Dre Irizarry

Abstract 68: Deferoxamine Preconditioning of Irradiated Tissue Increases Fat Graft Volume Retention

PURPOSE: Inflammatory breast cancer (IBC) is an aggressive disease characterized by the formation of tumor emboli, rapid local invasion, and lymphatic dissemination. Furthermore, IBC rapidly develops therapeutic resistance and evades immune surveillance and attack. For these reasons, the treatment of inflammatory breast cancer is extremely challenging and new therapeutic approaches are needed. Numerous studies have shown that adipose derived stem cells (ASCs), which are abundant in breast tissue, are recruited to the tumor microenvironment where they influence tumor progression. We have previously demonstrated the feasibility of using nanoparticles in conjunction with ASCs in treatmentresistant breast cancer. In this study, we show that ASCs localize to IBC tumor emboli and can be used as a targeted delivery vehicle for cancer nanotherapeutics.

The Role of Skeletal Stem Cells in the Reconstruction of Bone Defects

Abstract Craniofacial surgery, since its inauguration, has been the culmination of collaborative efforts to solve complex congenital, dysplastic, oncological, and traumatic cranial bone defects. Now, 50 years on from the first craniofacial meeting, the collaborative efforts between surgeons, scientists, and bioengineers are further advancing craniofacial surgery with new discoveries in tissue regeneration. Recent advances in regenerative medicine and stem cell biology have transformed the authors’ understanding of bone healing, the role of stem cells governing bone healing, and the effects of the niche environment and extracellular matrix on stem cell fate. This review aims at summarizing the advances within each of these fields.

Cell-Based Soft Tissue Reconstruction in a Hydrogel Scaffold.

Background Renevia is a hyaluronin-gelatin crosslinked matrix scaffold that has been studied as an alternative to adipose transfer in soft tissue reconstruction. It is designed to emulate the native extracellular matrix environment by supporting stromal vascular fraction (SVF) cell attachment, survival, and proliferation, thus promoting cell-based volume restoration. However, the concentration of incorporated cells for a clinically relevant result has yet to be determined. Methods Five experimental groups of seven CD-1 nude immunodeficient mice were given 250 &mgr;L grafts of the following composition: 1 million human SVF cells per mL of Renevia scaffold, 6 million human SVF cells per mL scaffold, 12 million human SVF cells per mL scaffold, Renevia scaffold-alone or human adipose tissue–alone. Volumetric analysis was conducted at discrete time points over 16 weeks using 3-dimensional ultrasound, after which time the grafts were explanted for histologic analysis. Results At the conclusion of the study at week 16, the Renevia scaffold group incorporating the highest concentration of human SVF cells (12 million cells per mL scaffold) had significantly greater volume retention compared with the 2 lower concentrations, scaffold-alone and fat-alone groups. Histology of the 12 million scaffold group revealed abundant adipocyte formation within the scaffold, exceeding that observed in the 6 million, 1 million, and scaffold-alone groups. The 12 million group also demonstrated significantly increased vascularity per CD31 staining. Conclusions Stromal vascular fraction cells coupled with Renevia hydrogel scaffold can enhance soft tissue volume reconstruction. In this study, we observed the greatest effect with 12 million cells per mL. From the perspective of volume retention, incorporation of higher concentrations of SVF cells with Renevia may be an alternative to conventional adipose tissue grafting.