الفهرس 
MATERIALS AND METHODSOnly 14 pages are availabe for public view
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Abstract
Oral squamous cell carcinoma is recognized worldwide as a major health problem. It is an aggressive malignant invasive carcinoma with high incidence and mortality rates. Despite the major progress in conventional treatment choices, mainly surgical excision with or without chemo- and radio-therapy, the prognosis is still far from optimal. Cancer research society is focusing now on other advanced, less invasive treatment remedies to concur this lethal disease. Using different types of nanoparticles for selective targeting of cancer cells is considered one of them. Nanoparticles have been introduced in literature as successful drug carriers, gene delivery systems, and in conjunction with phothermal therapy. The objective of the present study was to assess the short-term effect of citrate-capped gold nanospheres combined with visible laser irradiation as a treatment protocol for DMBA-induced HBP carcinoma. Eighty eight Syrian golden hamsters were used as animal models. They were grouped into 2 study groups and 2 control groups. In the study groups, DMBA was applied to right and left buccal HP for 18 weeks to induce SCC. Meanwhile, approximately 30 nm AuNPs were synthesized using citrate reduction method. The developed HBP carcinoma was directly injected by citrate capped AuNPs followed by visible laser application to induce selective apoptosis, cease cell proliferation and result in tumor regression. The main purpose was to use the unique plasmon resonance field of AuNPs to induce selective hyperthermia to cancer cells resulting in cellular protein denaturation, and consequent cell death. The therapeutic effect of laser on HBP carcinoma versus the combined effect of both AuNPs and laser was placed into comparison. Clinical data showed the minimal therapeutic effect of laser as a single modality when compared to PPTT at the same temperatures. PPTT caused tumor size regression greater than eighty percent and increased survival of the treated animals by an average of six weeks.
Moreover,quantification of tumor apoptotic indices treated under different conditions revealed a significantly increased AI/TV in PPTT treated tumors compared to the controls. PCNA immunoreactivity was markedly decreased in tumor biopsies treated with PPTT when compared to controls. These data further confirmed the sharp decrease in proliferation rates for cancer cells upon PPTT application.The nanoparticles were passively targeted to the HBP carcinoma through defective tumor vasculature via EPR effect. On the other hand, applying the same treatment protocol to control groups did not cause any harmful effect on the normal HBP, indicating its highly selective approach. Finally, TEM imaging was used successfully to demonstrate different stages of apoptosis associated with PPTT in cancer cells.