Polylactic acid-titanium oxide micro-nano multi-stage structure composite microsphere material and application thereof

Abstract

The invention discloses a polylactic acid-titanium oxide micro-nano multi-stage structure composite microsphere material and application thereof. The polylactic acid-titanium oxide micro-nano multi-stage structure composite microsphere material provided by the invention is prepared by dissolving polylactic acid in dichloromethane to obtain a polylactic acid solution, and adopting a microfluidic technology to drip the polylactic acid solution into a polyvinyl alcohol aqueous solution; controlling the concentration and dropping rate of the polylactic acid, the concentration of the polyvinyl alcohol aqueous solution and the stirring speed to obtain polylactic acid microspheres; dipping the polylactic acid microspheres into a titanium tetrachloride-hydrochloric acid solution, and stirring forcarrying out a reaction in a constant temperature water bath at 60-100 DEG C for 4-24h; washing with deionized water and absolute ethanol, and drying to obtain polylactic acid composite microspheres with surfaces coated with a titanium oxide nanostructure. The obtained microspheres are stable in structure and uniform in size, and have diameters of 100-500mu m; the lengths of titanium oxide nanorods are 10-50nm. When human adipose-derived mesenchymal stem cells are inoculated onto the microspheres, the proliferation of the stem cells can be promoted, and the dryness of the stem cells is maintained.

Description

technical field [0001] The invention relates to the technical field of biomedical engineering, in particular to a polylactic acid-titanium oxide micro-nano multi-level structure composite microsphere material and its application in maintaining stem cell stemness. Background technique [0002] Stem cell therapy technology has shown great clinical application prospects in gene therapy, autoimmune diseases, brain and nervous system diseases, and cardiovascular diseases. Among them, the advantages of autologous adult stem cell transplantation are particularly prominent. [0003] Adult stem cells refer to undifferentiated cells present in an already differentiated tissue. Under certain conditions, adult stem cells either produce new stem cells, or differentiate according to a certain program to produce various specific cell types. Compared with embryonic stem cells, adult stem cells have many advantages, for example: (1) Since the major histocompatibility complex (MHC) of each ...

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Problems solved by technology

(2) Although embryonic stem cells can differentiate into various cell types, this differentiation is "non-localized". At present, it is not possible to control the differentiation of embryonic stem cells into corresponding cells in specific parts. The current practice can easily lead to teratomas ; and the above-mentioned problems do not exist in the application of adult stem cells

However, there are many problems in the titanium oxide-polylactic acid composite material prepared by the prior art. One is that the preparation process is complicated; the other is that the titanium oxide is unevenly dispersed in the polylactic acid matrix; The form of mixed titanium oxide exists in the matrix, and few titanium oxide-polylactic acid composites are made into microspheres

[0006] In addition, microspheres are currently mainly used in the fields of drug sustained release, cell scaffolding, and cell injection. There are no reports on the use of microspheres to promote the proliferation of adult stem cells and maintain the stemness of adult stem cells.

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