Synthesis and Different Effects of Biotinylated PAMAM G3 Dendrimer Substituted with Nimesulide in Human Normal Fibroblasts and Squamous Carcinoma Cells

Nanoparticle-mediated active and passive drug targeting in oral squamous cell carcinoma: current trends and advances

Oral squamous cell carcinoma (OSCC) is an invasive and highly malignant cancer with significant morbidity and mortality. Existing treatments including surgery, chemotherapy and radiation have poor overall survival rates and prognosis. The intended therapeutic effects of chemotherapy are limited by drug resistance, systemic toxicity and adverse effects. This review explores advances in OSCC treatment, with a focus on lipid-based platforms (solid lipid nanoparticles, nanostructured lipid carriers, lipid-polymer hybrids, cubosomes), polymeric nanoparticles, self-assembling nucleoside nanoparticles, dendrimers, magnetic nanovectors, graphene oxide nanostructures, stimuli-responsive nanoparticles, gene therapy, folic acid receptor targeting, gastrin-releasing peptide receptor targeting, fibroblast activation protein targeting, urokinase-type plasminogen activator receptor targeting, biotin receptor targeting and transferrin receptor targeting. This review also highlights oncolytic viruses as OSCC therapy candidates.

Lapatinib- and fulvestrant-PAMAM dendrimer conjugates promote apoptosis in chemotherapy-induced senescent breast cancer cells with different receptor status

Lapatinib (L) and fulvestrant (F) are used in targeted anticancer therapies, in particular, against phenotypically different breast cancer cells. L, a dual inhibitor of EGFR and HER2 tyrosine kinases, is active against HER2-positive breast cancer cells, while F, a selective estrogen receptor degrader (SERD), is active against ER-positive breast cancer cells. However, the action of L and F can be limited due to their relatively low water solubility and bioavailability. In the present study, poly(amidoamine) (PAMAM) dendrimer G3 was functionalized with L or F or L and F to compare their effects with free L or F against breast cancer cells with different receptor status (ER-positive MCF-7, triple negative MDA-MB-231 and HER2-positive SK-BR-3 cells). L-PAMAM and F-PAMAM conjugates potentiated cytostatic and cytotoxic action of L and F that was accompanied by elevated levels of autophagy. TRDMT1, RNA methyltransferase, was also involved in this response as judged by TRDMT1 nuclear translocation and nano-drug resistance of TRDMT1 gene knockout cells. Nano-drugs also promoted elimination of doxorubicin-induced senescent breast cancer cells by apoptosis-mediated senolysis regardless of receptor status. In conclusion, we propose a novel anticancer approach based on L-PAMAM and F-PAMAM nanoplatforms being effective, at least, against breast cancer cells with different phenotypic features.

Drug repurposing for Chagas disease: In vitro assessment of nimesulide against Trypanosoma cruzi and insights on its mechanisms of action

Chagas disease is a neglected illness caused by Trypanosoma cruzi and its treatment is done only with two drugs, nifurtimox and benznidazole. However, both drugs are ineffective in the chronic phase, in addition to causing serious side effects. This context of therapeutic limitation justifies the continuous research for alternative drugs. Here, we study the in vitro trypanocidal effects of the non-steroidal anti-inflammatory drug nimesulide, a molecule that has in its chemical structure a toxicophoric nitroaromatic group (NO2). The set of results obtained in this work highlights the potential for repurposing nimesulide in the treatment of this disease that affects millions of people around the world.

Can Nimesulide Nanoparticles Be a Therapeutic Strategy for the Inhibition of the KRAS/PTEN Signaling Pathway in Pancreatic Cancer?

Pancreatic cancer is an aggressive, devastating disease due to its invasiveness, rapid progression, and resistance to surgical, pharmacological, chemotherapy, and radiotherapy treatments. The disease develops from PanINs lesions that progress through different stages. KRAS mutations are frequently observed in these lesions, accompanied by inactivation of PTEN, hyperactivation of the PI3K/AKT pathway, and chronic inflammation with overexpression of COX-2. Nimesulide is a selective COX-2 inhibitor that has shown anticancer effects in neoplastic pancreatic cells. This drug works by increasing the levels of PTEN expression and inhibiting proliferation and apoptosis. However, there is a need to improve nimesulide through its encapsulation by solid lipid nanoparticles to overcome problems related to the hepatotoxicity and bioavailability of the drug.

Cell death-inducing properties of selected dendrimers against different breast cancer and leukemia cell lines

Dendrimers represent an opportunity for targeted drug delivery into tumor cells. This is facilitated, for example, by loading of dendrimers with anticancer compounds. However, to assess the effects caused by such conjugates, knowledge of the cytotoxicity of the dendrimers themselves is necessary. The poly(amido amine)-derived dendrimers G₁ (Phe)₆ , G₁ (Dan)₃ , and G₂ were selected due to their different numbers of free amino groups and the poly(propylene imine) (PPI) dendrimer PPI-G₃ served as a reference. The compounds were evaluated for cell-death induction using breast cancer (MCF-7, MDA-MB-231) and leukemia (LAMA-84, K562, SD-1, SUP-B15) cell lines. The compounds exhibited concentration-dependent effects in the low micromolar range against the mammary carcinoma cells. A dependency on the generation, and particularly on the type of dendrimer, was deduced while the quantity of the free amino groups was subsidiary. G₂ revealed to be most cytotoxic, also against all tested leukemia cell lines. The cell line SD-1, however, was susceptible to all dendrimers. The mode of cell death was mainly determined by necrosis, especially at higher concentrations, while apoptosis played a subordinate role. The other dendrimers exerted no antimetabolic effects against LAMA-84, K562, and SUP-B15 cells. Therefore, these dendrimers are generally suitable as nontoxic drug carriers for leukemia cells.

Stepwise Glucoheptoamidation of Poly(Amidoamine) Dendrimer G3 to Tune Physicochemical Properties of the Potential Drug Carrier: In Vitro Tests for Cytisine Conjugates

Third-generation poly(amidoamine) dendrimer (PAMAM) was modified by stepwise primary amine group amidation with d-glucoheptono-1,4-lactone. The physicochemical properties of the conjugates—size, ζ potential in lysosomal pH 5 and in neutral aqueous solutions, as well as intramolecular dynamics by differential scanning calorimetry—were determined. Internalization and toxicity of the conjugates against normal human fibroblasts BJ were monitored in vitro in order to select an appropriate carrier for a drug delivery system. It was found that initial glucoheptoamidation (up to 1/3 of amine groups of neat dendrimers available) resulted in increase of conjugate size and ζ potential. Native or low substituted dendrimer conjugates accumulated efficiently in fibroblast cells at nontoxic 1 µM concentration. Further substitution of dendrimer caused consistent decrease of size and ζ potential, cell accumulation, and toxicity. All dendrimers are amorphous at 36.6 °C as determined by differential scanning calorimetry (DSC). The optimized dendrimer, half-filled with glucoheptoamide substituents, was applied as carrier bearing two covalently attached cytisine molecules: a rigid and hydrophobic alkaloid. The conjugate with 2 cytisine and 16 glucoheptoamide substituents showed fast accumulation and no toxicity up to 200 µM concentration. The half-glucoheptoamidated PAMAM dendrimer was selected as a promising anticancer drug carrier for further applications.

Mixed-Generation PAMAM G3-G0 Megamer as a Drug Delivery System for Nimesulide: Antitumor Activity of the Conjugate Against Human Squamous Carcinoma and Glioblastoma Cells

Polyhydroxylated dendrimer was synthesized from poly(amidoamine) (PAMAM) dendrimer generation 3 by addition of glycidol (G3^gl). G3^gl megamer was further modified by binding PAMAM G0 dendrimers by activation of G3^gl with p-nitrophenylchloroformate, followed by the addition of excess PAMAM G0 and purification using dialysis. The maximum G0 binding capacity of G3^gl was 12 in the case when G0 was equipped with two covalently attached nimesulide equivalents. Nimesulide (N) was converted into N-(p-nitrophenyl) carbonate derivative and fully characterized using X-ray crystallography and spectral methods. Nimesulide was then attached to G0 via a urea bond to yield G0^2N. The mixed generation G3^gl–G0^2N megamer was characterized using ¹H NMR spectroscopy, and its molecular weight was estimated to be 22.4 kDa. The AFM image of G3^gl–G0^2N deposited on mica demonstrated aggregation of nimesulide-covered megamer. The height of the deposited megamer was 8.5 nm. The megameric conjugate with nimesulide was tested in vitro on three human cell lines: squamous cell carcinoma (SCC-15) and glioblastoma (U-118 MG) overexpressing cyclooxygenase-2 (COX-2), and normal skin fibroblasts (BJ). The conjugate efficiently penetrated into all cells and was more cytotoxic against SCC-15 than against BJ. Moreover, the conjugate produced a strong and selective antiproliferative effect on both cancer cell lines (IC₅₀ < 7.5 µM).