由於皮膚是人體最大的器官，而皮膚傷口對公眾健康的威脅日益嚴重，因此開發有效且具有促進傷口癒合的傷口敷料是十分重要的。然而，目前常見的傷口敷料仍然有著各種問題需要克服，包括傷口癒合成效不佳或宿主組織的不良貼合。在此論文研究中，通過3D列印技術製成了以玻尿酸（HA）為基底的傷口敷料，用來解決這些問題。 玻尿酸與可光固化的生物相容性高分子聚合物（甲基丙烯酸明膠（GelMA）或聚（乙二醇）二丙烯酸酯（PEGDA））混合，用來作為3D列印的生物墨水。在這項研究中，擠壓式生物3D列印機( Extrusion bioprinter, BioX) 和數位光處理積層3D列印機（Digital Light Processing- Additive Manufacturing, DLP-AM）都被使用於製造傷口敷料。由於玻尿酸有著高功效促進傷口癒合過程的能力，因此提升玻尿酸於傷口敷料中的比例至關重要。同時，為了確保3D列印機台的可列印性，維持足夠量的光固化高分子比例也十分重要。在混合較高量的光固化生物可相容高分子和較高量的玻尿酸之間存在權衡，因此在可列印材料中產生高玻尿酸含量組成是十分困難的。然而，在這項研究中，我們的3D列印傷口敷料中所含的玻尿酸含量可高達16.7 wt. %，遠高於大多數的產品。另外，於流變學的測試中，經由流變儀的偵測，我們的傷口敷料被證明其顯示出出色的剪切稀化效果（Shear thinning effect）和適當的粘度，是適用於擠壓式生物3D列印機的生物墨水。此外，我們的傷口敷料被證明與人體皮膚的機械性質相似。同時，高膨潤率表明此玻尿酸傷口敷料有吸收傷口滲出組織液的強大功效。最後，玻尿酸釋放檢測和細胞活性測試證明我們的材料是具有高生物相容性的生物主動性傷口敷料（Bioactive dressings），使其成為組織工程中的理想傷口敷料。從以上結果來看，這些以玻尿酸為基底的3D列印材料顯示出製成傷口敷料的潛力，並且值得在臨床醫學中作進一步研究和利用。

As skin is the largest organ in human body and skin wounds are a major growing threat for public health, it is essential to create skin substitutes. However, currently wound dressings often suffer from a variety of problems including wound contraction and poor integration with host tissue. In this project, hyaluronic acid (HA)-based wound dressings are fabricated by 3D-printing technology to solve these problems. HA is mixed with photocurable and biocompatible polymers, Gelatin methacrylate (GelMA) or poly (ethanol glycol) diacrylate (PEGDA), as the bioink for 3D-printing. In this study, extrusion bioprinter, BioX, and DLP-AM printer are both used to fabricate wound dressings. In order to accelerate the wound healing process of a skin wound, it is the purpose of this work to create a bioink with high HA composition, as HA has previously been reported as a crucial accelerant for wound regeneration. Meanwhile, it is important to make sure the printability of the bioinks created. There is a trade-off between mixing higher amount of photocurable polymer and higher amount of HA, making it difficult to achieve high HA composition in printable materials. Nevertheless, in this study, up to 16.7 wt.% of HA is contained in our 3D-printed dressing which is significantly higher than most common products. Additionally, it is proven that our dressing materials, which show a great shear thinning effect and proper viscosities in rheology tests, are suitable bioinks for extrusion bioprinters. Moreover, our wound dressings are proven to match the mechanical properties of human skin. Also, the high swelling ratio indicates the great ability of our materials to absorb tissue fluid exuded from the wound. Finally, the detection of HA released and the cell viability test prove our materials to be bioactive wound dressings with high biocompatibility, making them great candidates for tissue engineering. From the above results, these HA-based materials show promising potential to create wound dressings and are worth further investigation and utilization in clinical practice.

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