Preparation of targeted ?-T-FU-PLGA-NPs & Non-targeted 5-FU-PLGA-NPs
5-FU was conjugated to PLGA by the ionic cross-linking and ?-tocopherol 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 added to 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 functionalized 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 (phosphate buffer saline) 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, ?-T-FU-PLGA & Non-targeted, 5-FU-PLGA nanoparticles were optimized through the instrument Malvern Zetasizer ver.7.12, (Malvern Instrument, U.K.), and morphology of the nanoparticles was characterized through scanning electron microscope (SEM), (Quanta 450 FEG, Netherlands).
In-vitro drug release system and drug entrapment efficiency
To study the release system and entrapment efficiency 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 ultra-violet (UV) spectrophotometer (PerkinElmer, Lambda 25, US) 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 (Sigma Aldrich, India) 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. The entrapment efficiency, also quantify with standard curve plotted for 5-FU solution, the weigh sample of 5-FU-PLGA/?-tocopherol-FU-PLGA nanoparticles undergone at high rpm (rotation per minutes) centrifugation at approximately 12000 rpm for 45 minutes and collect the supernatant and filter with 0.2µm membrane filter, and further absorbance monitored, and percentage calculated through given formula.
In-vitro drug release (%): Concentration of drug at different time interval/total amount of drug × 100.
Entrapment efficiency (%): Total amount of drug – the free drug in supernatant/total amount of drug × 100.
Human tongue squamous cell carcinoma cells, SCC15, 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 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 (methyl thiazolyl tetrazolium) (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 cells were 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.
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, 0.5mg/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 (fluorescein isothiocyanate) for 4 to 6 hours and the cellular uptake and targeting were observed through fluorescent microscopy (Carl Zeiss, Germany) 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 (Invitrogen, Thermo Fisher, India) 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 and defended from light, and the fluorescence of the SCC15 cells was examined through flow cytometry (BD Influx Model, US).
All the scientific data was expressed as in the standard deviation & mean and one way ANOVA analysis & least significance difference test applied for comparison of the groups. GraphPad Prism 7.0, software was used for the statistical analysis. (p > 0.05).