MICROCARRIERS FROM INORGANIC MATERIALS - PHASE I

THE LONG TERM OBJECTIVE OF THIS STUDY IS TO DEVELOP A MICROCARRIER SUBSTRATE FOR GROWING FASTIDIOUS ANCHORAGE DEPENDENT CELLS WHICH IS SUPERIOR TO CURRENT MICROCARRIER PRODUCTS. MICROCARRIER SYSTEMS SHOW GREAT POTENTIAL FOR THE LARGE SCALE GROWTH OF CELLS AND THE PRODUCTION OF THEIR METABOLIC PRODUCTS. THE AIM OF PHASE I IS TO PRODUCE MICROCARRIERS OF NEAR IDEAL SIZE AND DENSITY FROM SEVERAL INORGANIC MATERIALS AND THEN TO EVALUATE THEIR ABILITY TO SUPPORT THE GROWTH OF HUMAN DIPLOID FIBROBLASTS IN SMALL SCALE STATIONARY AND SUSPENSION CULTURES. INORGANIC MATERIALS HAVE THE POTENTIAL TO BE COST EFFECTIVE IN INDUSTRIAL SYSTEMS BECAUSE OF THEIR EXPECTED DURABILITY AND THUS THEIR POTENTIAL FOR REUSE. CURRENT POLYMER BASED MICROCARRIERS HAVE LITTLE POTENTIAL FOR OR ARE INTRINSICALLYNOT REUSABLE. THE MATERIAL SELECTED FOR THIS STUDY (SI, SIO(2) ONE TYPE OF GLASS) HAVE BEEN SHOWN TO SUPPORT GROWTH IN A CONVENTIONAL MONOLAYER CULTURE. IN ADDITION A LARGE AMOUNT OF RECENT DATA FROM THE FIELD OF CELL BIOLOGY SHOWS THE TREMENDOUS INFLUENCE THE SUBSTRATE HAS ON THE BIOLOGICALBEHAVIOR OF CELLS. THUS THE INORGANIC MATERIALS CHOSEN MAY ALSO HAVE THE POTENTIAL FOR SUPPORTING IMPROVED CELL GROWTH AND/OR MORE FAVORABLE METABOLIC ACTIVITY. PRELIMINARY STUDIES HAVE SHOWN THAT A VARIETY OF CELLS GROWN ON ONE TYPEOF GLASS MICROCARRIER WERE INDEED BIOLOGICALLY DIFFERENT FROM CELLS GROWN ON DEXTRAN BASED MICROCARRIERS. THE MICROCARRIERS WILL BE PRODUCED BY PHYSICAL VAPOR DEPOSITION SPECIFICALLY SPUTTERING. USING THIS TECHNIQUE THE OXYGEN CONTENT CAN BE CONTROLLED FROM SI (NO OXYGEN) TO SIO(2); THUS ALTERING THE SURFACE CHARGE STATE OF THE MICROCARRIER. THE SIMPLICITY AND ECONOMY OF THE FABRICATION PROCESSES WILLALSO BE CONSIDERED. THE MICROCARRIERS WILL BE 100-150 M IN DIAMETER WITH THE DENSITY OF .04 G/CC. THESE PARAMETERS MAXIMIZE THE SURFACE AREA WHILE STILL SUPPORTING CELL GROWTHAND ARE NEARLY NEUTRALLY BOUYANT IN OUR CULTURE MEDIA. HOWEVER, BOTH THE SIZE AND DENSITY CAN READILY BE VARIED IN THE APPLICANT'S MANUFACTURING PROCESS. BIOLOGICAL ACTIVITY WILL BE EVALUATED BY CONVENTIONAL CELL CULTIVATION PROTOCOLSAND QUANTITATION TECHNIQUES. GROWTH OF THE MRC-5 STRAIN OF HUMAN DIPLOID FIBROBLASTS ON THE TEST MATERIALS WILL BE COMPARED TO MONOLAYER CULTURES AND COMMERCIALLY AVAILABLE DEAE DEXTRAN TYPE MICROCARRIERS IN STATIONARY AND SUSPENSIONCULTURES.