Microfluidic technology for one-step continuous preparation of calcium alginate microgel

Abstract

The invention relates to a microflow droplet technology-based method for one-step continuous preparation of multi-chamber calcium alginate microgel for immobilization of bioactive substances. The method realizes high-throughput continuous production of a microgel material. The method comprises forming a parallel and stable flow field through different hydrogel prepolymer solutions in a microfluidic channel, pouring the hydrogel prepolymer solutions for forming different chambers of the microgel into a microfluidic chip to form water phase solutions of multiple phase parallel fluids, mixing thewater phase solutions and an immiscible fluid (oil phase) through a T-shaped channel or a fluid focusing design to obtain water-in-oil emulsion drops and then alginic acid in the drops is linked immediately so that multi-chamber microgel is prepared, and cleaning the emulsion drops on the microfluidic chip so that the microgel is fast conveyed into a water phase. The method realizes one-step preparation of the calcium alginate microgel immobilized with bioactive substances and is suitable for industrial application.

Description

technical field [0001] The invention belongs to the field of material microprocessing, the field of biomaterial preparation technology, the field of tissue engineering and cell therapy, and particularly relates to a microgel prepared by using a microfluidic device to embed immobilized living cells or bioactive molecular drugs. Background technique [0002] In recent years, hydrogels have been widely used in many biomedical fields, especially in the field of tissue engineering, where hydrogels have become very important biomaterials. Hydrogel is a cross-linked network composed of water-insoluble but water-swellable polymers. Similar to human tissues and organs, it is composed of a porous network rich in water. Such a porous structure is similar to human tissues and organs, very Conducive to the effective exchange of materials. At the same time, some hydrogels composed of natural polymers have good biocompatibility and biodegradability, as well as mechanical properties simila...

AI Technical Summary

Problems solved by technology

Although hydrogel, as a biomedical material, has been extensively studied and used in the field of tissue engineering, there are still many problems that need to be solved urgently in the application of traditional hydrogel-embedded cell technology: 1) Bulk hydrogel The size is large (>1 cm), and the pore size of the polymer network is at the nanoscale. Due to the low diffusion rate and distance of biological macromolecules, the living cells embedded in the bulk gel have low exchange efficiency of nutrients and metabolites. Decreased survival rate; 2) Hydrogel is not injectable as a delivery carrier for biologically active substances, and can only be implanted in blocks instead of minimally invasive interventions; 3) The use of block hydrogels During the embedding process of macromolecules or cells, it is difficult to ensure the uniform distribution of load substances in the gel system

These traditional emulsion methods have the following problems: 1) The living cells need to be dispersed in the dispersed microemulsion for a long time, and the cells cannot exchange nutrients and gases with the outside of the droplets, so the metabolic activity of the cells gradually weakens, and the long-term Being in the emulsion will cause the reduction of cell activity; 2) In order to form a stable emulsion, it is often necessary to add surfactants to the oil phase or water phase, and surfactants tend to destroy cell membranes and produce cytotoxicity, so cells are exposed to them for a long time. Surfactants also have potential cytotoxicity problems; 3) In order to trigger the polymerization or crosslinking of hydrogels, it is usually necessary to use cytotoxic crosslinking agents or crosslinking reaction initiators, and long-term exposure of cells to these components also has cytotoxicity The problem

This method usually requires a severe gelation reaction to quickly fix the multi-chamber structure. When applied to the embedding of biologically active substances, protein molecules tend to lose their biological activity and the cell survival rate decreases; at the same time, the existing process first uses microfluidic Chips prepare microgel particles. After collection, a second step of washing is required to elute the oil phase, so that the microgels can be redispersed in aqueous solution. Therefore, continuous sample preparation cannot be achieved, and it is not suitable for industrial applications.

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