Final Report Summary - IMCOSS (Injectable Medical Ceramics for Bone Repair and Augmentation)
Executive Summary:
Reconstruction of missing or damaged bone in maxillofacial and orthopaedic surgery following trauma, for correction of congenital or acquired deformities and following excision of tumours presents a major surgical challenge. Current techniques for the repair and regeneration of these defects are satisfactory although problems such as donor site morbidity, risk of disease transmission, limited supply, inconsistent healing and poor graft material properties remain. Synthetic bone grafts are becoming increasingly attractive to surgeons however these materials can have limited success. Of these commercial bone grafts relatively few non-setting materials are capable of being injected directly into the defect and shaping in situ due to their high viscosity. The limited performance of bone grafts, particularly in elderly patients, presents a pressing need to develop new materials for the repair and regeneration of bone. In addition, there is no single use device on the market which can accurately deliver bone grafts dose per dose and eliminate the large forces and burst release associated with the delivery of viscous materials.
The aim of this project was to undertake basic scientific research to underpin the development of a new injectable bone graft substitute and a advanced delivery system which will provide the surgeon with a high degree of control and dose per dose delivery. The structured work packages of this project were designed to mirror the supply chain from raw material to clinical application.
Material and in vitro characterisation were initially carried out on a basic paste which was composed of nanoparticles of hydroxyapatite (nHA) manufactured using the patented NETmix technology. After consultation with surgeons and analysis of the results the IMCOSS team proceeded to make several developments to the paste which involved changes to the solid content (optimised paste) and addition of metal ions (advanced paste). The materials characterisation demonstrated that the optimised and advanced materials had flatter viscosity profiles and the nHA particles varied in shape and size compared to the basic pastes. The modifications to the fabrication techniques did not however affect the purity and homogeneity of the nHA particles. The advanced materials were observed to have metal ions substituted into the nHA lattice and this substitution was confirmed to be of the required level.
The in vitro study of basic paste showed some reduction in cell viability in the 2D-cell cultures with mesenchymal stem cells (MSCs) and more mature osteoblastic cells being the most sensitive. However, in a 3D-cell culture system using MG63 and MSCs showed significantly less toxicity and may therefore be more reflective of the reported in vivo data of nHA on bone regeneration. Evaluation of the optimised and advanced pastes showed improved biocompatibility and most significantly the metal-ion doped nHA stimulated an increase in cellular activity therefore demonstrating the enhanced potential of the advanced pastes for bone repair. The in vivo response of the basic and optimised pastes was evaluated. Healing of the defect was achieved within 6 months with no signs of inflammation. However, the basic paste was shown to resorb to a greater extent compared to the ‘optimised’ pastes suggesting that the optimal concentration of nHA in this type of material had been reached in the basic paste.
Alongside the development of the bone graft materials a advanced delivery device was produced in order to facilitate dose per dose delivery of these viscous materials eliminating the increased forces associated with this type of the material. During two clinical workshops the IMCOSS team gained valuable feedback from clinicians which informed the modifications to the device. The device was fully optimised with increased flexibility for dose variations and precision delivery of the pastes.
In conclusion, the IMCOSS project has been very successful with the initial development of advanced bone graft paste and a delivery device which is capable of accurately delivering viscous materials. The anticipated impact of these results for the SMEs is excellent and the data obtained from the scientific research will contribute to the advancement of knowledge in the biomaterial and clinical fields.
Project Context and Objectives:
The repair and regeneration of bone remains a significant challenge in orthopaedics, dentistry, and maxillofacial surgery due to problems with current techniques such as donor site morbidity, limited supply and complicating factors such as the ageing population. Synthetic biomaterials are becoming very attractive to the surgeon due to their ability to overcome some of these current issues. In addition, the ease of use of the product is of particular concern to the surgeon when performing bone grafting procedures. Most current commercial products are presented in block or particulate form, with relatively few non-setting bone graft substitutes being capable of delivery into a defect via syringe and shaping in situ. However, one problem with syringe-based devices for the delivery of materials with high viscosity is that large forces are required in order to deliver the product. This may result in over filling of the defect and when considerable force is used inaccurate placement of the material may lead to graft failure. Moreover, it is widely recognised that tissue response to existing synthetic bone graft substitutes is frequently inconsistent, particularly in older or compromised patients, resulting in a pressing need for improved bone graft materials. Nanostructured materials have the potential benefit of ultra high-surface area to volume ratio increasing the adsorption of biomolecuels and thus improving cellular interactions. Nano-hydroxyapatite is of particular interest as it mimics the natural apatite crystals found in bone and therefore provides cells with an optimum environment for the repair of bone.
The aim of the IMCOSS project was to undertake scientific research on nanostructured biomaterials which informed the development of an injectable synthetic bone graft substitute and an advanced delivery device that will provide the surgeon with a high degree of control during clinical use.
The SME partners within this consortium were brought together as they represent different parts of the supply chain and have the expertise to translate basic research to the market. The aim of the SMEs was to utilise the data generated by the RTD performers to develop new and innovative products which will generate growth through increased sales and market share. The main technological outcomes from this project were anticipated to be a new delivery device and an injectable bone graft substitute which will be suitable for use in dental, maxillofacial and orthopaedic surgery. In addition, the platform technology that underpins the injectable nano-materials was expected to be sufficiently versatile to act as a foundation for the development of advanced materials with improved properties. The project success was aided by the development of excellent working relationships between the different partners which will in turn provide opportunities for future research and innovation.
The central concept of this project was to develop new nanostructured, injectable bone graft substitute and a dedicated advanced delivery system. The structured work packages of this project were designed to mirror the supply chain from raw material to clinical application.
In order to achieve this concept the following objectives for the project were set:
- Understand the structure-property relationships of the injectable materials that underpin their fabrication and performance.
- Optimise the nanostructured materials and investigate novel (advanced) materials which will offer superior performance over basic materials.
- Develop a advanced delivery system which will facilitate controlled delivery into challenging clinical sites and ease of use.
This project was an excellent collaboration between industry, scientific and clinical expertise that together will facilitate the translation of basic science through applied research and on to the development of a new medical device. It was anticipated that the new products developed as part of this project will be available on the market within 2-3 years of the project end date.
Project Results:
The IMCOSS project had several scientific and technological objectives in order to achieve the overall aim of the project which was to develop a new injectable bone graft substitute and novel delivery device.
During this project several nano-hydroxyapatite (nHA) slurries were developed using the expertise of the consortium partners and patented NETmix technology. These raw materials were then incorporated into bone graft pastes for subsequent materials and biological testing. The technology underpinning the development of the nHA was demonstrated to be flexible enough to produce nHA particles with varying shape and morphology along with incorporation of metal ion-doped materials with superior biological properties.
A greater understanding of the relationship between nano-particle size, morphology, rheology and effects of processing modifications was obtained and in turn informed further development of the basic nano-hydroxyapatites (nHA). In particular, it was observed that nHA pastes have a thixotropic behaviour which results in a shear thinning effect when they are extruded from a syringe. Interestingly, the basic paste became easier to handle on cooling. X-ray diffraction (XRD) and fourier transform infra-red (FT-IR) analysis demonstrated the purity of the nHA phase and specific surface area and the porosity of the pastes were also evaluated. The data on the basic paste was used along with the in vitro data to inform developments of the basic nHA paste to improve its handling and biological response.
In combination, the multi-technique characterisation has confirmed that the changes in processing steps introduced when switching from “Basic Paste” to “Optimised Paste” did not adversely affect the purity and homogeneity of the materials. XRD, FT-IR and TGA analysis of basic and optimised materials showed no change in their chemical/structural fingerprints. The most important differences was the change to viscosity, with optimised pastes having superior flow compared to basic pastes even at higher HA-load. Not only is the viscosity lower, also the problematic onset-viscosity due to shear-thinning was largely reduced, leading to much flatter viscosity-time behaviour. This suggests the possibility to increase the content of the solid phase further, while retaining minimum fluidity necessary for syringe operation. Transmission electron microscopy (TEM) comparisons between slurries and optimised pastes (the final products made from slurries) confirm that the particle morphology does not significantly change during the processing steps converting slurries into pastes. Additionally, TEM comparisons between slurries made at different reaction temperatures, confirmed a moderate change to particle size and aspect ratio. The separation of rheological properties from nano-morphology suggests that a wider range of nanoparticle shapes and multi-dispersed particle sizes could be trialled while retaining low viscosity through appropriate choice of HA-load and paste manufacturing conditions.
After careful consideration of both material characterisation and in vitro data, the advanced materials were synthesised with metal dopants. Phase pure hydroxyapatite phase was confirmed by XRD. The HA / water ratio checked by TGA and were found to be in the region of those claimed. The particles of the advanced materials appeared to be made of irregular shaped nanoparticles having varying particle shape and size distribution and differing from the optimised materials (TEM). Moreover, the viscosities of these materials seem to be similar to that of optimised pastes (the same order of magnitude). Finally the quantification of the metal doping was confirmed by inductively coupled plasma optical emission spectrometry (ICP-OES). The level of substitution was shown to be sufficient to promote an improved biological response in vitro.
High quality in vitro studies were performed which demonstrated a cell specific response of the basic paste. The basic paste showed some reduction in cell viability in the 2D-cell cultures with mesenchymal stem cells and more mature osteoblastic cells being the most sensitive compared to the immature osteoblastic cells. Transmission electron microscopy (TEM) showed numerous nHA particles in the cell cytoplasm of the cells which may have resulted in the observed toxicities. However, in 3D-cell culture system using MG63 and MSCs were showed significantly less toxicity and may therefore be more reflective of the reported in vivo data of nHA on bone regeneration. Since 2D cultures were more sensitive to cytotoxicity by the nHA than 3D cultures an indirect protocol of exposing cells to the pastes was developed. Osteogenic cells cultured by indirect contact with basic paste investigated with the optimised indirect protocol showed a considerable increase in cell metabolic activity. Further investigation of the nHA basic paste on gene transcription demonstrated the osteogenic potential of the basic paste by the stimulation of osteogenic differentiation of immature osteogenic cells.
Due to the limited published information on the cellular responses to nHA pastes the IMCOSS team carefully developed specific culture protocols for the assessment of the pastes in this project. The in vitro tests on the optimised and advanced materials were based on the ISO standard 10993-5-2009. However, several additional techniques were used including PrestoBlue, Live/Dead staining, transmission electron microscopy (TEM) and 3D in vitro models. The PrestoBlue assays indicated that optimised pastes increased the metabolic activity of the cells, compared with the basic paste for all cell types but the metabolic activity remained lower than the cell only control. Cells incubated with optimised pastes showed similar morphology to each other but were slightly more rounded than cells alone suggesting some loss of viability. Indirect exposure of the cells to a nHA-preconditioned medium reduced the apparent cytotoxic effect of the nHA pastes on the cell metabolic activity compared to the exposure of cells in direct contact with the nHA pastes. The in vitro biocompatibility of the advanced materials was studied with the direct and the indirect method using human osteogenic cells and hMSCs. When cultured in indirect contact with the advanced pastes, the osteoblastic cell lines showed a metabolic activity equivalent to that of the cell only control, in contrast to the basic and optimised pastes. However, in direct contact with primary bone cells (HOBs) and hMSC the advanced pastes stimulated the metabolic activity of the cells over the cell only control. These experiments indicated that the advanced pastes showed a better biocompatibility in direct contact with osteogenic cells and MSCs compared to the basic and optimised pastes. This enhanced in vitro biocompatibility was hypothesised to be due to a lower/no release of nanoparticles from the advanced pastes compared to the other pastes. The ion release from the nHA pastes is most likely the cause of stimulation of the osteoblastic and MSC cell activity and promotion of osteogenic differentiation. Studies were performed to allow the consortium to begin to understand the mechanisms of action behind this superior cellular response. In conclusion the cellular response to the optimised and advanced materials was improved compared to the basic pastes, with the advanced metal ion doped materials being the most biocompatible.
During the development of the nano-pastes a delivery device was designed, modified and fabricated. Through consultation with clinical experts and feedback on its performance at clinical workshops the device was optimised resulting in an advanced system which smoothly delivers the viscous pastes without the need for high extrusion forces associated with conventional syringes. In addition, the device has been produced with several options to alter the dosage to suit the application, e.g. dental or orthopaedic. Overall the device is ergonomic and will provide the operator with a disposable delivery device which can be used single handedly and with a high degree of control.
The basic and advanced pastes were evaluated for their ability to repair and regenerate bone in a critical size defect where the bone would not heal sufficiently on its own. Utilising a relatively new in vivo model the pastes were evaluated using histology and CT imaging and were observed to stimulate bone formation and healing of the defect within six months. No inflammation was observed however the slower degradation of the optimised paste resulting in reduced cellular infiltration into the graft material suggesting that the optimal composition of an injectable paste is closer to the solid content of the basic paste. This finding will inform future development of the most promising advanced pastes.
Throughout this project the consortium has engaged with end users in the field of orthopeadics and dentistry in order to assess the suitability of the new technologies for therapeautic use. The IMCOSS team held two clinical wetlab workshops where suggested improvements and modifications were made to the pastes and device. The workshops provided the clinicians with hands on experience of using the device and pastes and overall the feedback at both workshops was positive. The team was encouraged by this feedback and is very confident that the products developed as part of this project will be well received by surgeons and practitioners once they are launched onto the market. Another benefit of having the wetlab workshops was that the SMEs had the opportunity of one to one time with the clinicians and were able to gain valuable information on product requirements, clinical need and ideas for further research and development. Clinical engagement has played a key role in the decisions made on the material development and the delivery device and has been critical to the project’s success. It is anticipated that the advanced bone graft substitutes and delivery device will be exploited within 1-3 years of this project. The new material and delivery devices also have vast potential be translated into commercial products for other disciplines such as cosmetics, oral hygiene and the delivery of viscous therapeutics.
The IMCOSS project has been an excellent opportunity to develop a new class of injectable bone graft substitutes for bone tissue regeneration which will benefit the whole supply chain from material fabrication to medical device manufacture. The results obtained as part of the project will significantly benefit the SME partners and contribute to European excellence and competitiveness in the healthcare field.
Potential Impact:
This project will have significant positive implications for the SME participants, patients and the European and global medical devices/health technologies sector. The project will add substantially to scientific knowledge to develop new medical products that is only achievable due the unification of the individual SME partners in combination with the RTD performers. The team methodically characterised and optimised the nanostructured biomaterials and generated a customised delivery device. An inherent benefit of this project was the formation of relationships between the supply-chain SMEs which was strengthened by the shared execution of an integrated scientific programme.
The new bone graft paste, delivery device and the knowledge gained from the basic research, will increase the SMEs presence and opportunities for sales in the medical device market along with potential for expansion into other markets such as oral care, cosmetics and delivery of therapeutics. The SMEs have worked together to jointly develop new products by exchanging knowledge between the different stages of the supply chain. This project is expected to increase the SMEs turnover due to new and existing products and provide them with a significantly greater international profile.
The EU medical device industry relies on continued high quality research and the development of high performance and high added value technologies in order to remain successful in the global markets. The new products developed during IMCOSS will ensure that the consortium partners maintain their international competitiveness in a rapidly growing market. The growth of the SMEs and their supply chains within the EU will also in the medium term benefit the EU economically bringing a return on the RTD investment through increased economic activity, employment and exports. The EU industry will obtain a competitive advantage over other non-EU based companies who are seeking to acquire similar technologies, and this advantage will be reflected in the SME participants international profile and a societal and economic benefit for the EU in terms of improved patient care and economic activity internally and by export. All partner SMEs will also benefit from the stronger ties developed with the other partners in this proposal, and this will in turn lead to further collaboration and technology transfer. The consortium will aim to translate the science and technology developed during this project to new products and the market soon after the conclusion of the project. In particular, the foreground products are relatively near market, and this will provide the SME’s with a major competitive advantage. The consortium estimates that new nanostructured materials and optimised delivery device will be commercialised within 1-3 years after the conclusion of the project. This is expected to generate growth and employment along with obvious benefits mentioned above for the European economy. An estimation of the economic impact of the project results is anticipated to result in an increase in annual turnover for each SME 1 year after EU regulatory approvals and will continue to increase as the products become established on the market.
This project aimed to provide surgeons with an injectable bone graft substitute which will enhance the treatment of patients by improving the consistency of high quality bone tissue regeneration, reducing surgery times and post-op healing, particularly in challenging clinical sites. In addition the ability to accurately deliver viscous materials from a unique delivery system will offer substantial benefits over conventional syringes and will also permit the delivery of viscous materials which had previously unsuitable for delivery via syringe. The overall project results are anticipated to not only benefit orthopaedic and dental surgeons but to also result in products and componants for other markets such as oral hygiene, delivery of therapeutics and other healthcare applications. This in turn will benefit the SMEs by resulting in growth and access to new markets, in particularly for the delivery device and raw materials.
The research data obtained during this project is of high scientific quality and has been performed by talented scientists and engineers who are experienced in several fields (including medical and dental materials, nanostructured materials, electron microscopy and biological evaluation). The data obtained will be published in scientific journals and will act as a catalyst for further research and innovation. The project results are expected to make a significant impact within the scientific and clinical fields which will in turn add to the prestige of the SME partners. The RTD performers have likewise benefited from interaction with the industrial partners, increasing their understanding and capacity for knowledge and technology transfer along with contributing towards the professional development of post-doctoral researchers.
The main goal of the dissemination activities was to demonstrate the project research results in the dental and orthopaedic markets worldwide. Throughout the project the IMCOSS consortium have disseminated the project results and the key dissemination activities are as follows:
a) The production of hand-out describing the project objectives and technologies. These were produced to create awareness of the project. They were distributed at conferences where the RTD performers were presenting or the SMEs have exhibition stands.
b) The consortium set up a website to promote the project and can be viewed at the following address www.imcoss.eu. A Google site has also been created to ensure that the web presence beyond the project.
c) The IMCOSS project participated in the European Commission Forum at the Materials in Medicine International Conference, in Faenza, Italy, on 9th October 2013, alongside other European projects on biomaterials (http://mime.centuria-agenzia.it/).
d) A short film has been produced to disseminate the project results. This film has been posted on the project website and on You-Tube. The You-Tube link is: http://www.youtube.com/watch?v=POM4b6HE9HQ
e) The consortium had an exhibition stand at a clinically orientated international conference, where they promoted the results of the project and gained feedback on the delivery device and nano-paste. The conference was the International Association for Dental Research/ Pan-European Region in Dubrovnik, Croatia on the 10th – 13th September 2014. The stand had a lot of interest from the dental community with many eagerly anticipating commercialisation of the product and delivery device.
Dissemination of the project results will continue following the successful conclusion of the project and as the final products receives CE marking and subsequent launch onto the market.
In summary, the main beneficiaries for this research will be the SME partners, but in turn the EU medical device industry, academic sector, and patients will all also benefit greatly. Ultimately, the IMCOSS consortium anticipate clinical and market impact on an international scale from this project and will continue to work together to make further innovative developments capitalising on the platform technologies which form the exploitable results of this project.
List of beneficiaries and contact information:
Ceramisys Ltd.
914 Herries Road
Sheffield
South Yorkshire
S6 1QW. UK +441142327070
r.goodchild@ceramisys.com
Fluidinova SA
TECMAIA - Parque de Ciência e Tecnologia da Maia
Rua Engº Frederico Ulrich, 2650
4470-605 Moreira da Maia
Portugal
+351220119746
Hugo.Ramos@Fluidinova.com
Primequal SA
Rue des Pierres du Niton 17
CH-1207 Geneva
Switzerland
+41223540550
DWeill@Primequal.com
University of Sheffield
The School of Clinical Dentistry
University of Sheffield
19 Claremont Crescent
Sheffield
S10 2TA. UK
+441142717852
C.A.Miller@sheffield.ac.uk
Ludwig Boltzmann Institute
for Experimental & Clinical Traumatology
Donaueschingenstraße 13
A-1200 Vienna
Austria
+43133110464
Office@Trauma.lbg.ac.at
List of Websites:
A project website was set up to promote the project and can be found at the following link: www.imcoss.eu. The website contains the project logo and a link to the You-Tube video. The contact for the project is Dr Becci Goodchild, email: r.goodchild@ceramisys.com.
Reconstruction of missing or damaged bone in maxillofacial and orthopaedic surgery following trauma, for correction of congenital or acquired deformities and following excision of tumours presents a major surgical challenge. Current techniques for the repair and regeneration of these defects are satisfactory although problems such as donor site morbidity, risk of disease transmission, limited supply, inconsistent healing and poor graft material properties remain. Synthetic bone grafts are becoming increasingly attractive to surgeons however these materials can have limited success. Of these commercial bone grafts relatively few non-setting materials are capable of being injected directly into the defect and shaping in situ due to their high viscosity. The limited performance of bone grafts, particularly in elderly patients, presents a pressing need to develop new materials for the repair and regeneration of bone. In addition, there is no single use device on the market which can accurately deliver bone grafts dose per dose and eliminate the large forces and burst release associated with the delivery of viscous materials.
The aim of this project was to undertake basic scientific research to underpin the development of a new injectable bone graft substitute and a advanced delivery system which will provide the surgeon with a high degree of control and dose per dose delivery. The structured work packages of this project were designed to mirror the supply chain from raw material to clinical application.
Material and in vitro characterisation were initially carried out on a basic paste which was composed of nanoparticles of hydroxyapatite (nHA) manufactured using the patented NETmix technology. After consultation with surgeons and analysis of the results the IMCOSS team proceeded to make several developments to the paste which involved changes to the solid content (optimised paste) and addition of metal ions (advanced paste). The materials characterisation demonstrated that the optimised and advanced materials had flatter viscosity profiles and the nHA particles varied in shape and size compared to the basic pastes. The modifications to the fabrication techniques did not however affect the purity and homogeneity of the nHA particles. The advanced materials were observed to have metal ions substituted into the nHA lattice and this substitution was confirmed to be of the required level.
The in vitro study of basic paste showed some reduction in cell viability in the 2D-cell cultures with mesenchymal stem cells (MSCs) and more mature osteoblastic cells being the most sensitive. However, in a 3D-cell culture system using MG63 and MSCs showed significantly less toxicity and may therefore be more reflective of the reported in vivo data of nHA on bone regeneration. Evaluation of the optimised and advanced pastes showed improved biocompatibility and most significantly the metal-ion doped nHA stimulated an increase in cellular activity therefore demonstrating the enhanced potential of the advanced pastes for bone repair. The in vivo response of the basic and optimised pastes was evaluated. Healing of the defect was achieved within 6 months with no signs of inflammation. However, the basic paste was shown to resorb to a greater extent compared to the ‘optimised’ pastes suggesting that the optimal concentration of nHA in this type of material had been reached in the basic paste.
Alongside the development of the bone graft materials a advanced delivery device was produced in order to facilitate dose per dose delivery of these viscous materials eliminating the increased forces associated with this type of the material. During two clinical workshops the IMCOSS team gained valuable feedback from clinicians which informed the modifications to the device. The device was fully optimised with increased flexibility for dose variations and precision delivery of the pastes.
In conclusion, the IMCOSS project has been very successful with the initial development of advanced bone graft paste and a delivery device which is capable of accurately delivering viscous materials. The anticipated impact of these results for the SMEs is excellent and the data obtained from the scientific research will contribute to the advancement of knowledge in the biomaterial and clinical fields.
Project Context and Objectives:
The repair and regeneration of bone remains a significant challenge in orthopaedics, dentistry, and maxillofacial surgery due to problems with current techniques such as donor site morbidity, limited supply and complicating factors such as the ageing population. Synthetic biomaterials are becoming very attractive to the surgeon due to their ability to overcome some of these current issues. In addition, the ease of use of the product is of particular concern to the surgeon when performing bone grafting procedures. Most current commercial products are presented in block or particulate form, with relatively few non-setting bone graft substitutes being capable of delivery into a defect via syringe and shaping in situ. However, one problem with syringe-based devices for the delivery of materials with high viscosity is that large forces are required in order to deliver the product. This may result in over filling of the defect and when considerable force is used inaccurate placement of the material may lead to graft failure. Moreover, it is widely recognised that tissue response to existing synthetic bone graft substitutes is frequently inconsistent, particularly in older or compromised patients, resulting in a pressing need for improved bone graft materials. Nanostructured materials have the potential benefit of ultra high-surface area to volume ratio increasing the adsorption of biomolecuels and thus improving cellular interactions. Nano-hydroxyapatite is of particular interest as it mimics the natural apatite crystals found in bone and therefore provides cells with an optimum environment for the repair of bone.
The aim of the IMCOSS project was to undertake scientific research on nanostructured biomaterials which informed the development of an injectable synthetic bone graft substitute and an advanced delivery device that will provide the surgeon with a high degree of control during clinical use.
The SME partners within this consortium were brought together as they represent different parts of the supply chain and have the expertise to translate basic research to the market. The aim of the SMEs was to utilise the data generated by the RTD performers to develop new and innovative products which will generate growth through increased sales and market share. The main technological outcomes from this project were anticipated to be a new delivery device and an injectable bone graft substitute which will be suitable for use in dental, maxillofacial and orthopaedic surgery. In addition, the platform technology that underpins the injectable nano-materials was expected to be sufficiently versatile to act as a foundation for the development of advanced materials with improved properties. The project success was aided by the development of excellent working relationships between the different partners which will in turn provide opportunities for future research and innovation.
The central concept of this project was to develop new nanostructured, injectable bone graft substitute and a dedicated advanced delivery system. The structured work packages of this project were designed to mirror the supply chain from raw material to clinical application.
In order to achieve this concept the following objectives for the project were set:
- Understand the structure-property relationships of the injectable materials that underpin their fabrication and performance.
- Optimise the nanostructured materials and investigate novel (advanced) materials which will offer superior performance over basic materials.
- Develop a advanced delivery system which will facilitate controlled delivery into challenging clinical sites and ease of use.
This project was an excellent collaboration between industry, scientific and clinical expertise that together will facilitate the translation of basic science through applied research and on to the development of a new medical device. It was anticipated that the new products developed as part of this project will be available on the market within 2-3 years of the project end date.
Project Results:
The IMCOSS project had several scientific and technological objectives in order to achieve the overall aim of the project which was to develop a new injectable bone graft substitute and novel delivery device.
During this project several nano-hydroxyapatite (nHA) slurries were developed using the expertise of the consortium partners and patented NETmix technology. These raw materials were then incorporated into bone graft pastes for subsequent materials and biological testing. The technology underpinning the development of the nHA was demonstrated to be flexible enough to produce nHA particles with varying shape and morphology along with incorporation of metal ion-doped materials with superior biological properties.
A greater understanding of the relationship between nano-particle size, morphology, rheology and effects of processing modifications was obtained and in turn informed further development of the basic nano-hydroxyapatites (nHA). In particular, it was observed that nHA pastes have a thixotropic behaviour which results in a shear thinning effect when they are extruded from a syringe. Interestingly, the basic paste became easier to handle on cooling. X-ray diffraction (XRD) and fourier transform infra-red (FT-IR) analysis demonstrated the purity of the nHA phase and specific surface area and the porosity of the pastes were also evaluated. The data on the basic paste was used along with the in vitro data to inform developments of the basic nHA paste to improve its handling and biological response.
In combination, the multi-technique characterisation has confirmed that the changes in processing steps introduced when switching from “Basic Paste” to “Optimised Paste” did not adversely affect the purity and homogeneity of the materials. XRD, FT-IR and TGA analysis of basic and optimised materials showed no change in their chemical/structural fingerprints. The most important differences was the change to viscosity, with optimised pastes having superior flow compared to basic pastes even at higher HA-load. Not only is the viscosity lower, also the problematic onset-viscosity due to shear-thinning was largely reduced, leading to much flatter viscosity-time behaviour. This suggests the possibility to increase the content of the solid phase further, while retaining minimum fluidity necessary for syringe operation. Transmission electron microscopy (TEM) comparisons between slurries and optimised pastes (the final products made from slurries) confirm that the particle morphology does not significantly change during the processing steps converting slurries into pastes. Additionally, TEM comparisons between slurries made at different reaction temperatures, confirmed a moderate change to particle size and aspect ratio. The separation of rheological properties from nano-morphology suggests that a wider range of nanoparticle shapes and multi-dispersed particle sizes could be trialled while retaining low viscosity through appropriate choice of HA-load and paste manufacturing conditions.
After careful consideration of both material characterisation and in vitro data, the advanced materials were synthesised with metal dopants. Phase pure hydroxyapatite phase was confirmed by XRD. The HA / water ratio checked by TGA and were found to be in the region of those claimed. The particles of the advanced materials appeared to be made of irregular shaped nanoparticles having varying particle shape and size distribution and differing from the optimised materials (TEM). Moreover, the viscosities of these materials seem to be similar to that of optimised pastes (the same order of magnitude). Finally the quantification of the metal doping was confirmed by inductively coupled plasma optical emission spectrometry (ICP-OES). The level of substitution was shown to be sufficient to promote an improved biological response in vitro.
High quality in vitro studies were performed which demonstrated a cell specific response of the basic paste. The basic paste showed some reduction in cell viability in the 2D-cell cultures with mesenchymal stem cells and more mature osteoblastic cells being the most sensitive compared to the immature osteoblastic cells. Transmission electron microscopy (TEM) showed numerous nHA particles in the cell cytoplasm of the cells which may have resulted in the observed toxicities. However, in 3D-cell culture system using MG63 and MSCs were showed significantly less toxicity and may therefore be more reflective of the reported in vivo data of nHA on bone regeneration. Since 2D cultures were more sensitive to cytotoxicity by the nHA than 3D cultures an indirect protocol of exposing cells to the pastes was developed. Osteogenic cells cultured by indirect contact with basic paste investigated with the optimised indirect protocol showed a considerable increase in cell metabolic activity. Further investigation of the nHA basic paste on gene transcription demonstrated the osteogenic potential of the basic paste by the stimulation of osteogenic differentiation of immature osteogenic cells.
Due to the limited published information on the cellular responses to nHA pastes the IMCOSS team carefully developed specific culture protocols for the assessment of the pastes in this project. The in vitro tests on the optimised and advanced materials were based on the ISO standard 10993-5-2009. However, several additional techniques were used including PrestoBlue, Live/Dead staining, transmission electron microscopy (TEM) and 3D in vitro models. The PrestoBlue assays indicated that optimised pastes increased the metabolic activity of the cells, compared with the basic paste for all cell types but the metabolic activity remained lower than the cell only control. Cells incubated with optimised pastes showed similar morphology to each other but were slightly more rounded than cells alone suggesting some loss of viability. Indirect exposure of the cells to a nHA-preconditioned medium reduced the apparent cytotoxic effect of the nHA pastes on the cell metabolic activity compared to the exposure of cells in direct contact with the nHA pastes. The in vitro biocompatibility of the advanced materials was studied with the direct and the indirect method using human osteogenic cells and hMSCs. When cultured in indirect contact with the advanced pastes, the osteoblastic cell lines showed a metabolic activity equivalent to that of the cell only control, in contrast to the basic and optimised pastes. However, in direct contact with primary bone cells (HOBs) and hMSC the advanced pastes stimulated the metabolic activity of the cells over the cell only control. These experiments indicated that the advanced pastes showed a better biocompatibility in direct contact with osteogenic cells and MSCs compared to the basic and optimised pastes. This enhanced in vitro biocompatibility was hypothesised to be due to a lower/no release of nanoparticles from the advanced pastes compared to the other pastes. The ion release from the nHA pastes is most likely the cause of stimulation of the osteoblastic and MSC cell activity and promotion of osteogenic differentiation. Studies were performed to allow the consortium to begin to understand the mechanisms of action behind this superior cellular response. In conclusion the cellular response to the optimised and advanced materials was improved compared to the basic pastes, with the advanced metal ion doped materials being the most biocompatible.
During the development of the nano-pastes a delivery device was designed, modified and fabricated. Through consultation with clinical experts and feedback on its performance at clinical workshops the device was optimised resulting in an advanced system which smoothly delivers the viscous pastes without the need for high extrusion forces associated with conventional syringes. In addition, the device has been produced with several options to alter the dosage to suit the application, e.g. dental or orthopaedic. Overall the device is ergonomic and will provide the operator with a disposable delivery device which can be used single handedly and with a high degree of control.
The basic and advanced pastes were evaluated for their ability to repair and regenerate bone in a critical size defect where the bone would not heal sufficiently on its own. Utilising a relatively new in vivo model the pastes were evaluated using histology and CT imaging and were observed to stimulate bone formation and healing of the defect within six months. No inflammation was observed however the slower degradation of the optimised paste resulting in reduced cellular infiltration into the graft material suggesting that the optimal composition of an injectable paste is closer to the solid content of the basic paste. This finding will inform future development of the most promising advanced pastes.
Throughout this project the consortium has engaged with end users in the field of orthopeadics and dentistry in order to assess the suitability of the new technologies for therapeautic use. The IMCOSS team held two clinical wetlab workshops where suggested improvements and modifications were made to the pastes and device. The workshops provided the clinicians with hands on experience of using the device and pastes and overall the feedback at both workshops was positive. The team was encouraged by this feedback and is very confident that the products developed as part of this project will be well received by surgeons and practitioners once they are launched onto the market. Another benefit of having the wetlab workshops was that the SMEs had the opportunity of one to one time with the clinicians and were able to gain valuable information on product requirements, clinical need and ideas for further research and development. Clinical engagement has played a key role in the decisions made on the material development and the delivery device and has been critical to the project’s success. It is anticipated that the advanced bone graft substitutes and delivery device will be exploited within 1-3 years of this project. The new material and delivery devices also have vast potential be translated into commercial products for other disciplines such as cosmetics, oral hygiene and the delivery of viscous therapeutics.
The IMCOSS project has been an excellent opportunity to develop a new class of injectable bone graft substitutes for bone tissue regeneration which will benefit the whole supply chain from material fabrication to medical device manufacture. The results obtained as part of the project will significantly benefit the SME partners and contribute to European excellence and competitiveness in the healthcare field.
Potential Impact:
This project will have significant positive implications for the SME participants, patients and the European and global medical devices/health technologies sector. The project will add substantially to scientific knowledge to develop new medical products that is only achievable due the unification of the individual SME partners in combination with the RTD performers. The team methodically characterised and optimised the nanostructured biomaterials and generated a customised delivery device. An inherent benefit of this project was the formation of relationships between the supply-chain SMEs which was strengthened by the shared execution of an integrated scientific programme.
The new bone graft paste, delivery device and the knowledge gained from the basic research, will increase the SMEs presence and opportunities for sales in the medical device market along with potential for expansion into other markets such as oral care, cosmetics and delivery of therapeutics. The SMEs have worked together to jointly develop new products by exchanging knowledge between the different stages of the supply chain. This project is expected to increase the SMEs turnover due to new and existing products and provide them with a significantly greater international profile.
The EU medical device industry relies on continued high quality research and the development of high performance and high added value technologies in order to remain successful in the global markets. The new products developed during IMCOSS will ensure that the consortium partners maintain their international competitiveness in a rapidly growing market. The growth of the SMEs and their supply chains within the EU will also in the medium term benefit the EU economically bringing a return on the RTD investment through increased economic activity, employment and exports. The EU industry will obtain a competitive advantage over other non-EU based companies who are seeking to acquire similar technologies, and this advantage will be reflected in the SME participants international profile and a societal and economic benefit for the EU in terms of improved patient care and economic activity internally and by export. All partner SMEs will also benefit from the stronger ties developed with the other partners in this proposal, and this will in turn lead to further collaboration and technology transfer. The consortium will aim to translate the science and technology developed during this project to new products and the market soon after the conclusion of the project. In particular, the foreground products are relatively near market, and this will provide the SME’s with a major competitive advantage. The consortium estimates that new nanostructured materials and optimised delivery device will be commercialised within 1-3 years after the conclusion of the project. This is expected to generate growth and employment along with obvious benefits mentioned above for the European economy. An estimation of the economic impact of the project results is anticipated to result in an increase in annual turnover for each SME 1 year after EU regulatory approvals and will continue to increase as the products become established on the market.
This project aimed to provide surgeons with an injectable bone graft substitute which will enhance the treatment of patients by improving the consistency of high quality bone tissue regeneration, reducing surgery times and post-op healing, particularly in challenging clinical sites. In addition the ability to accurately deliver viscous materials from a unique delivery system will offer substantial benefits over conventional syringes and will also permit the delivery of viscous materials which had previously unsuitable for delivery via syringe. The overall project results are anticipated to not only benefit orthopaedic and dental surgeons but to also result in products and componants for other markets such as oral hygiene, delivery of therapeutics and other healthcare applications. This in turn will benefit the SMEs by resulting in growth and access to new markets, in particularly for the delivery device and raw materials.
The research data obtained during this project is of high scientific quality and has been performed by talented scientists and engineers who are experienced in several fields (including medical and dental materials, nanostructured materials, electron microscopy and biological evaluation). The data obtained will be published in scientific journals and will act as a catalyst for further research and innovation. The project results are expected to make a significant impact within the scientific and clinical fields which will in turn add to the prestige of the SME partners. The RTD performers have likewise benefited from interaction with the industrial partners, increasing their understanding and capacity for knowledge and technology transfer along with contributing towards the professional development of post-doctoral researchers.
The main goal of the dissemination activities was to demonstrate the project research results in the dental and orthopaedic markets worldwide. Throughout the project the IMCOSS consortium have disseminated the project results and the key dissemination activities are as follows:
a) The production of hand-out describing the project objectives and technologies. These were produced to create awareness of the project. They were distributed at conferences where the RTD performers were presenting or the SMEs have exhibition stands.
b) The consortium set up a website to promote the project and can be viewed at the following address www.imcoss.eu. A Google site has also been created to ensure that the web presence beyond the project.
c) The IMCOSS project participated in the European Commission Forum at the Materials in Medicine International Conference, in Faenza, Italy, on 9th October 2013, alongside other European projects on biomaterials (http://mime.centuria-agenzia.it/).
d) A short film has been produced to disseminate the project results. This film has been posted on the project website and on You-Tube. The You-Tube link is: http://www.youtube.com/watch?v=POM4b6HE9HQ
e) The consortium had an exhibition stand at a clinically orientated international conference, where they promoted the results of the project and gained feedback on the delivery device and nano-paste. The conference was the International Association for Dental Research/ Pan-European Region in Dubrovnik, Croatia on the 10th – 13th September 2014. The stand had a lot of interest from the dental community with many eagerly anticipating commercialisation of the product and delivery device.
Dissemination of the project results will continue following the successful conclusion of the project and as the final products receives CE marking and subsequent launch onto the market.
In summary, the main beneficiaries for this research will be the SME partners, but in turn the EU medical device industry, academic sector, and patients will all also benefit greatly. Ultimately, the IMCOSS consortium anticipate clinical and market impact on an international scale from this project and will continue to work together to make further innovative developments capitalising on the platform technologies which form the exploitable results of this project.
List of beneficiaries and contact information:
Ceramisys Ltd.
914 Herries Road
Sheffield
South Yorkshire
S6 1QW. UK +441142327070
r.goodchild@ceramisys.com
Fluidinova SA
TECMAIA - Parque de Ciência e Tecnologia da Maia
Rua Engº Frederico Ulrich, 2650
4470-605 Moreira da Maia
Portugal
+351220119746
Hugo.Ramos@Fluidinova.com
Primequal SA
Rue des Pierres du Niton 17
CH-1207 Geneva
Switzerland
+41223540550
DWeill@Primequal.com
University of Sheffield
The School of Clinical Dentistry
University of Sheffield
19 Claremont Crescent
Sheffield
S10 2TA. UK
+441142717852
C.A.Miller@sheffield.ac.uk
Ludwig Boltzmann Institute
for Experimental & Clinical Traumatology
Donaueschingenstraße 13
A-1200 Vienna
Austria
+43133110464
Office@Trauma.lbg.ac.at
List of Websites:
A project website was set up to promote the project and can be found at the following link: www.imcoss.eu. The website contains the project logo and a link to the You-Tube video. The contact for the project is Dr Becci Goodchild, email: r.goodchild@ceramisys.com.