Mercaptopurine-Loaded Sandwiched Tri-Layered Composed of Electrospun Polycaprolactone/Poly(Methyl Methacrylate) Nanofibrous Scaffolds as Anticancer Carrier with Antimicrobial and Antibiotic Features: Sandwich Configuration Nanofibers, Release Study and in vitro Bioevaluation Tests

BACKGROUND: 6-Mercaptopurine (6-MP) is a potential anti-cancer agent which its therapeutic and limitation applicability due to its high toxicity. OBJECTIVE: Herein, 6-MP was loaded into tri-layered sandwich nanofibrous scaffold (the top layer composed of poly methyl methacrylate/polycaprolactone (PMMA/PCL), the middle layer was PCL/PMMA/6-MP, and the bottom layer was PCL/PMMA to improve its bioactivity, adjusting the release-sustainability and reduce its toxicity. METHODS: Electrospun tri-layered nanofibers composed of PCL/PMMA were utilized as nano-mats for controlling sustained drug release. Four groups of sandwich scaffold configurations were investigated with alteration of (PMMA: PCL) composition. RESULTS: The sandwich scaffold composed of 2%PCL/4%PMMA/1%6-MP showed the best miscibility, good homogeneity and produced the smoothest nanofibers and low crystallinity. All fabricated 6-MP-loaded-PCL/PMMA scaffolds exhibited antimicrobial properties on the bacterial and fungal organisms, where the cytotoxicity evaluation proved the safety of scaffolds on normal cells, even at high concentration. Scaffolds provided a sustained-drug release profile that was strongly dependent on (PCL: PMMA). As (PCL: PMMA) decreased, the sustained 6-MP release from PCL/PMMA scaffolds increased. Results established that ~18% and 20% of 6-MP were released after 23h from (4%PCL/4%PMMA/1%6-MP) and (2%PCL/4%PMMA/1%6-MP), respectively, where this release was maintained for more than 20 days. The anti-cancer activity of all fabricated scaffolds was also investigated using different cancerous cell lines (e.g., Caco-2, MDA, and HepG-2) results showed that 6-MP-loaded-nanofibrous mats have an anti-cancer effect, with a high selective index for breast cancer. We observed that viability of a cancer cell was dropped to about 10%, using nanofibers containing 2%PCL/4%PMMA/1%6-MP. CONCLUSION: Overall, the PCL: PMMA ratio and sandwich configuration imparts a tight control on long-term release profile and initial burst of 6-MP for anticancer treatment purposes.