Effect of 660 nm visible red light on cell proliferation and viability in diabetic models in vitro under stressed conditions.

The current study evaluated the photobiomodulatory effect of visible red light on cell proliferation and viability in various fibroblast diabetic models in vitro, namely, unstressed normal (N) and stressed normal wounded (NW), diabetic wounded (DW), hypoxic wounded (HW) and diabetic hypoxic wounded (DHW). Cells were irradiated at a wavelength of 660 nm with a fluence of 5 J/cm2 (11.23 mW/cm2), which related to an irradiation time of 7 min and 25 s. Control cells were not irradiated (0 J/cm2). Cells were incubated for 48 h and cellular proliferation was determined by measuring 5-bromo-2'-deoxyuridine (BrdU) in the S-phase (flow cytometry), while viability was assessed by the Trypan blue exclusion test and Apoptox-glo triplex assay. In comparison with the respective controls, PBM increased viability in N- (P ≤ 0.001), HW- (P ≤ 0.01) and DHW-cells (P ≤ 0.05). HW-cells showed a significant progression in the S-phase (P ≤ 0.05). Also, there was a decrease in the G2M phase in HW- and DHW-cells (P ≤ 0.05 and P ≤ 0.05, respectively). This study concludes that hypoxic wounded and diabetic hypoxic wounded models responded positively to PBM, and PBM does not damage stressed cells but has a stimulatory effect on cell viability and proliferation to promote repair and wound healing. This suggests that the more stressed the cells are the better they responded to photobiomodulation (PBM).

Cellular imaging and folate receptor targeting delivery of gum kondagogu capped gold nanoparticles in cancer cells.

In this study, the green synthesis of gum kondagogu capped gold nanoparticles (GK-GNPs) was prepared using a naturally available polysaccharide. The anionic gum capped GK-GNPs enabled the successful coupling of folic acid (FA) and fluorescein isothiocyanate (FITC) to produce a fluorescently labelled GNP (F2-GNP). F2-GNPs were further characterized using different physicochemical methods Cellular viability, cellular imaging, and targeted delivery of F2-GNPs were further evaluated in both folate receptor positive (MCF-7) and folate receptor negative (A549) cancer cells. Physicochemical characterization revealed a nanoparticle with a small size (37 nm), smooth surface (surface charge of -23.7 mV), crystallinity of gold nanoparticles and existence of gum kondagogu in the F2-GNPs. Cellular uptake of F2-GNPs indicated a greater affinity towards folate receptor positive cells. This study shows that the F2-GNPs is as an effective nanocarrier for targeted drug delivery and cellular imaging via folate receptors.

Recent Trends of Biocompatible and Biodegradable Nanoparticles in Drug Delivery: A Review.

A vast amount of research on nanoparticles has been conducted in recent years with versatile applications in the field of drug delivery systems. Nanoparticles are designed as a carrier molecule to deliver drugs in a sustained and stimuli response manner. Recent advances in nanotechnology have led to the development of long circulating nanoparticles with high encapsulation efficiency. This article focuses on the properties such as biocompatibility and biodegradability, which are considered as essential criteria for nanoparticles to be successfully used as a carrier molecule in drug delivery systems. Physicochemical characterization of the nanoparticles such as size and size distribution, surface morphology, zeta potential and surface chemistry has a significant role in the successful formulation and applications in drug delivery systems. Mostly, the size and surface characteristics of nanoparticles enable enhanced intracellular accumulation in tumor cells through passive targeting mechanisms and rapid development of nanoengineering, and aid towards attaining active targeting delivery by co-functionalization of nanoparticles using appropriate targeting ligands. This article reviews the recent progress and development of employing different biocompatible and biodegradable nanoparticles in drug delivery systems. It also briefly recaps the important methods available to evaluate its biocompatibility, the mechanism of biodegradability and clearance properties of NPs.

The primary subcellular localization of Zinc phthalocyanine and its cellular impact on viability, proliferation and structure of breast cancer cells (MCF-7).

The development of curative techniques which are selective for neoplasms is one of the main focal areas in cancer research. The mechanism of cell damage due to Zinc phthalocyanine (ZnPcSmix)-mediated photodynamic therapy (PDT) in a breast cancer cell line (MCF-7) was assessed by inverted light microscopy for morphology, the Trypan blue exclusion assay and adenosine triphosphate (ATP) luminescence assay for cell viability, alamarBlue for proliferation, Lactate Dehydrogenase (LHD) membrane integrity for cytotoxicity and fluorescent microscopy for ZnPcSmix localization. Fluorescent microscopy revealed that ZnPcSmix was localized in both mitochondria and lysosomes, and PDT treated cells showed damaging structural changes and decreased cell viability and proliferation. The light-dependent ZnPcSmix displayed appreciable photosensitivity and the intensity of damage was directly related to its concentration.

Phototherapy promotes cell migration in the presence of hydroxyurea.

Phototherapy has been shown to cause an increase in cell proliferation and migration. This study focused on viability (trypan blue), proliferation [sodium 3'-(1-(phenylaminocarbonyl)-3,4-tetrazolium)-bis(4-methoxy-6-nitro)-benzene sulphonic acid hydrate (XTT) and adenosine triphosphate (ATP)] and migration of WS1 cells following irradiation in the presence of hydroxyurea (HU), which is an inhibitor of proliferation. Wounded cells were irradiated on days 1 and 4 with a fluence of 5 J/cm(2) with a helium-neon (He-Ne) laser at 632.8 nm. After a repair time of 24 h, cellular responses were assessed. Wounded irradiated cells without HU showed an increase in cell viability and proliferation, which was confirmed by complete wound closure by day 4. Although wounded irradiated cells treated with 5 mM HU showed incomplete wound closure, these cells showed increased migration compared with that of control cells. This study showed that laser irradiation using an He-Ne laser with a fluence of 5 J/cm(2) stimulates cell viability. The HU results confirmed that laser irradiation promotes cell migration and proliferation.

Laser light influences cellular viability and proliferation in diabetic-wounded fibroblast cells in a dose- and wavelength-dependent manner.

Phototherapy stimulates metabolic processes in healing wounds. Despite worldwide interest, phototherapy is not firmly established or practiced in South Africa. This study aimed to determine which dose and wavelength would better induce healing in vitro. Diabetic-induced wounded fibroblasts were irradiated with 5 or 16 J/cm(2) at 632.8, 830, or 1,064 nm. Cellular morphology, viability (Trypan blue and apoptosis), and proliferation (basic fibroblast growth factor) were then determined. Cells irradiated with 5 J/cm(2) at 632.8 nm showed complete wound closure and an increase in viability and basic fibroblast growth factor (bFGF) expression. Cells irradiated at 830 nm showed incomplete wound closure and an increase in bFGF expression. Cells irradiated at 1,064 nm showed incomplete closure and increased apoptosis. All cells irradiated with 16 J/cm(2) at all three wavelengths showed incomplete wound closure, increased apoptosis, and decreased bFGF expression. This study showed that diabetic-wounded cells respond in a dose- and a wavelength-dependent manner to laser light. Cells responded the best when irradiated with a fluence of 5 J/cm(2) at a wavelength of 632.8 nm.

Effectiveness of helium-neon laser irradiation on viability and cytotoxicity of diabetic-wounded fibroblast cells.

OBJECTIVE: This study investigated the effectiveness of helium-neon (He-Ne) laser irradiation at increasing intervals on diabetic-induced wounded human skin fibroblast cells (WS1) at a morphological, cellular, and molecular level. BACKGROUND DATA: The controversies over light therapy can be explained by the differing exposure regimens and models used. No therapeutic window for dosimetry and mechanism of action has been determined at the level of individual cell types, particularly in diabetic cells in vitro. METHODS: WS1 cells were used to simulate an in vitro wounded diabetic model. The effect of the frequency of He-Ne irradiation (632.8 nm) at a fluence of 5 J/cm(2) was determined by analysis of cell morphology, viability, cytotoxicity, and DNA damage. Cells were irradiated using three different protocols: they were irradiated at 30 min only; irradiated twice, at 30 min and at 24 h; or irradiated twice, at 30 min and at 72 h post-wound induction. RESULTS: A single exposure to 5 J/cm(2) 30 min post-wound induction increased cellular damage. Irradiation of cells at 30 min and at 24 h post-wound induction decreased cellular viability, cytotoxicity, and DNA damage. However, complete wound closure as well as an increase in viability and a decrease in cytotoxicity and DNA damage occurs when cells were irradiated at 30 min and at 72 h post-wound induction. CONCLUSIONS: Wounded diabetic WS1 cells irradiated to 5 J/cm(2) showed increased cellular repair when irradiated with adequate time between irradiations, allowing time for cellular response mechanisms to take effect. Therefore, the irradiation interval was shown to play an important role in wound healing in vitro and should be taken into account.