5-Fluorouracil (5-FU) 99% purchased from (Cas No. 51.21.9) Sigma-Aldrich, India, ?-Tocopherol was purchased from TCI chemicals (India) Pvt. Ltd (Cas No. 59-02-8). PLGA purchased from Sigma-Aldrich, India (Product No. 808482-5G), SCC-15 cell lines procured from National Centre for Cell Sciences, Pune, India. The other entire chemicals (analytical grade) were purchased from Sigma-Aldrich, India.
Preparation of targeted ?-Tocopherol-PLGA functionalized 5-FU (?-T-FU-PLGA) Nanoparticles & Non-targeted 5-FU-PLGA Nanoparticles:
5-FU was conjugated to PLGA by the ionic cross-linking and ?-Tocopherol (?-T) use as a functionalized surface moiety for the preparation of ?-T-FU-PLGA nanoparticles. PLGA 34.50 mg was dissolved in 10 ml acetic acid 1% w/v, pH was maintained at 4.8. The drug 5-FU was than engulf in that solution. The solution was added in 0.5% polyvinyl alcohol (PVA) solution and allow for magnetic stirring for one hour. The 5-FU-PLGA solution was allowed to ultrasonicated for 12 minutes at 20% amplitude to facilitate the solubility and retrieved a homogeneous amalgamation followed by washing with deionized water, then lyophilized and stored at 4 °C.
Surface functionalization of ?-Tocopherol as targeted moiety on 5-FU-PLGA nanoparticles:
30.25 mg of ?-Tocopherol added in pH 7.4 phosphate buffer saline (PBS) and Subsequently, 17.5 ml 0.1% (w/v) 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide aqueous solution was added dropwise, under low velocity magnetic stirring condition about two hours to form cross-links. The formations of nanoparticles have been formed impulsively under the carbodiimide reaction. The prepared 5-FU-PLGA nanoparticles were activated by adding in 7.4 PBS solutions and 250 ul of N-hydroxysuccinimide (NHS, 1 mg/ml) under magnetic stirring for 3 hours after that un-reacted chemical have been washed with PBS buffer. Both the solution was added under magnetic stirring further for 3 hours followed by overnight incubation and ultra-sonicated for 15 min and pellets were collected after washed with PBS. Eventually, the targeted ?-T-FU-PLGA nanoparticles were obtained and used for furthermore experiments.
Characterization of ?-T-FU-PLGA/5-FU-PLGA NPs: The particle size, zeta potential and PDI of targeted 5-FU (?-T-FU-PLGA) & Non-targeted (5-FU-PLGA) nanoparticles were optimized through the instrument Malvern zetasizer ver.7.12, serial no MAL1021384.
In-vitro drug release system:
To study the release system of 5-FU-PLGA/?-Tocopherol-FU-PLGA nanoparticles, a standard curve has been plotted between 5-FU concentration (µg/ml) and absorbance (nm). The absorbance of the solution of 5-FU was established by the UV spectrophotometer at absorption maxima 267 nm. The ?-Tocopherol-FU-PLGA/5-FU-PLGA nanoparticles were accommodated into a dialysis bag and engrossed at different pH 7.4 & pH 4.5 in PBS. The dialysis bag procured as per the protocol. The USP dissolution appliance grade 1 basket type was used to perform the analysis, the speed of the apparatus 100 rpm, 37 ºC. The dialysis bag was poured into the dissolution solution (gastric fluid maintained pH 7.4 & 4.5), and the 5 ml supernatant at definite time interval in hours (0, 20, 40, 60, 80, 120, 160) was withdrawn and further analyzed for drug content through established standard calibration curve of the 5-FU solution using UV visible spectrophotometer and in-vitro drug release were calculated through given formula.
Human tongue squamous cell carcinoma cells, SCC-15, as oral cancer cell lines, were procured from National Centre for Cell Sciences, Pune, India, and cultured in a suitable medium (DMEM/F12) and supplemented with 10% heat-inactivated fetal bovine serum followed by addition of 1% antibiotic cocktail of streptomycin and penicillin. Cells will be maintained in a standard humidified incubator supplied with 5% CO2, 95% air at 37±0.50C.
Cytotoxicity of ?-Tocopherol-FU-PLGA/5-FU-PLGA nanoparticles by MTT assay:
SCC15 cells were seeded with the density of 1×104 cells into 96 well plates and acquiesce to abide by 24 hours. The SCC15 cells were exhibited to 10µL of ?-Tocopherol-FU-PLGA/5-FU-PLGA nanoparticles at predetermined time intervals (24, 48, 72 hours) in a different dose, MTT (0.2mg/mL) was composite to all the well plate and sustenance for 4 to 6 hours. 250 µL, DMSO was mixed after the removal of medium and further vibrated for 12 minutes. Then absorbance was measured at 490 nm. All the experiments were performed in triplets (n=3).
Cytotoxicity of ?-Tocopherol-FU-PLGA/5-FU-PLGA nanoparticles in drug-resistant SCC15 cell lines:
The drug-resistant SCC15 cell lines were placed in into 96 well plates with density of 1×104 cells per plates for 24 hours, centrifuged and procured, the drug-resistant cell was again incubated different drug concentration of ?-Tocopherol-FU-PLGA/ 5-FU-PLGA nanoparticles at dose 0, 0.25, 1.50, 3.0, 4.5, 6.0, 7.5 µg/ml, MTT assay was performed to optimized the cytotoxicity of the SCC15.
The therapeutic productivity of prepared nanoparticles against SCC15: The therapeutic productivity of targeted ?-Tocopherol-FU-PLGA and non-targeted 5-FU-PLGA nanoparticles as anti-proliferating agent established against SCC15 cell lines through MTT method. The malignant calls, SCC15 were seeded in 96 well plates at a density of 5×103 cells per plates for overnight incubation, and the cells were treated with different concentration 1.0mg/ml, .05mg/ml & 0.1mg/ml and the anti-proliferating effect of the ?-Tocopherol-FU-PLGA/5-FU-PLGA nanoparticles was examined. The cell viability of the nanoparticles was quantified in 96 hours and indirectly the cytotoxicity effects of the targeted & non-targeted nanoparticles.
In vitro cellular uptake of targeted ?-Tocopherol-FU-PLGA and non-targeted 5-FU-PLGA nanoparticles:
SCC15 cell lines were seeded into six-well plates and allow treating with for one day after that the cells were exhibited to formulated ?-Tocopherol-FU-PLGA and non-targeted 5-FU-PLGA nanoparticles labeled with distinct concentration of FITC for 4 to 6 hours and the cellular uptake and targeting were observed through fluorescent microscopy using 485 nm excitation for FITC and fluorescence intensity within the treated SCC15 cells were quantified by microplate reader.
Cell apoptosis by nanoparticles:
Cell apoptosis induction within the SCC15 cell determined through a programmed cell death characterized by absolute cell investigation. The apoptotic denizen of SCC15 cells, when incubated with formulated ?-tocopherol-FU-PLGA/5-FU-PLGA nanoparticles, AV-FITC/PI apoptotic staining assay was decisive by flow cytometry. The SCC15 cells treated with ?-tocopherol-FU-PLGA/5-FU-PLGA nanoparticles were matured in six-well plates at the density 5×103 cells. The treated cells were washed with PBS and 10 µL, AV-FITC conjugate and PI staining solution were poured to each cells solution and incubated at 25 ºc for 15 minutes