Organic/Inorganic Hybrid 'Bioinks' for 3D Bioprinting

随着我们获得更好的医疗保健和饮食，我们的器官寿命越来越长，如果不及时移植，我们的器官在生命的后期就会衰竭，可悲地导致死亡。因此，随着人口平均年龄的增长，等待器官移植的人数增加，但供体和可用器官的数量仍然很低。目前，在英国，平均每年有1300人在等待名单上死亡，或者病得太重而无法接受器官移植。更多的人也因为选择有限的或糟糕的植入物来修复和再生因疾病或创伤而受损的组织而受苦。为了克服器官短缺和可用植入物的局限性，已经探索了几种组织工程策略。一种很有前途的方法是3D生物打印，这是一种使用活细胞、生物分子和生物材料生产可植入器官和组织贴片的逐层制造技术。每个器官都是由硬（骨）或软（皮肤、肺、心脏等）组织组成的复杂结构，在某种程度上，它的结构和组成对每个人来说都是独一无二的。在这里，生物打印是一种很有前途的技术，可以在手术室里按一下按钮，就能生产出与病人自身器官和组织贴片非常相似的器官和组织贴片。然而，在这成为现实之前，存在几个关键挑战。一个主要的挑战是开发新的功能性生物材料，也称为3D生物打印的“生物墨水”。生物墨水是生物打印的重要组成部分，它们为生物货物提供结构支持和安全环境。目前的生物墨水是由软水凝胶制成的，它不能很好地保持打印的形状；生理条件下力学性能差；并且是自然起源的，因此具有固有的批次到批次的变化。理想的生物链接应该是完全合成的，易于打印，具有可调节的机械性能，一旦植入应该产生良好的宿主组织-材料相互作用。我们建议通过自下而上的生物友好工艺开发硅胶基有机/无机杂化生物链接来实现这一目标。基于低温溶液的技术可用于生产具有一系列性能的材料，从与骨骼形成粘合的高强度生物活性玻璃到适合软骨和皮肤再生的柔软柔性有机/无机混合物。首先，我们将开发新的前体，并研究生物友好的加工条件来生产生物墨水。然后使用3D打印机制造类似于人体组织的组织结构。

With access to better healthcare and diet we are outliving our organs which at latter stages of life fail tragically leading to death if not transplanted on time. Therefore with increasing average age of the population, the number of people on the waiting list for an organ transplant increases, yet the amount of donors and available organs remains at a low. Currently, in the UK on average >1300 people per year either die whilst on the waiting list or became too sick to receive an organ transplant. Many more people are also suffering from limited or poor implant choices for repair and regeneration of tissue damaged from disease or trauma. To overcome this shortage of organs and the limitations of available implants several tissue engineering strategies have been explored. One promising approach is 3D bioprinting, which is a layer-by-layer fabrication technique for the production of implantation-ready organs and tissue patches using living cells, biomolecules and biomaterials. Every organ is a complex structure of either hard (bone) or soft (skin, lung, heart, etc) tissues, and to some degree its structure and composition are unique to every person. Here, bioprinting is a promising technique for the production of organs and tissue patches that are a close mimic of the patient's own, within the operating theatre at the touch of a button. However, several key challenges exist before this becomes a reality. One major challenge is the development of new functional biomaterials also called "bioinks" for 3D bioprinting. Bioinks are an important part of bioprinting, they provide structural support and a safe environment for the living cargo. Current bioinks are made of soft hydrogels which: do not maintain the printed shaped very well; have poor mechanical properties at physiological conditions; and are of natural origin hence have an inherent batch-to-batch variation. An ideal bioink should be fully synthetic and easily printable, have tuneable mechanical properties, and once implanted should produce a favourable host tissue-material interaction. We propose that this can be achieved by developing a silica-gel-based organic/inorganic hybrid bioink via a bio-friendly bottom-up process. Low temperature solution-based technique can be used to produce materials with a range of properties, from high strength bioactive glasses that form bond to bone to soft and flexible organic/inorganic hybrids that are suitable for cartilage and skin regeneration. First, we will develop novel precursors and investigate bio-friendly processing conditions to produce the bioinks. Then using a 3D printer produce tissues constructs resembling those of human tissues.