Engineered biomaterials for promoting lymphatic regeneration in lymphedema - PROJECT SUMMARY Lymphedema results from the underdevelopment or destruction of the lymphatic system, causing fluid and fat accumulation in the affected limb, immune imbalance, repetitive infections, and limb deformity. This condition severely compromises the patient's quality of life, functionality, and aesthetics. Over 35 million Americans and 150 million people worldwide suffer from lymphedema, making it a significant global healthcare issue. Vascularized lymph node transfer (VLNT) has emerged as a therapeutic treatment for patients, although currently less than half of patients treated with VLNT will have a therapeutically beneficial response to treatment. The primary goal of this research initiative is to integrate advanced biomaterials and targeted delivery of lipid nanoparticles into current lymphedema surgical procedures with the aim of augmenting lymphangiogenesis for enhanced lymphedema treatment. Various formulations of lymphangiogenic hydrogels, conjugated with either wild-type or mutant Vascular Endothelial Growth Factor-C (VEGF-C) targeting Vascular Endothelial Growth Factor Receptor-3 (VEGFR3), along with a specialized lymphatic-targeting lipid nanoparticle for delivery of VEGF-C mRNA, will be evaluated for their synergistic effects in ameliorating the consequences of vascularized lymph node transfer (VLNT) and mitigating lymphedema following lymph node dissection and irradiation. A rat hindlimb model of lymphedema induced by inguinal lymph node dissection and irradiation will facilitate this investigation due to its superior physiological relevance and disease persistence compared to mouse models of secondary lymphedema. Monitoring of limb volumetry, lymphatic function, and drug biodistribution throughout disease progression and therapeutic intervention will be conducted using techniques including iPhone volumetry, dual-wavelength near-infrared imaging, and isolated vessel biomechanics testing. This comprehensive study is structured around three specific aims: Aim 1 will evaluate lymphangiogenic hydrogels and their capacity to induce lymphangiogenesis and facilitate engraftment of transplanted lymph nodes into the host lymphatic vasculature. Aim 2 will assess the efficacy of the controlled release of vascular growth factors from the hydrogel to enhance its integration into the host lymphatic vasculature and restore lymphatic function without the need for a transplanted lymph node. Aim 3 will investigate the combined approach of mRNA delivery utilizing Lymphatic Endothelial Cell-targeting Lipid Nanoparticles (LECs-LNPs) and hydrogel to bolster lymphangiogenesis further, thereby augmenting the effectiveness of vascularized lymph node transfer and preventing lymphedema post- lymph node dissection and irradiation.
