A preparation method and device for microfluidic two-phase monodisperse calcium alginate microspheres

Abstract

The invention discloses a preparation method of microfluidic two-phase monodisperse calcium alginate microspheres, which comprises the following steps: taking polyethylene glycol aqueous solution as the outer water phase, and dextran+sodium alginate aqueous solution as the inner water phase ; A two-phase sodium alginate droplet is produced at the tip of the cone through a coaxial capillary device; wherein the outer water phase is a continuous sample injection, and the inner water phase is a periodic intermittent sample injection; the two-phase sodium alginate droplet is passed through into the calcium chloride aqueous solution to generate the required monodisperse calcium alginate microspheres; the present invention does not require complex pretreatment processes for sodium alginate or two-phase aqueous phase, and the generation method is simple and fast, and has good biocompatibility; The formed microspheres are all stable, and the size of the microspheres can be controlled; the device has a simple structure, flexible and convenient manufacture, precise operation control, and is easy to produce in batches.

Description

technical field [0001] The invention relates to a preparation method and device of calcium alginate microspheres, in particular to a preparation method and device of microfluidic two-phase monodisperse calcium alginate microspheres. Background technique [0002] Alginate gel microspheres have the characteristics of good biodegradability, biocompatibility, and non-toxicity. They can be used as carriers for encapsulating cells and drugs, and are widely used in drug delivery, drug release, enzyme engineering reactions, and 3D cell culture. ; At present, most of the traditional processes produce calcium alginate microspheres by dripping method, electrospray method, inkjet printing method, etc.; in 2016, Gu Xiaolong et al. Although this method can produce microspheres of uniform size, the size of the microspheres is large and cannot be adjusted; 2013 Alessandri et al. (Alessandri, Proceedings of the National Academy of Sciences of the United States of America, 2013,37,14843) Pra...

AI Technical Summary

Problems solved by technology

[0002] Alginate gel microspheres have the characteristics of good biodegradability, biocompatibility, and non-toxicity. They can be used as carriers for encapsulating cells and drugs, and are widely used in drug delivery, drug release, enzyme engineering reactions, and 3D cell culture. ; At present, most of the traditional processes produce calcium alginate microspheres by dripping method, electrospray method, inkjet printing method, etc.; in 2016, Gu Xiaolong et al. Although this method can produce microspheres of uniform size, the size of the microspheres is large and cannot be adjusted; 2013 Alessandri et al. (Alessandri, Proceedings of the National Academy of Sciences of the United States of America, 2013,37,14843) Practical inkjet printing method to produce alginate microgels, but the size of the produced alginate microgels is not uniform and the size is uncontrollable; in 2015 Nguyen et al. (Duy Khiem Nguyen, Advanced Healthcare Materials, 2015,10,1537) used Electrospray method is used to produce calcium alginate microgels, but the high-voltage electric field in this equipment can damage cells, and cells cannot be directly wrapped for subsequent operations, which limits the use of microgels

[0003] In recent years, single-size and controllable alginic acid microspheres can be produced using emerging microfluidic technology, but most microfluidic methods mainly use oil-water two-phase to generate water-in-oil alginic acid droplets to produce microspheres; Although this type of method can produce microspheres with good monodispersity, due to the introduction of oil phase and surfactant, the biocompatibility of microspheres can be reduced (Marcoux, Colloids and Surfaces A:Physicochemical and Engineering Aspects, 2011,377 ,54); In addition, when the oil-water sodium alginate droplet is introduced into the chip for cross-linking, the droplet will be deformed due to various unbalanced forces during the process of falling into the receiving liquid and when passing through the oil-water interface of the receiving liquid , the generated microspheres often have a "tail", which is in the shape of teardrops or tadpoles (Yung-Sheng Lin, Electrophoresis, 2013, 34, 425), and the sphericity is not good, which will affect the drug release effect

[0004] Aqueous solutions of polyethylene glycol and dextran at a certain concentration can spontaneously separate phases to form a two-phase aqueous system. Due to the good biocompatibility and selective distribution of this system, it is often used as a base for biological macromolecules such as proteins and nucleic acids. Separation and extraction; in recent years, the research on the preparation of calcium alginate microspheres by microfluidics has focused on the preparation of oil-water droplets, but few people have studied the preparation of calcium alginate microspheres with good biocompatibility two-water phase ; The reason is that the low surface tension and shear force between the two water phases are difficult to directly form stable droplets of water-in-water; sodium alginate needs to be pretreated, and the operation is cumbersome; 2017 Liu et al. (Yang Liu, Biomedical Microdevices, 2017, 19, 55) Aqueous two-phase calcium alginate microspheres can be prepared through PDMS microfluidic chips; however, this method not only needs to modify sodium alginate, but also uses oxidizing agents that affect biocompatibility and Catalase, while producing microspheres of non-uniform size

Images