Periodic Reporting for period 2 - INTEGRATE (Personalised Medicine for Intervertebral Disc Regeneration- Integrating Profiling, Predictive Modelling and Gene Activated Biomaterials)
Reporting period: 2022-03-01 to 2023-08-31
Back pain is a global epidemiological and socioeconomic problem affecting up to 80% of people at some stage during their life and is believed to be due to degeneration of the intervertebral disc (IVD). In a European context, back/neck pain is the most prevalent representing 40% of participants in the European Social Survey (ESS). Annual costs for society are approximately €8k per chronic discogenic low back pain patient (CDP) comprising of 51% healthcare and 49% societal costs. Biomaterial and cell-based therapies have been pursued for the treatment of degenerated intervertebral disc (IVD), with a number of clinical trials underway. However, the degenerated intervertebral disc has a distinct environment (e.g. altered oxygen, glucose, acidity, inflammatory cytokine levels) that is unique to an individual (i.e. patient-specific) and will ultimately determine the likelihood and rate at which regeneration can occur. A “one size fits all” approach will lead to the failure to demonstrate efficacy of advanced therapies, as they are not being designed or personalised for individual patients. This proposal envisions a future whereby advanced gene activated cell therapies are personalised (targeting regeneration and modulating inflammation) to treat back pain based on knowing the individuals unique disc microenvironment. This will be achieved through profiling of individual patient disc microenvironmental factors, with in vitro screening and in silico modelling to design cell therapies and predict regeneration outcomes (Aim 1) combined with the development of tailored functionalised gene activated biomaterials (Aim 2), to enhance matrix formation and modulate the inflammatory processes (Aim 3). Gene-based therapy offers several advantages over direct delivery of proteins or small molecules, among them the possibility of sustained efficacy and endogenous synthesis of growth factors or suppression of inflammatory factors and pathways. The platform technology (personalised gene activated biomaterials to regulate regeneration and inflammation) and knowledge (tailoring cell therapies to suit patient-specific microenvironments) generated through this research are beyond the current state-of-the-art and will provide a significant transformative scientific and clinical step change opening new horizons in minimally-invasive therapeutic strategies.
Since the commencement of the ERC award in September 2020, the team has made significant progress in all three Aims.
AIM1: The first aim involves microenvironmental profiling, predictive screening, and in silico modeling. The work performed under this aim involves (1) obtaining human nucleus pulposus (NP) and annulus fibrosus tissue from patients undergoing discectomy procedures and animal tissues and (2) to determine the microenvironmental profile with respect to pH, glucose, oxygen, osmolarity, and cytokine presence within the tissue. A high throughput micro-spheroid culture system was developed to determine metabolic consumption rates and matrix synthesis rates of both NP and annulus fibrosus cells in a 3D configuration. In silico models were developed to predict the effect of cell injection on the disc microenvironment and matrix regeneration capacity. The results showed that regeneration is feasible in the rat within a 12-week timeframe and in the goat within a 12-month timeframe. Further, it predicts deterioration of a mildly degenerated Grade III disc over ten years without curative cell injection, while five million cells are necessary to prevent GAG content from diminishing further in the substantially larger human IVD.
AIM2: The second aim involves developing injectable gene-activated biomaterials to modulate regeneration and inflammation. Work performed under this aim involved screening several vectors for miRNA delivery and identifying suitable miRNA-activated cell types. A homing effect was observed when using the FLR-mediated nanoparticle delivery, which provides a promising approach for therapies of the intradiscal space. Work has also commenced to develop injectable miRNA-activated stem cell microcapsules and extracellular matrix hydrogels to modulate matrix synthesis and inflammation.
AIM: The third aim focuses on pre-clinical evaluation in a large animal model. The team have conducted substantial work in order to prepare for the large animal study, including characterising the lumbar discs of goats. This information is important in designing the animal study, as it will guide decisions regarding the assignment of lumbar levels, injectable treatment volumes, and cell doses relative to the native cell population. An ethics application for the large animal work is currently underway.
AIM1: The first aim involves microenvironmental profiling, predictive screening, and in silico modeling. The work performed under this aim involves (1) obtaining human nucleus pulposus (NP) and annulus fibrosus tissue from patients undergoing discectomy procedures and animal tissues and (2) to determine the microenvironmental profile with respect to pH, glucose, oxygen, osmolarity, and cytokine presence within the tissue. A high throughput micro-spheroid culture system was developed to determine metabolic consumption rates and matrix synthesis rates of both NP and annulus fibrosus cells in a 3D configuration. In silico models were developed to predict the effect of cell injection on the disc microenvironment and matrix regeneration capacity. The results showed that regeneration is feasible in the rat within a 12-week timeframe and in the goat within a 12-month timeframe. Further, it predicts deterioration of a mildly degenerated Grade III disc over ten years without curative cell injection, while five million cells are necessary to prevent GAG content from diminishing further in the substantially larger human IVD.
AIM2: The second aim involves developing injectable gene-activated biomaterials to modulate regeneration and inflammation. Work performed under this aim involved screening several vectors for miRNA delivery and identifying suitable miRNA-activated cell types. A homing effect was observed when using the FLR-mediated nanoparticle delivery, which provides a promising approach for therapies of the intradiscal space. Work has also commenced to develop injectable miRNA-activated stem cell microcapsules and extracellular matrix hydrogels to modulate matrix synthesis and inflammation.
AIM: The third aim focuses on pre-clinical evaluation in a large animal model. The team have conducted substantial work in order to prepare for the large animal study, including characterising the lumbar discs of goats. This information is important in designing the animal study, as it will guide decisions regarding the assignment of lumbar levels, injectable treatment volumes, and cell doses relative to the native cell population. An ethics application for the large animal work is currently underway.
• Gene activated (miRNA/siRNA) matrices (iGAMs) to upregulate glycosaminoglycan synthesis of stem cell microcapsules (Strategy 1) or suppress inflammatory cytokine production of resident nucleus pulposus cells in the disc (Strategy 2): We have successfully developed a dual mir strategy complexed with a novel cell penetrating peptide (CPP) to knock down inflammation in nucleus pulposus cells using in-vitro and ex-vivo models (Strategy 2). An unexpected result of this work was the homing ability of the FLR CPP, which we have identified as colocalising with COL VI, which is normally found in the pericellular region of the nucleus pulpous cells. This is an exciting finding for therapies of the intradiscal space, by directly target the cells and reducing off target effects. Despite these exciting results we believe more work can be done to upregulate matrix synthesis (Strategy 1) and our current and future work is focusing on specifically targeting Sox9 and ACAN to upregulate matrix formation, as well as developing complementary biomimetic biomaterials for delivery.
• In silico modelling of intradiscal cell delivery and matrix synthesis to predict regeneration: We have demonstrated using our first-generation diffusion reaction models the first-ever in silico models to simulate intradiscal cell delivery and matrix synthesis, which can predict regeneration effects in both animal and human discs. Our findings correlate favourably to the pre-clinical literature in terms of the capabilities of animal regeneration and predict that compromised nutrition is not a significant challenge in small animal discs. On the contrary, it highlights a very fine clinical balance between an adequate cell dose for sufficient repair, through de novo matrix deposition, without exacerbating the human microenvironmental niche. Our current work is focused on refining these models by profiling of microenvironmental factors from extracted human and animal disc tissue to determine how specific factors alter metabolism and matrix synthesis. By the end of this award, it is anticipated that we will have the first complete measurements of intradiscal microenvironmental factors in human discs. Ultimately, this work provides a platform to inform the design of clinical trials, and as computing power and software capabilities increase, it is conceivable that the future holds the generation of patient-specific models which could be used for patient assessment, as well as pre- and intraoperative planning.
• In silico modelling of intradiscal cell delivery and matrix synthesis to predict regeneration: We have demonstrated using our first-generation diffusion reaction models the first-ever in silico models to simulate intradiscal cell delivery and matrix synthesis, which can predict regeneration effects in both animal and human discs. Our findings correlate favourably to the pre-clinical literature in terms of the capabilities of animal regeneration and predict that compromised nutrition is not a significant challenge in small animal discs. On the contrary, it highlights a very fine clinical balance between an adequate cell dose for sufficient repair, through de novo matrix deposition, without exacerbating the human microenvironmental niche. Our current work is focused on refining these models by profiling of microenvironmental factors from extracted human and animal disc tissue to determine how specific factors alter metabolism and matrix synthesis. By the end of this award, it is anticipated that we will have the first complete measurements of intradiscal microenvironmental factors in human discs. Ultimately, this work provides a platform to inform the design of clinical trials, and as computing power and software capabilities increase, it is conceivable that the future holds the generation of patient-specific models which could be used for patient assessment, as well as pre- and intraoperative planning.