Cannabidiol-loaded microparticles embedded in a porous hydrogel matrix for biomedical applications.

In this study, poly (lactic-co-glycolic acid) (PLGA) microparticles loaded with cannabidiol (CBD) were synthesized (PLGA@CBD microparticles) and embedded up to 10 wt% in a chondroitin sulfate/polyvinyl alcohol hydrogel matrix. In vitro chemical, physical, and biological assays were carried out to validate the potential use of the modified hydrogels as biomaterials. The microparticles had spherical morphology and a narrow range of size distribution. CBD encapsulation efficiency was around 52%, loading was approximately 50%. Microparticle addition to the hydrogels caused minor changes in their morphology, FTIR and thermal analyses confirmed these changes. Swelling degree and total porosity were reduced in the presence of microparticles, but similar hydrophilic and degradation in phosphate buffer solution behaviors were observed by all hydrogels. Rupture force and maximum strain at rupture were higher in the modified hydrogels, whereas modulus of elasticity was similar across all materials. Viability of primary human dental pulp cells up to 21 days was generally not influenced by the addition of PLGA@CBD microparticles. The control hydrogel showed no antimicrobial activity against Staphylococcus aureus, whereas hydrogels with 5% and 10% PLGA@CBD microparticles showed inhibition zones. In conclusion, the PLGA@CBD microparticles were fabricated and successfully embedded in a hydrogel matrix. Despite the hydrophobic nature of CBD, the physicochemical and morphological properties were generally similar for the hydrogels with and without the CBD-loaded microparticles. The data reported in this study suggested that this original biomaterial loaded with CBD oil has characteristics that could enable it to be used as a scaffold for tissue/cellular regeneration.

Advances in porphyrins and chlorins associated with polysaccharides and polysaccharides-based materials for biomedical and pharmaceutical applications.

Over the last decade, the convergence of advanced materials and innovative applications has fostered notable scientific progress within the biomedical and pharmaceutical fields. Porphyrins and their derivatives, distinguished by an extended conjugated π-electron system, have a relevant role in propelling these advancements, especially in drug delivery systems, photodynamic therapy, wound healing, and (bio)sensing. However, despite their promise, the practical clinical application of these macrocycles is hindered by their inherent challenges of low solubility and instability under physiological conditions. To address this limitation, researchers have exploited the synergistic association of porphyrins and chlorins with polysaccharides by engineering conjugated systems and composite/hybrid materials. This review compiles the principal advances in this growing research field, elucidating fundamental principles and critically examining the applications of such materials within biomedical and pharmaceutical contexts. Additionally, the review addresses the eventual challenges and outlines future perspectives for this poignant research field. It is expected that this review will serve as a comprehensive guide for students and researchers dedicated to exploring state-of-the-art materials for contemporary medicine and pharmaceutical applications.

Association between the intensity of obstructive sleep apnea and skeletal alterations in the face and hyoid bone.

INTRODUCTION: The association between the intensity of obstructive sleep apnea and skeletal alterations in the face and hyoid bone is still scarcely addressed in the literature. OBJECTIVE: To evaluate whether the intensity of obstructive sleep apnea is associated with craniofacial alterations and the position of the hyoid bone in children with mixed dentition. METHODS: 76 children aged 7 to 10 years old were examined by otorhinolaryngological evaluation, polysomnography, and orthodontic assessment, including cephalometry. The participants were divided in 3 groups: primary snoring, mild obstructive sleep apnea and moderate to severe obstructive sleep apnea. Cephalometric measures of the face and hyoid bone were assessed. These measures were compared among the different groups by unpaired Student's t test. Moreover, these measures were correlated with the patient's obstructive apnea and hypopnea index variable using Pearson's correlation test. RESULTS: Of the 76 children, 14 belonged to group 1, with primary snoring; 46 to group 2, with mild obstructive sleep apnea; and 16 to group 3, with moderate-severe obstructive sleep apnea. There was no difference between the groups regarding the craniofacial variables. Children with obstructive sleep apnea showed a longer distance from the hyoid bone to the mandibular plane when compared to the primary snoring group (p<0.05). Between the two obstructive sleep apnea subgroups, patients with moderate or severe disease showed significantly shorter horizontal distance between the hyoid bone and the posterior pharyngeal wall (p<0.05), when compared to the groups with mild obstructive sleep apnea. We also observed a significant positive correlation between obstructive apnea and hypopnea index and the distance from the hyoid to the mandibular plane (p<0.05) as well as a significant negative association between obstructive apnea and hypopnea index and the horizontal distance from the hyoid to the posterior pharyngeal wall (p<0.01). CONCLUSION: We did not observe any association between obstructive sleep apnea and linear lateral alterations of the face. In contrast, there is a direct association between obstructive sleep apnea severity and the inferior and posterior position of the hyoid bone in children aged 7 to 10 years old.

Magnetic microspheres based on pectin coated by chitosan towards smart drug release.

This study reports the preparation of microspheres of pectin and magnetite nanoparticles coated by chitosan to encapsulate and deliver drugs. Magnetic-pectin microspheres were obtained by ionotropic gelation followed by polyelectrolyte complexation with chitosan. Characterization data show that magnetite changes the physicochemical and morphological properties of the microspheres compared to the non-magnetic samples. Using metamizole (Mtz) as a drug model, the magnetic microspheres showed appreciable encapsulation efficiency (85 %). Release experiments performed in simulated gastric (pH 1.2) and intestinal (pH 6.8) fluids suggested that the release process is pH-dependent. At pH 6.8, the Mtz release is favored achieving 75 % after 12 h. The application of an external magnetic field increased the release to 91 % at pH 6.8, indicating that the release also is magnetic-dependent. The results suggest that the magnetic microspheres based on pectin/chitosan biopolymers show the potential to be used as a multi-responsive drug delivery system.

The efficacy of microemulsion-based delivery to improve vitamin E properties: evaluation of the antinociceptive, antioxidant, antidepressant- and anxiolytic-like activities in mice.

OBJECTIVES: A microemulsion-based delivery system was designed to improve vitamin E (VE) properties, and its antinociceptive, antioxidant, antidepressant- and anxiolytic-like activities in mice were evaluated. METHODS: Male Swiss mice received, by intragastric route, canola oil (20 ml/kg), blank microemulsion (B-ME) (20 ml/kg), VE free (VE-F) (200 mg/kg) or VE microemulsion (VE-ME) (200 mg/kg). In acute treatment, a single dose of treatments was administrated and 30 min after behavioural tests were performed. In the subchronic treatment, mice received such treatments, once a day, for 8 days. On the eighth day, behavioural tests were performed. KEY FINDINGS: In the subchronic treatment, VE-ME increased entries and spent time in the open arms in the elevated plus-maze test and decreased the immobility time in the tail suspension test, but no change was found after acute treatment. Acute and subchronic treatments with VE-ME increased response latency to thermal stimulus in the hot-plate test. VE-ME decreased the thiobarbituric acid reactive species levels in the acute and subchronic protocols. Additionally, in subchronic treatment, VE-ME increased renal catalase activity, but VE-F reduced its activity. CONCLUSIONS: Vitamin E-microemulsions showed antioxidant, antinociceptive, antidepressant- and anxiolytic-like actions; thus, ME-based delivery improved pharmacological properties of VE.

Therapeutic and technological potential of 7-chloro-4-phenylselanyl quinoline for the treatment of atopic dermatitis-like skin lesions in mice.

This study investigated the main effects of the oral treatment with 7-chloro-4-phenylselanyl quinoline (4-PSQ) on symptoms, inflammatory and oxidative parameters in an atopic dermatitis (AD) model in BALB/c mice. In addition, the possibility of antioxidant property of 4-PSQ improves the potential of a biofilm (based on chitosan/poly(vinyl alcohol) (PVA)/ bovine bone powder (BBP)) for the treatment of AD-like skin lesions was evaluated. 2,4-Dinitrochlorobenzene (DNCB) was applied to the dorsal skin on days 1-3 for sensitization. Mice were challenged with DNCB on the ear (on days 14-29) and dorsal skin (on days 14, 17, 20, 23, 26, and 29) and treated with 4-PSQ, dexamethasone, biofilm (biofilm sample without 4-PSQ) or 4-PSQ-loaded biofilms. On the day 30, skin severity scores and scratching behavior were determined. After that, animals were sacrificed, and ears and dorsal skin were removed for determination of inflammatory and oxidative parameters. DNCB induced the skin lesions, scratching behavior and ear swelling, increased myeloperoxidase (MPO) activity (ear and back) and reactive species (RS) levels (back). 4-PSQ, 4-PSQ-loaded biofilms and biofilm treatments ameliorated skin severity scores, scratching behavior and inflammatory response induced by DNCB. 4-PSQ and 4-PSQ-loaded biofilm treatments partially protected against the increase in the RS levels induced by DNCB. Our results revealed that the incorporation of 4-PSQ improved the therapeutic effect of the biofilm. The efficacy of 4-PSQ in treating AD-like lesions was similar or better than dexamethasone. In summary, 4-PSQ has a potential therapeutic advantage in the treatment and management of AD.

Chitosan-based film supported copper nanoparticles: A potential and reusable catalyst for the reduction of aromatic nitro compounds.

In this study, copper nanoparticles (CuNPs) were synthesized and stabilized into a chitosan/poly(vinyl alcohol) (CP) based film using a simple protocol under mild conditions. The polymeric matrix utilized in this study allows synthesizing stable nanoparticle with narrow size distribution within the film matrix. Further, this system showed very attractive properties, such as good mechanical properties, chemical resistance, easy handling during use and recovery, relatively low-cost as compared to other similar systems, among others. The catalytic performance of CP-Cu film was tested in the reduction reaction of nitrobenzene (NB) to aniline (AN). Our findings reveal that CP-Cu film catalyzes the reaction efficiently and also decreases the energy of activation (Ea) as compared to other catalysts. The catalytic efficiency of CP-Cu regarding this reaction was kept even after 6 consecutive reuse cycles. All these results rank this novel system as a promising catalyst in the reduction of aromatic nitro compounds to aromatic amines.