Nanoemulsions containing amphotericin b and paromomycin for the treatment of cutaneous leishmaniasis

Cutaneous leishmaniasis (CL) is a vector-borne disease characterized by skin lesions that can evolve into high-magnitude ulcerated lesions. Thus, this study aimed to develop an innovative nanoemulsion (NE) with clove oil, Poloxamer® 407, and multiple drugs, such as amphotericin B (AmB) and paromomycin (PM), for use in the topical treatment of CL.

METHODS

Droplet size, morphology, drug content, stability, in vitro release profile, in vitro cytotoxicity on RAW 264.7 macrophages, and antileishmanial activity using axenic amastigotes of Leishmania amazonensis were assessed for NEs.

RESULTS

After optimizing the formulation parameters, such as the concentration of clove oil and drugs, using an experimental design, it was possible to obtain a NE with an average droplet size of 40 nm and a polydispersion index of 0.3, and these parameters were maintained throughout the 365 days. Furthermore, the NE showed stability of AmB and PM content for 180 days under refrigeration (4 °C), presented a pH compatible with the skin, and released modified AmB and PM. NE showed the same toxicity as free AmB and higher toxicity than free PM against RAW 264.7 macrophages. The same activity as free AmB, and higher activity than free PM against amastigotes L. amazonensis.

CONCLUSION

It is possible to develop a NE for the treatment of CL; however, complementary studies regarding the antileishmanial activity of NE should be carried out.

Bacaba, Pracaxi and Uxi Oils for Therapeutic Purposes: A Scoping Review

Fruits such as bacaba (Oenocarpus bacaba Mart), pracaxi (Pentaclethra macroloba Kuntze) and uxi (Endopleura uchi (Huber) Cuatrec), from the Amazon rainforest, are potentially interesting for studies of natural products. The current article aims at mapping and characterizing studies on the bacaba, pracaxi and uxi species. This review reports the main bioactive compounds identified in these species and discusses their therapeutic potential. Searches were performed in MEDLINE (Via Pubmed) and Web of Science. Thirty-one studies that described or evaluated the development of formulations aimed at the therapeutic use of the species were included. The findings suggest that species have the potential for the development of pharmaceutical formulations due to their therapeutic properties. However, further studies are required to assess safety and efficacy of these products. Therefore, it is suggested that new research studies propose strategies so that technological development is based on awareness and preservation of the biome.

Promising natural products for the treatment of cutaneous leishmaniasis: A review of in vitro and in vivo studies

Although there are available treatments for cutaneous leishmaniasis (CL), the drugs used are far from ideal, toxic, and costly, in addition to the challenge faced by the development of resistance. Plants have been used as a source of natural compounds with antileishmanial action. However, few have reached the market and become phytomedicines with registration in regulatory agencies. Difficulties related to the extraction, purification, chemical identification, efficacy, safety, and production in sufficient quantity for clinical studies, hinder the emergence of new effective phytomedicines against leishmaniasis. Despite the difficulties reported, the major research centers in the world see that natural products are a trend concerning the treatment of leishmaniasis. The present work consists of a literature review of articles with in vivo studies, covering the period from January 2011 to December 2022, providing an overview of promising natural products for CL treatment. The papers show encouraging antileishmanial action of natural compounds with reduced parasite load and lesion size in animal models, suggesting new strategies for the treatment of the disease. The results reported in this review show advances in using natural products as safe and effective formulations, which can stimulate clinical studies to establish clinical therapy. In conclusion, the information in this review article serves as a preliminary basis for establishing a therapeutic protocol for future clinical trials that can validate the safety and efficacy of natural compounds, providing the development of affordable and safe phytomedicines for the treatment of CL.

Nanocarriers for Sirna Delivery Aimed at the Treatment of Melanoma: Systematic Review

BACKGROUND

Melanoma is a malignant skin cancer type with a high lethality rate due to active metastasis. Among the risk factors for its development is exposure to ultraviolet radiation (UV) and phenotypical characteristics such as clear skin and eyes. Given the difficulties of the conventional therapy, the high cost of the treatment and the low bioavailability of drugs, it is important to develop new therapeutic methods to circumvent this situation. Nanosystems such as micelles, liposomes and nanoparticles present advantages when compared to conventional treatments.

OBJECTIVE

The objective of this paper is to carry out a literature review based on articles that dealt with the use of siRNA-loaded nanosystems for the treatment of melanoma, with trials carried out in vivo to assess tumor size.

METHODS

The search was conducted in the Web of Science and PubMed databases considering the last 5 years, that is, the period between January 2017 to December 2021. The "SiRNA and Drug Delivery Systems and Melanoma" keywords were used in both databases, and the articles were analyzed using the inclusion and exclusion criteria established for this paper.

RESULTS

The results obtained indicated that using siRNA transported via nanosystems was capable of silencing the BRAF tumor genes and of reducing tumor size and weight, not presenting in vitro and/or in vivo toxicity.

CONCLUSION

Such being the case, the development of these systems becomes a non-invasive and promising option for the treatment of melanoma.

Radiopharmacokinetics of Graphene Quantum Dots Nanoparticles In vivo: Comparing the Pharmacokinetics Parameters in Long and Short Periods

BACKGROUND

Nanoparticles (NPs) have gained great importance during the last decades for developing new therapeutics with improved outcomes for biomedical applications due to their nanoscale size, surface properties, loading capacity, controlled drug release, and distribution. Among the carbon-based nanomaterials, one of the most biocompatible forms of graphene is graphene quantum dots (GQDs). GQDs are obtained by converting 2D graphene into zero-dimensional graphene nanosheets. Moreover, very few reports in the literature reported the pharmacokinetic studies proving the safety and effectiveness of GQDs for in vivo applications.

OBJECTIVES

This study evaluated the pharmacokinetics of GQDs radiolabeled with ^99mTc, administered intravenously, in rodents (Wistar rats) in two conditions: short and long periods, to compare and understand the biological behavior.

METHODS

The graphene quantum dots were produced and characterized by RX diffractometry, Raman spectroscopy, and atomic force microscopy. The pharmacokinetic analysis was performed following the radiopharmacokinetics concepts, using radiolabeled graphene quantum dots with technetium 99 metastable (99mTc). The radiolabeling process of the graphene quantum dots with 99mTc was performed by the direct via.

RESULTS

The results indicate that the pharmacokinetic analyses with GQDs over a longer period were more accurate. Following a bicompartmental model, the long-time analysis considers each pharmacokinetic phase of drugs into the body. Furthermore, the data demonstrated that short-time analysis could lead to distortions in pharmacokinetic parameters, leading to misinterpretations.

CONCLUSION

The evaluation of the pharmacokinetics of GQDs over long periods is more meaningful than the evaluation over short periods.

Pharmaceutical Nanotechnology Applied to Phthalocyanines for the Promotion of the Antimicrobial Photodynamic Therapy: A Literature Review

Phthalocyanines are photosensitizers activated by light at a specific wavelength in the presence of oxygen and act topically through the production of Reactive Oxygen Species, which simultaneously attack several biomolecular targets in the pathogen agent and, therefore, have multiple and variable action sites. This nonspecific action site delineates the conventional resistance mechanisms. Antimicrobial Photodynamic Therapy (aPDT) is safe, easy to implement and, unlike conventional agents, the activity spectrum of photoantimicrobials. This work is a systematic review of the literature based on nanocarriers containing phthalocyanines in aPDT against bacteria, fungi, viruses, and protozoa. The search was performed in two different databases (MEDLINE/PubMed and Web of Science) between 2011 and May 2021. Nanocarriers often improve the action or are equivalent to free drugs, but their use allows substituting the organic solvent in the case of hydrophobic phthalocyanines, allowing for a safer application of aPDT with the possibility of prolonged release. In the case of hydrophilic phthalocyanines, they would allow for nonspecific site delivery with a possibility of cellular internalization. A single infectious lesion can have multiple microorganisms, and PDT with phthalocyanines is an interesting treatment given its ample spectrum of action. It is possible to highlight the upconversion nanosystems, which allow for the activation of phthalocyanine in deeper tissues by using longer wavelengths, as a system that has not yet been studied, but which could provide treatment solutions. The use of nanocarriers containing phthalocyanines requires more studies in animal models and clinical studies to establish the use of aPDT in humans.

Preliminary studies on drug delivery of polymeric primaquine microparticles using the liver high uptake effect based on size of particles to improve malaria treatment

Malaria is the most common parasitic disease around the world, especially in tropical and sub-tropical regions. This parasitic disease can have a rapid and severe evolution. It is transmitted by female anopheline mosquitoes. There is no reliable vaccine or diagnostic test against malaria; instead, Artesunate is used for the treatment of severe malaria and Artemisinin is used for uncomplicated falciparum malaria. However, these treatments are not efficient against severe malaria and improvements are needed. Primaquine (PQ) is one of the most widely used antimalarial drugs. It is the only available drug to date for combating the relapsing form of malaria. Nevertheless, it has severe side effects. Particle drug-delivery systems present the ability to enhance the therapeutic properties of drugs and decrease their side effects. Here, we report the development of Polymeric Primaquine Microparticles (PPM) labeled with 99mTc for therapeutic strategy against malaria infection. The amount of primaquine encapsulated into the PPM was 79.54%. PPM presented a mean size of 929.47 ± 37.72 nm, with a PDI of 0.228 ± 0.05 showing a homogeneous size for the microparticles and a monodispersive behavior. Furthermore, the biodistribution test showed that primaquine microparticles have a high liver accumulation. In vivo experiments using mice show that the PPM treatments resulted in partial efficacy and protection against the development of the parasite compared to free Primaquine. These results suggest that microparticles drug delivery systems of primaquine could be a possible approach for malaria prevention and treatment.

Radioactive polymeric nanoparticles for biomedical application

Nowadays, emerging radiolabeled nanosystems are revolutionizing medicine in terms of diagnostics, treatment, and theranostics. These radionuclides include polymeric nanoparticles (NPs), liposomal carriers, dendrimers, magnetic iron oxide NPs, silica NPs, carbon nanotubes, and inorganic metal-based nanoformulations. Between these nano-platforms, polymeric NPs have gained attention in the biomedical field due to their excellent properties, such as their surface to mass ratio, quantum properties, biodegradability, low toxicity, and ability to absorb and carry other molecules. In addition, NPs are capable of carrying high payloads of radionuclides which can be used for diagnostic, treatment, and theranostics depending on the radioactive material linked. The radiolabeling process of nanoparticles can be performed by direct or indirect labeling process. In both cases, the most appropriate must be selected in order to keep the targeting properties as preserved as possible. In addition, radionuclide therapy has the advantage of delivering a highly concentrated absorbed dose to the targeted tissue while sparing the surrounding healthy tissues. Said another way, radioactive polymeric NPs represent a promising prospect in the treatment and diagnostics of cardiovascular diseases such as cardiac ischemia, infectious diseases such as tuberculosis, and other type of cancer cells or tumors.

Clove oil nanoemulsion showed potent inhibitory effect against Candida spp

Increasing resistance to current fungicides is a clinical problem that leads to the need for new treatment strategies. Clove oil (CO) has already been described as having antifungal action. However, it should not be applied directly to the skin as it may be irritating. One option for CO delivery and suitable topical application would be nanoemulsions (NEs). NEs have advantages such as decreased irritant effects and lower dose use. The purpose of this work was the development of NEs containing CO and in vitro evaluation against Candida albicans and Candida glabrata. The NEs were produced by an ultrasonic processor with different proportions of CO and Pluronic^® F-127. In order to determine the best composition and ultrasound amplitude, an experimental design was performed. For the evaluation, droplet size and polydispersity index (PdI) were used. After the stability study, in vitro activity against C. albicans and C. glabrata was evaluated. NEs selected for the stability study, with diameter <40 nm and PdI <0.2, remained stable for 420 d. Activity against Candida spp. was improved when the CO was nanoemulsified, for it possibly leads to a better interaction between the active and the microorganisms, mainly in C. albicans.