| With the development of nanotechnology, multifunctional nanoparticle having anticancer-drug, fluorescence probe and tumor cell targeting groups for the tumor targeting drug delivery and bioimaging, is an effective strategy to study tumor targeting theranostic, in vivo drug delivery and cellular uptake. In this study, mesoporous β-Ga2O3:Cr3+ nanoparticles with near infrared persistent luminescence (NIPL) and fluorescence properties were synthesized. Doxorubicin hydrochloride (DOX) which was used as a model anticancer drug was loaded into β-Ga2O3:Cr3+ nanoparticles for the construction of tumor targeting drug delivery system. To achieve tumor cell active targeting delivery and intracellular GSH-sensitive drug release, drug loaded nanoparticle was further coated by HA modified by L-Cys. The study mainly includes the following five aspects:1. GaOOH:Cr3+ nanoparticle was synthesized by hydrothermal method at 120℃ under high-pressure and then GaOOH:Cr3+ was characterized by TEM, XRD and DLS. The results showed that GaOOH:Cr3+ nanoparticle had a rod-like shape (length:500 nm, width:250 nm, particle size:360 ± 87 nm). The crystal structure of GaOOH didn’t change after the dope of Cr3+. GaOOH:Cr3+ was then converted into P-Ga2O3:Cr3+ by calcination at 1000℃ keeping its original shape, but the mesoporous structure appeared. Cell viabilities of L929 and MCF-7 cells were both above 80% even when the concentration of P-Ga2O3:Cr3+ reached 800 ug/ml. Furthermore, β-Ga2O3:Cr3+ didn’t induce the macrophages RAW 264.7 to produce inflammatory cytokines NO. The NIPL of β-Ga2O3:Cr3+ could be detected by in vivo imaging system. After being irradiated by UV, the long afterglow of β-Ga2O3:Cr3+ could last more than 72 h, and could be reactivated by white light. The NIPL signal in vivo of β-Ga2O3:Cr3+ which was irradiated by UV before subcutaneous injection or intravenous injection could be detected by in vivo imaging system. Using the NIPL for bioimaging, the autofluorescence of the tissues and organs could be eliminated.2. Hydrothermal method was improved and three different sizes of GaOOH:Cr3+ nanoparticles were synthesized at 95 ℃ under atmosphere in water system by manipulating the pH of the reaction medium. Rhombus-like GaOOH:Cr3+ nanoparticles with 126 ± 36.9 nm average particle size were acquired under pH 4.5 (Gl’).The GaOOH:Cr3+nanoparticles with a nanorod shape having aspect ratio 1:1 and 201 ±30.6 nm average particle size were obtained under pH 5.5 (G25), and the GaOOH:Cr3+ nanoparticles with nanorod shape having aspect ratio 1.5:1 and 314 ± 87.4 nm average particle size were prepared under pH 7.0 (G3’). GaOOH:Cr3+ was then converted to 0-(G1, G2, G3) by calcination with its original shape, but the mesoporous structure appeared as a result of the calcination. The crystal structure of β-Ga2O3:Cr3+ didn’t change with the dope of Cr3+. An emission spectrum from 700 to 750 nm was obtained after the dope of Cr3+. The more amount of Cr3+ in the β-Ga2O3, the stronger of the near infrared fluorescence intensity of β-Ga2O3:Cr3+ was.3. HA-L-Cys was synthesized by the formation of amido linkage between HA and L-Cys. And then the structure of HA-L-Cys was confirmed by 1H NMR and FTIR.β-Ga2O3:Cr3+ nanoparticles were then coated by HA-L-Cys through the electrostatic attraction and the formation of disulfide bond (HA-L-Cys/β-Ga2O3:Cr3+: H/G1, H/G2, H/G3), and after the coating, the stability of (3-Ga2O3:Cr3+ in PBS was significantly improved. The cell viabilities of MCF-7 and Hela cell were all above 80% even when the concentration of H/Gl, H/G2, H/G3 reached 1000 g/ml. For the tumor targeting drug delivery, DOX loaded (3-Ga2O3:Cr3+ nanoparticle was then coated by HA-L-Cys (HA-L-Cys/β-Ga2O3:Cr3+/DOX:H/G1/D, H/G2/D, H/G3/D). The release test showed that drug release behavior was GSH-sensitive. Drug release was slow in the low concentration of GSH environment (PBS7.4+10 uM GSH), and the drug release rate could be accelerated in the high concentration of GSH environment (PBS5.5+10 mM GSH). The pH change (pH5.5, pH7.0) of release medium had no significant effect to the release behavior.4. Cytotoxicities of H/G1/D, H/G2/D, H/G3/D and free DOX to MCF-7 and Hela cells were assessed by MTT method. The result showed that cytotoxicities of H/G1/D, H/G2/D, H/G3/D to Hela cell were higher than that of the free DOX. Cellular uptake of H/G1/D and G1/D (β-Ga2O3:Cr3+/DOX) by MCF-7 and Hela cell was studied by CLSM using the luminescent property of P-Ga2O3:Cr3+ nanoparticle. The results showed that the surface modification by HA-L-Cys could promote the cellular uptake. After being pre-treated by HA, the cellular uptake of H/G1/D by Hela cell was decresed. This meant that the cellular uptake of the nanoparticle was partly due to the HA receptor-mediated endocytosis. The cellular uptake of H/G1/D, H/G2/D, H/G3/D by Hela cell was studied by CLSM and FCM. The results showed that H/G2/D was most easily taken up by Hela cell than the other two kinds, which may be related to the size, shape and surface modification of the nanoparticle.5. Nude mice bearing Hela tumor were used as the model animal to study the bio-distribution of H/G1, H/G2, H/G3 by in vivo imaging system and the β-Ga2O3:Cr3+ was used as the fluorescent probe. The results showed that H/G1/D could accumulate into tumor tissue prominently compared to H/G2 and H/G3.In summary, this study constructed a multifunctional nano-drug delivery system. The β-Ga2O3:Cr3+ nanoparticle with excellent fluorescent properties and mesoporous structure was used as the fluorescence probe and anticancer drug carrier. Further, the HA modified with L-Cys was used as the tumor targeting group. The study provided a novel theoretic platform to expand the application of β-Ga2O3:Cr3+ in the bio-medicine field. |
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