Chemical Modification to the Surface of Mesoporous Silica Nanoparticles Effects on the Blood-Brain-Barrier Permeability, Nano-Hazard, and Immune-Enhance

The development of new nanomaterials in biotechnology could result in significant benefits for health impacts. Mesoporous silica nanoparticle (MSN) due to tunable particle size, pore structure, surface functionalization and biocompatibility became a promising drug delivery system or biomedical research tool. For providing clinical applications, studies focusing on biocompatibility, bio-hazard and bio-adhesive properties should be conducted. However, lack of knowledge about how the protein corona alters the cell response, particularly at the molecular level since even a little difference in the surface heterogeneity can result in profoundly different interactions with cells and tissues. In present proposal, we are going to investigate the surface modification which may benefit the BBB permeationvia protein corona, nano-hazards exposed from the conjugation of linkers and the neutralization of cytotoxic charged MSN and immune enhancer DNA. For the study of protein corona of charged MSNs and BBB permeability, we aim to evaluate the charge and size effect in zebrafish in vivo. (i) We will synthesize four types of 50 nm MSNs (wn-, sn-, wp-, sp-R-MSN@PEG, zeta potentials around -10.0, -40.0, +10.0, +40.0 mV) and four more negative charged MSNs (around -20.0, -30.0, and -50.0 mV) with different sizes of around 50, 150, 200 nm; (ii) Evaluation the permeability into BBB by thoracic injection by confocal microscopy; (iii) The proteomic analysis to identify the possible proteins involving in protein corona; (iv) Evaluation the BBB permeability on the complex of R-MSN@PEG and candidate proteins; (v) cellular toxicity test in several related brain cell lines. For the study on Nano-hazards of MSN conjugated linkers, we investigate the cell responses of MSN-Linkers in Raw 264.7 macrophages. (i) We prepared MSN with conjugation of four kind linkers, i.e. AMAS, MBS, SMCC and MAL-PEG-SCM, onto the surface of MSN; (ii) Cell responses in Raw 264.7 on the cell uptake efficiency, ROS generation, p38 or p21 activation; (iii) Cell responses of NF-kB p65 by confocal imaging and cell cycle progression by flow cytometry; (iv) In addition, we conjugate of BSA or TAT to block the linker and observe the hindrance effects. For the study of charge neutralization and immune enhancer, our strategy is to choose a functional IRF9S2C DNA to neutralize the positive charge of embryo-toxic MSN and further which is delivered as carrier into zebrafish embryo to exhibit the immune promotion. (i) synthesis of sp-R-MSN@PEG (POS-MSN); (ii) IRF9S2C encoded DNA loaded POS-MSN; (iii) IRF9S2C DNA loaded POS-MSN (red) soaked in larval fish; (iv) Evaluation the expression of IRF9S2C by confocal microscopy; (v) Quantification of mRNA and anti-viral evaluation by TCID.