High therapeutic efficacy of 5-Fluorouracil-loaded exosomes against colon cancer cells.

The successful chemotherapeutic regime required for the clinical management of different cancers largely depends on the efficient drug delivery within the cancer cells. Exosomes have emerged as an enticing candidate for exploring their role as delivery vehicles. Exosomes are reported to be intrinsically nanosized vesicles competent for efficient delivery across the cellular membrane. In the present study, we assessed the feasibility of an autologous exosome-based drug delivery platform for delivering 5-Fluorouracil (5-FU) against human colon cancer HCT116 cells. Autologous exosomes have shown probable tropism toward the tumor microenvironment, which makes them the most competitive vehicle for drug delivery. It was observed that the autologous exosomes loaded with 5-FU showed an enhanced rate of drug release under acidic conditions. The result of the cell viability assay showed that treatment of 5-FU-loaded exosomes (equivalent to 5 µg 5-FU) resulted in enhanced cytotoxic effect in HCT116 cells as compared to an equivalent amount of free 5-FU (5 µg), which elucidated the efficient delivery of the 5-FU by exosomes inside the cancer cells. Subsequently, 5-FU-loaded exosomes led to increased nuclear condensation and fragmentation along with increased ROS production. In addition, 5-FU-loaded exosomes caused enhanced dissipation of mitochondrial membrane potential and caspase-3 activation, resulting in increased apoptosis induction. Our study also revealed that 5-FU-loaded exosomes upsurged the arrest in the cell cycle at the G0/G1 stage in HCT-116 cells and it was found to be associated with decreased CDK4 and Cyclin D1 expression concomitantly with the upregulation of CDK inhibitor, p21Cip1 expression. Thus, the findings from the present study highlight the advantages of autologous exosomes as a natural drug carrier which could efficiently deliver chemotherapeutic drugs to cancer cells.

Production and characterization of carboxymethyl cellulase from Paenibacillus polymyxa using mango peel as substrate.

Mango peel, a solid mango processing waste, comprises 15-20% of total fruit weight. This, being a rich source of lignocelluloses, was used as substrate for carboxymethyl cellulase (CMCase) production using Paenibacillus polymyxa. Maximum CMCase production (7.814 U mg(-1)) was observed in a medium containing 7% mango peel (w/v) with 1.5% ammonium sulphate (w/v) at 37 degrees C and pH 5.5. Purification to an extent of 28.24 fold was achieved by affinity column chromatography. Bands corresponding to 26.5 and 34.0 kDa molecular sizes were observed on 12% denaturing Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) while of 72 kDa on 10% non-denaturing Native-PAGE, proving its heteromeric multienzyme nature. The enzyme was stable over a range of 20-60 degrees C and pH of 4.0-7.5. Michaelis-Menten equation constant (Km and Vmax) values of purified CMCase were 8.73 mg ml(-1) and 17.805 mM ml(-1) min(-1), respectively.