An injectable, self-assembled multicellular microsphere with the

incorporation of fibroblast-derived extracellular matrix for therapeutic

angiogenesis

Ping Du1, 2, Avelino Dos Santos Da Costa2, Cininta Savitri2, 3, Sang Su Ha2, 3, Peng-Yuan Wang1 and

Kwideok Park2,3 *

1Center for Human Tissues & Organs Degeneration, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China

2Center for Biomaterials, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea

3Division of Bio-Medical Science and Technology, KIST School, University of Science and Technology (UST), Seoul 02792, Republic of Korea

Running title: Multicellular microsphere with bioactive materials for ischemia therapy

Submitted to Materials Science and Engineering: C

*Correspondence: Kwideok Park, Ph.D.E-mail: kpark@kist.re.kr

Tel: +82-2-958-5288Fax: +82-2-958-5308

December 2019

Fig.S1. HUVECs/MSCs ratio effect on vasculature formation in 3D hydrogel. Images of

capillary-like structure (CLS) at different magnification. Scale bar in A, B and C is 500, 200, and 200

µm, respectively. Red is PKH-26 labeled MSCs, while green is GFP labeled HUVECs. Quantitative

comparison of CLS occupied area with different cell ratios (D). Statistically significant difference

is indicated as *(p<0.05), **(p<0.01) or ***(p<0.001), respectively.

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Fig. S2. Multicellular microspheres fabrication in collagen hydrogel. The mixtures of

HUVECs/MSCs in Col (20 µL) with or without the incorporation of hFDM are dropped on

petri-dish, which form sphere shapes after cultivation for 1 day. Phase-contrast images show

cells are homogeneously dispersed in hydrogel upon preparation (left), and cells condense to

cell aggregates (right) in hydrogel after 1 day (A). Scale bar is 100 µm. The size of Col and

Col/hFDM microsphere is reducing over time (B), and the diameter of Col and Col/hFDM is

quantitatively compared at different time points (C). Scale bar is 500 µm. Two-tailed student t

test show that there is no significant different with the diameter between Col and Col/hFDM

microsphere.

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Fig. S3. Characterization of Col-based constructs with different compositions. Gross images

of Col, Col/hFDM (Col mixed with hFDM), Col/HUVECs (HUVECs cultured in Col),

Col/MSCs (MSCs cultured in Col), Col/HUVECs/MSCs (HUVECs and MSCs cocultured in

Col), and Col/hFDM/HUVECs/MSCs (HUVECs and MSCs cocultured in Col/hFDM) at day

0 and 3 (A). Scale bar is 5 mm. Compression modulus of different construct at day 3 (B).

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Fig. S4. Vasculature formation of HUVECs in Col/Fibrin hydrogel with the coculture of MSCs.

GFP-HUVECs (Green) and PKH-MSCs (labelled with a cell tracker, PKH-26, red) mixed at a cell

ratio of 4:1 and cocultured in Col/Fibrin for 5 days. Scale bar is 200 µm.

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