Cells encapsulation

An interesting application of polycations is the encapsulation of cells, which can be considered as a form of a drug if used therapeutically, e.g. as implants or due to the substances they secrete, e.g. erythropoietin (EPO) or insulin. 

Alginate-poly(L-lysine)-alginate (APA) microcapsules were used to entrap EPO-secreting cells. Implantable and injectable hydrogel-based scaffolds containing the cells have been developed. The implantation of the cell-loaded capsules containing hydrogel-based scaffolds in mice revealed that hematocrit levels were maintained up to 80% for at least 2 months. 

HUVEC human umbilical vein endothelial cells 

Pillai and R. Panchagnula, Curr. Opin. Chem. Biol., 2001, 5, 447. 

Philipp, H. Dautzenherg, K. Linow, J. Kotz and W. Dawydoff, Prog. Polym. Sci., 1989,14, 91. 

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M. F. A. Goosen, ed., Eundamentals of Animal Cell Encapsulation and Immobilisation, CRC Press, Boca Raton, Fla., 1993. 

It appears that none of these process techniques is dominant, at least with the lactide/glycolide materials. Researchers have considerable choices available in regard to fabrication of microspheres from these polymers. The most commonly used procedures employ relatively mild conditions of pH and temperature and are usually quite compatible with the bioactive agents to be entrapped, including proteins and other macromolecules. Only in the case of live virus and living cell encapsulation have serious deactivation problems been encountered and those problems were due to solvents used in the process. 

Such hydrogels have been suggested to be suitable for biotechnological applications (DNA delivery vehicles, cell encapsulation) [28]. Recently, amphiphilic dibock copolypeptide hydrogels of KigoL2o were used in an in vivo study where the hydrogels were injected into the mouse forebrain. Evaluation of samples displayed substantial tissue integration with little or no detectable toxicity in the central nervous system [148]. 

Foo C, Lee JS, Mulyasasmita W et al (2009) Two-component protein-engineered physical hydrogels for cell encapsulation. Proc Natl Acad Sci 106 22067-22072... 

LS and CLS are solid microparticles with a mean diameter usually between 0.2 and 500 pm, composed of a solid hydrophobic fat matrix in which (in the case of LS) the bioactive compound or compounds are dissolved or dispersed. Because of their large range in particle size, LS can be administered by different routes, such as orally, subcutaneously, intramuscularly, or topically, or they can be used for cell encapsulation, thus allowing them to be proposed for treatment of a number of diseases [26-28], The in vivo distribution of LS demonstrated a high affinity to vascular wells (including capillaries), to inflamed tissues, and to granulocytes [29,30],... 

Keywords Cell encapsulation Cell engineering Cytocompatibility Hydrogel Phospholipid polymers... 

Gene Expression of Cells Encapsulated in PMBV/PVA Hydrogel. 155... 

Similarly to the phospholipid polymers, the MPC polymers show excellent biocompatibility and blood compatibility [43—48]. These properties are based on the bioinert character of the MPC polymers, i.e., inhibition of specific interaction with biomolecules [49, 50]. Recently, the MPC polymers have been applied to various medical and pharmaceutical applications [44-47, 51-55]. The crosslinked MPC polymers provide good hydrogels and they have been used in the manufacture of soft contact lenses. We have applied the MPC polymer hydrogel as a cell-encapsulation matrix due to its excellent cytocompatibility. At the same time, to prepare a spontaneously forming reversible hydrogel, we focused on the reversible covalent bonding formed between phenylboronic acid and polyol in an aqueous system. 

Cell encapsulation method using PMBV/PVA hydrogel... 

Figure 9 shows the proliferation of cells encapsulated in the PMBV/PVA hydrogel. The encapsulated cells (L929) did not proliferate with the excessive proliferation seen on the TCPS. The encapsulated cells were recovered from the PMBV/PVA... 

Fig. 14 Alkaline phosphatase staining of recovered ES cells after dissociation of PMBV/PVA hydrogel (left), and of the ES cells cultured on PMB30 (right). The undifferentiated ES cells were well stained. ES cells encapsulated in the PMBV/PVA hydrogel maintained their undifferentiated character during the 3 days of encapsulation...

Fig. 16 Fluorescence images of LIVE/DEAD assays of the L929 cells encapsulated for 4 days (a) in the miniaturized PMBV/PVA hydrogel formed in the microfluidic chip, and (b) in the bulk PMBV/PVA hydrogel formed in the 96-well microplate. Green fluorescence indicates live cells and red fluorescence indicates dead cells. Scale bar 100 pm...

Konno T, Ishihara K (2007) Temporal and spatially controllable cell encapsulation using a water-soluble phospholipid polymer with phenylboronic acid moiety. Biomaterials 28 1770-1777... 

Chou Al, Nicoll SB (2009) Characterization of photocrosslinked alginate hydrogels for nucleus pulposus cell encapsulation. J Biomed Mater Res A 91(1) 187-194... 

Whole-cell encapsulation in sol-gels and their applications... 

WHOLE-CELL ENCAPSULATION IN SOL-GELS AND THEIR APPLICATIONS... 

Stevenson WTK, Sefton MV (1993). In Goosen MFA (ed) Fundamentals of animal cell encapsulation and immobilization. CRC Press, Boca Raton, FL... 

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