A bolus is a kind of tissue equivalent material used in radiotherapy for treating superficial lesions. Despite the availability of various commercial boluses, it is hard for them to form full contact with the irregular surface of patients’ skin, such as the scalp, nose, and ear, resulting in air gaps and leading to a discrepancy between the delivered dose and planned dose. To solve this problem, we provided a photocurable bioink created from chitosan (CHI) for digital light processing (DLP) three-dimensional (3D) printing the bolus in radiotherapy application. The chitosan-based bioink (CHI–MA) was obtained by a methacrylation process using methacrylic anhydride (MA). Photosensitive crosslinkers with different molecular weights were introduced into the bioink. The photocuring efficiency and mechanical properties of CHI–MA hydrogels can be well modulated by varying the crosslinkers. This CHI–MA bioink allowed us to create complex structures with reliable biocompatibility, good flexibility, and excellent structural stability. Furthermore, the nose bolus processed by 3D printing this bioink proved to be a good fit for the nose model and showed a desirable radiotherapy effect. This suggests that DLP 3D printing of the CHI–MA bioink would be a promising approach to obtain the customized bolus in the application of radiotherapy.

中文翻译：

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用于放射治疗的 3D 打印壳聚糖基丸剂

丸剂是一种用于放射治疗的组织等效材料，用于治疗浅表病变。尽管有各种商业药丸可供使用，但它们很难与患者皮肤的不规则表面（例如头皮、鼻子和耳朵）形成完全接触，从而导致气隙并导致递送剂量和给药剂量之间的差异。计划剂量。为了解决这个问题，我们提供了一种由壳聚糖 (CHI) 制成的光固化生物墨水，用于数字光处理 (DLP) 三维 (3D) 打印放射治疗应用中的丸剂。基于壳聚糖的生物墨水（CHI-MA）是通过使用甲基丙烯酸酐（MA）的甲基丙烯酸化过程获得的。将具有不同分子量的光敏交联剂引入生物墨水中。通过改变交联剂可以很好地调节 CHI-MA 水凝胶的光固化效率和机械性能。这种 CHI-MA 生物墨水使我们能够创建具有可靠的生物相容性、良好的柔韧性和出色的结构稳定性的复杂结构。此外，通过 3D 打印这种生物墨水处理的鼻团被证明非常适合鼻子模型，并显示出理想的放射治疗效果。这表明 CHI-MA 生物墨水的 DLP 3D 打印将是一种在放射治疗应用中获得定制推注的有前途的方法。通过 3D 打印这种生物墨水处理的鼻团块被证明非常适合鼻子模型，并显示出理想的放射治疗效果。这表明 CHI-MA 生物墨水的 DLP 3D 打印将是一种在放射治疗应用中获得定制推注的有前途的方法。通过 3D 打印这种生物墨水处理的鼻团块被证明非常适合鼻子模型，并显示出理想的放射治疗效果。这表明 CHI-MA 生物墨水的 DLP 3D 打印将是一种在放射治疗应用中获得定制推注的有前途的方法。