Mesoporous bioactive glass-polyurethane nanocomposites as reservoirs for sustained drug delivery

The materials capable of sustained drug release are highly desired in the biomedical field, and for this purpose, mesoporous bioactive glass (MBG) and polyurethanes (PUs) are being used along with various other materials. However, MBG is highly brittle and PUs suffer from the lower tensile strength value. Therefore, to overcome these shortcomings, bioactive nanocomposites were designed and fabricated by using MBG and biodegradable PUs. MBG with variable percentages was used as filler in arginine and starch-based PU matrices. The structural, mechanical and physicochemical properties were evaluated by fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), stress-strain curves and MTT assay. All the nanocomposites exhibited high cell viability (96-100%) and are therefore designated as biocompatible. The young's modulus is in the range of 0.5-0.8 MPa, which perfectly matches with that of cancellous bones. The nanocomposites were further studied for sustained drug delivery of an anti-cancer drug, imatinib. There was no burst effect and 52-84% of the drug was released over a period of three weeks. Consequently, these nanocomposites behaved as reservoirs for sustained drug release and can be applied for reducing the dose frequency where required.