Department of Biomedical Engineering, Bangladesh University of Engineering and Technology (BUET), Dhaka 1205, Bangladesh.
J Mater Chem B. 2024 Oct 30;12(42):11025-11041. doi: 10.1039/d4tb00608a.
The development of bioadhesives that concurrently exhibit high adhesion strength, biocompatibility, and tunable properties and involve simple fabrication processes continues to be a significant challenge. In this study, a novel bioadhesive named DOTAGEL is synthesized by crosslinking gelatin (GA), dopamine (DA), and tannic acid (TA) in an unoxidized environment due to the advantage of controlling the degree of protonation in GA and TA, as well as controlling the degree of intermolecular amide and hydrogen bonding in the acidic medium. DOTAGEL (DA + TA + GA) shows superior adhesion strengths of 104.6 ± 46 kPa on dry skin and 35.6 ± 4.5 kPa on wet skin, up to 13 attachment-detachment cycles, retains adhesion strength under water for up to 10 days and is capable of joining two cut parts of internal organs of mice. Moreover, DOTAGEL shows strong antibacterial properties, self-healing, and biocompatibility since it contains TA, a natural and antibacterial cross-linker with abundant hydroxyl groups and the capability of forming non-covalent bonds in an unoxidized environment, and dopamine hydrochloride, a mussel inspired biomaterial containing both the amine and catechol groups for amide bonding and hydrogen bonding with TA and GA. The cross-linking among 20% (w/v) GA, 0.2% (w/v) DA, and 20% (w/v) TA is done by the centrifugation process at room temperature. Two different acids, hydrochloric acid and acetic acid, were used for tuning the pH of the medium, which led to two different samples named DOTAGEL/AA and DOTAGEL/HCL. The degree of cross-linking and mechanical and biochemical properties, like adhesion strength, degradation rate, antibacterial properties, stickiness, , are tuned by adjusting the pH of the medium. DOTAGEL/HCL showed 6.5 times faster degradation in 10 days, a faster release rate in the antibacterial study, 2 times adhesion strength in a dry medium, and more stickiness. The novelty lies not only in increased adhesion strength but also in the single-step fabrication process of the adhesive in the acidic medium. This research proposes the formation of a tunable antibacterial adhesive that is capable of working on wet surfaces within the body and that has the potential to become a successful tissue adhesive with a wide range of possibilities in controlled drug delivery at wound sites and other biomedical applications.
生物黏合剂的发展需要同时具备高黏附强度、生物相容性和可调性能，并涉及简单的制造工艺，这仍然是一个重大挑战。在这项研究中，由于可以控制 GA 和 TA 的质子化程度以及控制酸性介质中分子间酰胺和氢键的程度，一种名为 DOTAGEL 的新型生物黏合剂是通过交联明胶（GA）、多巴胺（DA）和鞣酸（TA）在未氧化的环境中合成的。DOTAGEL（DA+TA+GA）在干燥皮肤的黏附强度高达 104.6±46 kPa，在湿润皮肤的黏附强度为 35.6±4.5 kPa，可进行 13 次附着-脱附循环，在水中保持黏附强度长达 10 天，并能够连接小鼠内部器官的两个切割部分。此外，DOTAGEL 具有较强的抗菌性能、自修复性能和生物相容性，因为它含有 TA，这是一种天然的抗菌交联剂，具有丰富的羟基，并且能够在未氧化的环境中形成非共价键，还含有盐酸多巴胺，这是一种受贻贝类启发的生物材料，既含有胺基又含有儿茶酚基，可与 TA 和 GA 形成酰胺键和氢键。在室温下，通过离心过程将 20%（w/v）GA、0.2%（w/v）DA 和 20%（w/v）TA 进行交联。使用两种不同的酸，盐酸和醋酸，来调节介质的 pH 值，得到了两种不同的样品，分别命名为 DOTAGEL/AA 和 DOTAGEL/HCL。通过调节介质的 pH 值，来调节交联程度以及机械和生化性能，如黏附强度、降解率、抗菌性能、粘性等。DOTAGEL/HCL 在 10 天内的降解速度快了 6.5 倍，在抗菌研究中的释放速度更快，在干燥介质中的黏附强度提高了 2 倍，粘性更强。这项研究的新颖之处不仅在于增加了黏附强度，还在于在酸性介质中实现了黏合剂的单步制造工艺。本研究提出了一种可调节的抗菌黏合剂的形成，它能够在体内的湿表面上工作，并有可能成为一种成功的组织黏合剂，在控制药物输送到伤口部位和其他生物医学应用方面具有广泛的应用前景。
