近年來，CO2雷射燒蝕在微加工已經被視為作為快速、高通量以及符合經濟效應的替代方法，雷射燒蝕主要是透過施加聚焦後具有高能脈衝的雷射來消除基材上的目標區域，且已經被證明在生物領域具有相當大的應用潛力。在許多相關研究之中，為了廣泛的生物相關應用，已經為各種材料的製程提供了簡化的方法。但是，在各種材料和應用方面仍然沒有全面和系統的研究。因此，我們希望對現有的CO2雷射燒蝕研究結果進行完整的分析及後續的相關應用。
　　在我們的實驗中，我們展示了CO2雷射燒蝕用於不同的生物相容性材料，包括硼矽玻璃（borosilicate glass）、聚二甲基矽氧烷（PDMS）、聚甲基丙烯酸甲酯（PMMA）和聚苯乙烯（PS），並用於各種後續生物相關應用。基於CO2雷射燒蝕對於微加工上的應用，可產生玻璃孔徑並用於細胞抓取，此外，燒蝕後的聚甲基丙烯酸甲酯（PMMA）和聚二甲基矽氧烷（PDMS）模塑可用於具生物降解性的聚乙烯醇/聚乙烯吡咯烷酮（PVP/PVA）微針陣列的快速塑型。最後，利用聚苯乙烯（PS）這個培養裝置中常見的基材，進行微孔和通孔結構的快速塑行，並成功進行三維細胞的培養。微孔和懸滴是基於不同原理的兩種不同的多細胞腫瘤聚集體（MCA）培養技術，它們各別是具有物理邊界的超低附著培養系統，和僅透過重力相互作用的無支架懸滴技術。
　　結果表明，CO2雷射燒蝕在各種應用中表現良好。我們利用CO2雷射燒蝕複製了玻璃孔進行單細胞捕獲的應用，並通過原位熒光染色驗證分離細胞具有良好活性。在我們的研究中，PDMS在CO2雷射加工後的凹微孔周圍顯示出良好的表面光滑度，在製造具有足夠強度與適當縱橫比的微針上要比PMMA更為優異。此外，無論是透過PDMS或PMMA所製造的微針陣列，藉由包埋熒光標記物（分子量為155 kDa之FITC-dextran）顯示出良好的高分子遞送能力，以及透過藍色組織染料進行染色標記，並顯示具有良好的穿刺能力。微孔和懸滴均具有形成良好細胞活性之MCAs的能力。其中，微孔的尺寸不僅可透過CO2雷射能量來控制，而且能夠培養均勻且具特定尺寸的MCAs（90-140 μm），而微孔作為限制MCA生長的物理性邊界，除此之外，我們同樣在懸滴陣列中成功使用抗癌藥物，如：阿黴素（Doxorubicin）進行MCA的藥物篩選。最後，我們完整地提供了CO2雷射燒蝕在生物領域上的應用。

CO2 laser processing has been explored as an alternative high-throughput and cost-effective method for rapid microfabrication of lab-on-chip devices. Laser ablation works by applying high-energy pulses of focused laser light to remove targeted sections of a substrate material by vaporization, chipping, or other erosive processes. Protocols have been developed to provide a streamlined methodology for the fabrication of various materials for a wide range of biological applications in many studies. However, there are still no comprehensive and systematic studies in diverse materials and applications. Our work is validating existing results as a study with the complete context and integration.
　　In our study, we demonstrate CO2 laser ablation on different biocompatible materials, including borosilicate glass, polydimethylsiloxane (PDMS), polymethylmethacrylate (PMMA) and polystyrene (PS), for various downstream applications. Based on CO2 laser ablation for microfabrication, glass apertures were created for cell trapping, and ablated PMMA and PDMS molding was demonstrated for the rapid prototyping of biodegradable polyvinyl alcohol/polyvinylpyrrolidone (PVP/PVA) microneedle arrays. Finally, in PS, which is a conventional substrate of culture devices, concave microwells and through holes were obtained for three-dimensional cell culture. Microwells and hanging drops are two different multicellular cancer aggregate (MCA) cultivation techniques based on different principles for 3D culture: ultra-low-attachment culture systems with physical boundaries and scaffold-free hanging-drop-only interactions by gravity, respectively.
　　We created glass apertures by CO2 laser ablation for single-cell trapping and validated by in situ fluorescent staining that the isolated cells retained viability. PDMS showed good surface smooth-ness around the concave microwells after CO2 laser processing and better than PMMA for fabricating a sufficient-strength microneedle with a suitable aspect ratio. Microneedle arrays fabricated by both PDMS or PMMA showed good ability for encapsulating high-molecular-weight (MW) particle fluorescence markers (155 kDa MW for FITC-dextran) and good insertion ability for penetrating porcine skin, as verified by staining with blue tissue marking dye. Microwells and hanging drops used as 3D culture platforms were found to form MCAs with good cell viability. The microwells, whose sizes were controllable by setting the CO2 laser energy, were capable of culturing consistent and homogeneous MCAs sized approximately 90 to 140 μm and served as a physical boundary to constrain MCA growth. Finally, drug screening with anticancer drugs such as doxorubin (DOX) was successfully performed within the hanging drop array. Here, we present comprehensive insights into CO2 laser ablation for various biological applications.

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