This study aims to design a pH-responsive dual-loaded nanosystem based on PEGylated chitosan nanoparticles loaded with ascorbic acid (AA) and oxaliplatin (OX) for the effective treatment of breast cancer. In this regard, non-PEGylated and PEGylated chitosan nanoparticles (CS NPs) loaded with either ascorbic acid (AA), oxaliplatin (OX), or dual-loaded with AA-OX were fabricated using the ionotropic gelation method. The hydrodynamic diameters of the fabricated AA/CS NPs, OX/CS NPs, and AA-OX/CS NPs were 157.20 ± 2.40, 188.10 ± 9.70, and 261.10 ± 9.19 nm, respectively. While the hydrodynamic diameters of the designed AA/PEG-CS NPs, OX/PEG-CS NPs, and AA-OX/PEG-CS NPs were 152.20 ± 2.40, 156.60 ± 4.82, and 176.00 ± 4.21 nm, respectively. The ζ-potential of the prepared nanoparticles demonstrated high positive surface charges of +22.02 ± 1.50, +22.58 ± 1.85 and +40.4 ± 2.71 mV for AA/CS NPs, OX/CS NPs, and AA-OX/CS NPs, respectively. The ζ-potential of the PEGylated CS NPs was reduced owing to the shielding of the positive charges by the PEG chains. Additionally, all the prepared nanoparticles exhibited high entrapment efficiencies (EE%) and spherical-shaped morphology. The chemical features of the prepared nanoparticles were investigated using Fourier transform infrared (FTIR) spectroscopy. Release studies showed the capability of the prepared non-PEGylated and PEGylated chitosan NPs to release their cargo in the acidic environment of cancer tissue (pH 5.5). Furthermore, the AA/CS NPs, AA/PEG-CS NPs, OX/CS NPs, OX/PEG-CS NPs, AA-OX/CS NPs and AA-OX/PEG-CS NPs exhibited remarkable cytotoxic activities against breast adenocarcinoma (MCF-7) cells with IC₅₀ values of 44.87 ± 11.49, 23.3 ± 3.73, 23.88 ± 6.29, 17.98 ± 3.99, 18.69 ± 2.22, and 7.5 ± 0.69 µg/mL, respectively; as compared to free AA and OX (IC₅₀ of 150.80 ± 26.50 and 147.70 ± 63.91 µg/mL, respectively). Additionally, treatment of MCF-7 cells with IC₅₀ concentrations of AA, AA/CS NPs, AA/PEG-CS NPs, OX, OX/CS NPs, OX/PEG-CS NPs, AA-OX/CS NPs or AA-OX/PEG-CS NPs increased the percentages of early apoptotic cells to 5.28%, 9.53%, 11.20%, 5.27%, 13.80%, 8.43%, 2.32%, and 10.10%, respectively, and increased the percentages of late apoptotic cells to 0.98%, 0.37%, 2.41%, 2.06%, 0.97%, 9.66%, 56%, and 81.50%, respectively. These results clearly indicate that PEGylation enhances the apoptotic effect of AA and OX alone, in addition to potentiating the apoptotic effect of AA and OX when combined on MCF-7 cells. In conclusion, PEGylated chitosan nanoparticles encapsulating AA, OX, or AA and OX represent an effective formula for induction of apoptosis in MCF-7 cells.

New sets of ibuprofen and indomethacin conjugates comprising triazolyl heterocycle were synthesized via click chemistry, adopting an optimized protocol through the molecular hybridization approach affording the targeted agents in good yields. The new non-steroidal anti-inflammatory drug (NSAID) conjugates were designed and synthesized and could be considered as potential drug candidates for the treatment of pain and inflammation. The anti-inflammatory properties were investigated for all the synthesized conjugates. Among 14 synthesized conjugates, four (5a, 5b, 5d, and 5e) were found to have significant anti-inflammatory properties potency 117.6%, 116.5%, 93.8%, and 109.1% in comparison to reference drugs ibuprofen (97.2%) and indomethacin (100%) in the rat paw edema carrageenan test without any ulcerogenic liability. The suppression effect of cytokines IL-6, TNF-α, and iNOS in addition to NO in the LPS-induced RAW264.7 cells supports the promising anti-inflammatory properties observed in the ibuprofen conjugates. In addition, several conjugates showed promising peripheral and central analgesic activity. The selectivity index (SI) of compound 5a (23.096) indicates the significant efficacy and selectivity for COX-2 over COX-1. Molecular modeling (docking and QSAR) studies described the observed biological properties.

Photodynamic therapy (PDT) is a non-invasive treatment strategy that includes the combination of three components—a photosensitizer, a light source, and tissue oxygen. PDT can be used for the treatment of skin diseases such as squamous cell carcinoma. The photosensitizer used in this study is the naturally derived chlorophyll derivative chlorin e6 (Ce6), which was encapsulated in ultradeformable ethosomes. Singlet oxygen production by Ce6 upon laser light irradiation was not significantly affected by encapsulation into ethosomes. PDT of squamous cell carcinoma cells treated with Ce6 ethosomes triggered increased mitochondrial superoxide levels and increased caspase 3/7 activity, resulting in concentration- and light-dose-dependent cytotoxicity. Ce6 ethosomes showed good penetration into 3D squamous cell carcinoma spheroids, which upon laser light irradiation exhibited reduced size, proliferation, and viability. The PDT effect of Ce6 ethosomes was specific and showed higher cytotoxicity against squamous cell carcinoma spheroids compared to normal skin fibroblast spheroids. In addition, PDT treatment of squamous cell carcinoma xenografts grown on chorioallantoic membranes of chick eggs (CAM) exhibited reduced expression of Ki-67 proliferation marker and increased terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) staining, indicating reduced proliferation and activation of apoptosis, respectively. The results demonstrate that Ce6-loaded ethosomes represent a convenient formulation for photodynamic treatment of squamous cell carcinoma.