Nanocarriers, circulation stability

Due to its hydrophilic nature, dextrans have also been used to conjugate bioactive substances (e.g., dmgs, enzymes, hormones, and antibodies) to prolong circulation lifetimes, increase stability in vivo, or depress antigenicity. For example, dextran nanoparticles have been conjugated with insulin for oral delivery. These nanocarriers can protect insulin from degradation in the gut and modulate release profiles. ... 

A combinatorial coating of PEG and cationic WSC, on PLA nanoparticles, has yielded greatly prolonged circulation time for the nanocarriers in vivo. In contrast to PLA nanoparticles treated with PEG or WSC alone, PEG and WSC synergisticaUy provided a strong inhibition of macrophage uptake and extended the circulation half-life up to 63.5 h, with concomitant reduced liver sequestration. This ty2 value was much longer than that of control PEG/PVA nanoparticles (1.1 h) as well as that of PLA nanoparticles stabilized with PEG/CPCTS (anionic N-carboxy propionyl... 

The functionalization of the external surface plays an important role in the colloidal stability of the INPs and their interactions with the environment, that is, with living cells and other biological substrates. In particular, the functionalization of the outer NP surface with PEG was well developed due to the remarkable ability of PEG to resist protein adsorp-tion. ° ° All these features inaease the NP blood circulation time for in vivo applications. ° ° PEGylated silica NPs produced through the sol-gel method have received great attention in recent years, as nanocarriers for biomedical appli-cations. The synthesis of the PEGylated NPs was carried out in two steps (Figure 10(a)). 

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