Toll-like receptor 4 (TLR4) is the major pattern recognition receptor triggering the protective effect of a Candida albicans extracellular vesicle-based vaccine prototype in murine systemic candidiasis.

Systemic candidiasis remains a significant public health concern worldwide, with high mortality rates despite available antifungal drugs. Drug-resistant strains add to the urgency for alternative therapies. In this context, vaccination has reemerged as a prominent immune-based strategy. Extracellular vesicles (EVs), nanosized lipid bilayer particles, carry a diverse array of native fungal antigens, including proteins, nucleic acids, lipids, and glycans. Previous studies from our laboratory demonstrated that Candida albicans EVs triggered the innate immune response, activating bone marrow-derived dendritic cells (BMDCs) and potentially acting as a bridge between innate and adaptive immunity. Vaccination with C. albicans EVs induced the production of specific antibodies, modulated cytokine production, and provided protection in immunosuppressed mice infected with lethal C. albicans inoculum. To elucidate the mechanisms underlying EV-induced immune activation, our study investigated pathogen-associated molecular patterns (PAMPs) and pattern recognition receptors (PRRs) involved in EVs-phagocyte engagement. EVs from wild-type and mutant C. albicans strains with truncated mannoproteins were compared for their ability to stimulate BMDCs. Our findings revealed that EV decoration with O- and N-linked mannans and the presence of ß-1,3-glucans and chitin oligomers may modulate the activation of specific PRRs, in particular Toll-like receptor 4 (TLR4) and dectin-1. The protective effect of vaccination with wild-type EVs was found to be dependent on TLR4. These results suggest that fungal EVs can be harnessed in vaccine formulations to selectively activate PRRs in phagocytes, offering potential avenues for combating or preventing candidiasis.IMPORTANCESystemic candidiasis is a serious global health concern with high mortality rates and growing drug resistance. Vaccination offers a promising solution. A unique approach involves using tiny lipid-coated particles called extracellular vesicles (EVs), which carry various fungal components. Previous studies found that Candida albicans EVs activate the immune response and may bridge the gap between innate and adaptive immunity. To understand this better, we investigated how these EVs activate immune cells. We demonstrated that specific components on EV surfaces, such as mannans and glucans, interact with receptors on immune cells, including Toll-like receptor 4 (TLR4) and dectin-1. Moreover, vaccinating with these EVs led to strong immune responses and full protection in mice infected with Candida. This work shows how harnessing fungal EVs might lead to effective vaccines against candidiasis.

Anti-Inflammatory Activity and Acute Toxicity Of Pereskia aculeata, In Zophobas morio Larvae.

Pereskia aculeata has been widely investigated due to its anti-inflammatory potential. Among the metabolites found in this species are the phytosterols beta-sitosterol (ß-SIT) and stigmasterol (STIG). The objective of the study was to evaluate the anti-inflammatory and toxicity activities of the hexane partition of P. aculeata (PHEX), as well as ß-SIT and STIG. PHEX was prepared and the phytosterols were quantified. In terms of toxicity against L929 fibroblast cells, PHEX showed toxicity up to 200 µg/mL; STIG and ß-SIT showed toxicity up to 25 µg/mL. PHEX inhibited 66 % of nitric oxide radicals, while STIG and ß-SIT inhibited 33.73 % and 34.94 %, respectively. In an anti-inflammatory test against Zophobas morio larvae, all samples significantly reduced hemocyte levels. Additionally, the LD50 values were calculated: 229.6 mg/kg for PHEX, 101.5 mg/kg for STIG, and 103.8 mg/kg for ß-SIT. In conclusion, the study indicates that the phytosterols present in PHEX may contribute to its anti-inflammatory activity.

Metabolic organization of pregnant freshwater stingray and their offspring.

The elucidation of energetic patterns in adult viviparous elasmobranchs and their offspring can contribute to understanding ecophysiological questions, such as maternal-fetal metabolism and group life-history traits. We characterized the energetic substrates in pregnant individuals and stages of offspring development in the freshwater stingray Potamotrygon amandae. Our results show that the energetic distribution of the yolk is composed of more lipids than proteins, whereas the inverse pattern is observed in the egg and uterus, proving the plasticity of the energy provision of the species. As a novelty, we describe that yolk/intestine transfer occurs in this species.

Effects of local and systemic treatment with human natural killer-1 mimetic peptide (HNK-1) after ventral root avulsion and reimplantation in mice.

Background: Spinal ventral root injuries generate significant motoneuron degeneration, which hinders full functional recovery. The poor prognosis of functional recovery can be attributed to the use or combination of different therapeutic approaches. Several molecules have been screened as potential treatments in combination with surgical reimplantation of the avulsed roots, the gold standard approach for such injuries. Among the studied molecules, human natural killer-1 (HNK-1) stands out as it is related to the stimulation of motor axon outgrowth. Therefore, we aimed to comparatively investigate the effects of local administration of an HNK-1 mimetic peptide (mp-HNK-1) and systemic treatment with ursolic acid (UA), another HNK-1 mimetic, after ventral root avulsion and reimplantation with heterologous fibrin biopolymer (HFB). Methods: Female mice of the isogenic strain C57BL/6JUnib were divided into five experimental groups: Avulsion, Reimplantation, mp-HNK-1 (in situ), and UA (systemic treatment). Mice were evaluated 2 and 12 weeks after surgery. Functional assessment was performed every four days using the Catwalk platform. Neuronal survival was analyzed by cytochemistry, and glial reactions and synaptic coverage were evaluated by immunofluorescence. Results: Treatment with UA elicited long-term neuroprotection, accompanied by a decrease in microglial reactions, and reactive astrogliosis. The neuroprotective effects of UA were preceded by increased glutamatergic and GABAergic inputs in the ventral spinal cord two weeks after injury. However, a single application of mp-HNK-1 had no significant effects. Functional analysis showed that UA treatment led to an improvement in motor and sensory recovery. Conclusion: Overall, the results indicate that UA is neuroprotective, acting on glial cells and synaptic maintenance, and the combination of these findings led to a better functional recovery.

Comparison between contact diode laser with 980 nm and 1470 nm wavelengths for posterior laryngofissure in pigs.

To compare two different wavelengths of the surgical contact diode laser (CDL) for producing a posterior laryngofissure in in-vivo pigs. Anesthetized pigs underwent a tracheostomy and an anterior laryngofissure through a cervicotomy. They were randomly selected for the CDL wavelength and Power, according to the peak of Power set at device (980nm wavelength: Ppeak power of 10 W, 15 W, and 20 W, or 1470 nm wavelength: Ppeak 3 W, 5 W, 7 W, 10 W). At the end of the experiment, the laryngotracheal specimen was extracted and sent for histology and morphometry measurements (incision size, depth, area, and lateral thermal damage). Hemodynamic data and arterial blood gases were recorded during the incisions. Statistical analysis of the comparisons between the parameters and groups had a level of significance of p < 0.05. Twenty-six pigs were divided into CDL 980 nm (n = 11) and 1470 nm (n = 15). There was a greater incision area at the thyroid level in the 980 nm CDL and a wider incision at the trachea level, with a larger distance between mucosa borders. There were no significant differences in the area of lateral thermal damage between the two groups and neither difference among the power levels tested. Both wavelengths tested showed similar results in the various combinations of power levels without significant differences in the lateral thermal damage. The posterior laryngofissure incision can be performed by either of the wavelengths at low and medium power levels without great difference on lateral thermal damage.

Characterization of the patterns of care, access, and direct cost of systemic lupus erythematosus in Brazil: findings from the Macunaíma study.

BACKGROUND: A cost of illness (COI) study aims to evaluate the socioeconomic burden that an illness imposes on society as a whole. This study aimed to describe the resources used, patterns of care, direct cost, and loss of productivity due to systemic lupus erythematosus (SLE) in Brazil. METHODS: This 12-month, cross-sectional, COI study of patients with SLE (ACR 1997 Classification Criteria) collected data using patient interviews (questionnaires) and medical records, covering: SLE profile, resources used, morbidities, quality of life (12-Item Short Form Survey, SF-12), and loss of productivity. Patients were excluded if they were retired or on sick leave for another illness. Direct resources included health-related (consultations, tests, medications, hospitalization) or non-health-related (transportation, home adaptation, expenditure on caregivers) hospital resources.Costs were calculated using the unit value of each resource and the quantity consumed. A gamma regression model explored cost predictors for patients with SLE. RESULTS: Overall, 300 patients with SLE were included (92.3% female,mean [standard deviation (SD)] disease duration 11.8 [7.9] years), of which 100 patients (33.3%) were on SLE-related sick leave and 46 patients (15.3%) had stopped schooling. Mean (SD) travel time from home to a care facility was 4.4 (12.6) hours. Antimalarials were the most commonly used drugs (222 [74.0%]). A negative correlation was observed between SF-12 physical component and SLE Disease Activity Index (- 0.117, p = 0.042), Systemic Lupus International CollaboratingClinics/AmericanCollegeofRheumatology Damage Index (- 0.115, p = 0.046), medications/day for multiple co-morbidities (- 0.272, p < 0.001), SLE-specific drugs/day (- 0.113, p = 0.051), and lost productivity (- 0.570, p < 0.001). For the mental component, a negative correlation was observed with medications/day for multiple co-morbidities (- 0.272, p < 0.001), SLE-specific medications/day (- 0.113, p = 0.051), and missed appointments (- 0.232, p < 0.001). Mean total SLE cost was US$3,123.53/patient/year (median [interquartile range (IQR)] US$1,618.51 [$678.66, $4,601.29]). Main expenditure was medication, with a median (IQR) cost of US$910.62 ($460, $4,033.51). Mycophenolate increased costs by 3.664 times (p < 0.001), and inflammatory monitoring (erythrocyte sedimentation rate or C-reactive protein) reduced expenditure by 0.381 times (p < 0.001). CONCLUSION: These results allowed access to care patterns, the median cost for patients with SLE in Brazil, and the differences across regions driven by biological, social, and behavioral factors. The cost of SLE provides an updated setting to support the decision-making process across the country.

Ionizable Lipid Nanoparticle-Mediated TRAIL mRNA Delivery in the Tumor Microenvironment to Inhibit Colon Cancer Progression.

Introduction: Immunotherapy has revolutionized cancer treatment by harnessing the immune system to enhance antitumor responses while minimizing off-target effects. Among the promising cancer-specific therapies, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has attracted significant attention. Methods: Here, we developed an ionizable lipid nanoparticle (LNP) platform to deliver TRAIL mRNA (LNP-TRAIL) directly to the tumor microenvironment (TME) to induce tumor cell death. Our LNP-TRAIL was formulated via microfluidic mixing and the induction of tumor cell death was assessed in vitro. Next, we investigated the ability of LNP-TRAIL to inhibit colon cancer progression in vivo in combination with a TME normalization approach using Losartan (Los) or angiotensin 1-7 (Ang(1-7)) to reduce vascular compression and deposition of extracellular matrix in mice. Results: Our results demonstrated that LNP-TRAIL induced tumor cell death in vitro and effectively inhibited colon cancer progression in vivo, particularly when combined with TME normalization induced by treatment Los or Ang(1-7). In addition, potent tumor cell death as well as enhanced apoptosis and necrosis was found in the tumor tissue of a group treated with LNP-TRAIL combined with TME normalization. Discussion: Together, our data demonstrate the potential of the LNP to deliver TRAIL mRNA to the TME and to induce tumor cell death, especially when combined with TME normalization. Therefore, these findings provide important insights for the development of novel therapeutic strategies for the immunotherapy of solid tumors.

Chia nanoemulsion: anti-inflammatory mechanism, biological behavior and cellular interactions.

Aim: This study explores chia oil, rich in ω-3 fatty acids and nutraceutical components, as a potential remedy for diseases, especially those linked to inflammation and cancer. Methods/materials: A chia oil-based nanoemulsion, developed through single emulsification, underwent comprehensive analysis using various techniques. In vitro and in vivo assays, including macrophage polarization, nitrite and cytokine production, cellular uptake and biodistribution, were conducted to assess the anti-inflammatory efficacy. Results & conclusion: Results reveal that the chia nanoemulsion significantly inhibits inflammation, outperforming pure oil with twice the efficacy. Enhanced uptake by macrophage-like cells and substantial accumulation in key organs indicate its potential as an economical and effective anti-inflammatory nanodrug, addressing global economic and health impacts of inflammation-related diseases.

Micellar solution of [223Ra]RaCl2: Reaching renal excretion, potent efficacy in osteoblastic osteosarcoma in PDX model, biochemistry alterations and pharmacokinetics.

Despite the successful use of the radiopharmaceutical radium-223 dichloride ([223Ra]RaCl2) for targeted alpha therapy of castration-resistant prostate cancer patients with bone metastases, some short-term side effects, such as diarrhea and vomiting, have been documented, causing patient discomfort. Hence, we prepared a nanosized micellar solution of [223Ra]RaCl2 and evaluated its biodistribution, pharmacokinetics, and induced biochemical changes in healthy mice up to 96 h after intraperitoneal administration as an alternative to overcome the previous limitations. In addition, we evaluated the bone specificity of micellar [223Ra]RaCl2 in patient-derived xenografts in the osteosarcoma model. The biodistribution studies revealed the high bone-targeting properties of the micellar [223Ra]RaCl2. Interestingly, the liver uptake remained significantly low (%ID/g = 0.1-0.02) from 24 to 96 h after administration. In addition, the micellar [223Ra]RaCl2 exhibited a significantly higher uptake in left (%ID/g = 0.85-0.23) and right (%ID/g = 0.76-0.24) kidneys than in small (%ID/g = 0.43-0.06) and large intestines (%ID/g = 0.24-0.09) over time, suggesting its excretion pathway is primarily through the kidneys into the urine, in contrast to the non-micellar [223Ra]RaCl2. The micellar [223Ra]RaCl2 also had low distribution volume (0.055 ± 0.003 L) and longer elimination half-life (28 ± 12 days). This nanosystem was unable to change the enzymatic activities of alanine aminotransferase, aspartate aminotransferase, gamma GT, glucose, and liquiform lipase in the treated mice. Finally, microscopic examination of the animals' osteosarcoma tumors treated with micellar [223Ra]RaCl2 indicated regression of the tumor, with large areas of necrosis. In contrast, in the control group, we observed tumor cellularity and cell anaplasia, mitotic figures and formation of neoplastic extracellular bone matrix, which are typical features of osteosarcoma. Therefore, our findings demonstrated the efficiency and safety of nanosized micellar formulations to minimize the gastrointestinal excretion pathway of the clinical radiopharmaceutical [223Ra]RaCl2, in addition to promoting regression of the osteosarcoma. Further studies must be performed to assess dose-response outcomes and organ/tissue dosimetry for clinical translation.

Nanoparticle-based DNA vaccine protects against SARS-CoV-2 variants in female preclinical models.

A safe and effective vaccine with long-term protection against SARS-CoV-2 variants of concern (VOCs) is a global health priority. Here, we develop lipid nanoparticles (LNPs) to provide safe and effective delivery of plasmid DNA (pDNA) and show protection against VOCs in female small animal models. Using a library of LNPs encapsulating unique barcoded DNA (b-DNA), we screen for b-DNA delivery after intramuscular administration. The top-performing LNPs are further tested for their capacity of pDNA uptake in antigen-presenting cells in vitro. The lead LNP is used to encapsulate pDNA encoding the HexaPro version of SARS-CoV-2 spike (LNP-HPS) and immunogenicity and protection is tested in vivo. LNP-HPS elicit a robust protective effect against SARS-CoV-2 Gamma (P.1), correlating with reduced lethality, decreased viral load in the lungs and reduced lung damage. LNP-HPS induce potent humoral and T cell responses against P.1, and generate high levels of neutralizing antibodies against P.1 and Omicron (B.1.1.529). Our findings indicate that the protective efficacy and immunogenicity elicited by LNP-HPS are comparable to those achieved by the approved COVID-19 vaccine from Biontech/Pfizer in animal models. Together, these findings suggest that LNP-HPS hold great promise as a vaccine candidate against VOCs.

Nanoceria Anti-inflammatory and Antimicrobial Nanodrug: Cellular and Molecular Mechanism of Action.

INTRODUCTION: Nanoceria is a well-known nanomaterial with various properties, including antioxidant, proangiogenic, and therapeutic effects. Despite its potential, there are still aspects that require further exploration, particularly its anti-inflammatory and antimicrobial activities. METHOD: The global demand for novel anti-inflammatory and antimicrobial drugs underscores the significance of understanding nanoceria in both contexts. In this study, we evaluated the effect of nanoceria on macrophage polarization to better understand its anti-inflammatory effects. Additionally, we investigated the mechanism of action of nanoceria against Cryptococcus neoformans (ATCC 32045), Candida parapsilosis (ATCC 22019), Candida krusei (ATCC 6258), and Candida albicans. RESULT: The results demonstrated that nanoceria can polarize macrophages toward an anti-inflammatory profile, revealing the cellular mechanisms involved in the anti-inflammatory response. Concerning the antimicrobial effect, it was observed that nanoceria have a more pronounced impact on Candida parapsilosis, leading to the formation of pronounced pores on the surface of this species. CONCLUSION: Finally, biochemical analysis revealed transitory alterations, mainly in liver enzymes. The data support the use of nanoceria as a potential anti-inflammatory and antimicrobial drug and elucidate some of the mechanisms involved, shedding light on the properties of this nanodrug.

siRNA lipid nanoparticles for CXCL12 silencing modulate brain immune response during Zika infection.

CXCL12 is a key chemokine implicated in neuroinflammation, particularly during Zika virus (ZIKV) infection. Specifically, CXCL12 is upregulated in circulating cells of ZIKV infected patients. Here, we developed a lipid nanoparticle (LNP) to deliver siRNA in vivo to assess the impact of CXCL12 silencing in the context of ZIKV infection. The biodistribution of the LNP was assessed in vivo after intravenous injection using fluorescently tagged siRNA. Next, we investigated the ability of the developed LNP to silence CXCL12 in vivo and assessed the resulting effects in a murine model of ZIKV infection. The LNP encapsulating siRNA significantly inhibited CXCL12 levels in the spleen and induced microglial activation in the brain during ZIKV infection. This activation was evidenced by the enhanced expression of iNOS, TNF-α, and CD206 within microglial cells. Moreover, T cell subsets exhibited reduced secretion of IFN-É£ and IL-17 following LNP treatment. Despite no observable alteration in viral load, CXCL12 silencing led to a significant reduction in type-I interferon production compared to both ZIKV-infected and uninfected groups. Furthermore, we found grip strength deficits in the group treated with siRNA-LNP compared to the other groups. Our data suggest a correlation between the upregulated pro-inflammatory cytokines and the observed decrease in strength. Collectively, our results provide evidence that CXCL12 silencing exerts a regulatory influence on the immune response in the brain during ZIKV infection. In addition, the modulation of T-cell activation following CXCL12 silencing provides valuable insights into potential protective mechanisms against ZIKV, offering novel perspectives for combating this infection.

Characterization of the patterns of care, access, and direct cost of systemic lupus erythematosus in Brazil: findings from the Macunaíma study

Abstract Background A cost of illness (COI) study aims to evaluate the socioeconomic burden that an illness imposes on society as a whole. This study aimed to describe the resources used, patterns of care, direct cost, and loss of productivity due to systemic lupus erythematosus (SLE) in Brazil. Methods This 12-month, cross-sectional, COI study of patients with SLE (ACR 1997 Classification Criteria) collected data using patient interviews (questionnaires) and medical records, covering: SLE profile, resources used, morbidities, quality of life (12-Item Short Form Survey, SF-12), and loss of productivity. Patients were excluded if they were retired or on sick leave for another illness. Direct resources included health-related (consultations, tests, medications, hospitalization) or non-health-related (transportation, home adaptation, expenditure on caregivers) hospital resources. Costs were calculated using the unit value of each resource and the quantity consumed. A gamma regression model explored cost predictors for patients with SLE. Results Overall, 300 patients with SLE were included (92.3% female, mean [standard deviation (SD)] disease duration 11.8 [7.9] years), of which 100 patients (33.3%) were on SLE-related sick leave and 46 patients (15.3%) had stopped schooling. Mean (SD) travel time from home to a care facility was 4.4 (12.6) hours. Antimalarials were the most commonly used drugs (222 [74.0%]). A negative correlation was observed between SF-12 physical component and SLE Disease Activity Index (- 0.117, p = 0.042), Systemic Lupus International CollaboratingClinics/AmericanCollegeofRheumatology Damage Index (- 0.115, p = 0.046), medications/day for multiple co-morbidities (- 0.272, p < 0.001), SLE-specific drugs/day (- 0.113, p = 0.051), and lost productivity (- 0.570, p < 0.001). For the mental component, a negative correlation was observed with medications/day for multiple co-morbidities (- 0.272, p < 0.001), SLE-specific medications/day (- 0.113, p = 0.051), and missed appointments (- 0.232, p < 0.001). Mean total SLE cost was US$3,123.53/patient/year (median [interquartile range (IQR)] US$1,618.51 [$678.66, $4,601.29]). Main expenditure was medication, with a median (IQR) cost of US$910.62 ($460, $4,033.51). Mycophenolate increased costs by 3.664 times (p < 0.001), and inflammatory monitoring (erythrocyte sedimentation rate or C-reactive protein) reduced expenditure by 0.381 times (p < 0.001). Conclusion These results allowed access to care patterns, the median cost for patients with SLE in Brazil, and the differences across regions driven by biological, social, and behavioral factors. The cost of SLE provides an updated setting to support the decision-making process across the country.

Oil reaching the coast: Is Brazil on the route of international oceanic dumping?

After the oil spill disaster occurred in 2019, various events of tar balls reaching the Brazilian coast and archipelagos have been reported. The hypothesis here is that the oil/waste dumped in international waters by ships on-route to Cape of Good Hope is reaching the Brazilian coast. On that account, 30-year probabilistic simulations were used to estimate the probability of dumped oil residue reaching the Brazilian coast. The simulations considered three Zones following the South Atlantic route. The results have shown that up to 28.5 % of large ships could dump oil on-route. Inside the Brazilian Exclusive Economic Zone, the probability of dumped oil/waste reaching the coastline is about 62 % and quickly decreases for Dumping Zones 2 and 3. Equatorial and Northeast shores of Brazil are the most vulnerable to oceanic dumping when compared to other regions.

Urinary Aspergillosis in a Patient with Systemic Lupus Erythematosus (SLE).

Aspergillosis is an opportunistic mycosis that generally affects the lungs. The fungus was cleared by the immune system of a healthy host. Extrapulmonary forms are very rare, and there are few reports of urinary aspergillosis. In this case report, we describe a 62-year-old woman with systemic lupus erythematosus (SLE) with complaints of fever and dysuria. The patient had recurrent episodes of urinary tract infection and several hospitalizations. A computed tomography revealed an amorphous mass in the left kidney and bladder. After partial resection of the material was referred for analysis, Aspergillus infection was suspected and confirmed by culture. Successful treatment with voriconazole was provided. Diagnosis of localized primary renal Aspergillus infection in a patient with SLE requires careful investigation due to its benign presentation and lack of associated systemic clinical features.

Methyl gallate nanomicelles impairs neutrophil accumulated in zymosan-induced arthritis.

Arthritis is a chronic disease that affects, approximately, 1 % of the total global population. It is characterized by chronic inflammation, accompanied in most of the cases of motor disability and sever pain. The main therapies available have high risk of failure and advanced treatments are scarce and highly cost. In this scenario, search for effective, safe and low-cost treatments is quite desirable. Methyl gallate (MG) is a plant-derived phenolic compound described to present remarkable anti-inflammatory effect in experimental models of arthritis. Thus, in this study we formulated nanomicelles of MG using Pluronic (F-127) as matrix and evaluated in vivo the pharmacokinetic, biodistribution and its effect in the mice model of zymosan-induced arthritis. The nanomicelles were formed with a size 126 nm. The biodistribution showed a ubiquitous tissue deposition with a renal excretion. The pharmacokinetics showed elimination half-life of 1.72 h and a clearance of 0.006 L/h. The oral pretreatment with nanomicelles containing MG (3.5 or 7 mg/kg) demonstrated a reduction in total leukocytes, neutrophils, and mononuclear cells from the inflammation site. The data supports the use of methyl gallate nanomicelles as an alternative drug for arthritis. DATA AVAILABILITY: All the data of this study are transparent.

The Impact of Radiolabeled Nanomaterials.

Nanotechnology has changed the world, with a great impact on industry and medicine. In this commentary, we discuss the importance of radiolabeled nanomaterials for the construction of theranostic, imaging and therapeutic agents in order to pave the future of medicine.

pH-Sensitive Degradable Oxalic Acid Crosslinked Hyperbranched Polyglycerol Hydrogel for Controlled Drug Release.

pH-sensitive degradable hydrogels are smart materials that can cleave covalent bonds upon pH variation, leading to their degradation. Their development led to many applications for drug delivery, where drugs can be released in a pH-dependent manner. Crosslinking hyperbranched polyglycerol (HPG), a biocompatible building block bearing high end-group functionality, using oxalic acid (OA), a diacid that can be synthesized from CO2 and form highly activated ester bonds, can generate this type of smart hydrogel. Aiming to understand the process of developing this novel material and its drug release for oral administration, its formation was studied by varying reactant stoichiometry, concentration and cure procedure and temperature; it was characterized regarding gel percent (%gel), swelling degree (%S), FTIR and thermal behavior; impregnated using ibuprofen, as a model drug, and a release study was carried out at pH 2 and 7. Hydrogel formation was evidenced by its insolubility, FTIR spectra and an increase in Td and Tg; a pre-cure step was shown to be crucial for its formation and an increase in the concentration of the reactants led to higher %gel and lower %S. The impregnation resulted in a matrix-encapsulated system; and the ibuprofen release was negligible at pH 2 but completed at pH 7 due to the hydrolysis of the matrix. A pH-sensitive degradable HPG-OA hydrogel was obtained and it can largely be beneficial in controlled drug release applications.

Ionizing Radiation: Chemical Kinetics, Chemical Bounds, and Radiation Chemistry on Polymers.

Ionizing radiation has been used for decades and expanded to several applications in multivariate sectors, becoming an important tool to promote controlled chemical reactions in polymeric structures, according to their chemical properties for developing new materials. In addition, the use of radiation can also be applied in order to reduce or eliminate compounds from solutions that may be harmful or of low interest. In this review, we overviewed the chemistry behind material irradiation and the attractive use of ionizing radiation in scientific and industrial development. In this regard, the review was divided into three main sections titled (1) chemical kinetics intermediated by radiation, (2) chemical bonds intermediated by radiation, and (3) radiation chemistry on polymers. We concluded that graft polymerization, crosslinking and chain scission reactions induced by ionizing radiation are very efficient and green strategies for developing new materials with improved properties. Furthermore, water radiolysis plays a key role in the degradation of several contaminants, including pharmaceuticals and microplastics, in aqueous solutions. However, more studies must be conducted to complement the existing theory about the proposed mechanisms responsible for modifying the chemical, mechanical, thermal, optical, and so forth properties of irradiated materials.