Nanocoating with plant-derived pectins activates osteoblast response in vitro

Abstract: A new strategy to improve osseointegration of implants is to stimulate adhesion of bone cells, bone matrix formation, and mineralization at the implant surface by modifying surface coating on the nanoscale level. Plant-derived pectins have been proposed as potential candidates for surface nanocoating of orthopedic and dental titanium implants due to 1) their osteogenic stimulation of osteoblasts to mineralize and 2) their ability to control pectin structural changes. The aim of this study was to evaluate in vitro the impact of the nanoscale plant-derived pectin Rhamnogalacturonan-I (RG-I) from potato on the osteogenic response of murine osteoblasts. RG-I from potato pulps was isolated, structurally modified, or left unmodified. Tissue culture plates were either coated with modified RG-I or unmodified RG-I or – as a control – left uncoated. The effect of nanocoating on mice osteoblast- like cells MC3T3-E1 and primary murine osteoblast with regard to proliferation, osteogenic response in terms of mineralization, and gene expression of Runt-related transcription factor 2 (Runx2), alkaline phosphate (Alpl), osteocalcin (Bglap), α-1 type I collagen (Col1a1), and receptor activator of NF-κB ligand (Rankl) were analyzed after 3, 7, 14, and 21 days, respectively. Nanocoating with pectin RG-Is increased proliferation and mineralization of MC3T3-E1 and primary osteoblast as compared to osteoblasts cultured without nanocoating. Moreover, osteogenic transcriptional response of osteoblasts was induced by nanocoating in terms of gene induction of Runx2, Alpl, Bglap, and Col1a1 in a time-dependent manner – of note – to the highest extent under the PA-coating condition. In contrast, Rankl expression was initially reduced by nanocoating in MC3T3-E1 or remained unaltered in primary osteoblast as compared to the uncoated controls. Our results showed that nanocoating of implants with modified RG-I beneficially 1) supports osteogenesis, 2) has the capacity to improve osseointegration of implants, and is therefore 3) a potential candidate for nanocoating of bone implants

Introduction

The concept of Responsible Research and Innovation (RRI) originates in discourses on emerging technologies and research ethics in contested innovative fields, such as nanotechnologies or geo-engineering, and has been predominantly driven by European research and innovation policy over the past 10 years. The concept was initially developed and introduced by policy makers and social scientists, but recent studies have aimed to shed light on the implementation of responsible research and innovation practices in business. The contributions collected in this book are a result of work conducted by seven partner organisations in the European funded Horizon 2020 project "COMPASS – Evidence and opportunities for responsible innovation in SMEs". In combination, they illustrate that responsible innovation (RI) has been emerging as a new field in the ongoing discourse on the role and responsibility of business in society

Pectin as a Biomaterial in Regenerative Endodontics—Assessing Biocompatibility and Antibacterial Efficacy against Common Endodontic Pathogens: An In Vitro Study

Regenerative endodontics (REP) is a new clinical modality aiming to regenerate damaged soft and hard dental tissues, allowing for root completion in young adults’ teeth. Effective disinfection is crucial for REP success, but commonly used antimicrobials often harm the niche dental pulp stem cells (DPSCs). To our knowledge, this is the first study to explore the biocompatibility and antimicrobial potential of pectin as a potential natural intracanal medicament for REPs. Low methoxyl commercial citrus pectin (LM) (pectin CU701, Herbstreith&Fox.de) was used in all experiments. The pectin’s antibacterial activity against single species biofilms (E. faecalis and F. nucleatum) was assessed using growth curves. The pectin’s antimicrobial effect against mature dual-species biofilm was also evaluated using confocal laser scanning microscopy (CLSM) after 30 min and 7 days of treatment. The DPSC biocompatibility with 2% and 4% w/v of the pectin coatings was evaluated using live/dead staining, LDH, and WST-1 assays. Pectin showed a concentration-dependent inhibitory effect against single-species biofilms (E. faecalis and F. nucleatum) but failed to disrupt dual-species biofilm. Pectin at 2% w/v concentration proved to be biocompatible with the HDPSCs. However, 4% w/v pectin reduced both the viability and proliferation of the DPSCs. Low concentration (2% w/v) pectin was biocompatible with the DPSCs and showed an antimicrobial effect against single-species biofilms. This suggests the potential for using pectin as an injectable hydrogel for clinical applications in regenerative endodontics

Plant-derived rhamnogalacturonan-I’s modulate proinflammatory cytokine gene expression in neutrophils stimulated by E. coli LPS and P. gingivalis bacteria

Titanium dental implants often induce the foreign body immune response. The duration of the inflammatory process determines the initial stability and biocompatibility of the implant. The challenge for bone tissue engineering is to develop implant biocompatible and bioactive surface coatings that regulate the inflammatory response and enhance osseointegration. Pectins, plant-derived polysaccharides, have been shown to be potential candidates for surface coating due to their possible roles in improving osseointegration and bone healing. The aim of this study was to evaluate in vitro the effect of plant-derived pectin rhamnogalacturonan-I (RG-I) nanocoating on pro- and anti-inflammatory human polymorphonuclear leucocytes (PMN) responses to E. coli LPS or P. gingivalis bacteria. In this study unmodified RG-I and structurally modified RG-I from potato were examined. All in vitro studies were performed on tissue culture polystyrene surfaces (TCPS) or titanium (Ti) discs coated with unmodified and modified RG-Is. Changes in PMN gene expression occurred on both surfaces. The presence of RG-Is down-regulated proinflammatory genes, IL1B, IL8, TNFA. Our results clearly showed that pectin RG-I nanocoating decreased the level of proinflammatory genes expression in stimulated PMN and may therefore be considered as a potential candidate for modulation of the inflammatory response elicited by insertion of implants into living tissue

Nanocoating with plant-derived pectins activates osteoblast response in vitro

J Folkert,1 A Meresta,1 T Gaber,2 K Miksch,1 F Buttgereit,2 J Detert,2 N Pischon,3,* K Gurzawska3,4,* 1Environmental Biotechnology Department, Faculty of Power and Environmental, Silesian University of Technology, Gliwice, Poland; 2Department of Rheumatology and Clinical Immunology, 3Department of Periodontology, Charité-Universitätsmedizin, Berlin, Germany; 4Department of Oral Surgery, The School of Dentistry, University of Birmingham, Birmingham, UK *These authors contributed equally to this work Abstract: A new strategy to improve osseointegration of implants is to stimulate adhesion of bone cells, bone matrix formation, and mineralization at the implant surface by modifying surface coating on the nanoscale level. Plant-derived pectins have been proposed as potential candidates for surface nanocoating of orthopedic and dental titanium implants due to 1) their osteogenic stimulation of osteoblasts to mineralize and 2) their ability to control pectin structural changes. The aim of this study was to evaluate in vitro the impact of the nanoscale plant-derived pectin Rhamnogalacturonan-I (RG-I) from potato on the osteogenic response of murine osteoblasts. RG-I from potato pulps was isolated, structurally modified, or left unmodified. Tissue culture plates were either coated with modified RG-I or unmodified RG-I or – as a control – left uncoated. The effect of nanocoating on mice osteoblast-like cells MC3T3-E1 and primary murine osteoblast with regard to proliferation, osteogenic response in terms of mineralization, and gene expression of Runt-related transcription factor 2 (Runx2), alkaline phosphate (Alpl), osteocalcin (Bglap), α-1 type I collagen (Col1a1), and receptor activator of NF-κB ligand (Rankl) were analyzed after 3, 7, 14, and 21 days, respectively. Nanocoating with pectin RG-Is increased proliferation and mineralization of MC3T3-E1 and primary osteoblast as compared to osteoblasts cultured without nanocoating. Moreover, osteogenic transcriptional response of osteoblasts was induced by nanocoating in terms of gene induction of Runx2, Alpl, Bglap, and Col1a1 in a time-dependent manner – of note – to the highest extent under the PA-coating condition. In contrast, Rankl expression was initially reduced by nanocoating in MC3T3-E1 or remained unaltered in primary osteoblast as compared to the uncoated controls. Our results showed that nanocoating of implants with modified RG-I beneficially 1) supports osteogenesis, 2) has the capacity to improve osseointegration of implants, and is therefore 3) a potential candidate for nanocoating of bone implants. Keywords: nanocoatings, osseointegration, osteoblasts, mineralization, Rhamnogalacturonan-

Plant-derived pectin nanocoatings to prevent inflammatory cellular response of osteoblasts following Porphyromonas gingivalis infection

Anna Meresta,1 Justyna Folkert,1 Timo Gaber,2 Korneliusz Miksch,1 Frank Buttgereit,2 Jacqueline Detert,2 Nicole Pischon,3,* Katarzyna Gurzawska3,4,* 1Environmental Biotechnology Department, Faculty of Power and Environmental, Silesian University of Technology, Gliwice, Poland; 2Department of Rheumatology and Clinical Immunology, 3Department of Periodontology, Charité University Medicine, Berlin, Germany; 4Oral Surgery Department, The School of Dentistry, University of Birmingham, Birmingham, UK *These authors contributed equally to this work Background: Bioengineered plant-derived Rhamnogalacturonan-Is (RG-Is) from pectins are potential candidates for surface nanocoating of medical devices. It has recently been reported that RG-I nanocoatings may prevent bacterial infection and improve the biocompatibility of implants. The aim of the study was to evaluate in vitro impact of bioengineered RG-I nanocoatings on osteogenic capacity and proinflammatory cytokine response of murine osteoblasts following Porphyromonas gingivalis infection.Methods: Murine MC3T3-E1 osteoblasts and isolated primary calvarial osteoblasts from C57BL/6J (B6J osteoblasts) mice were infected with P. gingivalis and incubated on tissue culture polystyrene plates with or without nanocoatings of unmodified RG-Is isolated from potato pulps (PU) or dearabinanated RG-Is (PA). To investigate a behavior of infected osteoblasts cultured on RG-Is cell morphology, proliferation, metabolic activity, mineralization and osteogenic and pro-inflammatory gene expression were examined.Results: Following P. gingivalis infection, PA, but not PU, significantly promoted MC3T3-E1 and BJ6 osteoblasts proliferation, metabolic activity, and calcium deposition. Moreover, Il-1b, Il-6, TNF-α, and Rankl gene expressions were downregulated in cells cultured on PU and to a higher extent on PA as compared to the corresponding control, whereas Runx, Alpl, Col1a1, and Bglap gene expressions were upregulated vice versa.Conclusion: Our data clearly showed that pectin RG-Is nanocoating with high content of galactan (PA) reduces the osteoblastic response to P. gingivalis infection in vitro and may, therefore, reduce a risk of inflammation especially in immunocompromised patients with rheumatoid or periodontal disorders. Keywords: nanocoatings, Rhamnogalacturonan-I, Porphyromonas gingivalis, osteoblasts, inflammatio

Phenolic-enriched collagen fibrillar coatings on titanium alloy to promote osteogenic differentiation and reduce inflammation

The adsorption of biomolecules on biomaterial surfaces can promote their integration with surrounding tissue without changing their bulk properties. For biomaterials in bone reconstruction, the promotion of osteogenic differentiation and reduction of inflammation are desirable. Fibrillar coatings are interesting because of fibrils’ high surface area-volume ratio, aiding adsorption and adhesion. Fibrils also serve as a matrix for the immobilization of biomolecules with biological activity, such as the phenolic compound phloroglucinol (PG), the subunit of marine polyphenols. The aim of this work was to investigate the influence of PG coatings on fibroblast-and osteoblast-like cells to increase the osseointegration of titanium implants. Collagen fibril coatings, containing PG at low and high concentrations, were produced on titanium alloy (Ti6Al4V) scaffolds generated by additive manufacturing (AM). These coatings, especially PG-enriched coatings, reduced hydrophobicity and modulated the behavior of human osteosarcoma SaOS-2 and mouse embryonic fibroblast 3T3 cell lines. Both osteoblastic and fibroblastic cells spread and adhered well on PG-enriched coatings. Coatings significantly reduced the inflammatory response. Moreover, osteogenic differentiation was promoted by collagen coatings with a high PG concentration. Thus, the enrichment of collagen fibril coatings with PG is a promising strategy to improve Ti6Al4V implants for bone contact in orthopedics and dentistry and is worthy of further investigation.