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Sefton, M. V.

Publications and source records attributed to Sefton, M. V..

2 recordsLinked to original sources

Methacrylic acid-based biomaterials promote peripheral innervation in the subcutaneous space of mice

Peripheral nerve innervation is essential for regulating tissue repair and regeneration. MAA-based biomaterials have been previously shown to promote angiogenesis. Here we show a new role for MAA-based biomaterials in promoting terminal axon nerve growth. Our results demonstrate that MAA-based biomaterials promote peripheral nerve growth in an Igf-1 and Shh dependent manner. The resulting nerves increased the sensitivity of treated mice paws to nociception. iDISCO clearing showed that MAA increased the presence of peripheral nerve structures in whole explants. MAA was also able to increase the expression of key neuronal markers and growth factors in a peripheral neuropathy model, the diabetic db/db mouse, suggesting that MAA-based biomaterials may be relevant to treatment of peripheral neuropathy. Moreover, in a peripheral neuropathy model, MAA was able to up-regulate the expression of growth factors for an extended duration suggesting MAA may prevent degeneration through an effect on factors that promote survival. As all tissues are innervated, MAA-based biomaterials could have broad applications in the promoting regeneration and preventing degeneration of peripheral nerves. HIGHLIGHTSO_LIMethacrylic acid-based biomaterials promote axon growth in-situ without exogenous growth factors or cells C_LIO_LIMethacrylic acid-based biomaterial induced terminal axon growth displays nociception, an indicator of functional outgrowth C_LIO_LIMethacrylic acid-based biomaterials terminal axon growth is Igf-1 and Shh driven C_LI

bioengineering↗

A scalable device-less biomaterial approach for subcutaneous islet transplantation

The subcutaneous space has been shown to be a suitable site for islet transplantation, however an abundance of islets is required to achieve normoglycemia, often requiring multiple donors. The loss of islets is due to the hypoxic conditions islets experience during revascularization, resulting in apoptosis. Therefore, to reduce the therapeutic dosage required to achieve normoglycemia, pre-vascularization of the subcutaneous space has been pursued. In this study, we highlight a biomaterial-based approach using a methacrylic acid copolymer coating to generate a robust pre-vascularized subcutaneous cavity for islet transplantation. We also devised a simple, but not-trivial, procedure for filling the cavity with an islet suspension in collagen. We show that the pre-vascularized site can support a marginal mass of islets to rapidly return streptozotocin-induced diabetic SCID/bg mice to normoglycemia. Furthermore, immunocompetent Sprague Daley rats remained normoglycemia for up to 70 days until they experienced graft destabilization as they outgrew their implants. This work highlights methacrylic acid-based biomaterials as a suitable pre-vascularization strategy for the subcutaneous space that is scalable and doesn’t require exogenous cells or growth factors.Summary In this study methacrylic acid copolymer coated tubes generated a robust vascular response in the subcutaneous space, which was critical to support islet transplantation in a streptozotocin-induced diabetic mouse model. More importantly, the subcutaneous pre-vascularization approach using this copolymer coating was scalable into a larger allogeneic rat model and returned animals to normoglycemia for up to 70 days. This platform highlights the potential of a scalable biomaterial approach for pre-vascularization of the subcutaneous space in larger animal models.Competing Interest StatementThe authors have declared no competing interest.View Full Text

bioengineering↗