Enhancing Singlet Oxygen Generation by Self-Assembly of a Porphyrin Entrapped in Supramolecular Fibers

Singlet oxygen (SO) is one of the reactive oxygen species that is effective in various uses, including performing chemical reactions, treating water impurities, and aiding in medicinal therapy. The generation of SO is often efficient in solution, although generation from the solid phase in nanomaterials is less reliable. Here, we report the preparation of hybrid supramolecular materials that incorporate a photosensitizer within their nanostructured fibers and demonstrate their high efficiency in promoting SO formation. The incorporation of tetrakis(4-carboxyphenyl)porphyrin within the nanofibers of a bis-imidazolium gelator was proved by various techniques, including super-resolution radial fluctuations (SRRF) microscopy, which shows the location of the chromophore precisely. SO is generated from the dispersed nanofibers far more efficiently than the dissolved porphyrin; a 14-fold higher rate is observed initially. These results point to an effective approach to the generation of SO for several applications, from optimizing synthetic protocols to photomedicine

Cationic supramolecular hydrogels for overcoming the skin barrier in drug delivery

A cationic bis‐imidazolium‐based amphiphile was used to form thermoreversible nanostructured supramolecular hydrogels incorporating neutral and cationic drugs for the topical treatment of rosacea. The concentration of the gelator and the type and concentration of the drug incorporated were found to be factors that strongly influenced the gelling temperature, gel‐formation period, and overall stability and morphology. The incorporation of brimonidine tartrate resulted in the formation of the most homogeneous material of the three drugs explored, whereas the incorporation of betamethasone resulted in a gel with a completely different morphology comprising linked particles. NMR spectroscopy studies proved that these gels kept the drug not only at the interstitial space but also within the fibers. Due to the design of the gelator, drug release was up to 10 times faster and retention of the drug within the skin was up to 20 times more effective than that observed for commercial products. Experiments in vivo demonstrated the rapid efficacy of these gels in reducing erythema, especially in the case of the gel with brimonidine. The lack of coulombic attraction between the gelator-host and the guest-drug seemed particularly important in highly effective release, and the intermolecular interactions operating between them were found to lie at the root of the excellent properties of the materials for topical delivery and treatment of rosacea

Supramolecular Hydrogels Consisting of Nanofibers Increase the Bioavailability of Curcuminoids in Inflammatory Skin Diseases

The low bioavailability of curcuminoids (CCMoids) limits their use in the treatment of inflammatory skin diseases. Our work shows that this constraint can be overcome upon their incorporation into supramolecular hydrogels assembled from a gemini-imidazolium amphiphilic gelator. Three structural CCMoid analogues were used to prepare supramolecular hydrogels, and it was observed that the concentration of both the gelator and CCMoid and the proportion of solvents influence the self-assembly process. Moreover, the mechanical properties of the nanostructured gels were studied to find the optimum gels, which were then further characterized microscopically, and their ability to release the CCMoid was evaluated. The physicochemical properties of the CCMoids play a fundamental role in the interaction with the gelator, influencing not only the gelation but also the morphology at the microscopic level, the mechanical properties, and the biopharmaceutical behavior such as the amount of CCMoid released from the gels. The nanostructured supramolecular hydrogels, which contain the CCMoids at much lower concentrations (μg/mL) in comparison to other products, promote the penetration of the CCMoids within the skin, but not their transdermal permeation, thus preventing any possible systemic effects and representing a safer option for topical administration. As a result, the CCMoid-containing hydrogels can effectively reduce skin inflammation in vivo, proving that these supramolecular systems are excellent alternatives in the treatment of inflammatory skin diseases

Micro- and nanomaterials for drug delivery in skin diseases

[eng] anostructured supramolecular hydrogels and gold nanoparticles, as two kinds of nanomaterials, were synthsized, characterized and evaluated for their potential as drug delivery systems. Two bis-imidazolium cationic surfactants (1·2Br and 2·2Br) were used as low molecular weight gelators that can incorporate anionic neutral and cationic drugs which can be used in the treatment of skin diseases such as Rosacea and Psoriasis. With either gelator and drug, optimum conditions for gel formation were found to be 5 mg/mL concentration of gelator, 50:50 ethanol:water proportion, and room temperature. 2·2Br forms a gel in 90 min while 1·2Br does it in 10 min. 1·2Br and 2·2Br gels can be formed in presence of anionic drugs sodium ibuprofen and indomethacin while 1·2Br gels can also be formed with other anionic, neutral, and cationic drugs such as sodium methotrexate, triamcinolone acetonide, betamethasone 17-valerate, tacrolimus brimonidine tartrate, AEBSF·HCl, and gemcitabine hydrochloride. The type and concentration of drug widely influence the gelling times, rheological behavior, and microscopic morphology of the gel. All formed gels are stable at room temperature for at least six months. Gels from both gelators can incorporate the drug not only at the intersticial space of the gel but also within the fibers. Gels of 1·2Br incorporate not only anionic drugs but also neutral and even cationic drugs, proving that the electrostatic atraction between the cationic gelator and a drug is not the main force driving this fiber-incorporation. The fiber-incorporation of AEBSF·HCl and further release to the intersticial space results in remarkable fiber twisting and subsequent coiling, being the first time a morphological change in supramolecular structures as a result of the exit of a guest substance (drug) has been reported. Suitable drug release from the gel matrix is observed from either gel. Gels of 1·2Br permit the release of up to ten-times more drug from the matrix than the commercial products studied. Application of gels on human skin permit a suitable permeation of drug, except for gels with tacrolimus and gemcitabine hydrochloride due to the drug physicochemical properties. The application of gel with sodium methotrexate does not involve systemic toxicity. The gels promote the retention of either drug beneath the skin, more than the commercial products studied. Gels of 2·2Br incorporating NSAID effectively inhibited inflammation in mice ears in vivo, with no significant differences as compared to gels of 1·2Br. A fast and reliable in vivo model of Rosacea was developed in rabbits. Gels of 1·2Br with triamcinolone acetonide and especially with brimonidine tartrate showed effective in vivo vasoconstrictive and anti-erythema activity using this model, being gel with brimonidine tartrate faster than the commercial Mirvaso®. Gold nanoparticles (GNP) for the treatment of Rosacea were designed and synthesized using thiolated PEG molecules of sufficient length with a mixture of hydroxyl and carboxyl groups on their surface (GNP.OH/COOH). GNP were further functionalized through their carboxylic acid group with the serine protease inhibitor AEBSF·HCl (covalently or ionically), the anti-KLK5 antibody (covalently), or the α-adrenergic agonist brimonidine tartrate (ionically). All synthesized and functionalized GNP were highly soluble in water. GNP are monodisperse in solution, comprised of a gold core of a ca. 1.5 nm diameter, and hydrodynamic diameters of around 10 nm. GNP.OH/COOH showed a high in vitro Kallikrein-5 (KLK5) inhibition comparable to AEBSF·HCl alone and to other particles. The highest inhibitions were reached by electrostatically AEBSF functionalized nanoparticles (GNP.COOH AEBSF) and by anti-KLK5 antibody-functionalized particles (GNP.antiKLK5). Fluorophore-labelled GNP.OH/COOH can be internalized in HaCaT human keratinocytes. The majority of GNP present no toxicity in keratinocytes at the concentrations tested (including KLK5-inhibiting concentrations) with viabilities around 75%. The ionic, and especially, the covalent bond of AEBSF importantly increase cell viabilities as compared to the drug alone. An in vitro model of Rosacea was developed by stimulating TLR-2 ligands in keratinocytes, which increases their intracellular KLK5 activity and increases IL-8 secretion, also confirming the biochemical pathway of Rosacea. GNP.OH/COOH, and especially GNP.AEBSF and GNP.antiKLK5 significantly reduce intracellular KLK5 in keratinocytes, which is related to their effective decrease in IL-8 secretion, for which they seem to be most promising option for becoming a new therapeutic strategy in the treatment of Rosacea.[spa] Geles supramoleculares nanoestructurados y nanopartículas de oro, como dos tipos de nanomateriales, fueron sintetizados, caracterizados y evaluados como posibles sistemas de drug delivery. Dos tensioactivos catiónicos derivados de bis-imidazolio (1·2Br y 2·2Br) se usaron como gelificantes de bajo peso molecular para incorporar fármacos aniónicos, neutros y catiónicos, que pueden usarse en el tratamiento de enfermedades inflamatorias de la piel como Rosácea y Psoriasis. Con cada gelificante y fármaco se encontraron las condiciones óptimas de gelificación. Geles de 1·2Br and 2·2Br pueden ser formados en presencia de fármacos aniónicos ibuprofenato de sodio e indometacina, mientras que que geles de 1·2Br también se forman con otros fármacos aniónicos, neutros y catiónicos como metrotrexato de sodio, triamcinolona acetónido, betametasona 17-valerato, tacrolimus, brimonidina tartrato, AEBSF·HCl, y gemcitabina hidrocloruro. El tipo y concentración de fármaco influencia el tiempo de gelificación, comportamiento reológico y la morfología microscópica del gel. Todos los geles son estables a temperatura ambiente por lo menos seis meses. Los geles incorporan fármacos aniónicos, neutros y catiónicos, no sólo en el espacio intersticial sino también dentro de las propias fibras. La incorporación de AEBSF·HCl dentro de las fibras y su posterior liberación propicia un importante trenzado y y posterior enrollamiento de las fibras, siendo la primera vez que se observa un cambio morfológico en un material supramolecular debido a la salida de una sustancia huésped. Los geles permiten la liberación de hasta diez veces más fármaco que los productos comerciales estudiados, y permiten una mejor permeación y retención del fármaco en la piel humana que los productos comerciales. Se desarrolló un nuevo modelo in vivo de Rosácea en conejos. Geles con triamcinolona acetónido y brimonidina tartrato mostraron vasoconstricción y reducción del eritema, este último siendo más rápido que el gel Mirvaso®. Nanopartículas de oro (GNP) altamente solubles en agua fueron diseñadas para el tratamiento de la Rosácea y sintetizadas usando moléculas de PEG tioladas, con una mezcla de grupos hidroxilo y carboxilo en la superficie (GNP.OH/COOH). Las GNP se funcionalizaron con el inhibidor de serina proteasa AEBSF·HCl, el anticuerpo anti-KLK5, o brimonidina tartrato. Las partículas se forman de un núcleo de oro de cerca de 1.5 nm de diámetro y un radio hidrodinámico de 10 nm. Las GNP inhiben la actividad de la Kallikrein-5 (KLK5) in vitro, pueden internalizarse en keratinocitos HaCaT (marcadas con fluoróforo), y la mayoría no presentan citotoxicidad a las concentraciones inhibitorias. La unión del AEBSF a las GNP reduce la citotoxicidad del fármaco. Se desarrolló un nuevo modelo in vitro de Rosácea en keratinocitos, en el cual las GNP.OH/COOH y, especialmente partículas con AEBSF y con anticuerpo reducen significativamente la actividad de KLK5 intracelular y la secreción de IL-8, mostrándose como promesas en el tratamiento de la Rosácea y convirtiéndose, en tal caso, en una nueva estrategia terapéutica

Galenic and Biopharmaceutical Study of the Triamcinolone Acetonide and Lidocaine Hydrochloride Semisolid Formulations for Buccal Administration

The mouth can be affected by important inflammatory processes resulting from localized or systemic diseases, such as diabetes, AIDS, and leukemia, among others, which are manifested in various types of buccal sores, typically presenting pain [1]. The present work focuses on the design, formulation, and characterization of four semi-solid formulations for oral mucosa in order to symptomatically treat these painful processes. The formulations have two active pharmaceutical ingredients: triamcinolone acetonide (TA) and lidocaine hydrochloride (LIDO). The formulations also contain Orabase® as an excipient, which is a protective, hydrophobic, and anhydrous adhesive vehicle, used to retain or facilitate the application of active pharmaceutical ingredients (APIs) to the oral mucosa. After designing the formulations, the validation of the analytical method was performed to achieve reliable analytical results. Franz-type diffusion cells were used to perform drug release studies using synthetic membrane, and permeation studies using buccal mucosa, permitting the estimation of the amount and rate of TA permeated across this mucous membrane. Further, the amount of TA retained within the tissue was estimated, as this is where it performs its anti-inflammatory activity, and showed no significant differences between the 0.05% TA + LIDO and 0.1% TA + LIDO formulations (p > 0.05). Therefore, the results demonstrate the suitability of the administration of the lowest concentration of TA tested, which achieved a similar efficacy as higher concentrations and reduced the potential systemic effects of corticoid administration. Furthermore, sublingual permeation studies were carried out to evaluate a scenario of continuous contact of the tongue with the applied formulation. The four formulations studied show pseudoplastic and thixotropic behavior, ideal for topical application. These results provide evidence for the potential of these topical formulations for the treatment of inflammatory processes in the buccal mucosa. Keywords: triamcinolone acetonide; buccal administration; semisolid formulations; thixotropic behavior; lidocaine hydrochloride; Franz-type diffusion cell

Biopharmaceutical Study of Triamcinolone Acetonide Semisolid Formulations for Sublingual and Buccal Administration

The mouth can be affected by important inflammatory processes resulting from localized or systemic diseases such as diabetes, AIDS and leukemia, among others, and are manifested in various types of buccal sores typically presenting pain. This work focuses on the design, formulation, and characterization of four semisolid formulations for oral mucosa in order to symptomatically treat these painful processes. The formulations have two active pharmaceutical ingredients, triamcinolone acetonide (TA) and lidocaine hydrochloride (LIDO). The formula also contains, as an excipient, Orabase®, which is a protective, hydrophobic, and anhydrous adhesive vehicle, used to retain or facilitate the application of active pharmaceutical ingredients to the oral mucosa. After designing the formulations, an analytical method for TA was validated using HPLC so as to achieve reliable analytical results. Franz-type diffusion cells were used to perform drug release studies using synthetic membrane, and permeation studies using buccal mucosa, estimating the amount and rate of TA permeated across the tissue. Additionally, sublingual permeation studies were carried out to evaluate a scenario of a continuous contact of the tongue with the applied formulation. Permeation fluxes and the amount of TA retained within sublingual mucosa were similar to those in buccal mucosa, also implying anti-inflammatory activity in the part of the tongue that is in direct contact with the formulation. In addition, the dynamic conditions of the mouth were recreated in terms of the presence of phosphate buffered saline, constant movement of the tongue, pH, and temperature, using dissolution equipment. The amount of TA released into the phosphate buffered saline in dynamic conditions (subject to being ingested) is well below the normal oral doses of TA, for which the formulation can be considered safe. The formulations applied to buccal or sublingual mucosas under dynamic conditions permit the successful retention of TA within either tissue, where it exerts anti-inflammatory activity. The four formulations studied show a pseudoplastic and thixotropic behavior, ideal for topical application. These results evidence the potential of these topical formulations in the treatment of inflammatory processes in the buccal mucosa

Assessing the Chemical Stability and Cytotoxicity of Electrodeposited Magnetic Mesoporous Fe-Pt Films for Biomedical Applications

The development of feasible micro/nanoplatforms for various biomedical applications requires holistic research that explores scalable synthesis and design pathways and imposes an interdisciplinary integration of materials science, physical, medical, chemical, and biological knowledge. Thanks to their unique characteristics (i.e., structure, large specific surface areas, tuneability, versatility, and integrity), mesoporous materials have emerged as potential candidates for being part of micro/nanoplatforms for therapeutic, monitoring, and diagnostic applications. In this context, Fe-Pt mesoporous materials are excellent candidates to be part of biomedical micro/nanoplatforms, thanks to their chemical nature, structure, and magnetic properties, which endow them with magnetic locomotion, high cargo capability of therapeutic agents inside the mesoporous cavity, and large surface area for surface functionalization. However, the chemical stability in biological media and cytotoxicity of the Fe-Pt mesoporous material (without considering the effects of architecture and shape) are pivotal elements that determine the suitability of these materials for biomedical applications. This work demonstrates the following: (i) the potential of electrochemical deposition, based on the use of block copolymer micellar solutions as electrochemical media, as an easy, inexpensive, and scalable strategy to synthesize mesoporous Fe-Pt components with tunable chemical composition, porosity, magnetism, and shape (in this case films, but other architectures like nanowires can be easily fabricated using simultaneously hard templates); (ii) the excellent corrosion stability, which is comparable to bulk Au, and minimal chemical dissolution in biological media after 160 h of immersion (∼0.88% of Fe and ∼0.0019% of Pt), which confirms the robustness of Fe-Pt; and (iii) negligible cytotoxicity on HaCaT cells (human immortalized keratinocytes), which reinforces the biocompatibility of Fe-Pt mesoporous structures. Also, the presence of Fe-Pt mesoporous films seems to induce a slight increase in cell viability. These results confirm the biocompatibility of Fe-Pt mesoporous films, making them suitable for biomedical applications

Supramolecular and base-induced singlet oxygen generation enhancement of a water-soluble phthalocyanine

Investigation into the reactive oxygen species (ROS) generating abilities of photosensitizers outside of in-vitro/vivo conditions is a crucial element in the wider study of photodynamic therapy (PDT) in clinical settings. Zinc (II) phthalocyanine tetrasulfonic acid (ZnPcTS) is a water-soluble photosensitizer that can generate ROS as singlet oxygen (SO) under irradiation in the red and far-red region of the electromagnetic spectrum. The incorporation of ZnPcTS into nano-fibers of a bis-imidazolium hydrogel was demonstrated and the material was characterized with photophysical, rheological, and microscopy techniques. This supramolecular material containing ZnPcTS (named ZnPcTS_nEqBase@ Gels) was found to significantly enhance the SO generation rate with respect to that of ZnPcTS in an aqueous solution. The effect is attributed mainly to reduced aggregation within the gel microenvironment compared with

Synthesis and validation of DOPY: A new gemini dioleylbispyridinium based amphiphile for nucleic acid transfection

Nucleic acids therapeutics provide a selective and promising alternative to traditional treatments for multiple genetic diseases. A major obstacle is the development of safe and efficient delivery systems. Here, we report the synthesis of the new cationic gemini amphiphile 1,3-bis[(4-oleyl-1-pyridinio)methyl]benzene dibromide (DOPY). Its transfection efficiency was evaluated using PolyPurine Reverse Hoogsteen hairpins (PPRHs), a nucleic acid tool for gene silencing and gene repair developed in our laboratory. The interaction of DOPY with PPRHs was confirmed by gel retardation assays, and it forms complexes of 155 nm. We also demonstrated the prominent internalization of PPRHs using DOPY compared to other chemical vehicles in SH-SY5Y, PC-3 and DF42 cells. Regarding gene silencing, a specific PPRH against the survivin gene delivered with DOPY decreased survivin protein levels and cell viability more effectively than with N-[1-(2,3-Dioleoyloxy)propyl]-N,N,N-trimethylammonium methylsulfate (DOTAP) in both SH-SY5Y and PC-3 cells. We also validated the applicability of DOPY in gene repair approaches by correcting a point mutation in the endogenous locus of the dhfr gene in DF42 cells using repair-PPRHs. All these results indicate both an efficient entry and release of PPRHs at the intracellular level. Therefore, DOPY can be considered as a new lipid-based vehicle for the delivery of therapeutic oligonucleotides