Polymers with eugenol moieties covalently bonded to the macromolecular chains were synthesized for potential
application in orthopedic and dental cements. First, eugenol was functionalized with polymerizable groups. The
synthetic methods employed afforded two different methacrylic derivatives, where the acrylic and eugenol moieties
were either directly bonded, eugenyl methacrylate (EgMA), or separated through an oxyethylene group,
ethoxyeugenyl methacrylate (EEgMA). A typical Fisher esterification reaction was used for the synthesis of EgMA
and EEgMA, affording the desired monomers in 80% yields. Polymerization of each of the novel monomers, at
low conversion, provided soluble polymers consisting of hydrocarbon macromolecules with pendant eugenol
moieties. At high conversions only cross-linked polymers were obtained, attributed to participation of the allylic
double bonds in the polymerization reaction. In addition, copolymers of each eugenol derivative with ethyl
methacrylate (EMA) were prepared at low conversion, with the copolymerization reaction studied by assuming
the terminal model and the reactivity ratios determined according to linear and nonlinear methods. The values
obtained were r
EgMA = 1.48, r
EMA = 0.55 and r
EEgMA = 1.22, r
EMA = 0.42. High molecular weight polymers and
copolymers were obtained at low conversion. Analysis of thermal properties revealed a T
g of 95 °C for PEgMA
and of 20 °C for PEEgMA and an increase in the thermal stability for the eugenol derivatives polymers and
copolymers with respect to that of PEMA. Water sorption of the copolymers was found to decrease with the
eugenol derivative content. Both monomers EgMA and EEgMA showed antibacterial activity against Streptococcus
mutans, producing inhibition halos of 7 and 21 mm, respectively. Finally, cell culture studies revealed that the
copolymers did not leach any toxic eluants and showed good cellular proliferation with respect to PEMA. This
study thus indicates that the eugenyl methacrylate derivatives are potentially good candidates for dental and
orthopedic cements.
Bipolar patients experience lower functioning and well-being even in the stable phase of the disorder. Due to the great impact of bipolar disorder on many areas, it would be of interest to know the clinical predictors related to patient quality of life, as this would contribute to the design of different clinical interventions.
The development of bone replacement materials is an important healthcare objective due to the drawbacks of treating defects with bone autografts. In this work we propose a bone tissue engineering approach in which arginine-glycine-aspartic acid (RGD)-modified alginate hydrogels are crosslinked with bioactive strontium and zinc ions as well as calcium. Strontium was chosen for its ability to stimulate bone formation, and zinc is essential for alkaline phosphatase (ALP) activity. Calcium and strontium gels had similar stiffnesses but different stabilities over time. Strontium gels made with alginate with a high percentage of guluronic acid residues (high G) were slow to degrade, whereas those made with alginate rich in mannuronic acid (high M) degraded more quickly, and supported proliferation of Saos-2 osteoblast-like cells. After an initial burst, strontium release from alginate gels was steady and sustained, and the magnitude of release from high M gels was biologically relevant. Saos-2 cultured within alginate gels upregulated the osteoblast phenotypic marker genes RUNX2, collagen I (COL1A1) and bone sialoprotein (BSP), and ALP protein activity was highest in alginate gels cast with strontium ions. This strategy has the potential to be combined with other alginate-based systems for bone tissue engineering, or adapted to other tissue engineering applications.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.