Although the therapeutic effect of mycobacteria as antitumor agents has been known for decades, recent epidemiological and experimental studies have revealed that mycobacterium-related chronic inflammation may be a possible mechanism of cancer pathogenesis. Mycobacterium tuberculosis and non-tuberculous Mycobacterium avium complex infections have been implicated as potentially contributing to the etiology of lung cancer, whereas Mycobacterium ulcerans has been correlated with skin carcinogenesis. The risk of tumor development with chronic mycobacterial infections is thought to be a result of many host effector mechanisms acting at different stages of oncogenesis. In this paper, we focus on the nature of the relationship between mycobacteria and cancer, describing the clinical significance of mycobacteria-based cancer therapy as well as epidemiological evidence on the contribution of chronic mycobacterial infections to the increased lung cancer risk.

Drug delivery systems such as dendrimers, liposomes, polymers or gold/silver nanoparticles could be used to advance modern medicine. One significant pharmacological problem is crossing biological barriers by commonly used drugs, e.g., in the treatment of neurodegenerative diseases, which have a problem of the blood-brain barrier (BBB) restricting drug delivery. Numerous studies have been conducted to find appropriate drug carriers that are safe, biocompatible and efficient. In this work, we evaluate pegylated gold nanoparticles AuNP14a and AuNP14b after their conjugation with therapeutic siRNA directed against APOE4. This genetic risk factor remains the strongest predictor for late-onset Alzheimer’s disease. The study aimed to assess the biophysical properties of AuNPs/siAPOE complexes and to check their biological safety on healthy cells using human brain endothelial cells (HBEC-5i). Techniques such as fluorescence polarization, circular dichroism, dynamic light scattering, ζ-potential measurements and gel retardation assay showed that AuNPs form stable complexes with siRNA. Subsequently, cytotoxicity assays proved the biological safety of formed conjugates. Obtained results enabled us to find effective concentrations of AuNPs when complexes are formed and non-toxic for healthy cells. One of the studied nanoparticles, AuNP14b complexed with siRNA, displayed lower cytotoxicity (MTT assay, cells viability −74.8 ± 3.1%) than free nanoparticles (44.7 ± 3.6%). This may be promising for further investigations in nucleic acid delivery and could have practical use in treating neurodegenerative diseases.

Innovative drug delivery platforms are redefining the landscape of modern therapeutics, from dendrimers and liposomes to polymeric systems and metallic nanoparticles. The development of carrier systems that combine safety, biocompatibility and therapeutic efficacy is being focused upon in research. In this study, we designed and functionalised liposomes for the delivery of small interfering RNA (siRNA) that specifically targets and silences EGFR in triple-negative breast cancer (TNBC) cells characterized by EGFR overexpression. DOPE/TAP/R9-based liposomes conjugated with therapeutic siRNA directed against EGFR were investigated to assess their potential as a targeted delivery platform. The study focused on evaluating the biophysical properties of liposome:siEGFR complexes, intracellular trafficking capacity and effective change in EGFR expression at the gene and protein level. A suite of analytical techniques, including fluorescence polarisation, circular dichroism, dynamic light scattering, ζ-potential measurements, gel retardation assays and electrophoresis in the presence of nucleases, demonstrated that DOPE/TAP/R9-Chol liposomes form stable and protective complexes with siRNA. Subsequent cellular uptake studies, using flow cytometry and confocal microscopy, confirmed that there was efficient intracellular delivery into the MDA-MB-231 cell line and RT-PCR and western blot proved the effectiveness of gene silencing by transported siRNA. The results identified an optimal liposome:siRNA formulation and mark a promising step toward the development of a safe and effective siRNA delivery system for biomedical applications.

Understanding the physicochemical factors that govern siRNA nanocarrier assembly is essential for the rational design of effective delivery systems. By optimizing various lipid compositions, cholesterol content and PEG length we created a peptide-functionalized cationic liposomal platform made of DOPE/TAP lipids with cholesterol-anchored nona-arginine (R9-Chol) for siRNA complexation, intracellular transport and effective silencing of the target EGFR gene. Analysis of ζ-potential and dynamic light scattering allowed to rationally design formulation of stable, monodisperse nanoscale lipoplexes with a positive surface charge. With fluorescence polarization, circular dichroism and agarose gel electrophoresis we found an optimal siRNA:liposome complexation ratio of 1:77, which protected siRNA from ribonuclease-mediated degradation. Morphological imaging confirmed a shift from discrete vesicular structures to organized multilamellar lipoplexes, consistent with electrostatically driven self-assembly. In cellular studies, the optimized nanocarrier promoted efficient uptake of fluorescent siRNA in MDA-MB-231 cells and achieved functional delivery of anti-EGFR, leading to substantially reduced expression of the target gene at both transcript and protein levels. This work offers mechanistic understanding of peptide-assisted lipid:siRNA assembly and positions R9-functionalized DOPE/TAP liposomes as a promising platform for siRNA delivery.

Comparative oncology is a powerful means to understand the molecular mechanisms regulating the development of rare cancers and design more effective therapies. Nevertheless, the potential of such approach is often limited by the paucity of reagents available for studying animal models. In this contribution, we describe how new nanobodies have been isolated that can effectively discriminate between canine fibroblasts and mucosal melanoma cells. Such nanobodies were expressed as recombinant proteins in bacteria fused to either a rabbit Fc domain or to a free cysteine. The first option allowed flow cytometry characterization using standard settings, whereas the second is suitable for site-specific, 1:1 reproducible functionalization with any reagent provided with a maleimide group. The resulting modified nanobodies selectively recognized tumor cells in both mass cytometry and confocal microscopy experiments, with clones B9 and D12 performing consistently across all three detection platforms. Altogether, the results confirm that the proposed approach might be a convenient method to generate highly valuable reagents for studying canine models and that their recombinant nature allows their simple engineering and cost-effective production.