Functionalized lipid-based drug delivery nanosystems for the treatment of human infectious diseases.

Infectious diseases are still public health problems. Microorganisms such as fungi, bacteria, viruses, and parasites are the main causing agents related to these diseases. In this context, the search for new effective strategies in prevention and/or treatment is considered essential, since current drugs often have side effects or end up, causing microbial resistance, making it a serious health problem. As an alternative to these limitations, nanotechnology has been widely used. The use of lipid-based drug delivery nanosystems (DDNs) has some advantages, such as biocompatibility, low toxicity, controlled release, the ability to carry both hydrophilic and lipophilic drugs, in addition to be easel scalable. Besides, as an improvement, studies involving the conjugation of signalling molecules on the surfaces of these nanocarriers can allow the target of certain tissues or cells. Thus, this review summarizes the performance of functionalized lipid-based DDNs for the treatment of infectious diseases caused by viruses, including SARS-CoV-2, bacteria, fungi, and parasites.

Current applications of drug delivery nanosystems associated with antimicrobial photodynamic therapy for oral infections.

The oral cavity is colonized by several species of microorganisms that can cause dental caries, periodontal diseases, candidiasis, endodontic infections, and, among other diseases related to the dental field. Conventional treatment consists of mechanical removal associated with systemic administration of antimicrobials, which can cause various side effects and microbial resistance. In this context, alternative therapies have been developed, including Antimicrobial Photodynamic Therapy (aPDT). For the improvement of therapy, the implementation of nanotechnology is very important to optimize the delivery system of the dyes or photosensitizers on biological targets. Besides, this combination provides a non-invasive treatment, better solubility and bioavailability, delivery to the target site, controlled release and protection against external and physical-chemical factors, low side effects, and, unlikely resistant species. Although, there are numerous researches on aPDT and nanotechnology, few review articles based on the combination of these three aspects: nanosystems, aPDT and oral infections are available. For this reason, this article aims to discuss the advances and advantages of this combination. Therefore, this article was divided into different types of nanosystems (organic and inorganic nanoparticles) associated with aPDT bringing a description of it is definitions, properties, and, applications in oral infections.

New Silver(I) Coordination Compound Loaded into Polymeric Nanoparticles as a Strategy to Improve In Vitro Anti-Helicobacter pylori Activity.

Helicobacter pylori inhabits the gastric epithelium and can promote the development of gastric disorders, such as peptic ulcers, acute and chronic gastritis, mucosal lymphoid tissue (MALT), and gastric adenocarcinomas. To use nanotechnology as a tool to increase the antibacterial activity of silver I [Ag(I)] compounds, this study suggests a new strategy for H. pylori infections, which have hitherto been difficult to control. [Ag (PhTSC·HCl)2] (NO3)·H2O (compound 1) was synthesized, characterized, and loaded into polymeric nanoparticles (PN1). PN1 had been developed by nanoprecipitation with poly(ε-caprolactone) polymer and poloxamer 407 surfactant. System characterization assays showed that the PNs had adequate particle sizes and ζ-potentials. Transmission electron microscopy confirmed the formation of polymeric nanoparticles (PNs). Compound 1 had a minimum inhibitory concentration for H. pylori of 3.90 µg/mL, which was potentiated to 0.781 µg/mL after loading. The minimum bactericidal concentration of 7.81 µg/mL was potentiated 5-fold to 1.56 µg/mL in PN. Compound 1 loaded in PN1 displayed better activity for H. pylori biofilm formation and mature biofilm. PN1 reduced the toxicity of compound 1 to MRC-5 cells. Loading compound 1 into PN1 inhibited the mutagenicity of the free compound. In vivo, the system allowed survival of Galleria mellonella larvae at a concentration of 200 µg/mL. This is the first demonstration of the antibacterial activity of a silver complex enclosed in polymeric nanoparticles against H. pylori.