The O’Brien laboratory is interested in developing new regenerative therapeutic approaches for the treatment of diabetic complications. He is specifically interested in the use of advanced therapy medicinal products (ATMPs), which may include a combination of cell therapy products, such as mesenchymal stromal cells (MSCs)genetic engineering products (viral and non-viral), tissue engineering products (biomaterials/scaffolds), tissue architecture techniques (3D bioprinting) and/or medical devices.  

In parallel with the translational research program, work is ongoing in collaboration with other REMEDI scientists to develop GMP-compliant manufacturing strategies to fabricate these complex products. The ultimate goal is to bring laboratory based pre-clinical research to early phase clinical trials and/or ATMP commercialization for conditions of unmet medical need in a short-termThe complete infrastructure and network collaboration to enable this translation has been developed in Galway including research laboratories, pre-clinical testing facilities, a stem cell acquisition capacity, a GMP cell manufacturing centre and a clinical research facility. This work is done in close partnership with the Saolta University Healthcare group in Galway University hospital.  

Specific research projects undertaken at the O’Brien’s lab are outlined below. 

Cell Therapy Products 

MSC Therapy for CLIDr Aaron Liew and Dr Mikey Creane developed the pre-clinical data set which populated the regulatory dossier for a phase 1b clinical trial of MSCs in patients with no-option critical limb ischaemia (CLI).  Dr Sara Mohamed led on patient recruitment and oversaw the clinical trial. This was also accomplished with Professor Stewart Walsh and Professor MuhammaTubassam. Sara is completing her PhD project in which she has also focused on the characteristics of MSCs isolated from patients with CLI.

MSC Therapy for Muscle Regeneration in CLI: We have shown that MSC therapy results in accelerated skeletal muscle regeneration after hind limb ischemia injury. We observed larger muscle fibres and increased muscle mass, as well as reduced muscle inflammation, fibrosis, necrosis, and inter-muscle fat infiltration after MSC delivery. Dr Clara Sanz leads this research in collaboration with Dr Kasia Whysall with a goal of understanding the mechanisms of action by which MSCs enhance skeletal muscle regeneration after muscle ischemic injury.

Histological assessment of ischemia damage in skeletal muscle after MSC therapy or saline. Skeletal muscle treated with saline presented with widely spread inflammatory cell infiltration (H&E Stain) accompanied with a significant loss of muscle fibre integrity, muscle fibrosis and necrosis. Fibrosis is clearly observed as large areas of blue stained fibrillar material (collagen fibres), while necrotic cells are observed as large or swollen muscle cells stained in purple (Malory’s trichrome stain). Muscle ischemia damage gradually resolves towards baseline appearance (i.e. healthy tissue) after MSC treatment, where larger muscle fibres similar to those found in healthy muscle are observed, with centralized nuclei still present as a sign of muscle regeneration. Image author: Clara Sanz.   

MSC Therapy for Individual Diabetic Complications: This work includes the development of cell therapy products for the treatment of diabetic complications. Professor O’Brien coordinated an EU consortium, REDDSTAR, which explored the used of MSCs in a number of diabetic complications including nephropathy, neuropathy, diabetic foot ulcers, cardiomyopathy, retinopathy and osteopathy. This work has led to 2 clinical trials in Diabetic Foot Ulcers undertaken in Copenhagen and Diabetic Nephropathy with centres in Ireland, the UK and Italy. The latter project has resulted in an EU consortium, NEPHSTROM, also led by Professor O’Brien. The work on diabetic osteopathy is being continued by Dr Cindy Coleman, who is now a Lecturer in Medicine at NUI Galway and a PI in the REMEDI group.  

Website link: 


MSC Therapy for Multiple Diabetic Complications: Professor O’Brien, together with Professor Jun Ma and Dr Yan Liu, is supervising 2 PhD students in Hebei Medical University. Boxin Liu and Jingjing He  projects focus on the possibility of using umbilical cord-derived MSCs to treat multiple diabetic complications simultaneously, including nephropathy, retinopathy and cardiomyopathy. This work may lead to clinical trials of MSCs in patients with multiple diabetic complications, with an emphasis on the commonly occurring diabetic nephropathy and retinopathy. They will also be exploring the mechanism of action of MSCs in these disease states.       

ECFC and MSC Combinatorial Therapy for CLI: SFI have funded a programme on the development of combinatorial cell therapy approaches for CLI. This is a collaborative project with Professor Alan Stitt in Queens University Belfast. Both laboratories have worked together on the pathophysiology of endothelial progenitor cell dysfunction. By understanding the mechanism of such dysfunction, novel therapeutic approaches to CLI may be developed. Endothelial colony forming cells (ECFCs), the so-called true endothelial progenitor, are being isolated from patients with diabetes mellitus and/or vascular complications such as CLI. Dr Nadeem Soomro work focuses on characterizing the cells obtained from these patients towards establishing a potential disease stratification. Basic research on the mechanism of dysfunction is being undertaken by PhD student, Caomhán Lyons. This project is led by Dr Mikey Creane, who is developing a combinatorial cell therapy using ECFCs and MSCs isolated from umbilical cord blood and tissue. Yaqiong Liu, who is funded by a China Scholarship Council award, will work on the mechanisms of ECFC dysfunction in diabetes mellitus.

Peripheral blood derived endothelial colony forming cells (ECFCs) isolated from healthy age matched (A) and diabetic CLI (B) patients at day 14 post isolation displaying the characteristic colony cobblestone morphology indicative of ECFCs. Our results indicate that ECFCs can be successfully isolated at high efficiency from diabetic critical limb ischaemia (CLI) patients, in spite of the literature demonstrating high ECFC isolation failure from the peripheral blood of patients. Successful isolation of ECFCs from diabetic CLI patients will facilitate the investigation of the dysfunction of ECFCs from diabetic CLI patients for the development of a much needed modified cell therapy for these patients. Scale = 500µm. Image author: Caomhán Lyons. 

MSC Therapy for Renal Ischaemia-Reperfusion Injury. Professor O’Brien is supervising a Marie-Curie PhD student, Sandra Calcat i Cervera, who is working within the RenalToolBox ITN network to develop novel therapeutic strategies for kidney disease with a specific focus on cell-based therapies using MSCs. The goal of this project is to compare and characterise MSC from different tissue sources – including bone marrow, adipose tissue and umbilical cord – and their therapeutic efficacy in renal ischaemia reperfusion injury. 

Genetic Engineering & Cell Therapy Products  

Genetic Modification of MSC for CLI: The O’Brien laboratory has been interested in  augmentation of cell therapy using viral and non-viral genetic modification strategies, and has published a number of papers describing these strategies. Professor O’Brien is working with Dr Linda Howard, Lecturer in Medicine, on the use of adenoviral and lentiviral vectors to overexpress specific proteins. Dr Clara Sanz, currently funded by an SFI Industry Fellowship with Orbsen Therapeutics Ltd., is working on lentiviral mediated gene delivery to MSCs to enhance angiogenic and anti-inflammatory potential for application in CLI.

miRNA modification of MSCs for CLI: This work is being done in collaboration with Kasia Whysall, Senior Lecturer in Physiology. The goal of this project is to modify MSCs with specific miRNA to alter the biological properties of MSCs,  and/or to use the cell as a delivery system for the miRNA which may be delivered as part of the secretome, or packaged in exosomes. PhD student Alan Keane, who is funded by IRC, is doing this work. The aim of this research is to develop a pleiotropic therapy with capabilities of muscle regeneration, anti-inflammation and pro-angiogenesis. 

Tissue Engineering & Cell Therapy Products

Biomaterial and MSC Therapy Combinations for CLI:  This work is done in collaboration with Professor Abhay Pandit. Dr Dilip Thomas has previously demonstrated enhanced angiogenic paracrine response when combining MSCs with 3D collagen microgels. This work has been translated to pre-clinical CLI models and published. We are continuing to progress this strategy to develop a high throughput, scalable, miniaturized, GMP-compliant cell-gel construct using bioprinting technologyPhD student Dulan Jayasooriya, who is funded by IRC, is currently doing this work.

Brightfield microscope images of 3D-collagen microgel-cell platform at 1h post fabrication (A) and 28 days post fabrication (B). Confocal microscopy image showing >97% viable umbilical cord derived MSCs after 28 days of culture. Calcein (green) stains for live cells and Ethidium homodimer (red) stains for dead cells. Image authorDulan Jayasooriya. 

Tissue Engineering Using MSCs Manufactured Under Macromolecular Crowding Conditions for Diabetic Foot Ulcers: This work is done in collaboration with Professor Dimitrios Zeugolis who has developed a macromolecular crowding technology to enhance extracellular matrix deposition by MSCs. PhD student Shanshan Du has been leading on this project, which is funded by SFI as part of CURAM. The goal is to develop a therapeutic construct composed of MSCs cultured under macromolecular crowding conditions in a collagen scaffold, which will be taken to clinical trials for the treatment of diabetic foot ulcers as part of CURAM2. 

Umbilical cord-derived MSCs cultured with (A) or without (B) macromolecular crowding (MMC) conditions. MMC treatment enhanced collagen type I deposition in hUC-MSCs after 7 days in culture. Collagen type I: red. Nuclei: blue. Image Author: Shanshan Du.

Bioprinting of Cell-Gel Constructs for Use in the Treatment of Diabetic Foot Ulcers: Professor O’Brien is PI on a recently awarded Collaborative Doctoral Award from the Health Research Board. There are 6 PhD students working on the prevention and treatment of diabetic foot disease. Professor O’Brien is supervising a PhD student, Isha Sikri, along with Professor Caroline McIntosh, Gerard O’Connor and Yury Rochev. The goal of this project is to develop a bioprinted collagen-cell combination for the treatment of diabetic foot ulcers. 

Other Projects

iPS Derived Beta Cells and Transplantation: While the majority of research in the laboratory is focused on regenerative approaches for diabetic complications the PI is also interested in iPS derived beta cell lines for transplantation in collaboration with  Professor Garry Duffy, who leads this programme. 

iPS Derived Reporter Cell Lines for Drug Discovery:  Professor O’Brien and Professor Sanbing Shen with colleagues in the Nanjing University of Chinese Medicine established The Confucius Institute of Chinese and Regenerative Medicine. The goal of this programme is to undertake research in drug discovery from Chinese Medicine Products. Reporter cell lines will be derived using genome editing for beta cells, neurons and cardiomyocytes. The Chinese Director of this programme is Professor Guangming Yang.   

Please see here for research publications.


  • Science Foundation Ireland (SFI)
  • European Research Council (ERC)
  • Irish Research Council (IRC)
  • Health Research Board (HRB)
  • Enterprise Ireland (EI)
  • Galway University Foundation (GUF)
  • EU Marie Skłodowska-Curie actions