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
Reevaluation Of The Anatomy Of The Human Lymphatic Vessel Network
Funder
National Health and Medical Research Council
Funding Amount
$539,750.00
Summary
The mode of spread of cancer cells from a primary tumour to other parts of the body is still not completely understood, although the lymphatic system is known to be important in this process. Lymph vessels are tiny transparent channels that form a network over the entire body. They transport tissue fluid to regional lymph glands in the neck, armpits, groin, chest and abdomen where the immune response maybe initiated to combat foreign agents such as bacteria and cancer cells. Current knowledge of ....The mode of spread of cancer cells from a primary tumour to other parts of the body is still not completely understood, although the lymphatic system is known to be important in this process. Lymph vessels are tiny transparent channels that form a network over the entire body. They transport tissue fluid to regional lymph glands in the neck, armpits, groin, chest and abdomen where the immune response maybe initiated to combat foreign agents such as bacteria and cancer cells. Current knowledge of the anatomy of these tiny vessels is based on work done by Sappey more than a century ago. There is an urgent need to update this work as many of his conclusions have been found to be inaccurate. We will use our pioneering methods of microsurgical tissue transfer- now being used worldwide - and our extensive experience in delineating fine channels, to address some of the basic questions about the anatomical pathways of spread of cancer. We hope to discover for example: why cancer on one side of the back can spread to glands in the opposite groin or armpit, thought by Sappey to be impossible; why cancer on one side of the tongue can spread to lymph glands on the opposite side of the neck; and why there is sometimes swelling of the limbs following lymph gland ablation by surgery or radiotherapy of glands in the groin or armpit. Currently it is thought that the only major connections with the venous system are at the base of the neck. Our initial work has shown unexpected connections with blood vessels in the periphery and unreported lymphatic vessel pathways between the skin and deep tissues. The results of this research will give information that will aid in localizing and treating the spread of malignancies and will underlie future treatment of obstructed lymph vessels that are the cause of painful, disabling swelling (lymphoedema) of the limbs.Read moreRead less
The Sentinel Lymph Node Territories Of The Whole Body And Their Clinical Implications: A Human Cadaver Study
Funder
National Health and Medical Research Council
Funding Amount
$602,984.00
Summary
Lymph gland screening with isotopes (Lymphoscintigraphy) has revealed unexpected pathways of cancer spread. This study, using an X-ray injection technique in human cadavers, is re-evaluating the outdated Melways Roadmap of lymph vessel pathways. The aims are to give accurate predictions of cancer spread, explain unusual clinical manifestations and to provide a new method of treating lymphoedema, the incapacitating swelling of limbs that may complicate lymph gland surgery or radiotherapy.
Acute pancreatitis is an acute abdominal inflammatory process (the pancreas attempts to digest itself) with significant mortality in those patients having the severe form of the disease. The commonest causes of the disease are gallstones and excessive alcohol consumption. Approximately 80% of patients with acute pancreatitis recover, but 20% experience the severe form of the disease. In severe pancreatitis, 30% of patients die. Severe pancreatitis is associated with necrosis (cell death) of the ....Acute pancreatitis is an acute abdominal inflammatory process (the pancreas attempts to digest itself) with significant mortality in those patients having the severe form of the disease. The commonest causes of the disease are gallstones and excessive alcohol consumption. Approximately 80% of patients with acute pancreatitis recover, but 20% experience the severe form of the disease. In severe pancreatitis, 30% of patients die. Severe pancreatitis is associated with necrosis (cell death) of the pancreas which, results from reduced blood flow in the organ. This reduced blood flow may be secondary to increased pressure in the pancreatic duct following occlusion of the duct. Preliminary studies suggest that the reason why the pancreas may be susceptible to necrosis is the anatomical arrangement of its blood supply, being made up of many end arterioles (very small arteries) that do not connect with other arteries. The consequence of this arrangement is that if a particular end arteriole becomes blocked, the area of the tissue cannot obtain a blood supply from neighbouring arterioles (as in other organs). Blood supply is partly controlled by nerves. The nerve transmitter nitric oxide is one of the major chemicals involved in this regulation. Nitric oxide also regulates the pressure in the pancreatic duct by acting on the sphincter of Oddi, situated at the opening of the pancreatic duct. Consequently, the action of nitric oxide during pancreatitis may be crucial to the development of the severe disease. This proposal seeks to define the blood supply of the pancreas, its regulation, the effect that increased pancreatic duct pressure has on it and the role that nitric oxide plays in this. If the hypotheses regarding the role of nitric oxide on pancreatic blood flow is proven, then drugs which influence nitric oxide levels can be used to limit the production of pancreatic necrosis. In turn, such an effect will reduce the mortality and morbidity of acute pancreatitis.Read moreRead less