Biofunctionalization Of Amphiphilic Dextran Decorated Poly(D, L-lactide) Particles For Targeting To Brain Glioma

A series of cholesterol hydrophobic modified dextran derivates bearing aldehyde (Chol-Dex-CHO), hydrazide (Chol-Dex-NH2) and biotin (Chol-Dex-biotin) groups were synthesized respectively by first esterifying of dextran polyaldehyde with cholesterol-3-hemisuccinyl chloride, then reacting aldehyde groups with adipic dihydrazie, and finally conjugating carbodiimide-activated biotin to amino groups. The degree of oxidation (DO) and substitute of the amphiphilic dextran derivates was analysized by Fuchsin-UV-visible spectrophotometer and 1H-NMR spectra respectively. FTIR measurement demonstrated the presence of hydrazide groups in Chol-Dex-NH2, and 1H-NMR spectrum confirmed the conjugation of biotin.The self-aggregates properties of Chol-Dex-CHO derivates were investigated by surface tension, viscosity, fluorescent spectroscopy and dynamic light scattering measurement. The results showed that: 1. most of Chol-Dex-CHO derivates expressed CMC between 0.25-0.5mg/mL and CAC around 0.02 mg/mL in neuter medium; 2. acidic and alkaline medium changing caused CMC and CAC decrease; 3.micelles exhibited more aggregated and formed larger size in acidic medium; 4. lower DS and DO endowed the derivates with better surface activity; 5. viscosity of micelles solution decreased along with the increase of derivates'DS/DO value and system temperature, as well as acidic and alkaline medium.By co-dialyzing of poly(lactic acid) with Chol-Dex-CHO DMSO solutions against water, polysaccharide surface-ecorated poly(lactic acid) nanoparticles(NPs) and Hybrid Hollow microcapsules(HHMC) were obtained by control the ratio of poly(lactic acid) to Chol-Dex-CHO. The TEM, SEM and AFM observation showed that NPS and HHMC were spheral in shape, and DLS measurement showed both NPS and HHMC possess a narrow size distribution. XPS results suggest that the NPs surface was coated with a thick layer of polysaccharide derivate, while the HHMC was composed of poly(lactic acid) and Chol-Dex-CHO. FT-IR and DSC demonstrated the interaction between poly(lactic acid) and Chol-Dex-CHO molecules, and the 1H-NMR result indicated that no poly(lactic acid) was lost during dialysis process, so it can be concluded that the HHMC was formed through assembly mechanism.The biofunctionalization of NPs was performed using Rabbit IgG as model protein based on Schiff's base reaction, the process of covalent coupling was evaluated by ELISA and Fuchsin-UV-visible spectrophotometer method. Meanwhile,...