Patents by Inventor Shitu Ma

Shitu Ma has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20230098334
    Abstract: The invention discloses a thiolated chitosan and a preparation method thereof, which is chitosan co-modified by hydroxybutyl and sulfhydryl. The preparation method includes the following steps: firstly, hydroxybutyl is introduced into a chitosan molecular chain, and then sulfhydryl is introduced as a sulfhydryl moiety by a condensation reaction between free amino of hydroxybutyl chitosan and carboxyl of L-cysteine. An aqueous solution of the thiolated chitosan of the invention is in a solution state at low temperature, and can be flow-injected. When the temperature rises to around 37° C., a hydrogel can be formed. Due to the introduction of sulfhydryl, the antioxidant ability and tissue adhesion ability of the material are increased. The thiolated chitosan prepared according to the method may have wide application prospects in an aspect such as tissue engineering, drug delivery systems, cell culture, cosmetics, etc.
    Type: Application
    Filed: February 28, 2022
    Publication date: March 30, 2023
    Inventors: Feifei Wu, Zhongyi Chen, Wanjun Jiang, Jie Li, Shitu Ma, Mengjun Hu
  • Publication number: 20230067215
    Abstract: The present invention provides a gel for injection containing controlled degradation polyester microspheres. The gel for injection consists of crosslinked sodium hyaluronate gel, non-crosslinked sodium hyaluronate gel, polyester microspheres wrapped with hard fat and a balanced salt solution. The polyester microspheres are separated from water by means of wrapping and hydrophobic effect of the hard fat, and accordingly the present invention solve the problem that polyester materials are prone to degradation in gel. In the meantime, the hard fat has the characteristic of low melting point (melting point being 33° C.-39° C.), after the product is injected into human body, the hard fat is molten and separated under the action of human body temperature, and the wrapped polyester microspheres are released so that the microspheres can be degraded in the human body to achieve controlled degradation.
    Type: Application
    Filed: November 30, 2021
    Publication date: March 2, 2023
    Inventors: Jie Li, Yang Fu, Cuiying Zhou, Feifei Wu, Shitu Ma
  • Publication number: 20220081492
    Abstract: Provided are a chitin whisker-enhanced hyaluronic acid cell scaffold and a preparation method thereof. Components of the cell scaffold include chitin whiskers and cross-linked hyaluronic acid. The chitin whisker-enhanced hyaluronic acid cell scaffold is obtained by dispersing chitin whiskers into deionized water using ultrasound, followed by addition of hyaluronic acid and uniform mixing to obtain an aqueous solution, adjusting a pH value of the aqueous solution to be in a range of 4.0 to 6.0, subjecting the aqueous solution to a cross-linking reaction, dialyzing a reaction product in a phosphate buffer solution, and freeze drying a resulting product. The chitin whisker-enhanced hyaluronic acid cell scaffold and the preparation method thereof can increase a mechanical property and a resistance to degradation of a scaffold material and expand an application scope of hyaluronic acid cell scaffolds.
    Type: Application
    Filed: November 30, 2020
    Publication date: March 17, 2022
    Inventors: Feifei Wu, Jie Li, Jin Zeng, Caili Ma, Kui Zhou, Shitu Ma
  • Publication number: 20220064436
    Abstract: Provided is a gradient injection containing a mixture of polymer microspheres. The injection is a freeze-dried powder composed of a filler, cross-linked sodium hyaluronate microspheres, poly-L-lactic acid (PLLA) microspheres, and an excipient. The powder can be mixed with sterile water and then used for injection cosmetology. A triple gradient effectiveness is provided by mixing the filler, the cross-linked sodium hyaluronate microspheres, and the PLLA microspheres to improve the subcutaneous capacity of human skin and repair skin wrinkles, folds, scars, and aging. The gradient injection is also suitable for repairing large-volume facial fat loss without adverse reactions such as nodules and granulomas.
    Type: Application
    Filed: March 9, 2021
    Publication date: March 3, 2022
    Inventors: Jie Li, Feifei Wu, Kui Zhou, Yang Fu, Shitu Ma