A tough and novel dual-response PAA/P(NiPAAM-co-PEGDMA) IPN hydrogels with ceramics by photopolymerization for consolidation of bone fragments following fracture

Abstract

In this work, a novel dual-response hydrogel for enhanced bone repair following multiple fractures was investigated. The conventional treatment of multiple bone fracture consists on removing smaller bone fragments from the body in a surgery, followed by the fixation of the bone using screws and plates. This work proposes an alternative for this treatment via in situ UV-initiated radical polymerization of a novel IPN hydrogel composed of PAA/P(NiPAAM-co-PEGDMA) incorporated with ceramic additives. The influence of different additives on mechanical properties and sensitivity of the polymer, as well as the prepolymer mixture, were investigated in order to analyse the suitability of the composites for bone healing applications. This material exhibited an interpenetrating network, confirmed by FTIR, with ceramics particles dispersed in between the polymer network. These structures presented high strength by tensile tests, sensitivity to pH and temperature and a decrease on Tg values of NiPAAm depending on the amount of PEGDMA and ceramics added; although, the addition of ceramics to these composites did not decrease their stability drastically. Finally, cytotoxicity tests revealed variations on the toxicity, whereas the addition of TCP presented to be non-toxic and that the cell viability increased when ceramics additives were incorporated into the polymeric matrix with an increased reporter activity of NF-κB, associated with aiding fibroblast adhesion. Hence, it was possible to optimise feedstock ratios to increase the applicability of the prepolymer mixture as a potential treatment of multiple fractures.

Yerba Mate Extract in Microfibrillated Cellulose and Corn Starch Films as a Potential Wound Healing Bandage

“…Yerba mate extract has been shown to be good as an anti-inflammatory and to reduce the NF-κb phospolyrated levels [21]. However, in the present work, it did not self-regulate 3T3 cells and this increase has been previously shown to promote faster healing in vitro, related to promoting cell migration and proliferation via the NF-κb signalling pathway [69,70,72].…”

“…Nonetheless, NF-κB plays a crucial role in fibroblast healing since it can supervise the expression of genes involved in wound healing processes [68]. Furthermore, it also plays a key role in regeneration of various biomaterials [69,70]. In this case, the 3T3 cells were incubated in contact with the films to stimulate the signalling pathway, and the total protein was determined from the cell lysate using the NF-κB antibody cocktail.…”

Self-Photopolymerizable Hydrogel–Ceramic Composites with Scavenger Properties

“…FTIR spectra ( Figure 2 iii) exhibit the polymerization reaction using different ceramic photoinitiators for the PEGDMA network. The main bands of this hydrogel were assigned ( Appendix A Table A1 ) to its typical vibration modes [ 35 ]. The composite fabricated with ZnO nanoparticles was unique, as it was the only one that exhibited a shift from the band at 1093 cm −1 to 1097 cm −1 .…”

Magnetic Nanocomposite Hydrogels for Tissue Engineering: Design Concepts and Remote Actuation Strategies to Control Cell Fate

“…The characteristic very high toughness and stiffness of bone tissues limit the potential use of hydrogels in bone TE, particularly for the regeneration of critical size defects in load-bearing bones. , Notwithstanding, many composite hydrogel-based systems containing osteopromotive and reinforcing ceramic particles have been proposed for bone TE. − For example, the incorporation of hydroxyapatite microparticles or disk-shaped nanosilicates within GelMA hydrogels has been analyzed, observing high increases on the storage modulus of the scaffolds by the sole influence of the particles in the first case and the proliferation and osteogenic differentiation of the encapsulated stem cells in both.…”