Angiogenic biomaterials for cell delivery

• The subcutaneous space has been pursued as an alternative site for islet transplantation, however hypoxic conditions experienced during revascularization has resulted in islet loss.

• To reduce the therapeutic dosage, we highlight a biomaterial-based approach using a methacrylic acid copolymer coating to generate a robust pre-vascularized subcutaneous cavity for islet transplantation.

• In addition, we devised a simple, but not-trivial, procedure for filling the cavity with an islet suspension in collagen.

• We showed that the pre-vascularized cavity supported a marginal mass of islets in pre-clinical diabetic models of mice and rats.

For more information, check out our 2021 publication in Biomaterials.

• Here we report the preparation of a semi-interpenetrating polymer network (SIPN), and its evaluation as an injectable carrier to deliver cells and generate blood vessels in a subcutaneous implantation site.

• The SIPN was prepared by reacting a blend of vinyl sulfone-terminated polyethylene glycol (PEG-VS) and sodium polymethacrylate (PMAA-Na) with dithiothreitol.

• SIPN containing 20 mol% PMAA-Na generated a vascular network in the surrounding tissues, with 2–3 times as many vessels as was obtained with 10 mol% PMAA-Na or PEG alone.

• Using a streptozotocin-induced diabetic mouse model we validated the potential to use SIPN to deliver pancreatic islets into the subcutaneous space and return them to normoglycemic levels.

• Furthermore, transplanted islets were revascularized and reinnervated by day 70 in host-derived subcutaneous tissues.

For more information, please read our 2017, 2022, and 2023 work in Biomaterials.