Green Tea Polyphenols Coupled with a Bioactive Titanium Alloy Surface: In Vitro Characterization of Osteoinductive Behavior through a KUSA A1 Cell Study

Abstract

A chemically-treated titanium alloy (Ti6Al4V) surface, able to induce hydroxyapatite precipitation from body fluids (inorganic mineralization activity), was functionalized with a polyphenolic extract from green tea (tea polyphenols, TPH). Considering that green tea polyphenols have stimulating effects on bone forming cells (biological mineralization), the aim was to test their osteoinductive behavior due to co-operation of inorganic and biological mineralization on mesenchymal stem cells KUSA A1. The functionalized surfaces were characterized by using the Folin–Ciocalteu method and X-ray photoelectron spectroscopy to confirm the successful outcome of the functionalization process. Two cell cultures of mesenchymal stem cells, KUSA A1 were performed, with or without osteoinductive factors. The cells and surfaces were characterized for monitoring cell viability and hydroxyapatite production: Fourier Transform Infrared Spectroscopy and Raman spectroscopy analyses showed deposition of hydroxyapatite and collagen due to the cell activity, highlighting differentiation of KUSA A1 into osteoblasts. A higher production of extracellular matrix was highlighted on the functionalized samples by laser microscope and the fluorescence images showed higher viability of cells and greater presence of osteocalcin in these samples. These results highlight the ability of polyphenols to improve cell differentiation and to stimulate biological mineralization, showing that surface functionalization of metal implants could be a promising way to improve osteointegrability.

Polyphenols from grape pomace induce osteogenic differentiation in mesenchymal stem cells

“…direct osteoinductive effects of polyphenols on osteoblast differentiation, proliferation and protection have been well documented (21,22) and, as such, several bioactive polyphenols-coated biomaterials have been engineered (30)(31)(32)(33)(34)(35)(36)(37)(38), in order to improve osteogenesis and bone mineralization. despite the different content of phenolic classes in the tested PRPEs, a common trend of hMSc stimulation has been observed, suggesting that widely available, easy-to-obtain PRPEs can play a role in the biochemical modification of dental materials and devices.…”

“…The emerging field of biomolecular modifications of bone implants and dental biomaterials aims at enhancing the host tissue response through biologically active molecules delivered from the device or linked to the device surface (25)(26)(27)(28)(29). The biomolecular modification of dental devices and materials through polyphenols from different sources is being investigated (30)(31)(32)(33)(34)(35)(36)(37)(38).…”

Green tea extract rich in epigallocatechin gallate impairs alveolar bone loss in ovariectomized rats with experimental periodontal disease

“…The investigations carried out focusing on the association between green tea extract (GTE) and bone metabolism are increasing, thus emphasising the importance of this proposed theme for study. 30,31 T A B L E 1 Morphometric parameters obtained by means of microtomographic analysis of the first molar interradicular septum: bone surface (BS-mm 2 ), bone volume (BV-mm 3 The association of green tea extract with periodontal disease also brings results that suggest that catechins present in GTE offer a promising perspective for the development of a new treatment for periodontitis, due to the ability of the extract to decrease the secretion of metalloproteinases, enzymes responsible for tissue destruction. 12 We have not yet found in the current literature the simultaneous association of GTE with periodontal disease and osteoporosis, a situation proposed in this study.…”

Evaluation of Bone Regeneration Efficacy in a Rabbit Model of Femoral Condyles Defect by Polyphenols-Containing Bone Filler

“…The new approach involving the biomolecular modification of biomaterials aims at enhancing the host tissue response through biologically active molecules delivered from the device or linked to the device surface [35][36][37][38]. In this broad scenario, the use of polyphenols from different source is widely investigated [32,[39][40][41][42][43][44][45]. Grape pomace is an interesting source of polyphenols, and polyphenols-rich pomace extract are of particular interest due to the heterogeneity of the mixture, which makes these extract extremely interesting, since it contains a large number of polyphenols classes.…”