The effectiveness of TCPL devices to deliver various molecular weight proteins in vitro

This study was conducted: (i) to investigate the ability of tricalcium phosphate-lysine (TCPL) devices to deliver Bovine Serum Albumin (BSA), Gamma-Globulin (G), Thyroglobulin (THG), and Insulin (I) at sustained manner, and (ii) to study the effect molecular size and structures might have on the sustained delivery profiles of proteins. Forty-eight cylindrical blocks were fabricated by compressing TCPL-protein (90:3:10 mixtures) in a hydraulic press at 8600 Kg compression load. Each device was then suspended in individual serum bottles containing 100 ml of phosphate buffer saline (pH 7.4), and maintained in a water bath with a temperature setting of 37°C and agitating at 100 cpm. The amount of protein(s) released into the solution was determined colorimetrically. The results of this investigation revealed that: (i) TCPL devices are capable of delivering proteins at a sustained levels and the delivery rate was directly proportional to the molecular size of the protein molecules, and (ii) the rate of release of proteins from TCPL devices is influenced by the ionic interaction between the TCPL surface, solvent system, and stereochemistry of the materials to be delivered