Cancer is the type of disease system which distinguished through the uncontrolled growth of a cell to form a tumour and harm to other tissue of surrounding region. Cancer comes at second in the cause of death all around the world and the burden of new cases of cancer was increased around 15 million by 2012 and will be increasing with the rate of 50% in next decades and approximately 70% of total death caused by cancer fall in low & middle-income countries. (WHO Feb 2017). In India only, approximately 1.2 million new cases of cancer have been reported (Neevan DR Dsouza et al), with the equal ratio of male & female and a load of cancer will be increasing approximately 1 million by 2026. Oral cancer is the 11th most common cancer globally and 3rd most type of cancer in Asia, especially in south Asian countries. Oral cancer appears in the mouth such as tongue, lips, inside part of the cheek, gum area, floor-roof of the oral cavity and another related part. In the year 2015, 0.4 million new cases have been reported and this tumour accountable for the death of 0.15 million per year globally. In India, 0.1 million new cases of oral cancer reported in the year 2014 & the maximum cases having the average age of 40 to 50 years. The survival rate for five years of the patients with oral cancer is about 61.50%. The main risk factor for oral cancer is tobacco, about 80% of cases were due to the use of any form of tobacco such as smoking or smokeless & alcohol consumption. Squamous cell carcinoma (SCC) begin within the squamous cell, these are flat cells, underline all over the human body. The divergent of SCC are identified, and in which the most typical are verrucous & basaloid squamous cell carcinoma. There are many categories of oral cancer, but 85% of oral cancer is oral squamous cell carcinoma (OSCC). OSCC may also the outcome of one of persistent irritation, like a dental cavity, much use of mouthwash, betel quid, tobacco and alcohol consumption including other aspects, immune-suppression, destructive metabolism, inadequacy in the DNA-regulate enzyme, genetic susceptibility, diet and HPV (add in abbreviation). Many OSCC started on mucosa and premalignant condition mostly erythroplakia, leukoplakia, dysplasia, lichen planus, oral submucous fibrosis (add in abbreviation). Approximately 45% of OSCC initiated from the surface over the tongue within the mouth. Human OSCC, SCC-15 cell lines were quantified to explain the biological characteristics of this destructive infirmity & served as a comparative tool for to understand oral cancer.
The treatment for OSCC includes the surgical incision followed by chemotherapy and radiotherapy. There are the different chemotherapeutic class of drugs may be used against OSCC in single or combinational drug delivery, such as alkylating, nucleotide analogues, anthracylines, alkaloids and others. These antineoplastic agents have briefly damaged cancer extension through distraction in cell proliferation. 5-fluorouracil (5-FU), nucleotide analogue, has the consequential efficacy against OSCC through anticipating chromosomal cloning to suppress thymidylate synthesis exertion, ultimately block the transfiguration of dUMP to dTMP (add in abbreviation), resulting, inhibition of DNA replication through dTTP (add in abbreviation) and further cell proliferation. The conventional chemotherapy of 5-FU has utmost restriction over non-specificity, limited half-life, less bioavailability & limited therapeutic index besides less unyielding to OSCC. It was suggested that the drawback of 5-FU conventional dosage may be reduced through the targeted therapy specifically against OSCC. The targeted drug delivery has the ability to directly inflate over affected region, it could interim cancer cells through inhibiting the protein, which susceptible to tumour proliferation. The efficiency of 5-FU as a chemotherapeutic agent could be enhanced through a chambered drug-polymer nanoparticulate system that 963.targeted over a specific region. The 5-FU being designed to engulf in a bucket of polymer and surface would be protected through the target moiety, which has the capability to bind with a surface protein of the OSCC cells and made a way to transfer the drug directly on specific site and anti-proliferate OSCC cells exclusively and may not affect the normal cells. Additionally, the nanoformulation drug delivery has the competence of enhanced permeability & retention effect (EPR), which assist aggregation of the drug-loaded-nanoparticulate system on leaky tumour tissues as compare to normal tissues. The biodegradable polymer, PLGA is (add in abbreviation) extensively used for the formulation of nanoparticles for control release of drug system, the drug was enclosed within the polymer complex and specifically exaggerates the bioavailability of poor absorbed low lipophilic drug like 5-FU. The design of targeted-5-FU nanoparticles may be concentrated over OSCC cells through fleecing the distinct physical & chemical nature of tumor site and curtailed the metabolism of 5-FU in non-targeted normal cells, used for reconstruction, farthermost, this drug system provide a advanced platform to minimize the side effects, toxicity & non-specific inhibition of surrounded normal cell and improvement in drug efficacy, bioavailability, prolonged release and targeted over affected region. The targeting moiety has the ability to bind with a specific class of receptors over the surface of cancer cells and fabricate the path to deliver the anticancer drug. Infrequent target moieties such as peptides, folic acid, vitamins and antibodies were composite within a network for targeted drug delivery system. ?-Tocopherol, a fellow of vitamin E group, acquire phenol hydroxyl group having a maximal biological activity along with non-toxic characteristic and vigorous absorbed by humans. The concussion of ?-Tocopherol in the inhibition of chronic diseases affirmed to be concord with oxidative stress and influence apoptosis in OSCC cells and temper the accessibility of cancer cell surface that enhance the penetration of 5-FU. The goal of the study to formulate, ?-Tocopherol surface modified targeted PLGA nanoparticles engulfed 5-FU, and their evaluation on the basis of control release system and OSCC cell treatment. The ?-Tocopherol-FU-PLGA-NPs was compared with Non-targeted 5-FU-PLGA-NPs on SCC-15 cells and assessment the result through inhibitory cytotoxicity study, the affinity of in-vitro cellular uptake & cell targeting and cell apoptosis.
Materials & Methods:
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 and defended from light, and the fluorescence of the SCC15 cells was examined through flow cytometry.
Result & Discussion:
Characterization of ?-Tocopherol-PLGA functionalized 5-FU (?-T-FU-PLGA) & Non-targeted 5-FU Nanoformulations: The surface conjugation of ?-Tocopherol as a targeted moiety on 5-FU-PLGA nanoparticles eventually increased in average particle size from 145 nm to 160 nm as the non-targeted nanoparticles formulation having the negative surface charge about -17mV and increased in ?-Tocopherol functionalized ?-Tocopherol-FU-PLGA nanoformulation. The PDI, particle size and zeta potential were summarized in table no.1.
The standard calibration curve of the 5-FU solution was a linear regression in the ranges from 0.1 to 10 µg/ml, a straight line was found between 5-FU concentration (µg/ml) and absorbance (nm) through the UV spectrophotometer at absorption maxima 267 nm.
In-vitro drug release of Nanoparticles also depends upon particle size. When size is less, the surface area of Nanoparticles increase and more surface area come in contact with the medium, resulting in a faster release. The cumulative in-vitro drug release at pH 7.4 & pH 4.5 summarized in the table no. 03
The total amount of commutative in vitro drug release at the pH 4.5 was increased 70 % at the time range of up to 160 hours the results of 5-FU-PLGA nanoparticles showing steady state release approximately at the time 140 to 160 hours and 63% in ?-Tocopherol-FU-PLGA nanoparticles which was having targeted moiety. In vitro drugs release data for ?-Tocopherol-FU-PLGA & 5-FU-PLGA nanoparticles in pH 7.4 showed rapid releases at time range 40 to 60 hours about 35% to 60% & 25% to 50% respectively, which was followed by the cumulative drug release up to 160 hours about 85% & 82% respectively. The slope of the graph for in-vitro release system for the ?-Tocopherol-FU-PLGA & 5-FU-PLGA nanoparticles at different pH (7.4 & 4.5) ranges confirm the optimum drug release at different time interval up to 160 hours (image.3) and the release kinetic at the pH 7.4 & 4.5 confirm that cumulative drug release strongly influence the pH of the dissolution solution. The data for drug release summarized at a different time interval in table.03.
Cytotoxicity of ?-Tocopherol-FU-PLGA/5-FU-PLGA nanoparticles in dose-time dependent on SCC-15:
The figure 3 & figure 4 exhibit the cytotoxicity manner in reference to dose and time-dependent, 5-FU-PLGA/?-Tocopherol-FU-PLGA nanoparticles inhibited the escalation of OSCC at a different time. At the 24, 48, 72 hours, carcinoma escalation inhibition rate were in high level for ?-Tocopherol-FU-PLGA nanoparticles (8.0 µg/ml) in SCC-15 cells as 79.39%, 56.93% & 46.63 respectively, and comparatively low inhibition rate 69.45%, 48.96% & 36.28 at the time 24, 48, 72 hours respectively for 5-FU-PLGA NPs, the results confirmed the intense inhibition of OSCC by ?-Tocopherol-FU-PLGA nanoparticles. The inhibition rate for ?-Tocopherol-FU-PLGA nanoparticles was increased as non-target 5-FU-PLGA NPs approx in lesser intense 45.29 & 39.58% respectively for both at time 24 hrs in SCC-15, as the time increases the cytotoxicity effects of ?-Tocopherol-FU-PLGA nanoparticles in SCC-15 was showed higher percentage of inhibition, 79.98% at time 96 hrs and confirm approximately steady state inhibition 83.74% up to 160 hrs, as 5-FU-PLGA NPs was showed lower inhibition rate up to 59.25% at the time 160 hrs. (Figure 5)
Cytotoxicity of ?-Tocopherol-FU-PLGA/ 5-FU-PLGA nanoparticles in drug-resistant SCC-15: Drug resistance cell line was fixed to optimize the inhibitory activity of ?-Tocopherol-FU-PLGA/ 5-FU-PLGA nanoparticles in drug resistance SCC-15 cells. IC50 values of the inhibitory activity of ?-Tocopherol-FU-PLGA/5-FU-PLGA nanoparticles on drug-resistant SCC-15 cell were 13.19µg/ml & 23.25µg/ml. As shown in table.3 & figure no. 6, the drug-resistant for the cytotoxicity of ?-Tocopherol-FU-PLGA/ 5-FU-PLGA nanoparticles in respect to dose-dependent manner, inhibition was remarkably high in ?-Tocopherol-FU-PLGA approximately 80% at the concentration 8.0µg/ml with a comparison to inhibition rate for 5-FU-PLGA nanoparticles, 65%µg/ml. Figure 07 showed the inhibition rate with respect to time-dependent, cytotoxicity in ?-Tocopherol-FU-PLGA nanoparticles was higher (58%) in comparison to 5-FU-PLGA nanoparticles (45%).
Table. 3 Inhibitory effects of ?-Tocopherol-FU-PLGA/5-FU-PLGA nanoparticles on proliferation of the SCC-15 cell resistance to 5-FU
The therapeutic productivity of ?-Tocopherol-FU-PLGA/ 5-FU-PLGA nanoparticles in SCC15:
The therapeutic productivity of ?-Tocopherol-FU-PLGA/5-FU-PLGA nanoparticles was examined on the basis of the cellular update, cytotoxicity investigation of targeted nanoformulation, ?-Tocopherol-FU-PLGA nanoparticles and non-targeted, 5-FU-PLGA nanoparticles in the OSCC, (SCC-15) cell line. When the SCC-15, OSCC cell line was subjected to ?-Tocopherol-FU-PLGA/5-FU-PLGA nanoparticles, the nanoformulation produced excepted the level of toxicity to the cell at different concentration (0.1, 0.5, 1.0 mg/ml). The ?-Tocopherol-FU-PLGA nanoparticles produced higher percentage of cell viability, 83.59%, 67.82% & 41.25% in all concentration level 1mg/ml, 0.5mg/ml, 0.1mg/ml respectively, confirm the therapeutic productivity & internalization of 5-FU & non-targeted FU-PLGA nanoparticles produced less cell viability 65.23%, 39.82%, 29% at the concentration of 1.0mg/ml, 0.5mg/ml & 0.1mg/ml respectively, which confirm the comparatively less therapeutic productivity of 5-FU. (figure.8).
Figure-8: cell viability of ?-Tocopherol-FU-PLGA/ 5-FU-PLGA nanoparticles in SCC-15 at the concentration of 1.0mg/ml, .05mg/ml & 0.1mg/ml
In vitro cellular uptake & targeting of ?-Tocopherol-FU-PLGA/5-FU-PLGA NPs:
In vitro cellular uptake analysis of targeted drug loaded ?-Tocopherol-FU-PLGA NPs and non-targeted 5-FU-PLGA NPs were examined in SCC-15 cancer cells by fluorescent microscopy. FITC- labelled ?-Tocopherol-FU-PLGA nanoparticles crucially inflate the acquisition of drug into SCC-15 as compared with FITC-5-FU-PLGA nanoparticles. As shown in figure 9, FITC labelled ?-Tocopherol-FU-PLGA/5-FU-PLGA NPs assembled in the cytoplasm when treated with SCC-15. The robust colour fluorescence was distinguished in SCC-15 cells, designed the endocytosis of a vast number of ?-Tocopherol-FU-PLGA nanoparticles, and this is ascribed to extent of the targeting moiety. The exposure of SCC-15 to 5-FU-PLGA nanoparticles was showed modest strength fluorescence. The higher intensity of cellular uptake for ?-Tocopherol-FU-PLGA nanoparticles described that target moiety of NPs successfully invaded the cancer cells via receptor-mediated endocytosis in oral squamous cell carcinoma.
Figure: 10- Uptake of FITC labelled – (a) ?-Tocopherol-FU-PLGA & (b) 5-FU-PLGA NPs in SCC-15 by Fluorescent microscopy analysis on the scale bar is 50 ?m
Cell apoptosis by ?-Tocopherol-FU-PLGA/5-FU-PLGA NPs: Cell apoptosis assay further to reconfirm the viability assay, and investigate the apoptosis of SCC-15 instigate by non-targeted nanoparticles (5-FU-PLGA NPs) and targeted nanoparticles (?-Tocopherol-FU-PLGA NPs), to study the effect on SCC-15 cells after 96 hrs exposure with AV-FITC/PI staining protocol by flow cytometry. The data confirm the apoptosis for early and late phase was shown in figure 10, flow cytometry investigation for the ratio of AV/PI positive cells were treated with ?-tocopherol-FU-PLGA/5-FU-PLGA NPs. The observation for early apoptosis, 27.98% & 16.45%, and late apoptosis, 74.29% & 61.13% of SCC15 cells for ?-tocopherol-FU-PLGA/5-FU-PLGA NPs respectively.
Farthermost the objectives of the current work were to formulate the targeted nanoparticles specifically on oral cancer region and un-collision with beside healthy cells. In the study, targeted ?-Tocopherol functionalized surface moiety successfully attached within 5-FU- loaded PLGA nanoformulation and comparatively, non-targeted 5-FU-PLGA nanoformulation was also synthesized. The characterizations studies of blended nanoparticles in both formulations were confirmed the uniformed dispersion, particle size and negative charges. The cumulative in vitro drug release pattern of the ?-tocopherol-FU-PLGA/5-FU-PLGA NPs gradually increased with concentration-time dependent manner. The assessment of cytotoxicity in dose-time dependent & drug-resistant in SCC15 cells confirmed the ability of ?-tocopherol-FU-PLGA/5-FU-PLGA NPs to inhibit the growth of dividing cancer cells. The physiology of SCC15 cells and on the basis of result data of increased cellular uptake, cellular augmentation, specific cellular targeting, cell viability and cellular toxicity confirmed the successful formulation of targeted ?-tocopherol-FU-PLGA nanoparticles. It is concluded that the attractive targeted drug within the polymeric nanoformulation provides a possible platform for delivering the drug to the specific site for trigged therapeutic action for oral cancer.