Optimising Islet Transplantation With Vascularized Tissue Engineering Chambers
Funder
National Health and Medical Research Council
Funding Amount
$451,651.00
Summary
Diabetics have high blood sugar levels because cells in the pancreas known as islets produce too little of the hormone insulin. Most diabetics need daily insulin injections to maintain normal blood sugar levels. Transplanting islets is the most promising way to treat type 1 diabetes, but, apart from the obvious difficulty of rejection of foreign islets, several major problems remain: (1) there are insufficient pancreata (and therefore islets) for transplantation; and (2) the efficiency of delive ....Diabetics have high blood sugar levels because cells in the pancreas known as islets produce too little of the hormone insulin. Most diabetics need daily insulin injections to maintain normal blood sugar levels. Transplanting islets is the most promising way to treat type 1 diabetes, but, apart from the obvious difficulty of rejection of foreign islets, several major problems remain: (1) there are insufficient pancreata (and therefore islets) for transplantation; and (2) the efficiency of delivery of surviving islet transplants is too low. In pilot studies we have grown a new living pancreatic organ in mice by inserting islets from genetically-related mice together with a structural protein matrix, growth factors and blood vessels inside a plastic chamber. The blood vessels maintain nutrition to the islet cells and simultaneously allow insulin to be released into the bloodstream, thus normalising the high blood sugar in diabetics. In Aim 1 of these experiments we will find the optimal way to grow mature islets in blood vessel-containing chambers in diabetic mice, focusing on (a) the best time to add islets to the chamber - 0, 1 or 2 weeks after establishment, (b) the minimum number of islets to effectively normalise blood sugar and (c) how long we can keep islets alive and functional in chambers, examining periods up to 12 months. In Aim 2 we will test the ability of islet stem cells (provided by our co-investigators at Walter and Eliza Hall Institute, Melbourne) to survive in the chambers and to produce sufficient insulin to effectively lower blood sugar levels to normal in diabetic mice. In Aim 3 we will grow human islets in chambers in special diabetic mice that do not reject foreign tissue, in order to confirm similar behaviour of human islets in this controlled environment. Using this data, we hope to create a research model of functioning islets, that is accessible, retrievable and manipulable, for the further study of diabetes and transplantation.Read moreRead less
Evaluation A Novel Vitronectin:growth Factor Complex For Treatment Of Chronic Venous Leg Ulcers
Funder
National Health and Medical Research Council
Funding Amount
$854,975.00
Summary
Chronic leg ulcers in the elderly are an important problem, diminshing quality of life and costing at least A$1 billion per year. New treatments are urgently required. This study will test a new topical growth factor therapy designed to have greatly improved activity in wounds.The project is a collaboration between scientists and doctors at the Queensland Univeristy of Technology and the University of Western Australia. Many wound types may ultimately benefit from this treatment.
Developing In Vivo Methods Of Adipose Tissue Engineering
Funder
National Health and Medical Research Council
Funding Amount
$374,703.00
Summary
Surgical repair and replacement of soft tissues after tumour removal or to repair existing damage requires fat tissue with a good blood supply. Tissue engineering allows us to create new fat grafts for replacement tissue without causing unnecessary pain or trauma to the patient. We have developed a method for growing fat tissue using a chamber to maintain a space for the tissue to grow into, a blood vessel to supply nutrients to the growing tissue, cells or tissue from the host to encourage cell ....Surgical repair and replacement of soft tissues after tumour removal or to repair existing damage requires fat tissue with a good blood supply. Tissue engineering allows us to create new fat grafts for replacement tissue without causing unnecessary pain or trauma to the patient. We have developed a method for growing fat tissue using a chamber to maintain a space for the tissue to grow into, a blood vessel to supply nutrients to the growing tissue, cells or tissue from the host to encourage cell growth and migration and a matrix or scaffold to support the developing tissue and guide it to form the type of tissue we want (fat, muscle etc). We have shown that the tissue graft may cause fat to grow due to causing an inflammatory reaction and confirmed this by adding a mild inflammatory compound to the chamber instead of a tissue graft. This compound caused the chamber to grow fat tissue. The aim of this project is to determine which of the growth factors or other signaling factors released by the inflammation process is responsible for causing fat tissue production and to identify what cells are being attracted to the chamber to help grow the fat, so that we can further improve our engineering of fat tissue. Understanding the pathways which mediate or stimulate fat growth will provide new opportunities for improving fat growth and allow the engineering of larger fat grafts in larger animals and eventually human clinical application. Beyond that, inflammation is involved in many disease processes (eg. obesity, metabolic syndrome, diabetes, cancer), and these fields of study will also benefit from our research.Read moreRead less
GENERATION OF VASCULARISED, BIOENGINEERED SOFT TISSUES
Funder
National Health and Medical Research Council
Funding Amount
$445,045.00
Summary
One of the most exciting areas in reconstructive surgery today is the tissue engineering of body parts, the process by which blood vessels are implanted into skin, muscle, bone, cartilage or even synthetic materials, to build composite living structures. Once a circulation becomes established, the engineered part can be transferred by joining the implanted blood vessels to corresponding ones at the recipient site. We have discovered that new tissue will grow out of a surgically created blood ves ....One of the most exciting areas in reconstructive surgery today is the tissue engineering of body parts, the process by which blood vessels are implanted into skin, muscle, bone, cartilage or even synthetic materials, to build composite living structures. Once a circulation becomes established, the engineered part can be transferred by joining the implanted blood vessels to corresponding ones at the recipient site. We have discovered that new tissue will grow out of a surgically created blood vessel loop placed in a cylindrical plastic chamber filled with a scaffold made of naturally occurring structural molecules. In Part 1 of this project, it is planned to optimise the rate of new vascularised tissue growth through the addition to the growth chamber of various biodegradable scaffolds. In Part 2, we aim to produce fat by 3 possible methods using: (a) cells from the rat scrotum, (b) skeletal muscle separated from its blood supply for 24 hours, or (c) bone marrow-derived stem cells, as well as bone from stem cells of the same source. In Part 3, vascularised bone, fat and connective tissue, as produced in Part 2, will be microsurgically transferred to another site in the body to study the short-term (4 weeks) and long-term (12 weeks) survival and changes (if any) in these tissues. These unique methods are currently being patented. This technology introduces the possibility of producing tailor-made tissues of specific composition to suit the repair of a particular tissue type, for example, (1) myocutaneous flaps to replace tissue loss following traumatic injury, (2) bone for nose, digit or joint repair, and (3) fat to provide a bulky flap as required in contour defects of the face and neck. The development of new growth chambers of appropriate body shapes (eg. ears, noses, etc) has significant commercial implications.Read moreRead less
Optimizing Implanted Cell Survival Using A Tissue Engineering Model
Funder
National Health and Medical Research Council
Funding Amount
$589,175.00
Summary
Cell therapy and tissue engineering involve the insertion of specific cells into damaged tissues or into a bioraector in a patient's body to generate new replacement tissues. This project seeks to improve two factors associated with inserting cells : 1. The innate survival characteristics of the cells being inserted, and 2. The blood vessel supply at the site of insertion. These techniques will greatly improve the survival of inserted cells.
In Vivo Tissue Engineering Of Adipose Tissue For Reconstructive Surgery
Funder
National Health and Medical Research Council
Funding Amount
$713,545.00
Summary
We are able to grow vascularised tissue in implanted plastic chambers to a predetermined size and shape in the rat and mouse (NHMRC Project Grant 01-03; #145782; CIA Morrison). The basis of this growth is blood vessel sprouting from the surface of the vessel bundle or loop, followed by synthesis of structural molecules and the migration of surrounding cells into the vascularised network to form a stable tissue. Unlike other in vivo models of tissue engineering, the tissue grows spontaneously and ....We are able to grow vascularised tissue in implanted plastic chambers to a predetermined size and shape in the rat and mouse (NHMRC Project Grant 01-03; #145782; CIA Morrison). The basis of this growth is blood vessel sprouting from the surface of the vessel bundle or loop, followed by synthesis of structural molecules and the migration of surrounding cells into the vascularised network to form a stable tissue. Unlike other in vivo models of tissue engineering, the tissue grows spontaneously and is densely vascularised, enabling continuous growth and surgically transfer to another part of the body, or to another animal. In this renewal application of the above NHMRC grant, we propose to direct these findings towards the development of vascularised fat tissue which would be ideal for reconstructive surgery as a stable, inert tissue filler. Our efforts to grow fat tissue in vivo to date have identified 4 major requirements: a fat precursor cell source; an instructive basement membrane matrix (which may include growth-differentiation factors); space into which the tissue can grow; a stable blood supply. We will focus here on optimising the precursor cell source and instructive matrix to generate vascularised fat tissue around the blood supply we can engender in our tissue engineering chamber. We have found Matrigel, a mouse tumor-derived matrix rich in basement membrane components, to be instructive for growing fat, and will also build on preliminary observations that either muscle or fat tissue can provide the appropriate precursor cells for this process. Finally we propose to adapt and upsize the vascularised fat tissue chamber to the pig, in a step towards human use, and assess its transplantability and longevity. The clinical application of our work is to produce breast reconstruction tissue and lipo filling for contour deformities resulting from trauma, congenital deformity, ageing and cancer surgery, particularly breast reconstruction.Read moreRead less
Understanding The Mechanisms Of Development And Treatment In Hydrocephalus.
Funder
National Health and Medical Research Council
Funding Amount
$395,914.00
Summary
This project aims to investigate the progressive change in cerebrospinal fluid dynamics, axonal damage and tissue mechanical properties during the development and treatment of hydrocephalus in-vivo. Results from this study is important to elucidate the mechanisms of hydrocephalus and to improve treatment and diagnosis of hydrocephalus.
Improved Ex-vivo Culture Of Keratinocytes For Clinical Applications
Funder
National Health and Medical Research Council
Funding Amount
$275,203.00
Summary
Skin cells grown for clinical applications currently require animal-derived cells and-or non-defined products for their expansion in the laboratory; these reagents can potentially infect patients who receive these therapies. This project will identify the essential components provided by these reagents and develop a fully synthetic and defined culture system. This improvement will provide safer, cost-effective grafts and cell-based therapies that will benefit patients suffering burns and wounds.