Characterization and Determination of the Antibacterial Activity of Baccharis dracunculifolia Essential-Oil Nanoemulsions.

The aim of this study was to evaluate the antibacterial activity of nanoemulsions of Baccharis dracunculifolia essential oil. The volatile compounds of the essential oil were identified using gas chromatography-mass spectrometry. The properties of the nanoemulsions (droplet size, polydispersity index, pH, and electrical conductivity) were determined. The antibacterial activities of the essential oil and its nanoemulsions were evaluated using MIC, MBC, and disk diffusion. The microorganisms used were: Gram-positive bacteria (Staphylococcus aureus ATCC 25923, Bacillus cereus ATCC 14579, Streptococcus mutans ATCC 25175, and Enterococcus faecalis ATCC 29212) and Gram-negative bacteria (Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC BAA-1706, Salmonella enterica ATCC 14028, and Escherichia coli ATCC 25922). The major volatile compounds of the B. dracunculifolia essential oil were limonene (19.36%), (E)-nerolidol (12.75%), bicyclogermacrene (10.76%), and ß-pinene (9.60%). The nanoemulsions had a mean droplet size between 13.14 and 56.84 nm. The nanoemulsions presented lower and statistically significant MIC values compared to the essential oil, indicating enhancement of the bacteriostatic action. The disk diffusion method showed that both the nanoemulsions and the essential oil presented inhibition zones only for Gram-positive bacteria, while there were no results against Gram-negative bacteria, indicating that B. dracunculifolia essential oil has a better antimicrobial effect on Gram-positive microorganisms.

Multi-level toxicity assessment of the antidepressant venlafaxine in embryos/larvae and adults of zebrafish (Danio rerio).

The toxic effects of venlafaxine (VLX) on aquatic organisms have already been verified and therefore are a proven matter of concern. Herein, we evaluated zebrafish embryos/adults after acute exposure to VLX. Embryos/larvae were exposed to different concentrations of VLX (100-1000 mg/L; 1.33 as a dilution factor), to evaluate mortality/developmental changos and to analyze biomarkers (0.002-100 mg/L). For adults, mortality, genotoxicity, and biomarkers were assessed in five different concentrations of VLX (1-100 mg/L). The median lethal concentration (LC50-168h) was 274.1 mg/L for embryos/larvae, and >100 mg/L for adults (LC50-96h). VLX decreased the heart rate frequency and caused premature hatching and lack of equilibrium in embryos/larvae exposed to different concentrations ranging from 100 to 562.5 mg/L. The activity of acetylcholinesterase (AChE) was inhibited in larvae exposed to 1, 25 and 100 mg/L. Glutathione-S-transferase (GST) activity was reduced in both larvae and adults after exposure to different concentrations, mainly at 25 mg/L. For both larvae and adults, lactate dehydrogenase (LDH) activity increased after 100 mg/L of VLX exposure. No DNA damage was observed in peripheral erythrocytes. Exposure to VLX may cause adverse effects on zebrafish in their early and adult life stages, interfering with embryo-larval development, and can induce physiological disturbances in adults.

Extrusion-based systems for topical and transdermal drug delivery.

INTRODUCTION: Although the administration of drugs on the skin is a safe and noninvasive therapeutic alternative, producing formulations capable of disrupting the cutaneous barriers is still a challenge. In this scenario, extrusion-based techniques have emerged as disruptive technologies to ensure unique drug-excipient interactions that facilitate drug skin diffusion for systemic or local effect and even mean the key to obtain viable industrial products. AREAS COVERED: This article presents a comprehensive overview of extrusion-based techniques in developing pharmaceutical dosage forms for topical or transdermal drug delivery. First, the theoretical basis of how extrusion-based techniques can optimize the permeation of drugs through the skin is examined. Then, the current state-of-the-art of drug products developed by extrusion-based techniques, specifically by hot-melt extrusion (HME) and fused deposition modeling (FDM) 3D printing, are discussed and contrasted with the current pharmaceutical processes. EXPERT OPINION: A wide variety of pharmaceutical products can be obtained using HME and FDM 3D printing, including new dosage forms designed for a perfect anatomical fit. Despite the limitations of pharmaceutical products produced with HME and FDM 3D printing regarding thermal stability and available excipients, the advantages in industrial adaptability and improved bioavailability allied with patient-match devices certainly deserve full attention and investment.

Compounded drugs as an alternative to the therapeutical gaps of inborn errors of metabolism

Abstract Inborn errors of metabolism are rare disorders with few therapeutic options for their treatments, which can make patients suffer with complications. Therefore, compounded drugs might be a promising option given that they have the ability of meeting the patient's specific needs, (i) identification of the main drugs described in the literature; (ii) proposal of compounding systems and (iii) calculation of the budgetary addition for the inclusion of these drugs into the Brazilian Unified Health System. The research conducted a literature review and used management data as well as data obtained from official Federal District government websites. The study identified 31 drugs for the treatment of inborn errors of metabolism. Fifty eight percent (58%) (18) of the medicines had their current demand identified, which are currently unmet by the local Health System. The estimated budget for the production of compounded drugs was of R$363,16.98 per year for approximately 300 patients. This estimated cost represents a budgetary addition of only 0.17% from the total of expenditures planned for drug acquirement. There is a therapeutic gap for inborn errors of metabolism and compounding pharmacies show potential in ensuring access to medicine therapy with a low-cost investment.

Liquid chromatography-mass spectrometry for simultaneous determination of spironolactone and canrenone in plasma samples

Abstract n our study, we aimed to validate a method based on liquid chromatography-mass spectrometry (LC-MS) to quantify spironolactone (SPI) and its active metabolite canrenone (CAN) simultaneously in plasma samples to support in vivo experiments. Compounds were separated by using a C18 column with the isocratic elution of a mobile phase composed of 0.1% (v/v) formic acid in methanol-water (60:40 v/v) at a flow rate of 0.4 mL min−1. SPI and CAN were detected in na electrospray interface operating in a positive ionization mode and quantified using the selective ion mode monitoring of mass-charge ratios (m/z) of 439.0 for SPI and 363.1 for CAN. After calculating the matrix effect using theoretical equations, we observed the strong interference of plasma in the equipment-generated signal, which required creating analytical curves using the matrix as a solvent. The method was nevertheless linear (r 2 > 0.999) in a concentration range of 0.4-5.0 µg mL−1, as well as precise, with a coefficient of variation less than 5%. SPI's and CAN's recovery rates from the plasma ranged from 87.4% to 112.1%, while their limits of detection (i.e., 0.07 µg mL−1 and 0.03 µg mL−1, respectively) and quantification (i.e., 0.20 µg mL−1 and 0.08 µg mL−1, respectively) in the presence of plasma contaminants were low. Therefore, the bioanalytical method seems to be feasible for quantifying SPI and CAN in plasma

Medicine manipulation: An alternative to mitigate therapeutic gaps in the Brazilian Unified Health System?

Despite the various initiatives carried out in Brazil and in the world, the challenge of offering essential medicines in adequate presentations remains, especially to the public affected by diseases considered neglected and the pediatric population, for whom the therapeutic options remain limited. The main objective of this study was to evaluate the production of manipulated medicines as a strategy to mitigate therapeutic and access gaps to essential medicines within the Brazilian public health system, called the Unified Health System (SUS). The evaluation, carried out between 2020 and 2021, identified, among the medicines considered essential to the Brazilian health context, those unavailable, for which strategies were evaluated to mitigate the identified unavailability, which is conventionally called therapeutic gaps. For 57% (n = 235) of pharmaceutical presentations identified as therapeutic gaps in SUS, manipulation was identified as the best strategy to promote access. Of these presentations, 30% (n = 70) were identified as priorities in the context of patient care and were mainly related to the demands of the pediatric public and those affected by poverty-related diseases. Concerning poverty-related diseases, the absence of evidence on the development of a standard formula for drugs with indication for such diseases was demonstrated. The need for an annual investment of approximately US$74.75 per capita was estimated to offer treatments in adequate presentations to SUS users, which should reflect in the improvement of the quality of life of about 26 thousand people. It was observed that this investment amount corresponds to only 3% of the budget for the purchase of medicines financed exclusively by the Ministry of Health thorugh the Strategic Component of Pharmaceutical Assistance (CESAF) approved for 2021.

Active Potential of Bacterial Cellulose-Based Wound Dressing: Analysis of Its Potential for Dermal Lesion Treatment.

The use of innate products for the fast and efficient promotion of healing process has been one of the biomedical sector's main bets for lesion treatment modernization process. The aim of this study was to develop and characterize bacterial cellulose-based (BC) wound dressings incorporated with green and red propolis extract (2 to 4%) and the active compounds p-coumaric acid and biochanin A (8 to 16 mg). The characterization of the nine developed samples (one control and eight active wound dressings) evidenced that the mechanics, physics, morphological, and barrier properties depended not only on the type of active principle incorporated onto the cellulosic matrix, but also on its concentration. Of note were the results found for transparency (28.59-110.62T600 mm-1), thickness (0.023-0.046 mm), swelling index (48.93-405.55%), water vapor permeability rate (7.86-38.11 g m2 day-1), elongation (99.13-262.39%), and antioxidant capacity (21.23-86.76 µg mL-1). The wound dressing based on BC and red propolis was the only one that presented antimicrobial activity. The permeation and retention test revealed that the wound dressing containing propolis extract presented the most corneal stratum when compared with viable skin. Overall, the developed wound dressing showed potential to be used for treatment against different types of dermal lesions, according to its determined proprieties.

Skin Regenerative Potential of Cupuaçu Seed Extract (Theobroma grandiflorum), a Native Fruit from the Amazon: Development of a Topical Formulation Based on Chitosan-Coated Nanocapsules.

Scarless skin regeneration is a challenge in regenerative medicine. Herein, we explore the regenerative potential of a Cupuaçu seed extract (Theobroma grandiflorum) to develop an innovative skin regeneration formulation based on chitosan-coated nanocapsules. Cupuaçu seed extract significantly stimulated cell proliferation and migration. A reparative gene expression profile could be verified following extract treatment, which included high levels of MKI67, a cellular proliferation marker, and extracellular matrix genes, such as ELN and HAS2, which code for elastin and hyaluronic acid synthase 2. Formulations with Cupuaçu seed extract successfully entrapped into nanocapsules (EE% > 94%) were developed. Uncoated or coated nanocapsules with low-molecular-weight chitosan presented unimodal size distribution with hydrodynamic diameters of 278.3 ± 5.0 nm (PDI = 0.18 ± 0.02) and 337.2 ± 2.1 nm (PDI = 0.27 ± 0.01), respectively. Both nanosystems were physically stable for at least 120 days and showed to be non-irritating to reconstructed human epidermis. Chitosan coating promoted active penetration into undamaged skin areas, which were still covered by the stratum corneum. In conclusion, the present study demonstrated for the first time the biotechnological potential of the frequently discarded Cupuaçu seed as a valuable pharmaceutical ingredient to be used in regenerative skin products.

Follicular-targeted delivery of spironolactone provided by polymeric nanoparticles.

This study proposes developing a topical formulation based on poly-ε-caprolactone (PCL) or methacrylic acid/methyl methacrylate copolymer (EL100) nanoparticles to enable a safer and more effective therapy of alopecia and acne with spironolactone. The effect of the size of the nanoparticle on follicular-targeted drug delivery is also verified. Compatibility studies based on thermal analyses and complementary techniques showed a small interaction of the drug with excipients, which may not compromise the drug stability. PCL nanoparticles of 180.0 ±â€¯1.6 and 126.8 ±â€¯1.0 nm, and EL100 nanoparticles of 102.7 ±â€¯7.1 nm were then prepared. All nanoparticles entrapped more than 75 % of spironolactone, were physically stable, and stabilized the drug for at least 90 days. They were also non-irritant according to HET-CAM tests. Drug release from the nanoparticles was reduced in aqueous buffer media but fast when in contact with oil. Finally, in vitro skin penetration experiments revealed the largest nanoparticles (of 180 nm) targeted drug delivery to the hair follicles 5-fold (p < 0.05) more than the control solution, 2.1-fold (p < 0.05) more than nanoparticles produced with the same polymer (PCL) but with smaller size (123 nm), and 4.9-fold (p < 0.05) more than the 102-nm E100 nanoparticles. In conclusion, follicular targeting can be adjusted according to nanoparticle size, and this work succeeded in obtaining polymeric nanoparticles adequate to enable topical treatment of acne and alopecia with spironolactone.

Regulatory Requirements and Innovation: A Comparison of the Dermatologic Antifungal Drug Product Markets in Brazil and United States.

BACKGROUND: Development of novel dermatological topical products for the treatment of cutaneous fungal infections is a constant necessity, especially in developing countries. Through public health policies, many developing countries have facilitated in the last decades the entry of generic products, which can be superficially seen as a threat to innovation. To verify whether regulatory requirements, or the waiving of some requirements, could have an impact on innovation, we performed a detailed technical comparison of the dermatologic antifungal markets of Brazil and of the United States, taking Brazil as an example of a developing country with more lenient requirements regarding the registration of generic topical drug products. METHODS: The official databank of ANVISA (DATAVISA) and of US Food and Drug Administration (Orange Book) were assessed for valid topical dermatological antifungal drug products registered. RESULTS: The Brazilian market has a greater number of registered drug products encompassing a greater variety of drug substances than the US, but the latter comprises more products with novel technologies. In both countries, cream was the predominant dosage form and imidazoles were the major substance group. Ketoconazole was the lead active substance in Brazil and ciclopirox was the lead drug in the US. Generic products dominated both markets. CONCLUSIONS: Despite the great number of registered products, the Brazilian market lacks the latest technologies, reflecting that the ease of generics registration is not accompanied by innovation.

Topical ophthalmic antimicrobials: unfulfilled demands and possibility of new investments in Brazil and in the United States

In general, topical ophthalmic drug products, especially those used for treating infections, present low effectiveness because of various reasons, from unfavorable drug physicochemical properties to physiological protective mechanisms of the eye. The fact is such group of products holds room for improvement, which could mean the development of better drugs or dosage forms. To achieve this, the knowledge of market composition is essential. The present work studied and compared the antimicrobial ophthalmic markets of Brazil and of the United States (US). Official databank of Brazilian Health Regulatory Agency and of US Food and Drug Administration were assessed for registered antimicrobial topical ophthalmic drug products. Brazilian market has registered greater number of drug products (119) than the US (94), but the latter involves more variety of substances and dosage forms. In both countries, non-innovative products registered as solutions of antibacterials, especially fluoroquinolones and aminoglycosides lead the market. Despite the clinical demand, the US has only one group of antimycotics (polyenes) registered, while in Brazil, there is not any ophthalmic antimycotic product marketed. This study evidences there is not only space for development of newer drugs and formulations but also a demand for already existing technologies and products in both countries.

Simple and Selective HPLC-UV/Vis Bioanalytical Method to Determine Aluminum Phthalocyanine Chloride in Skin Permeation Studies.

Considering the feasibility of the aluminum phthalocyanine chloride (AlPcCl) application in the topical photodynamic therapy of cutaneous tumors and the lack of HPLC methods capable of supporting skin permeation experiments using this compound, the aim of this study was to obtain a simple and selective chromatographic method for AlPcCl determination in skin matrices. A HPLC-UV/Vis method was developed using a normal-phase column operating at 30°C, an isocratic mobile phase of methanol : phosphoric acid (0.01 M) at 1.5 mL/min, and detection at 670 nm. The method exhibited (i) selectivity against various contaminants found in the different skin layers, (ii) high drug extraction capacity from the hair follicle (>70%) and remaining skin (>80%), and (iii) low limits of detection and of quantification (0.03 and 0.09 µg/mL, resp.). The method was also linear in the range from 0.1 to 5.0 µg/mL (r = 0.9994) and demonstrated robustness with regard to experimental chromatographic parameters according to a factorial design. Lastly, the developed method was successfully tested in in vitro skin permeation studies of AlPcCl, proving its effectiveness in the development of pharmaceutical delivery systems containing this drug for topical photodynamic therapy of skin cancers.

Versatile chromatographic method for catechin determination in development of topical formulations containing natural extracts.

Catechin is found in several natural sources, as Eugenia dysenterica and Syzygium cumini extracts. Its antioxidant and UV-protective properties suggest a potential use in cosmetic and dermatological formulations. A simple analytical method capable of giving support to experiments performed along the development of topical formulations containing this natural substance (i.e. drug assay, skin permeation and stability studies), however, is still needed. Thus, this work aimed to develop and validate a selective HPLC method for catechin determination during the development of topical formulations. Separation was achieved using an RP-C18 column (300 × 3.9 mm; 10 µm), with a mobile phase of methanol-phosphoric acid 0.01 m (15: 85, v/v), a flow rate of 0.8 mL/min, temperature set at 40°C and UV detection at 230 nm. The method was linear in a range from 0.5 to 10.0 µg/mL (r = 0.9998), precise with an overall variation coefficient of 5.5% and accurate with catechin recovery from the skin layers >85%. Additionally, the method was sensitive (limit of detection, 0.109 µg/mL; limit of quantification, 0.342 µg/mL) and selective against plant extracts, skin matrices and formulation interferents, as well as catechin degradation products. It was also robust regarding both methodology parameters and analytical stability.

SLN- and NLC-encapsulating antifungal agents: skin drug delivery and their unexplored potential for treating onychomycosis.

BACKGROUND: Lipid nanoparticles have been extensively studied for drug delivery of antifungal drugs, especially for dermatophytosis treatments. They can accumulate in skin appendages and release drugs in a controlled manner and also increase skin moisture, due to the formation of an occlusive film. Since moisture heavily influences nail and skin permeability, these systems seem to pose great potential for antifungal drug delivery. METHODS: We therefore compare skin and nail physiopathological structure and discuss the potential use of lipid nanoparticles in managing skin and nail mycoses, highlighting their unexplored use in onychomycosis. RESULTS: Structural features become particularly relevant when treating local skin/nail disorders. Nail plate represents the most resistant barrier to the penetration of molecules. In recent years, at least 55 researches have been reported about lipid nanoparticles and, antifungal drugs. They have focused on production methods and nanoparticle ingredients influence on entrapment efficiency, fungal activity in vitro, stability, and drug release. Lipid nanoparticles such as SLN and NLC have shown great results in permeating the skin. Currently, however, there is just one study published using NLC applied directly to the nail plate. NLC containing voriconazole had a noteworthy impact on the penetration depth of a nanoencapsulated drug, which allowed its deeper penetration into porcine hooves than the unloaded drug. CONCLUSION: Evidence of the success of SLN and NLC in achieving high encapsulation efficiencies of antifungals and promoting cutaneous delivery indicates the potential of the systems in enhancing nail hydration and drug penetration into the nail plate.

Anti-inflammatory, antimycobacterial and genotoxic evaluation of Doliocarpus dentatus.

ETHNOPHARMACOLOGICAL RELEVANCE: Doliocarpus dentatus is a medicinal plant widely used in Mato Grosso do Sul State for removing the swelling pain caused by the inflammation process and for treating urine retention. AIM OF THE STUDY: The genotoxic aspects and the anti-inflammatory and antimycobacterial activity of the ethanolic extract obtained from the leaves of D. dentatus (EEDd) were investigated. MATERIALS AND METHODS: The EEDd was evaluated against Mycobacterium tuberculosis, and the compound composition was evaluated and identified by nuclear magnetic resonance (NMR). The mice received oral administration of EEDd (30-300mg/kg) in carrageenan models of inflammation, and EEDd (10-1000mg/kg) was assayed by the comet, micronucleus, and phagocytosis tests and by the peripheral leukocyte count. RESULTS: Phenols (204.04mg/g), flavonoids (89.17mg/g), and tannins (12.05mg/g) as well as sitosterol-3-O-ß-D-glucopyranoside, kaempferol 3-O-α-L-rhamnopyranoside, betulinic acid and betulin were present in the EEDd. The value of minimal inhibitory concentration (MIC) of EEDd was 62.5µg/mL. The EEDd induced a significant decrease in the edema, mechanical hypersensitivity and leukocyte migration induced by carrageenan. The comet and micronucleus tests indicated that the EEDd was not genotoxic. The EEDd also did not change the phagocytic activity or the leukocyte perLipheral count. CONCLUSIONS: The EEDd does not display genotoxicity, phagocytosis and could act as an antimycobacterial and anti-inflammatory agent. This study should contribute to ensuring the safe use of EEDd.

Chemical and physical strategies in onychomycosis topical treatment: A review.

Onychomycosis is a fungal infection of the fingernails or toenails caused by dermatophytes, nondermatophytes, moulds, and yeasts. This condition affects around 10-30% people worldwide, negatively influencing patients' quality of life, with severe outcomes in some cases. Since the nail unit acts as a barrier to exogenous substances, its physiological features hampers drug penetration, turning the onychomycosis treatment a challenge. Currently, there are several oral and topical therapies available; nevertheless, cure rates are still low and relapse rates achieves 10-53%. Also, serious side effects may be developed due to long-term treatment. In light of these facts, researchers have focused on improving topical treatments, either by modifying the vehicle or by using some physical technique to improve drug delivery trough the nail plate, hence increasing therapy effectiveness. Therefore, the aim of this paper is to explain these novel alternative approaches. First, the challenges for drug ungual penetration are presented. Then, the chemical and physical strategies developed for overcoming the barriers for drug penetration are discussed. We hope that the information gathered may be useful for the development of safer and more effective treatments for onychomycosis.

[Bioequivalence of dermatological topical medicines:the Brazilian scenario and the challenges for health surveillance]. / Bioequivalência de medicamentos tópicos dermatológicos: o cenário brasileiro e os desafios para a vigilância sanitária.

The comparative evaluation required for the registration of generic topical medicines in Brazil is conducted by means of a pharmaceutical equivalence study, which merely assesses the physical/chemical and microbiological parameters of the formulations. At the international level, clinical or pharmacodynamic studies are now being required to prove the efficacy and safety of semisolid topical generic formulations. This work presents a comparison of the different requirements for the registration of topical formulations, taking into consideration the various regulatory authorities, and presents a survey of topical medicines registered in Brazil prior to 2013. The survey revealed that in comparison with the USA there were many more copies of these formulations registered in Brazil. This fact, together with the large number of studies in the literature showing the lack of bioequivalence of topical medication, is clear proof of the major importance of the need to realign Brazilian legislation with respect to the technical requirements for the registration of generic and similar medication for dermatological topical application in Brazil.

Bioequivalência de medicamentos tópicos dermatológicos: o cenário brasileiro e os desafios para a vigilância sanitária / Bioequivalence of dermatological topical medicines: the Brazilian scenario and the challenges for health surveillance

A avaliação comparativa exigida para registro das formulações tópicas genéricas no Brasil é feita por meio do estudo de equivalência farmacêutica que avalia apenas os parâmetros físico-químicos e microbiológicos dos medicamentos. Internacionalmente, estudos clínicos ou farmacodinâmicos vêm sendo exigidos para comprovar a eficácia e a segurança das formulações genéricas tópicas semissólidas. Este trabalho apresenta uma comparação entre os diferentes requerimentos para registro de uma formulação tópica, considerando diferentes autoridades regulatórias, e faz um levantamento dos produtos tópicos dermatológicos registrados no Brasil até 2013. Tal levantamento demonstrou haver uma grande quantidade de cópias desse tipo de formulação no Brasil em comparação com os EUA. Este fato, associado à grande quantidade de estudos encontrados na literatura demonstrando bioinequivalência de medicamentos tópicos, evidencia a grande importância de uma readequação da legislação brasileira no que se refere aos requisitos técnicos para o registro de medicamentos genéricos e similares de aplicação tópica dermatológica no Brasil.

The comparative evaluation required for the registration of generic topical medicines in Brazil is conducted by means of a pharmaceutical equivalence study, which merely assesses the physical/chemical and microbiological parameters of the formulations. At the international level, clinical or pharmacodynamic studies are now being required to prove the efficacy and safety of semisolid topical generic formulations. This work presents a comparison of the different requirements for the registration of topical formulations, taking into consideration the various regulatory authorities, and presents a survey of topical medicines registered in Brazil prior to 2013. The survey revealed that in comparison with the USA there were many more copies of these formulations registered in Brazil. This fact, together with the large number of studies in the literature showing the lack of bioequivalence of topical medication, is clear proof of the major importance of the need to realign Brazilian legislation with respect to the technical requirements for the registration of generic and similar medication for dermatological topical application in Brazil.

Microspheres prepared with different co-polymers of poly(lactic-glycolic acid) (PLGA) or with chitosan cause distinct effects on macrophages.

Microencapsulation of bioactive molecules for modulating the immune response during infectious or inflammatory events is a promising approach, since microspheres (MS) protect these labile biomolecules against fast degradation, prolong the delivery over longer periods of time and, in many situations, target their delivery to site of action, avoiding toxic side effects. Little is known, however, about the influence of different polymers used to prepare MS on macrophages. This paper aims to address this issue by evaluating in vitro cytotoxicity, phagocytosis profile and cytokines release from alveolar macrophages (J-774.1) treated with MS prepared with chitosan, and four different co-polymers of PLGA [poly (lactic-co-glycolic acid)]. The five MS prepared presented similar diameter and zeta potential each other. Chitosan-MS showed to be cytotoxic to J-774.1 cells, in contrast to PLGA-MS, which were all innocuous to this cell linage. PLGA 5000-MS was more efficiently phagocytized by macrophages compared to the other MS tested. PLGA 5000-MS and 5002-MS induced significant production of TNF-α, while 5000-MS, 5004-MS and 7502-MS decreased spontaneous IL-6 release. Nevertheless, only PLGA 5002-MS induced significant NFkB/SEAP activation. These findings together show that MS prepared with distinct PLGA co-polymers are differently recognized by macrophages, depending on proportion of lactic and glycolic acid in polymeric chain, and on molecular weight of the co-polymer used. Selection of the most adequate polymer to prepare a microparticulate drug delivery system to modulate immunologic system may take into account, therefore, which kind of immunomodulatory response is more adequate for the required treatment.

Prostaglandin D2-loaded microspheres effectively activate macrophage effector functions.

Biodegradable lactic-co-glycolic acid (PLGA) microspheres (MS) improve the stability of biomolecules stability and allow enable their sustained release. Lipid mediators represent a strategy for improving host defense; however, most of these mediators, such as prostaglandin D2 (PGD2), have low water solubility and are unstable. The present study aimed to develop and characterize MS loaded with PGD2 (PGD2-MS) to obtain an innovative tool to activate macrophages. PGD2-MS were prepared using an oil-in-water emulsion solvent extraction-evaporation process, and the size, zeta potential, surface morphology and encapsulation efficiency were determined. It was also evaluated in vitro the phagocytic index, NF-κB activation, as well as nitric oxide and cytokine production by alveolar macrophages (AMs) in response to PGD2-MS. PGD2-MS were spherical with a diameter of 5.0±3.3 µm and regular surface, zeta potential of -13.4±5.6 mV, and 36% of encapsulation efficiency, with 16-26% release of entrapped PGD2 at 4 and 48 h, respectively. PGD2-MS were more efficiently internalized by AMs than unloaded-MS, and activated NF-κB more than free PGD2. Moreover, PGD2-MS stimulated the production of nitric oxide, TNF-α, IL-1ß, and TGF-ß, more than free PGD2, indicating that microencapsulation increased the activating effect of PGD2 on cells. In LPS-pre-treated AMs, PGD2-MS decreased the release of IL-6 but increased the production of nitric oxide and IL-1ß. These results show that the morphological characteristics of PGD2-MS facilitated interaction with, and activation of phagocytic cells; moreover, PGD2-MS retained the biological activities of PGD2 to trigger effector mechanisms in AMs. It is suggested that PGD2-MS represent a strategy for therapeutic intervention in the lungs of immunocompromised subjects.