Vivo Biocompatibility of Dextran Based Hydrogels

Both non-degradable dex-MA and degradable dex-lactateHEMA discshaped hydrogels varying in initial water content and degree of substitution were implanted subcutaneously in rats. The tissue reaction was evaluated over a period of 6 weeks.  

The initial foreign body reaction to the dex-MA hydrogels was characterized by infiltration of granulocytes and macrophages and formation of fibrin, exudate as well as new blood vessels. This reaction depended on the initial water content as well as the DS of the hydrogel and decreased within 10 days. The mildest tissue response was observed for the gel with the highest water content and intermediate DS. At day 21, all dex-MA 

A biodegradable and biocompatible dextran hydrogel system has been developed of which the degradation time can be tailored between 2 days and 3 months. This chapter shows that hydrogels based on crosslinked dextrans have unique properties as protein releasing matrices. Both the release pattern (first-order, zero-order or biphasic) as well as the duration of the release can be controlled by an appropriate selection of the characteristics and the geometry of the hydrogel. 

This research is supported by the Dutch Technology Foimdation (STW, grant numbers UPR 66.4049 and UFA55.3931). 

Crommelin and R.D. Sindelar (Eds.), 991, Pharmaceutical Biotechnology, Harwood Academic, Amsterdam. 

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Cadee JA, Van Luyn MJA, Brouwer LA, Plantinga JA, Van Wachem PB, De Groot CJ, Den Otter W, Hennink WE. In vivo biocompatibility of dextran-based hydrogels. J Biomed Mater Res 2000 50 397-404. 

Journal of Biomedical Materials Research 50, No.3, 5th June 2000, p.397-404 IN VIVO BIOCOMPATIBILITY OF DEXTRAN-BASED HYDROGELS... 

Dextran-based hydrogels were produced by the polymerisation of aqueous solutions of methacrylated dextran or lactate-hydroxyethyl methacrylate-derivatised dextran and implanted subcutaneously in rats for up to 6 weeks. The effects of initial water content and degree of substitution of these hydrogels on tissue response were examined and the relationship between in vitro and in vivo degradation behaviour was investigated. The results obtained indicated that these hydrogels were biocompatible and could be potential candidates for drug delivery systems. 20 refs. 

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