Advanced theranostic nanoplatforms for hypericin delivery in the cancer treatment.

Biomodified coated-lipid vesicles were obtained using the DPPC lipid (L) and F127 copolymer linked covalently with spermine (SN), biotin (BT), and folic acid (FA), resulting in LF127-SN, LF127-BT, and LF127-FA nanoplatforms. The photosensitizer hypericin (HY) was incorporated into the nanosystem by a thin-film method and characterized by dynamic light scattering, zeta potential, encapsulation efficiency, and transmission electronic microscopy. The results provided a good level of stability for all nanoplatforms for at least 5 days as an aqueous dispersion. The in vitro serum stability showed that the HY-loaded LF127-SN has a lower tendency to form complexes with BSA protein than with its analogs. LF127-SN was the most stable HY formulation, followed by LF127-BT and LF127-FA, confirmed by the association constant (Kd) values: 600 µmol L-1, 1100 µmol L-1, 515 µmol L-1, and 378 µmol L-1 for LF127, LF127 FA, LF127-BT, and LF127-SN, respectively. The photodynamic potential of HY was accessed by cytotoxicity assays using Caco-2, B16-F10, L-929, and HaCat cells. HY-loaded LF127-SN revealed a significant increase in the selectivity compared to other nanoplatforms. HY-loaded in LF127-BT and LF127-SN showed distinct uptake and biodistribution after 2 h of intravenous application. All biomodified coated-lipids showed satisfactory metabolism within 72 h after application, without significant accumulation or residue in any vital organ. These results suggest that incorporating HY-loaded in these nanosystems may be a promising strategy for future applications, even with a small amount of binders to the coating copolymer (0.02% w/v). Furthermore, these results indicate that the LF127-SN showed remarkable superiority compared to other evaluated systems, being the most distinct for future photodynamic therapy and theranostic applications.

Development of Environmentally Responsive Self-Emulsifying System Containing Copaiba Oil-Resin for Leishmaniasis Oral Treatment.

Leishmaniasis is a disease caused by protozoa species of the Leishmania genus, and the current treatments face several difficulties and obstacles. Most anti-leishmanial drugs are administered intravenously, showing many side effects and drug resistance. The discovery of new anti-leishmanial compounds and the development of new pharmaceutical systems for more efficient and safer treatments are necessary. Copaiba oil-resin (CO) has been shown to be a promising natural compound against leishmaniasis. However, CO displays poor aqueous solubility and bioavailability. Self-emulsifying drug delivery systems (SEDDS) can provide platforms for release of hydrophobic compounds in the gastrointestinal tract, improving their aqueous solubilization, absorption and bioavailability. Therefore, the present work aimed to develop SEDDS containing CO and Soluplus® surfactant for the oral treatment of leishmaniasis. The design of the systems was accomplished using ternary phase diagrams. Emulsification and dispersion time tests were used to investigate the emulsification process in gastric and intestinal environments. The formulations were nanostructured and improved the CO solubilization. Their in vitro antiproliferative activity against promastigote forms of L. amazonensis and L. infantum, and low in vitro cytotoxicity against macrophages were also observed. More studies are necessary to determine effectiveness of SOL in these systems, which can be candidates for further pharmacokinetics and in vivo investigations.

Formulation and performance evaluation of emulgel platform for combined skin delivery of curcumin and propolis.

The environment can modify the physiology and body protective function of the skin. Propolis (PRP) and curcumin (CUR) possess important antioxidant and antimicrobial properties, and they can be administered in a combined way and using photodynamic therapy (PDT). Emulgels can control drug release due to the physicochemical properties of the gel and the emulsion. They constitute a good strategy for achieving an improved platform for the combined delivery of PRP and CUR. There are no other studies of emulgels composed of PRP and CUR and their performance as antimicrobial and skin healing using or not PDT. This study aimed to investigate the effect of Carbopol 934 P (C934P), 974 P (C974P) or polycarbophil (PC) on physicochemical stability, antioxidant activity, drug release profile, antimicrobial activity, and ex vivo skin permeation and retention of emulgels containing PRP and CUR. Formulations containing C974P or PC displayed improved stability and antioxidant activity. They displayed activity against Staphylococcus aureus and modified (extended) drug release, governed mainly by non-Fickian anomalous transport. C974P and PC resulted in improved emulgels for combined CUR and PRP delivery, allowing the drugs to cross the stratum corneum, and permeate the epidermis, reaching the dermis. The selected emulgels are candidates for further studies to prove their action and benefits to skin health.

Melanoma-targeted photodynamic therapy based on hypericin-loaded multifunctional P123-spermine/folate micelles.

Multifunctional P123 micelle linked covalently with spermine (SM) and folic acid (FA) was developed as a drug delivery system of hypericin (HYP). The chemical structures of the modified copolymers were confirmed by spectroscopy and spectrophotometric techniques (UV-vis, FTIR, and 1H NMR). The copolymeric micelles loading HYP were prepared by solid dispersion and characterized by UV-vis, fluorescence, dynamic light scattering (DLS), ζ potential, and transmission electron microscopy (TEM). The results provided a good level of stability for HYP-loaded P123-SM, P123-FA, and P123-SM/P123-FA in the aqueous medium. The morphology analysis showed that all copolymeric micelles are spherical. Well-defined regions of different contrast allow us to infer that SM and FA were localized on the surface of micelles, and the HYP molecules are located in the core region of micelles. The uptake potential of multifunctional P123 micelle was accessed by exposing the micellar systems loading HYP to two cell lines, B16-F10 and HaCaT. HYP-loaded P123 micelles reveal a low selectivity for melanoma cells, showing significant photodamage for HaCat cells. However, the exposition of B16-F10 cells to Hyp-loaded SM- and FA-functionalized P123 micelles under light irradiation revealed the lowest CC50 values. The interpretation of these results suggested that the combination of SM and FA on P123 micelles is the main factor in enhancing the HYP uptake by melanoma cells, consequently leading to its photoinactivation.

Antileishmanial activity of neo-clerodane diterpenes from Croton echioides.

Nowadays, new leishmanicidal drugs are needed and natural products arise as a promising alternative source. Therefore, bioguided fractionation of a hydroethanolic extract from the stem bark of Croton echioides Baill. were conducted based on its antileishmanial activity. Two novel neo-clerodane diterpenoids methyl-15,16-epoxy-3,13(16),14-neo-clerodatrien-17,18-dicarboxylate (1) and dimethyl-3-oxo-15,16-epoxy-13(16),14-neo-clerodadien-17,18-dicarboxylate (2) were isolated, as well as four known compounds (3-6) and lupeol, from the hexane fraction. Their structures were established by NMR analysis. The crude extract, fractions and the compounds (1 and 3-6) were evaluated for their in vitro antileishmanial activity and cytotoxicity against macrophages J774A.1. The selectivity index (SI) were calculated. The most active compound against promastigote forms of L. amazonensis was the clerodane diterpene 4, with IC50 values of 8.3 µM and SI value of 80.9. Our results highlighted stem bark of Croton echioides Baill. as a promising source for the development of a new chemotherapeutic agent to combat leishmaniasis.

Design and Optimization of Stimuli-responsive Emulsion-filled Gel for Topical Delivery of Copaiba Oil-resin.

This study presents a phytotherapeutic emulsion-filled gel design composed of Pluronic® F127, Carbopol® C934P, and high level of copaiba oil-resin (PHY-ECO). Mathematical modeling and response surface methodology (RSM) were employed to access the optimal ratio between the oil and the polymer gel-matrix constituents. The chemometric approach showed robust mechanical and thermoresponsive properties for emulsion gel. The model predicts viscosity parameters at 35.0°C (skin temperature) from PHY-ECOs. Optimized PHY-ECOs were described by 18-20% (w/w) F127, 0.25% (w/w) C934P, and 15% (w/w) copaiba oil-resin, and showed interfacial layers properties that led to high physicochemical stability. Besides, it had thermal stimuli-responsive that led large viscosity range before and after skin administration, observed by oscillatory rheology. These behaviors give the optimized smart PHY-ECO high design potential to be used as a pharmaceutical platform for CO delivery, focusing on the anti-inflammatory therapy and skin wound care.

Multifunctional Nanoparticles as High-Efficient Targeted Hypericin System for Theranostic Melanoma.

Biotin, spermine, and folic acid were covalently linked to the F127 copolymer to obtain a new drug delivery system designed for HY-loaded PDT treatment against B16F10 cells. Chemical structures and binders quantification were performed by spectroscopy and spectrophotometric techniques (1NMR, HABA/Avidin reagent, fluorescamine assay). Critical micelle concentration, critical micelle temperature, size, polydispersity, and zeta potential indicate the hydrophobicity of the binders can influence the physicochemical parameters. Spermine-modified micelles showed fewer changes in their physical and chemical parameters than the F127 micelles without modification. Furthermore, zeta potential measurements suggest an increase in the physical stability of these carrier systems. The phototherapeutic potential was demonstrated using hypericin-loaded formulation against B16F10 cells, which shows that the combination of the binders on F127 copolymer micelles enhances the photosensitizer uptake and potentializes the photodynamic activity.

New cadinene-sesquiterpene from Chromolaena laevigata (lam.) R. M. King & H. Rob (Asteraceae) aerial parts and biological activities.

Phytochemical investigation of Chromolaena laevigata led to the isolation of a new cadinene-sesquiterpene, chromolaevigone glucoside (1), along with nine known compounds: daucosterol (2), stigmasterol glycoside (3), stigmasterol (4), ß-sitosterol (5), pilloin (6), gonzalitosin I (7), quercetin-3-O-α-rhamnopyranoside (8), 7,7-dihydroxy-calamen-12-oic acid lactone (9) and trachelanthic acid (10). Others 11 known compounds were identified by UHPLC-HRMS/MS. These compounds are being described for the first time in this species, with the exception of cadinene 9. Furthermore, due to the limitation of pharmacological studies, antiproliferative, antiviral, and antimicrobial activities of C. laevigata were evaluated. The best results in the cytotoxicity, antimicrobial and antiproliferative tests, presenting GI50 values on ovarian tumour cells (OVCAR-03) of 1.9 µg mL-1 and kidney (786-0) of 2.5 µg mL-1 were observed for the hexanic fraction.[Figure: see text].

The design, synthesis, and in vitro trypanocidal and leishmanicidal activities of 1,3-thiazole and 4-thiazolidinone ester derivatives.

Chagas and leishmaniasis are both neglected tropical diseases, whose inefficient therapies have made them remain the cause for millions of deaths worldwide. Given this, we synthesized 27 novel 1,3-thiazoles and 4-thiazolidinones using bioisosteric and esterification strategies to develop improved and safer drug candidates. After an easy, rapid and low-cost synthesis with satisfactory yields, compounds were structurally characterized. Then, in vitro assays were performed, against Leishmania infantum and Leishmania amazonensis promastigotes, Trypanosoma cruzi trypomastigotes and amastigotes, for selected compounds to determine IC50 and SI, with cytotoxicity on LLC-MK2 cell lines. Overall, 1,3-thiazoles exhibited better trypanocidal activity than 4-thiazolidinones. The compound 1f, an ortho-bromobenzylidene-substituted 1,3-thiazole (IC50 = 0.83 µM), is the most potent of them all. In addition, compounds had negligible cytotoxicity in mammalian cells (CC50 values > 50 µM). Also noteworthy is the examination of the cell death mechanism of T. cruzi, which showed that compound 1f induced necrosis and apoptosis in the parasite. Scanning electron microscopy analysis demonstrated that the treatment of Trypanosoma cruzi trypomastigote cells with the compound 1f at different IC50 concentrations promoted alterations in the shape, flagella and body surface, inducing parasite death. Together, our data revealed a novel series of 1,3-thiazole structure-based compounds with promising activity against Trypanosoma cruzi and Leishmania spp., broadening ways for scaffold optimization.

Hypericin photodynamic activity in DPPC liposomes - part II: stability and application in melanoma B16-F10 cancer cells.

Hypericin (Hyp) is considered a promising photosensitizer for Photodynamic Therapy (PDT), due to its high hydrophobicity, affinity for cell membranes, low toxicity and high photooxidation activity. In this study, Hyp photophysical properties and photodynamic activity against melanoma B16-F10 cells were optimized using DPPC liposomes (1,2-dipalmitoyl-sn-glycero-3-phosphocholine) as a drug delivery system. This nanoparticle is used as a cell membrane biomimetic model and solubilizes hydrophobic drugs. Hyp oxygen singlet lifetime (τ) in DPPC was approximately two-fold larger than that in P-123 micelles (Pluronic™ surfactants), reflecting a more hydrophobic environment provided by the DPPC liposome. On the other hand, singlet oxygen quantum yield values (ΦΔ1O2) in DPPC and P-123 were similar; Hyp molecules were preserved as monomers. The Hyp/DPPC liposome aqueous dispersion was stable during fluorescence emission and the liposome diameter remained stable for at least five days at 30 °C. However, the liposomes collapsed after the lyophilization/rehydration process, which was resolved by adding the lyoprotectant Trehalose to the liposome dispersion before lyophilization. Cell viability of the Hyp/DPPC formulation was assessed against healthy HaCat cells and high-metastatic melanoma B16-F10 cells. Hyp incorporated into the DPPC carrier presented a higher selectivity index than the Hyp sample previously solubilized in ethanol under the illumination effect. Moreover, the IC50 was lower for Hyp in DPPC than for Hyp pre-solubilized in ethanol. These results indicate the potential of the formulation of Hyp/DPPC for future biomedical applications in PDT treatment.