Engineering and Biobanking of Adipose Stem Cells Derived Exosomes as a Precision Therapeutic Platform for Diabetic Wound Healing

Current trends in cell therapy of wound healing, adipose stem cells (ASCs) represent an alternative source of pluripotent cells with advantages including ease of isolation, relative abundance, rapidity of expansion. This, coupled with issues related to cellular antigenicity, mutagenicity, oncogenicity, and poor engraftment, has prompted us to explore cell-free therapy for wound healing Exosomes are vesicles secreted by cells in response to certain stimuli which contain multiple substances including growth factors, proteins and mRNAs. They have a major advantage when used therapeutically in that they do not contain the similar antigens expressed by cells when secreted. They yet contain the benefits of the cells purified in a more potent fashion for maximum clinical effectiveness. Discovery of exosomes of different stem cells capable of instigating cell analogous response in target cells may provide a promising alternative for wound regeneration. In cell-based therapy, we have used fibrocyte, the progenitor cell of fibroblasts, to enhance diabetic wound healing (Kao HK et al. Ann Surg. 2011). We also prove pulsed radiofrequency could accelerate diabetic wound healing via wound contraction (Kao HK et al. PRS. 2013 & PRS. 2011). In micromechanical force to improve wound healing, our group found the external volume expansion could modulate vascular growth (Kao HK et al. Sci Rep. 2016). In multi-modality treatment, fat grafting combined with negative wound treatment device can enhance bone-exposed wound healing (Kao HK et al. Br J Surg 2015 & PRS. 2017). In exosome to improve fat retention, we found that exosomes are comparable to source adipose stem cells in fat graft retention with up-regulating early inflammation and angiogenesis (PRS. 2019). Based on our preliminary experimental results, exosomes derived from ASCs of db/+ mice (normal littermates of db/db mice) can enhance diabetic healing via cell proliferation, contraction, and angiogenesis. However, we found that diabetes impairs the angiogentic potential of adipose stem cells in a diabetic wound healing model. Investigating methods of increasing exosome production or increasing the specific components in exosome contents through the modification or engineering of ASC-exosomes may provide a novel strategy in wound healing. With the emerge of personalized regeneration medicine, exosome can be used as an advantageous therapeutic target and as an effective delivery vehicle. The purposes of this 3-year proposal are as followed: (1) (1st year) Investigate the mechanism of action of diabetic wound healing and the affected growth factors between db/db mice ASCs derived-exosomes, db/+ mice ASCs-derived exosomes, and control (PBS) group by using immunohistochemistry stain (Ki67 and CD31), western bloting, and Q-PCR. (2) (2nd year) Find the potential deficient protein associated with impaired diabetic wound healing. Use next generation sequence and cytokine array techniques to characterize the db/db- or db/+ ASC-Exo cargo biomolecules (miRNA or protein) and generate the specific miRNA or protein (associated with angiogenesis) overexpressing cell line using transfected adipose stem cells. (3) (3rd year) Test the wound healing rate of the specific miRNA or protein containing exosomes of adipose stem cells in a diabetic mice model and to explore the mechanism of action.

Project ID:PC10908-0050
External Project ID:MOST109-2314-B182-022