POSS/poly lactic acid and poly(n-isopropyl acrylamide) star block copolymer preparation

Abstract

According to the present invention, cage octa-aminopropyl silsesquioxane (POSS-NH2) is adopted as a starting molecule, an initiation effect of the surface amino in the POSS-NH2 is adopted to make the POSS containing a plurality of amino initiate active loop opening polymerization of D,L-lactide under catalysis of stannous octanoate to obtain a star polymer POSS-PLA having structural regularity, the terminal hydroxyl group of the star polymer is converted into a macromolecule initiator capable of initiating atom transfer radical polymerization (ATRP) to carry out an ATRP reaction of N-isopropyl acrylamide (NIPAAm) to synthesize a star block copolymer adopting the POSS as a center, adopting poly lactic acid as a core, and adopting poly(N-isopropyl acrylamide) as a shell, the star block copolymer is dissolved in DMF, the obtained solution is added to water in a dropwise manner to prepare micelles, a scanning electron microscopy (SEM) is adopted to observe a shape and a size of the micelle, and dynamic light scattering (DLS) is adopted to determine a particle size and distribution of the micelles and confirm structural regularity of the micelles, wherein a diameter of the micelles is about 170 nm, and the nanometer micelles have functions of drug loading and temperature control release.

Description

technical field [0001] The preparation of an inorganic / polymer star-shaped block copolymer involves step-by-step living polymerization of lactide and N-isopropylacrylamide with an inorganic nanoparticle as the central molecule to obtain a core-shell The invention relates to a star-shaped block copolymer of structure, which belongs to the technical field of functional materials. Background technique [0002] In recent years, people have paid great attention to the technology of using polymer nanomaterials as drug carriers. It is hoped that this technology can bring new insights into the treatment of some major human diseases such as cancer, cardiovascular diseases, infectious diseases and neurological diseases. Breakthrough. Preparation and research of nano-micelle with novel structure and excellent performance, and using it as a carrier for controlled drug release, which is of great significance for the development of new medical materials and the improvement of human health...

AI Technical Summary

Problems solved by technology

[0003] Most of the currently reported nanomicelles are formed by the self-assembly of block linear copolymers or graft copolymers in water, and the polymer molecules are aggregated by the interaction of hydrophobic segments, so such nanomicelles Bundles are not stable enough as drug controlled release carriers

When the micelle concentration is diluted below the critical micelle concentration in the blood, or when the micelle interacts with blood components such as serum proteins and cells, the micelle will dissociate, causing drug leakage and burst release, thus losing its original effects, and even produce toxic reactions

At the same time, the micelle structure is not very regular, the shape is changeable, the size is not uniform, and the mechanical strength is not enough, which causes its instability and affects the drug loading and drug release effects.

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