Design, synthesis and biological evaluation of novel cationic liposomes loaded with melphalan for the treatment of cancer.

Therapeutically active lipids in drug delivery systems offer customization for enhanced pharmaceutical and biological effects, improving safety and efficacy. Biologically active N, N-didodecyl-3,4-dimethoxy-N-methylbenzenaminium lipid (Q) was synthesized and employed to create a liposome formulation (FQ) encapsulating melphalan (M) through a thin film hydration method. Synthesized cationic lipids and their liposomal formulation underwent characterization and assessment for additive anti-cancer effects on myeloma and melanoma cancer cell lines. These effects were evaluated through various studies, including cytotoxicity assessments, cell cycle arrest analysis, apoptosis measurements, mitochondrial membrane potential depolarization, DNA fragmentation, and a significant reduction in tumorigenic potential, as evidenced by a decrease in both the number and percentage area of cancer spheroids.

Poly-L-lysine Coated Oral Nanoemulsion for Combined Delivery of Insulin and C-Peptide.

An attempt of co-delivery of insulin and C-peptide enclosed in linseed oil globules has been made employing a protective coating of positively charged poly-L-lysine to manage diabetes-associated complications. Oral water in oil in water (w/o/w) nanoemulsion manufactured by double emulsification method showed good entrapment efficiency of 87.6 ± 7.48% for insulin and 73.4 ± 6.44% for C-peptide. The optimized uncoated nanoemulsion showed a mean globule size of 210.6 ± 9.87 nm with a good PDI of 0.145 ± 0.033 and -21.7 ± 4.5 mV ZP. The poly-L-lysine coating of the nanoemulsion resulted in the reversal of surface charge to positive i.e. 18.3 ± 2.7 mV due to the cationic nature of poly-L-lysine. In vitro drug release showed an initial burst of 15-20% release within 4 h followed by controlled release up to 24 h. The poly-L-lysine coated nanoemulsion showed an 8.28-fold higher uptake than fluorescein isothiocyanate (FITC) solution in HCT116 intestinal cell lines. In vivo studies confirmed that orally administered insulin and C-peptide bearing coated nanoemulsion has the potential to improve glycemic control confirmed by blood glucose level under 200 mg/dL for 12 h compared to that of subcutaneous administration of insulin. The formulation was found stable at 25 °C as well as 4°C for up to 3 months. These findings show a promising approach for delivering oral insulin along with C-peptide for effective glycemic control and management of complications associated with diabetes.

Paclitaxel-loaded TPGS enriched self-emulsifying carrier causes apoptosis by modulating survivin expression and inhibits tumour growth in syngeneic mammary tumours.

Paclitaxel (PTX) in its commercial products exhibits adverse effects owing to excipients and also has poor oral bioavailability. Present work is directed towards development of tocopheryl polyethylene glycol succinate-assisted self-nanoemulsifying system (SEDDS) for oral delivery of PTX. Box-Behnken design of experiment was employed to optimize PTX-SEDDS and was characterized for droplet size (29.76 ± 2.64 nm), zeta potential (-21.46 ± 2.52 mV), PDI (0.177 ± 0.012), drug content (4.97 ± 0.98 mg), entrapment efficiency (98.33 ± 0.54%) and in vitro drug release (51.03 ± 2.23% PTX at 72 h). PTX-SEDDS exhibited IC50; 1.58 ± 0.12 µM and a 52.46-folds higher cell uptake in MDA-MB-231 cells along with cellular and nuclear morphology changes. Significantly higher G2M cell cycle arrest, apoptosis, mitochondrial membrane potential disruption and ROS production was exhibited by PTX-SEDDS in comparison to Taxol. Up-regulation of Bax, p21, cleaved-caspase 3, -caspase 9 and down-regulation of Bcl2 and survivin suggested apoptosis via intrinsic pathways. Pharmacokinetic study showed approximately 4-folds higher oral bioavailability of PTX-SEDDS than Taxol. Significant reduction in tumour volume and weight was observed in syngeneic mammary tumour in SD rats. Tumour histopathology and TUNEL assay showed apoptosis in tumour tissue. PTX-SEDDS caused low lung metastasis, and was safe and stable. Conclusively, PTX-SEDDS could be suitable option for oral delivery of PTX.

Synthesis and evaluation of thiouracil derivatives as dipeptidyl peptidase IV inhibitors.

A series of thiouracil derivatives were designed, synthesized and screened for in vitro inhibition of dipeptidyl peptidase IV. The SAR study indicated the influence of substituted chemical modifications on thiouracil scaffold. Compounds 8 (IC(50) = 0.32 µM), 9 (IC(50) = 0.29 µM), and 12 (IC(50) = 0.25 µM) showed excellent dipeptidyl peptidase IV inhibition having heterocyclic substituted piperazine with acetamide linker resulted as most potent dipeptidyl peptidase IV inhibitors among all the compounds screened. Single dose (10 mg/kg) of the compounds 8, 9, and 12 significantly reduced glucose excursion during oral glucose tolerance test in streptozotocin-induced diabetic rat model. The present study on substituted thiouracil derivatives shows good-to-moderate inhibitory potential of dipeptidyl peptidase IV enzyme.

Synthesis, evaluation and molecular docking of prolyl-fluoropyrrolidine derivatives as dipeptidyl peptidase IV inhibitors.

A series of prolyl-fluoropyrrolidine derivatives were designed, synthesized and screened for in vitro inhibition of dipeptidyl peptidase IV. The SAR study revealed the influence of substituted chemical modifications on dipeptidyl peptidase IV inhibitory activity. Among all the compounds screened, compound 9 (IC50  = 0.83 µm) and 10 (IC50  = 0.43 µm) possessing aryl substituted piperazine with acetamide linker resulted as most potent dipeptidyl peptidase IV inhibitors. Both the compounds 9 and 10 resulted significant reduction in glucose excursion during oral glucose tolerance test in streptozotocin-induced diabetic rat model at single dose of 10 mg/kg. Molecular docking studies were performed to illustrate the probable binding mode and interactions of prolyl-fluoropyrrolidine nucleus and its derivatives at binding site of receptor. The fluoropyrrolidine moiety of prolyl-fluoropyrrolidine derivatives occupied S1 pocket as observed in the crystal structure (PDB id: 2FJP). The compounds 9 and 10 were observed to occupy S2 binding pocket and were observed to have interaction with Arg125, Tyr547 and Ser630 acquired through hydrogen bond. The aryl moiety at piperazine ring was found to extend into the cavity and interacted with Arg358. The observed interactions signalled that occupancy of the highly hydrophobic S2 pocket is very crucial for dipeptidyl peptidase IV inhibitory activity.

Synthesis, evaluation and molecular docking of thiazolopyrimidine derivatives as dipeptidyl peptidase IV inhibitors.

A series of thiazolopyrimidine derivatives was designed, synthesized and screened for in-vitro inhibition of Dipeptidyl Peptidase IV (DPP IV). The SAR study indicated the influence of substituted chemical modifications on thiazolopyrimidine scaffold. Compound 9 (IC(50) = 0.489 µm) and 10 (IC(50) = 0.329 µm) having heterocyclic-substituted piperazine with acetamide linker resulted as most potent DPP IV inhibitors among all the compounds screened. Single dose (10 mg/kg) of both the compounds 9 and 10 significantly reduced glucose excursion during oral glucose tolerance test in streptozotocin induced diabetic rat model. Molecular docking studies illustrated the probable binding mode and interactions of thiazolopyrimidine nucleus and its derivatives at binding site of receptor. The binding site for DPP IV is composed of active site region (catalytic triad of Ser630, Asp708 and His740) including S1 and S2 sub-pocket. The aryl moiety of compounds 9, 10 and 11 were observed to occupy S2 binding pocket and interacted with aromatic ring of Tyr662 and Tyr666 acquired through π-π interaction. Thus, it is indicated that occupancy of the highly hydrophobic S2 pocket is more important for DPP IV inhibitory activity. The present study on substituted thiazolopyrimidine derivatives shows good to moderate inhibitory potential of DPP IV enzyme.