Nanoparticles formulated from the biodegradable copolymer poly(lactic-coglycolic acid) (PLGA) were investigated as a drug delivery system to enhance tissue uptake, permeation, and targeting of zinc(II) phthalocyanine (ZnPc) for photodynamic therapy. Three ZnPc nanoparticle formulations were prepared using a solvent emulsion evaporation method and the influence of sonication time on nanoparticle shape, encapsulation and size distribution, in vitro release, and in vivo photodynamic efficiency in tumor-bearing mice were studied. Sonication time did not affect the process yield or encapsulation efficiency, but did affect significantly the particle size. Sonication for 20 min reduced the mean particle size to 374.3 nm and the in vitro release studies demonstrated a controlled release profile of ZnPc. Tumor-bearing mice injected with ZnPc nanoparticles exhibited significantly smaller mean tumor volume, increased tumor growth delay and longer survival compared with the control group and the group injected with free ZnPc during the time course of the experiment. Histopathological examination of tumor from animals treated with PLGA ZnPc showed regression of tumor cells, in contrast to those obtained from animals treated with free ZnPc. The results indicate that ZnPc encapsulated in PLGA nanoparticles is a successful delivery system for improving photodynamic activity in the target tissue.

Objective: This paper introduces a simple one-step and ultra-fast method for synthesis of highly photothermally active polypyrrole-coated gold nanoparticles. The synthesis process is so simple that the reaction is very fast without the need for any additives or complicated steps. Methodology: Polypyrrole-coated gold nanoparticles (AuPpy NPs) were synthesized by reacting chloroauric acid (HAuCl 4) with pyrrole (monomer) in aqueous medium at room temperature. These nanoparticles were characterized by UV-visible-NIR spectrometry, transmission electron microscopy (TEM), AC conductivity, zeta sizer and were evaluated for dark cytotoxicity and photocytotoxicity using human hepatocellular carcinoma (HepG2) cell line as a model for cancer cells. Results: The synthesized AuPpy NPs showed a peak characteristic for gold nanoparticles (530-600 nm, molar ratio dependent) and a wide absorption band along the visible-NIR region with intensity about triple or even quadruple that of polypyrrole synthesized by the conventional FeCl 3 method at the same concentration and under the same conditions. TEM imaging showed that the synthesized AuPpy NPs were composed of spherical or semi-spherical gold core(s) of about 4-10 nm coated with distinct layer(s) of polypyrrole seen either loosely or in clusters. Mean sizes of the synthesized nanoparticles range between~25 and 220 nm (molar ratio dependent). Zeta potentials of the AuPpy NPs preparations indicate their good colloidal stability. AC conductivity values of AuPpy NPs highly surpass that of Ppy prepared by the conventional FeCl 3 method. AuPpy NPs were non-toxic even at high concentrations (up to 1000 µM pyrrole monomer equivalent) under dark conditions. Unlikely, light activated the photothermal activity of AuPpy NPs in a dose-dependent manner. Conclusion: This method simply and successfully synthesized AuPpy NPs nanoparticles that represent a safe alternative photothermally active multifunctional tool instead of highly toxic and non-biodegradable gold nanorods.

The use of (PEG)-grafted materials has a positive impact on drug delivery. In this study we designed PEGylated lipid nanocarriers (PLN) loaded with curcumin (Cur) to target skin cancer by photodynamic therapy. Cur is a polyphenolic compound having vast biological effects masked due to its low aqueous solubility. PLN were prepared using Tefose 1500 with different surfactants. PLN3, containing Tween 80, had the smallest particle size (167.60 ± 15.12 nm), Z = − 26.91 mV and, attained the highest drug release (Q24 = 75.02 ± 4.61% and Q48 = 98.25 ± 6.89%). TEM showed spherical, well-separated nanoparticles. The dark and photo-cytotoxicity study on a human skin cancer cell line (A431) revealed that, at all tested concentrations, the viability of cells treated with PLN3 was significantly lower than those treated by Cur suspension and, it decreased upon irradiation by blue light (410 nm). The amount of Cur extracted from the skin of mice treated by PLN3 was twice that of mice treated by aqueous drug suspension, this was confirmed by the increase in fluorescence intensity measured by confocal laser microscopy. Histopathological studies showed that PLN3 could extend Cur effect to deeper skin layers, especially after irradiation. This study highlights the possible efficacy of curcumin-loaded PEGylated lipidic nanoparticles to combat skin cancer by photodynamic therapy.

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Aims In a previous work, a pure crystalline titanium dioxide nanoparticles (TiO 2 NPs) were synthesized by green synthesis technique using Aloe vera leaves extract as reducing agent. In this work, we are aiming to investigate the potential of the novel greenly synthesized TiO 2 NPs as a nano-drug delivery system for the anticancer drug, doxorubicin (Dox). Main methods The cytotoxicity of the synthesized TiO 2 NPs was tested on two cell lines; normal human skin fibroblasts (HSF) and breast adenocarcinoma cells (MCF-7). Then, Dox was loaded to both TiO 2 NPs (Dox- TiO 2 NPs) and liposomes (Dox-Lip). The loaded nanoparticles were characterized by TEM, FTIR, encapsulation efficiency, particle size and zeta potential measurement. Moreover, in vitro drug release was studied. Ehrlich tumor-bearing mice were used to study the anticancer activity of Dox- TiO 2 NPs, Dox-Lip, and aqueous Dox solution. Tumor volume, survival rate, and histopathological alterations were compared in all groups. Key findings Dox was successfully loaded to both liposomes and TiO 2 NPs with an encapsulation efficiency of 77% and 65%, respectively. The particle size of Dox-TiO 2 NPs, and Dox-Lip was 14.53 nm, and 103 nm, respectively. The cumulative Dox released from TiO 2 NPs and liposomes after 4 h was 18 and 46%, respectively. Dox-Lip and Dox-TiO 2 NPs resulted in the highest degree of tumor growth inhibition with 100% and 83% of treated animals remained alive, respectively. Significance The greenly synthesized TiO 2 NPs were proved to be as effective as liposomes in enhancing the anticancer activity of Dox.