Synthesis of Novel Cationic Photosensitizers Derived from Chlorin for Application in Photodynamic Therapy of Cancer.

BACKGROUND: Chlorins (dihydroporphyrins) are tetrapyrrole-based compounds that are more effective in photodynamic therapy than porphyrins. The instability of the compounds and their oxidation to porphyrin limits the use of these compounds. However, the design and synthesis of new stable chlorin-based cationic photosensitizers with the potential for use in cancer photodynamic therapy can be interesting. METHODS: In this research, new tetracationic meso substituted chlorins were designed, synthesized, and characterized. After determining the chemical structure and spectroscopic properties of five new photosensitizers, their phototoxicity on breast cancer cell lines (MCF-7) was investigated under optimized conditions in terms of factors such as photosensitizer concentrations and light intensity. RESULTS: The results of cytotoxicity assayed by the MTT method showed that the synthesized compounds, even up to the concentration of 50 µM had very low toxicity in the absence of light, which indicates their safety under dark conditions. Compounds A1 and A3 with the best physicochemical properties such as solubility, high absorption intensity in the effective range of photodynamic therapy, and the high quantum yield of singlet oxygen, had a good toxic effect (IC50 = 0.5 µM) on the cancer cells (MCF-7) in the presence of laser light. CONCLUSION: According to the obtained results, compounds A1 and A3 have the potential to continue research on PDT for confirmation and use in treatment.

DITAS: An Integrated Gateway to E-health Communications.

Today, the demand for health-oriented systems to facilitate and improve treatment processes is growing. For different information systems with different structures and technologies to be able to communicate with each other, a single gateway is required. The gateway acts as an interface between information systems and unifies protocols, rules, and standards related to communication processes. Health-related systems need a unique regulator that explains data models, coding, and data exchange structures. Moreover, the gateway has control over information systems and the data transmitted between them. In this paper, we explain an integrated gateway of health information exchange named DITAS which is a bridging point between health-related systems.

Effect of a fluoride-releasing fissure sealant and a conventional fissure sealant on inhibition of primary carious lesions with or without exposure to fluoride-containing toothpaste.

Background. Fluoride-releasing capacity has been added to fissure sealants to benefit from the positive anticariogenic effects of both sealants and fluoride. This comparative research investigated the inhibitory effects of conventional and fluoridereleasing fissure sealants on initial lesions with or without exposure to fluoride toothpaste. Methods. Cavities were prepared on buccal surfaces of 24 premolar teeth which were randomly divided into three groups. In the cavities of the first group, a fluoride-releasing fissure sealant and in the second group, a conventional fissure sealant were placed; the third group was left intact. Incipient lesions were produced around the cavities. Each group was divided into two subgroups, which were exposed to fluoride-containing toothpaste or artificial saliva. Lesion depths were measured under a polarized light microscope before and after treatment. Changes in lesion depths in the samples were analyzed by SPSS 17. Results. Initial and final caries depths were significantly lower in the fluoride-releasing fissure sealant group compared to the other groups (P<0.001). The average depths of carious lesions were lower in subgroups exposed to fluoride-containing toothpaste than the subgroups exposed to artificial saliva and the difference was significant in the conventional sealant group and the group without sealant (P<0.001); however, the difference between the toothpaste-exposed and saliva-exposed subgroups was not significant in the fluoride-releasing fissure sealant group (P=0.721). Conclusion. Incorporation of fluoride into the fissure sealants can be effective in the inhibition of dental caries. It seems that fluoride, released from fluoride-releasing sealants, overwhelms the remineralizing capacity of fluoride released from the toothpaste on the same tooth.

Evaluation effect of low level Helium-Neon laser and Iranian propolis extract on Collagen Type I gene expression by human gingival fibroblasts: an in vitro study.

BACK GROUND AND AIM: production of collagen by fibroblast cells is a key component in wound healing. Several studies have shown that low level laser therapy (LLLT) and propolis extract stimulate collagen Type I production. The aim of this study is to evaluation the combined effect of LLL helium neon (632.8 nm) and Iranian propolis extract on collagen Type I gene expression by human gingival fibroblasts (HGF3-PI 53). METHODS AND MATERIALS: Human gingival fibroblasts after culturing divided into six experimental groups: G1-control group, which received no irradiation and propolis extract, G2-irradiated at1.5 J/cm2, G3-irradiated at 0.15 J/cm2, G4-recived extract of propolis, G5- combined extract of propolis and 1.5 J/cm2 laser irradiation and G6- combined extract of propolis and 0.15 J/cm2 laser irradiation. The experiments were conducted in triplicate. After 24 hour, the total RNA was extracted and cDNA synthesis was performed. Type I collagen mRNA expression was determined with real time PCR. RESULTS: The obtained results illustrated a statistically significant difference between G3 (0.15 J/cm2) and G1 (control group) in levels of collagen Type I messenger RNA (mRNA) expression (p<0.05). The irradiated cells showed a 1.4 times increase in mRNA expression of the collagen Type I gene. Expression of this gene decreases in other groups that this difference was statistically significant. CONCLUSION: LLLT in different dosage and propolis extract may result in decreased or increased collagen type I gene expression. However this effect should be investigated in clinical studies.