Preparation And In Vitro Drug Release Of GM/C_aSO₄/β-TCP/PPF Composite Biomaterials

The objective of the research presented here is to design local drug delivery system——CaSO₄/β-TCP,CaSO₄/β-TCP/PPF composite biomaterials. The drug loading and releaing in vitro were discussed.Preparedβ-TCP powder by chemical coprecipitation method, then investigated on the preparation of porous spherical CaSO₄/β-TCP granules by CaSO₄2·H₂O andβ-TCP powder. Poly(propylene fumarate)(PPF) was synthesized by a three-step method, and characterized with FT-IR, H-1NMR. PPF can be crosslinked with a vinyl pyrroliidinine at 37°C. N-viny pyrrolidinine(N-VP) was used as a crosslinking monomer, benzoyl peroxide(BPO) as a radical polymerization initiator and N,N-dimethyl-p-toluidine(DMPT) as an accelerator. CaSO₄/β-TCP/PPF composites were formed through the incorporation of porous spherical CaSO₄/β-TCP granules as an osteoconductive agent.GM loaded CaSO₄/β-TCP, CaSO₄/β-TCP/PPF composites were characterized by scaning electron microscopy (SEM), and UV spectrometer. The release performances of GM loaded CaSO₄/β-TCP, CaSO₄/β-TCP/PPF composites in vitro were also studied. SEM observation showed CaSO₄/β-TCP was spherical in shap and porous in nature. The average sizes of microspheres were 0.2-1.2 mm, The drug loading of CaSO₄/β-TCP, CaSO₄/β-TCP/PPF composites were 3.92%, 3.10%.There are two steps in releasing for CaSO₄/β-TCP, CaSO₄/β-TCP/PPF loading drug composites. The first step is abrupt release in initial 6 hours, release percentage is 41.62%, 36.16%; The second step is sustained release in 12h-36h, the accumulative release percentage is from 78.48% to 96.65% for CaSO₄/β-TCP and for CaSO₄/β-TCP/PPF composites is from 52.48% to 76.74%. As for the release rate curve, the CaSO₄/β-TCP/PPF composite is more mild. Conclusion is that the local drug delivery system has good drug-release performance in vitro and may possess potential value in clinical management.