# 820 Photocrosslinkable Acellular Dermal Matrix Bioink Promotes Beneficial Cellular Behavior and Wound Healing

## TL;DR

A new bioink combining acellular dermal matrix and GelMA improves wound healing by promoting cell behavior and tissue regeneration.

## Contribution

A novel ADM-GelMA bioink is developed to enhance printability, mechanical strength, and cytocompatibility for 3D bioprinting applications.

## Key findings

- The ADM-GelMA bioink showed better swelling ratio and printability compared to pure ADM or GelMA.
- In vivo experiments showed faster wound closure with the ADM-GelMA bioink compared to controls.
- The bioink supported higher cell proliferation and preserved key ECM components like collagen I and III.

## Abstract

Bioinks are highly important for three-dimensional (3D) bioprinting. Acellular dermal matrix (ADM), a decellularized matrix derived from the dermis, has attracted attention as a potential bioink because it provides a microenvironment similar to that of living cells. However, its poor printability and weak mechanical properties make it difficult to apply widely in 3D bioprinting.

For swelling ratio measurements, six sample from each group were immersed into PBS at 37°C for 24 h and measured the weights of the hydrated gels (Wwet). Then, the hydrated gels were freeze-dried for 24 h and measured the weight (Wdry). The swelling ratio was calculated according to the equation: SR = (Wwet - Wdry)/ Wdry × 100%.Rheological analysis was performed by using a rotational rheometer.Young’s modulus was measured by using a Park XE-70 atomic force microscopy and Triangular silicon nitride cantilever. Cell viability was assessed by a live/dead cell stain according to the manufacturer’s protocol after 1 and 7 days of cultivation in vitro. Cell proliferation was determined by the Cell Counting Kit-8 (Boster, China) according to the manufacturer’s protocol after 1 and 7 days of cultivation in vitro. In vivo, Mice were divided into three groups: blank, A+G and A+G+cell, which respectively treated with nothing, ADM-GelMA bioink and bioprinted ADM-GelMA fibroblast-laden construct. The bioprinted constructs with skin and surrounding tissues were sampled for histological analysis on Day 14 and 21.

1.Characterization of ADM:no nuclei stained blue with DAPI were observed in the ADM sections. IHC and IF staining were used for qualitative evaluation of the key ECM components after decellularization, and collagen I and collagen III were well preserved.2.Swelling ratio, rheology and printability of the ADM-GelMA bioink: The swelling ratio of the ADM-GelMA bioinks (22.27 ± 3.77) was lower than that of the ADM bioinks (42.26 ± 1.09) but greater than that of the GelMA bioinks (11.02 ± 0.89).The shear-thinning properties of the ADM-GelMA and GelMA bioinks were more pronounced than those of the ADM bioinks.ADM-GelMA and GelMA bioinks exhibited relatively high fidelity, while ADM bioinks collapsed without gaps. 3.Cytocompatibility of ADM-GelMA bioinks:the cell proliferation in the ADM-GelMA and ADM bioinks was significantly greater than that in the GelMA bioink. 4. in vivo: the wound closure of the A+G+cell group was the fastest, and complete healing was achieved on D21.

In this study, we developed a new bioink, a mixture of ADM and GelMA bioink, to increase the mechanical strength and printability of ADM while maintaining high cytocompatibility. Then, the ADM-GelMA construct was implanted in vivo to evaluate its ability to promote ECM formation and accelerate wound healing.

we developed a new bioink for wound healing

The National Natural Science Foundation of China (82202443)