Optimized Manufacture of Lyophilized Dermal Fibroblasts for Next-Generation Off-the-Shelf Progenitor Biological Bandages in Topical Post-Burn Regenerative Medicine

Cultured fibroblast progenitor cells (FPC) have been studied in Swiss translational regenerative medicine for over two decades, wherein clinical experience was gathered for safely managing burns and refractory cutaneous ulcers. Inherent FPC advantages include high robustness, optimal adaptability to industrial manufacture, and potential for effective repair stimulation of wounded tissues. Major technical bottlenecks in cell therapy development comprise sustainability, stability, and logistics of biological material sources. Herein, we report stringently optimized and up-scaled processing (i.e., cell biobanking and stabilization by lyophilization) of dermal FPCs, with the objective of addressing potential cell source sustainability and stability issues with regard to active substance manufacturing in cutaneous regenerative medicine. Firstly, multi-tiered FPC banking was optimized in terms of overall quality and efficiency by benchmarking key reagents (e.g., medium supplement source, dissociation reagent), consumables (e.g., culture vessels), and technical specifications. Therein, fetal bovine serum batch identity and culture vessel surface were confirmed, among other parameters, to largely impact harvest cell yields. Secondly, FPC stabilization by lyophilization was undertaken and shown to maintain critical functions for devitalized cells in vitro, potentially enabling high logistical gains. Overall, this study provides the technical basis for the elaboration of next-generation off-the-shelf topical regenerative medicine therapeutic products for wound healing and post-burn care.

Micellar Hyaluronidase and Spiperone as a Potential Treatment for Pulmonary Fibrosis

Concentration of hyaluronic acid (HA) in the lungs increases in idiopathic pulmonary fibrosis (IPF). HA is involved in the organization of fibrin, fibronectin, and collagen. HA has been proposed to be a biomarker of fibrosis and a potential target for antifibrotic therapy. Hyaluronidase (HD) breaks down HA into fragments, but is a subject of rapid hydrolysis. A conjugate of poloxamer hyaluronidase (pHD) was prepared using protein immobilization with ionizing radiation. In a model of bleomycin-induced pulmonary fibrosis, pHD decreased the level of tissue IL-1β and TGF-β, prevented the infiltration of the lung parenchyma by CD16+ cells, and reduced perivascular and peribronchial inflammation. Simultaneously, a decrease in the concentrations of HA, hydroxyproline, collagen 1, total soluble collagen, and the area of connective tissue in the lungs was observed. The effects of pHD were significantly stronger compared to native HD which can be attributed to the higher stability of pHD. Additional spiperone administration increased the anti-inflammatory and antifibrotic effects of pHD and accelerated the regeneration of the damaged lung. The potentiating effects of spiperone can be explained by the disruption of the dopamine-induced mobilization and migration of fibroblast progenitor cells into the lungs and differentiation of lung mesenchymal stem cells (MSC) into cells of stromal lines. Thus, a combination of pHD and spiperone may represent a promising approach for the treatment of IPF and lung regeneration.

Abstract 360: IL-10-inhibits Pressure Overload-induced Homing, Proliferation And Differentiation Of Non-resident Fibroblast Progenitors And Improve Heart Function.

Background: Recently we have shown that IL-10, an anti-inflammatory cytokine, markedly inhibited the pressure overload-induced cardiac fibrosis, however, antifibrotic mechanisms of IL-10 are largely unknown. In most of organs, including heart, extracellular matrix (ECM) remodeling is primarily mediated by excessive proliferation of activated fibroblasts and myofibroblasts. Here we hypothesized that IL-10 inhibits stress-induced homing, proliferation and differentiation of nonresident bone marrow-derived fibroblast progenitor cells and therefore, attenuates cardiac remodeling and improves of heart function. Methods and Results: Cardiac hypertrophy was induced in Wild-type (WT) and IL-10-knockout (KO) mice by transverse aortic constriction (TAC). TAC-induced left ventricular (LV) dysfunction and fibrosis were further exaggerated in KO mice compared to WT. TAC significantly increased TGF-β, collagen Iα and IIIα genes expression. Systemic recombinant mouse IL-10 administration markedly improved LV function, inhibited TAC-induced cardiac fibrosis and fibrosis associated genes expression. To identify the role of fibroblast progenitor cells (FPCs), we measured the mobilization of FPCs (Prominin1 positive cells) from bone marrow to heart by FACs. Exacerbated mobilization of FPCs in peripheral blood and heart in IL-10 KO mice were found 3 and 7 days after aortic constriction. Bone marrow transplantation experiments were performed where WT-GFP positive marrow was transplanted in BM depleted IL-10 KO mice. TAC-induced mobilization was significantly reduced in WT-transplanted marrow as compare to TAC-IL-10 KO mice. To identify the role IL-10 on TGFβ-induced endothelial cells trans-differentiation to myofibroblasts, we treated aortic endothelial cells with IL-10 and TGFβ2 for 96 hrs. Both Immunocytochemistry and Western blot analysis results suggested that TGF-β2-induced EndMT was significantly inhibited by IL-10 treatment. To understand the mechanisms, we found that TGF-β2-induced Notch1 signaling was reduced by IL-10. Conclusion: Taken together our observations suggest that the anti-fibrotic effects of IL-10 treatment are mediated by reduced proliferation and differentiation of non-resident myofibroblasts.