Search

Alginate is currently being employed and explored for a broad range of biomedical and biotechnology applications, due to its biodegradability and simple procedure for cell immobilization. However, cell immobilization was mostly aimed for immunoisolatory and biochemical processing applications and far less is known about potentials of alginate as a substrate for tissue formation. In the present work, isolation, immobilization and cultivation procedures of murine bone marrow stromal cells (BMSC) were studied and standardized in order to establish the alginate-bioreactor culture system for chondrogenic and/or hematopoiesis-supportive tissue progression. Two techniques for cell immobilization based on alginate were investigated: entrapment within gel matrix using electrostatic droplet generation and simple cell adsorption onto gel surfaces. Alginate gels in forms of microbeads and discs with immobilized culture expanded BMSC were cultivated for up to 30 days and analyzed for surface properties, cell concentration, viability, and differentiation.

Alginate is currently being employed and explored for a broad range of biomedical and biotechnology applications, due to its biodegradability and simple procedure for cell immobilization. However, cell immobilization was mostly aimed for immunoisolatory and biochemical processing applications and far less is known about potentials of alginate as a substrate for tissue formation. In the present work, isolation, immobilization and cultivation procedures of murine bone marrow stromal cells (BMSC) were studied and standardized in order to establish the alginate-bioreactor culture system for chondrogenic and/or hematopoiesis-supportive tissue progression. Two techniques for cell immobilization based on alginate were investigated: entrapment within gel matrix using electrostatic droplet generation and simple cell adsorption onto gel surfaces. Alginate gels in forms of microbeads and discs with immobilized culture expanded BMSC were cultivated for up to 30 days and analyzed for surface properties, cell concentration, viability, and differentiation.

Cartilage tissue engineering based on chondrogenic cells seeded onto biodegradable polymer supports and cultivated in bioreactors can potentially become an effective method for creating functional tissue equivalents. Cultivation in perfused bioreactors can improve the uniformity and structure of the engineered tissues. We report studies of two different supports for immunobilization of mouse bone marrow stromal cells (BMSC) for cultivation in perfused bioreactors: fibrous polyglycolic acid (PGA) scaffolds and alginate microbeads.

Cartilage tissue engineering based on chondrogenic cells seeded onto biodegradable polymer supports and cultivated in bioreactors can potentially become an effective method for creating functional tissue equivalents. Cultivation in perfused bioreactors can improve the uniformity and structure of the engineered tissues. We report studies of two different supports for immunobilization of mouse bone marrow stromal cells (BMSC) for cultivation in perfused bioreactors: fibrous polyglycolic acid (PGA) scaffolds and alginate microbeads.

Liposomes, closed spherical structures formed by phospholipid bilayers, have been recognized as a controlled drug delivery system. We have studied the preparation and biocompatibility of liposomes based on soya phospholipids encapsulated with alpha-tocopherol. The binding efficiency of alpha-tocopherol was analysed by comparing two methods for liposome preparation: a) dry film (DFM) and b) solvent infusion method (SIM). The degree of encapsulation achieved (88-93%) suggested a high affinity of alpha-tocopherol for liposome membrane binding. The initial concentration of alpha-tocopherol had a significant effect on the degree of encapsulation, while the effect of method used was less pronounced. In general, a higher degree of encapsulation was achieved with smaller liposome size fractions. Based on an experimentally obtained size distribution function, it can be concluded that if smaller liposomes are used, SIM seems to be more efficient due to the higher content of smaller vesicles. The in vivo application of the liposomes to CBA mice confirmed the biocompatibility and nontoxicity of such preparations. The analysis of hematological parameters in peripheral blood (determination of mature blood cells with differential count) revealed that liposomes did not express cytotoxic effects on any of the parameters tested.

Liposomes, closed spherical structures formed by phospholipid bilayers, have been recognized as a controlled drug delivery system. We have studied the preparation and biocompatibility of liposomes based on soya phospholipids encapsulated with alpha-tocopherol. The binding efficiency of alpha-tocopherol was analysed by comparing two methods for liposome preparation: a) dry film (DFM) and b) solvent infusion method (SIM). The degree of encapsulation achieved (88-93%) suggested a high affinity of alpha-tocopherol for liposome membrane binding. The initial concentration of alpha-tocopherol had a significant effect on the degree of encapsulation, while the effect of method used was less pronounced. In general, a higher degree of encapsulation was achieved with smaller liposome size fractions. Based on an experimentally obtained size distribution function, it can be concluded that if smaller liposomes are used, SIM seems to be more efficient due to the higher content of smaller vesicles. The in vivo application of the liposomes to CBA mice confirmed the biocompatibility and nontoxicity of such preparations. The analysis of hematological parameters in peripheral blood (determination of mature blood cells with differential count) revealed that liposomes did not express cytotoxic effects on any of the parameters tested.