CD BioSciences is a biotechnology company that provides a high resolution 3D printing technology platform called 3Dmicroflu for biological 3D printing. In addition, we also provide high quality bioinks and bioink customization services suitable for all types of 3D printers. If you don't find a bioink that meets your project needs in our product range, please contact us now for expert customization services. Below you will find an overview of CD BioSciences' customization services based on ionic crosslinking of bioinks in the physical crosslinking method.
The addition of metal ions to achieve ion-to-ion interactions through metal coordination is one of the most common hydrogel crosslinking methods used in 3D bioprinting. The ionic crosslinking approach usually involves the addition of multivalent cations to the polymer solution to induce gelation. This is a very fast cross-linking method and the hydrogels can be cross-linked under mild conditions at room temperature and physiological pH. However, the ionic cross-linking method has some drawbacks, such as weak mechanical properties, poor stacking ability, and the possibility of metal ion release into the body after implantation in vivo. Ion interactions are mainly used as a crosslinking strategy for 3D bioprinting of polysaccharides containing carboxyl groups such as sodium alginate. As shown in the figure below, carboxyl groups on adjacent polymer chains are able to bind to multivalent cations Mn+ to form ionic cross-linked gel networks through metal coordination. Polymer solution concentration and M-blocks/G-blocks ratio affect the physicochemical and mechanical properties of alginate gels. The higher G-content hydrogels with stronger mechanical properties and the type of ionic cross-linker also have a strong influence on the printability of the material.
Fig. 1. Chemical structure of sodium alginate and its network formation in the presence of calcium chloride. (Bruche, et al., 2015)
In addition, ionic crosslinking can be achieved without the addition of metal ions, for example, when there is an electrostatic interaction between ionic groups in the backbone of the polymer chain. In this crosslinking method, two hydrogels with opposite charges create an electrostatic interaction network without the addition of free metal ions. This type of ionic crosslinking is more conducive to cell growth and survival because potentially toxic metal ions are not present. These print materials include anionic hydrogels (e.g., alginate and xanthan), cationic hydrogels (e.g., gelatin and chitosan), and neutral hydrogels containing equal amounts of positive and negative charges (e.g., dextran and sulfobetaine).
Although ionic cross-linked bioinks are superior in terms of cross-linking speed, often too fast gelation can lead to poor stability of the final 3D printed structure, caused by the different deposition rate of Mn+ on the outside of the gel and the inside of the gel. The ability to control and obtain the most appropriate ionic crosslinking rate for different 3D bioprinting needs and when using different crosslinking materials is the most important prerequisite for the design and customization of ionic crosslinking inks. Therefore, CD BioSciences provides ionic crosslinking bioink customization service which focuses on helping you find the most suitable crosslinking rate to meet your printing needs by adjusting the ratio, concentration, and polymerization of crosslinking materials and crosslinkers.
After you place your order, one of CD BioSciences' professional experts will immediately communicate with you about your ionic crosslinking customization needs. Once your customization needs are clear, CD BioSciences will perform the following customization work.
CD BioSciences' experts will provide you with custom bioinks with optimal ratios for your project needs, taking into account cell viability, mechanical properties and cross-linking speed.
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If you are interested in our bioinks customization services, please contact us now for exclusive services. All services are available on a 24/7/365 basis.