedical applications

UPCommons. Portal del coneixement obert de la UPC
  • Lanzalaco, Sonia|||0000-0002-8604-5095
  • Armelín Diggroc, Elaine Aparecida|||0000-0002-0658-7696
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(e-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., Peer Reviewed




Toward the new generation of surgical meshes with 4D response: soft, dynamic and adaptable [Dataset]

UPCommons. Portal del coneixement obert de la UPC
  • Lanzalaco, Sonia|||0000-0002-8604-5095
  • Turón Dols, Pau
  • Weis, Christine
  • Mata, Christian
  • Planas Cuchi, Eulàlia|||0000-0002-7053-3959
  • Alemán Llansó, Carlos|||0000-0003-4462-6075
  • Armelín Diggroc, Elaine Aparecida|||0000-0002-0658-7696
These data are associated to the paper with the same title and are structured according to the figures in the paper. These data correspond to the research results of the WP3 of the European Project 4D-POLYSENSE., The present dataset reports the scientific results corresponding to a scientific study where a bidimensional (2D) polypropylene flexible mesh material has been converted into a fourth dimension (4D) dynamic system. The platform is composed by a fibres of isotactic polypropylene (iPP) mesh coated with thermosensitive poly(N-isopropylacrylamide-co-N,N'-methylene bis(acrylamide) (PNIPAAm-co-MBA) hydrogel, and undergoes variations in its geometry by reversible folding/unfolding behaviour. Folding and unfolding motion in aqueous solution of bilayer and monolayer systems composed by two or one layer of hydrogel, respectively, are reported in the present dataset. Furthermore, an infrared thermographic camera and an optical microscope were used to evaluate the macroscopic and microscopic structure stimulus response in air. Additionally, PP-g-PNIPAAm meshes showed an increase in the mechanical properties (bursting strength) with respect to the uncoated mesh.




Polymer hydrogels: looking for green synthesis and bioengineering applications

UPCommons. Portal del coneixement obert de la UPC
  • Lanzalaco, Sonia|||0000-0002-8604-5095
  • Armelín Diggroc, Elaine Aparecida|||0000-0002-0658-7696
A staggering number of medical devices, including healthcare products for diagnosis and therapy, have exploited biomaterials as platform technologies. Rational biomaterials design requires to pay attention to both, materials and biological considerations. They can be employed to treat or replace any tissues or function of living tissues and to engineer systems that could control, for example, the drug delivery [1]. The term biomaterial includes metals and ceramics, but polymers account for the vast majority and, among them, polymer hydrogels represent one of the most promising groups. Hydrogels consist of three-dimensional crosslinked networks able to absorb large amounts of water while maintaining their dimensional stability, also capable to act as stimuli-responsive to external and internal triggers [1]. Regarding the biomedical applications, the development of new synthetic routes to reduce the toxicity of residual monomer and chemicals (e.g., initiators, surfactants, etc.) is required. Recently, a green and straightforward approach for the production of polymer nanogels, used as nanovectors to deliver drug molecules, based on the recourse to high energy irradiation of aqueous solutions of preformed polymers has been reported [2]. Pulsed electron beams are usedto induce the generation of free radicals directly onto the polymer chains, without any additional reagent [2]. With a similar purpose, electrochemical advanced oxidation technologies may offer an interesting approach. As recently shown, the obtention of a crosslinked poly(vinylpyrrolidone)(PVP) hydrogel by means of electrogenerated of hydroxyl radicals is feasible [3]. The sensitivity of hydrogels to different stimuli opens new horizons in the design of biomedical devices interacting with the human body. By coupling a hard polymer currently used in the biomedical field to soft and sensitive gels, new smart materials with better performance than the former can be produced. Poly-(N-isopropylacrylamide) (PNIPAAm)-based hydrogels are particularly and extensively investigated as thermal actuators due to its critical temperature (LCST) close to that of the human body (around 36.5–37.5 ºC). Thus, several applications are possible, from drug delivery to tissue engineering, followed by stem cells, microf uidic devices, biosensors, and bioimaging [4]. An overview of innovative synthetic routes for hydrogels synthesis, such as the one based on the employment of electrochemical technologies, will be given. Further, a very appealing new class of thermoresponsive surgical meshes acting as thermosensitive biomedical sensors, currently investigated within the framework of the 4D-POLYSENSE European project, will be presented




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

UPCommons. Portal del coneixement obert de la UPC
  • Lanzalaco, Sonia|||0000-0002-8604-5095
  • Valle Mendoza, Luis Javier del|||0000-0001-9916-1741
  • Turón Dols, Pau
  • Weis, Christine
  • Estrany Coda, Francesc|||0000-0002-2696-1489
  • Alemán Llansó, Carlos|||0000-0003-4462-6075
  • Armelín Diggroc, Elaine Aparecida|||0000-0002-0658-7696
These data are associated to the paper with the same title and are structured according to the figures in the paper. These data correspond to the research results of the WP2 of the European Project 4D-POLYSENSE., The present dataset collects and reports the scientific results corresponding to a scientific study of a commercial and fully flexible versatile bilayer system, composed by a polypropylene (PP) mesh and a covalently bonded poly(N-isopropylacrylamide) (PNIPAAm) hydrogel. In this study the mechanism responsible for cell-adhesion and de-adhesion, when the PNIPAAm-co-MBA monolayer film (adherent on one hand to the PP substrate and anti-adherent on the other hand to cell proliferation) is being employed, has been elucidated. The grafting of the hydrogel was studied and the the graft yield as well as the spectroscopic characterization (FTIR and XPS) of samples treated at different concentration of the crosslinker and different grafting time are ported in the present dataset. The scientific results of cell adhesion and biocompatibility assay are also included, being the in vitro results with fibroblast (COS-1) and epithelial (MCF-7) cells obtained with a mesh modified with a porous iPP-g-PNIPAAm bilayer system, prepared via PNIPAAm grafting for 2 h at the lowest N,NI-methylene bis(acrylamide) (MBA) concentration (1 mM).




The mechanism of adhesion and graft polymerization of a PNIPAAm thermoresponsive hydrogel to polypropylene meshes [Dataset]

UPCommons. Portal del coneixement obert de la UPC
  • Lanzalaco, Sonia|||0000-0002-8604-5095
  • Turón Dols, Pau
  • Weis, Christina
  • Alemán Llansó, Carlos|||0000-0003-4462-6075
  • Armelín Diggroc, Elaine Aparecida|||0000-0002-0658-7696
These data are associated to the paper with the same title and are structured according to the figures in the paper.
These data correspond to the research results of the WP1 of the European Project 4D-POLYSENSE., In the scientific publication corresponding to the present dataset, a commercial and fully flexible monofilament polypropylene mesh has been used for the deposition of a thermosensitive hydrogel, generated by graft copolymerization of N-isopropylacrylamide (NIPAAm) and N,NI-methylene bis(acrylamide) (MBA) monomers. The study represents an initial step for the future development of a new generation of surgical meshes, able to interact with the complex three-dimensional structure of biological tissues, as smart materials working as self-evolving motion sensors. The meshes were previously functionalized by O2-plasma method and subsequently grafted with the thermoresponive hydrogel and the data related to micro- and standard spectroscopy techniques empoyed for the characterization, such as Raman spectroscopy, FTIR spectroscopy and XPS, are reported in the present dataset. Additionally, the data of graft yield and thermoresponsive properties of PNIPAAm (VPTT behaviour) are included in the dataset




Temperature-responsive bending studies of a PP-g-PNIPAAm mesh for hernia repair

UPCommons. Portal del coneixement obert de la UPC
  • Lanzalaco, Sonia|||0000-0002-8604-5095
  • Turon, Pau
  • Weis, Christine
  • Alemán Llansó, Carlos|||0000-0003-4462-6075
  • Armelín Diggroc, Elaine Aparecida|||0000-0002-0658-7696




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

UPCommons. Portal del coneixement obert de la UPC
  • Lanzalaco, Sonia|||0000-0002-8604-5095
  • Valle Mendoza, Luis Javier del|||0000-0001-9916-1741
  • Turón Dols, Pau
  • Weis, Christine
  • Estrany Coda, Francesc|||0000-0002-2696-1489
  • Alemán Llansó, Carlos|||0000-0003-4462-6075
  • Armelín Diggroc, Elaine Aparecida|||0000-0002-0658-7696
Herein, a versatile bilayersystem, composed by a polypropylene(PP)mesh and a covalently bonded poly(N-isopropylacrylamide) (PNIPAAm) hydrogel, is reported. The cell adhesion mechanism was successfully modulated by controlling the architecture of the hydrogel in terms of duration of PNIPAAm graftingtime, crosslinker content, and temperature of material exposure in PBS solutions (belowandabove the LCST of PNIPAAm). The best in vitroresults with fibroblast (COS-1) and epithelial (MCF-7) cells was obtained with a mesh modified with porous iPP-g-PNIPAAm bilayer system, prepared via PNIPAAm grafting for 2 h at the lowest N,N'-methylene bis(acrylamide) (MBA)concentration (1 mM). Under these conditions, the detachment of the fibroblast-like cells was 50% lower than that of the control, after 7 days of cell incubation, which represents a high de-adhesionof cellsin a short period. Moreover, the whole system showed an excellent stability in dry or wet media, proving that the thermosensitive hydrogel was well adhered to the polymer surface, after PP fibreactivation by cold plasma. This study opens new insights on the development of anti-adherent meshes for abdominal hernia repairs., Peer Reviewed




The mechanism of adhesion and graft polymerization of a PNIPAAm thermoresponsive hydrogel to polypropylene meshes

UPCommons. Portal del coneixement obert de la UPC
  • Lanzalaco, Sonia|||0000-0002-8604-5095
  • Turón Dols, Pau
  • Weis, Christina
  • Alemán Llansó, Carlos|||0000-0003-4462-6075
  • Armelín Diggroc, Elaine Aparecida|||0000-0002-0658-7696
In this study, a commercial and fully flexible monofilament mesh has been used for the deposition of a thermosensitive hydrogel, generated by graft copolymerization of N-isopropylacrylamide (NIPAAm) and N,N'-methylene bis(acrylamide) (MBA) monomers. The mechanism of adhesion and graft copolymerization have been elucidated combining micro- and standard spectroscopy techniques such as Raman spectroscopy, FTIR spectroscopy and XPS, before and after the activation of the polypropylene (PP) fibre surface by using oxygen-plasma. The good covalent interactions among NIPAAm monomers and PP fibres, and the hydrogel chain growth in such flexible bidimensional structures, were demonstrated. Additionally, the thermoresponsive properties of PNIPAAm were obtained (VPTT behaviour). The bilayer system is stable below and above a low critical solution temperature (LCST) of 33.2 °C, Peer Reviewed




Self-evolving thermal and motion sensor based on PP-g-PNIPAAm surgical meshes : From preparation to exploration of thermo-sensitivity

UPCommons. Portal del coneixement obert de la UPC
  • Lanzalaco, Sonia|||0000-0002-8604-5095
  • Turon, Pau
  • Weis, Christine
  • Alemán Llansó, Carlos|||0000-0003-4462-6075
  • Armelín Diggroc, Elaine Aparecida|||0000-0002-0658-7696




A flexible, smart and self-evolving actuator based on polypropylene mesh for hernia repair and a thermo-sensitive gel

UPCommons. Portal del coneixement obert de la UPC
  • Lanzalaco, Sonia|||0000-0002-8604-5095
  • Mata, Christian
  • Turon, Pau
  • Weis, Christine
  • Alemán Llansó, Carlos|||0000-0003-4462-6075
  • Armelín Diggroc, Elaine Aparecida|||0000-0002-0658-7696
Here, a smart mesh actuator, able to self-evolve under temperature and humidity control,has been developed. Thermo-responsive poly(N-isopropylacrylamide) (PNIPAAm)-based materialsare widely appliedin biomedical field owingto theirexcellent biocompatibility and abrupt conformational change at a critical temperature very close to that of human body(~32 °C) [1-2]. The actuator is based on PNIPAAmgrafted on a commercial polypropylene (PP)mesh used for hernia repair[3].Flexible devices composed of PP-g-PNIPAAm arranged inmonolayer (one layer of PNIPAAm) and bilayer (two layers of PNIPAAm) conformationswere synthesized. The microstructureof the gel chains (chain length measurements) and the macromotion(unfolding angle observations) behavior of the composite mesh in water and air at different temperatures were studied. The motion is affected by the amount and the position of the gel (upper fibers or among them) and by the crosslinking degree. For the first time,a self-evolving motion sensor based on commercial hernia repair mesh has beenproduced by using a biocompatible hydrogel. The strategy can be easily extrapolated to complex mesh architectures