Preparation and Characterization of Thermoresponsive Poly(N-isopropylacrylamide-co-acrylic acid)-Grafted Hollow Fe₃O₄/SiO₂ Microspheres with Surface Holes for BSA Release.

Jing Zhao,Ming Zeng,Kaiqiang Zheng,Xinhua He,Xiaoyi Fu,Minqiang Xie

doi:10.3390/ma10040411

Jing Zhao, Ming Zeng + Show 4 more

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https://doi.org/10.3390/ma10040411

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Abstract

Thermoresponsive P(NIPAM-AA)/Fe3O4/SiO2 microspheres with surface holes serving as carriers were prepared using p-Fe3O4/SiO2 microspheres with a thermoresponsive copolymer. The p-Fe3O4/SiO2 microspheres was obtained using a modified Pickering method and chemical etching. The surface pore size of p-Fe3O4/SiO2 microspheres was in the range of 18.3 nm~37.2 nm and the cavity size was approximately 60 nm, which are suitable for loading and transporting biological macromolecules. P(NIPAM-AA) was synthesized inside and outside of the p-Fe3O4/SiO2 microspheres via atom transfer radical polymerization of NIPAM, MBA and AA. The volume phase transition temperature (VPTT) of the specifically designed P(NIPAM-AA)/Fe3O4/SiO2 microspheres was 42.5 °C. The saturation magnetization of P(NIPAM-AA)/Fe3O4/SiO2 microspheres was 72.7 emu/g. The P(NIPAM-AA)/Fe3O4/SiO2 microspheres were used as carriers to study the loading and release behavior of BSA. This microsphere system shows potential for the loading of proteins as a drug delivery platform.

Highlights

IntroductionTargeted drug delivery systems are a hot topic in the fields of biology and medicine [1,2]
Targeted drug delivery systems are a hot topic in the fields of biology and medicine [1,2].In previous studies, the microspheres used as carriers usually have had a pore size of 2–3 nm, which restricts the selection of drug molecules that can be loaded and their biomedical applications [3].the microspheres are ruptured and destroyed by constructing large, dense holes in small particles with diameters of less than 200 nm
We developed a carrier based on bowl-like hollow p-Fe3 O4 /SiO2 microspheres with P(NIPAM-acrylic acid (AA)) serving as a gatekeeper that allows the encapsulation and transportation of drugs with little premature release to specific site tissue and organs where the drug can be released upon an external alternating magnetic field

Summary

Introduction

Targeted drug delivery systems are a hot topic in the fields of biology and medicine [1,2]. The microspheres are ruptured and destroyed by constructing large, dense holes in small particles with diameters of less than 200 nm. In this context, the design of small microspheres with macroporous holes that are structurally stable enough to carry large molecular drugs is an attractive and challenging subject. Among the potential delivery platform materials, such as mesoporous materials [4,5,6,7], hollow microspheres [8,9,10,11] and nanotubes [12,13] etc., Fe3 O4 /SiO2 hollow magnetic microspheres [14,15]

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