Encapsulation has been developed as a tool for the transport of cells or proteins into the human organism. The therapeutic potential of encapsulated cells or proteins is promising for treating patients who suffer from tissue loss, neurodegenerative disorders, diabetes, liver failure, and other diseases caused by specific vital cellular dysfunctions. However, those self-assembly hollow spheres lack biocompatibility and non-biodegradability because the rod-like blocks are π-conjugated long chains formed by synthesis method.
For responding this challenge, Prof Dr Li Bang-Jing’s group at Chengdu Institute of Biology (CIB, CAS) and Prof Dr Sheng Zhang’s group at State Key Laboratory of Polymer Materials Engineering, Sichuan University (SKLPME, SCU) have applied the inclusion complexes of polysaccharide (alginate, chtosan, konjac glucomannan)-graft–PEG and a-CD, F127 and β-CD as a rigid block to improve the biocompatibility and biodegradability of such self-assembly hollow spheres in previous reports.
Researchers made a system, in which a-CD or β-CD rings are stacked along the graft PEG or PO unit of F127 axis to form a channel-type crystalline structure. Meanwhile, since the good water solubility of polysaccharide and F127, the polysaccharide-g-PEG/a-CD or F127/β-CD complexes have both a rod block (PEG-a-CD or EO-β-CD) and a coil block (polysaccharide and F127 backone). In their selective solvent (water), the rod-like block in the rod-coil system preferred crowded parallel packing and resulted in the formation of hollow spheres for necessary of the efficient space-filling packing. Finally, with the formation of insoluble inclusion blocks, water became a selective solvent, so hollow spheres were formed.
In summary, those series of researches not only enriches the preparation methods of biocompatible hollow nanospheres, but also demonstrates that those novel hollow spheres have great therapeutic potential.
Main findings of those studies have been published on Langmuir, 2011, DOI: 10.1021/la2028803, Macromol. Rapid Commun. 2011, DOI: 10.1002/marc.201100514, Macromol. Rapid Commun. 2011,DOI: 10.1002/marc.201100272, Soft Matter, 2011, DOI: 10.1039/c0sm00896f, Soft Matter, 2010, DOI: 10.1039/b925747k, Chem. Commun., 2010, DOI: 10.1039/b916224k, J. Colloid Interf. Sci., 2010, DOI: 10.1016/j.jcis.2010.07.019, Carbohydr. Polym., 2011, DOI: 10.1016/j.carbpol.2011.04.01 etc.