Ultradeformable liposomes (UDLs) as a drug delivery system (DDS), prepared from the unsaturated phospholipid, dioleylphosphocholine (DOPC), and containing the non-ionic surfactant Tween 20 as edge activator, have been explored as topical vehicles for zinc phthalocyanine (ZnPc) and the nitrosyl ruthenium complex [Ru(NH.NHq)(tpy)NO]3+ (RuNO) as a photosensitizers for co-generation of 1O2 and NO as reactive species, respectively. However, in order to ensure that ZnPc was present in the UDLs in its monomeric form - essential for maximal ZnPc photophysical properties - it was necessary to replace 40wt% of the DOPC with the saturated phospholipid, dimyristoylphosphocholine (DMPC). The resultant ZnPc and complex [Ru(NH.NHq)(tpy)NO]3+ containing UDLs were stable for at least a month when stored at 4°C, six times more elastic/deformable than conventional liposome (c-Ls), i.e. liposome prepared using the same weight ratio of lipids but in the absence of Tween 20, and to significantly enhance the in vitro permeation of ZnPc across fresh pig ear skin. The UDLs DDS incorporating ZnPc and [Ru(NH.NHq)(tpy)NO]3+ were toxic (by the MTT assay) towards B16-F10 melanoma cells when irradiated with visible light at 670nm, the maximum absorption of ZnPc, and at a dose of 3.18J/cm2, but not when applied in the absence of light as expected. Based on these results it is proposed that the novel topical UDLs formulation developed is a suitable delivery vehicle for photodynamic therapy.

Carbonized polymer dots (CPDs) were obtained by using microwave irradiation under the same conditions. However, different carbogenic precursors were used, such as aromatic diamine molecules, ortho-phenylenediamine (o-OPDA), and 3,4-diaminobenzoic acid (3,4-DABA). Both carbon nanoparticles showed different structural results based on Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction, and atomic force microscopy analyses. However, there are similar spectroscopic (UV-visible and fluorescence emission) profiles. The photophysical results, like quantum yield (QY) and fluorescence lifetime, were not identical; CPDs-OPDA has a higher QY and fluorescence lifetime than CPDs-3,4-DABA. CPDs-3,4-DABA presents a more hydrophobic character than CPDs-OPDA and has a more negative superficial charge. Cell viability studies in both standard and tumor lines demonstrated higher cytotoxicity from CPDs-OPDA than that from CPDs-3,4-DABA. The oxidative stress identified in cells treated with CPDs-OPDA was based on reactive oxygen species and associated with nitric oxide production. CPDs-3,4-DABA showed more DPHH inhibition than CPDs-OPDA, indicating the antioxidant activity of CPDs.