Retrospective analysis of the efficacy and survival associated with cTACE and DEB-TACE in the palliative treatment of hepatocellular carcinoma: experience of a tertiary care hospital in southern Brazil.

Objective: To compare conventional transarterial chemoembolization (cTACE) and drug-eluting bead TACE (DEB-TACE) in terms of efficacy, survival, and adverse effects in patients with hepatocellular carcinoma who are not candidates for curative therapy. Materials and Methods: This was a retrospective study of patients with hepatocellular carcinoma who underwent cTACE or DEB-TACE for palliative treatment between January 2009 and December 2021. The Kaplan-Meier method was used for survival analysis. Values of p < 0.05 were considered statistically significant. Results: We evaluated 268 patients, of whom 70 underwent DEB-TACE and 198 underwent cTACE. There was no significant difference between the groups regarding sex, age, or etiology of cirrhosis. The proportion of patients achieving a complete response on imaging examinations was higher in the cTACE group (31.8% vs. 16.1%), whereas that of patients achieving a partial response was higher in the DEB-TACE group (33.9% vs.19.7%), and the differences were significant (p = 0.014). The mortality rate was similar between the groups. The survival rate in the DEB-TACE and cTACE groups, respectively, was 87.0% and 87.9% at one year, 35.1% and 32.9% at three years, and 20.5% and 18.1% at five years (p = 0.661). There was no significant difference between the DEB-TACE and cTACE groups in terms of the frequency of adverse events (7.1% vs. 17.8%; p = 0.052). The most common complication in both groups was post-embolization syndrome. Conclusion: Although a complete response was more common among the patients who underwent cTACE, there was no difference in survival between the groups and the frequency of adverse events was similar.

Objetivo: Comparar a eficácia, sobrevida e efeitos adversos entre cTACE e DEB-TACE em pacientes com carcinoma hepatocelular não candidatos a terapia curativa. Materiais e Métodos: Estudo retrospectivo de pacientes com carcinoma hepatocelular submetidos a cTACE ou DEB-TACE para tratamento paliativo entre janeiro de 2009 e dezembro de 2021. Foi utilizado o método Kaplan-Meier para análise de sobrevida. Valor de p < 0,05 foi considerado estatisticamente significante. Resultados: Foram avaliados 268 pacientes, dos quais 70 foram submetidos a DEB-TACE e 198 foram submetidos a cTACE. Não houve diferença em relação ao sexo, idade e etiologia da cirrose. O grupo cTACE apresentou maior porcentual de resposta completa em exames de imagem (31,8% vs. 16,1%) e o grupo DEB-TACE apresentou maior porcentual de resposta parcial (33,9% vs.19,7%), com valor de p = 0,014. A mortalidade foi semelhante. As taxas de sobrevivência para os grupos DEB-TACE e cTACE foram 87,0% e 87,9% em um ano, 35,1% e 32,9% em três anos e 20,5% e 18,1% em cinco anos, respectivamente (p = 0,661). Em relação à frequência de eventos adversos, não houve diferença significativa entre os grupos (7,1% na DEB-TACE vs. 17,8% na cTACE; p = 0,052). A complicação mais comum, em ambos os grupos, foi a síndrome pós-embolização. Conclusão: Embora tenha sido observada maior frequência de resposta completa em pacientes submetidos a cTACE, não houve diferença na sobrevida dos pacientes entre os grupos. A taxa de eventos adversos também foi semelhante.

Retrospective analysis of the efficacy and survival associated with cTACE and DEB-TACE in the palliative treatment of hepatocellular carcinoma: experience of a tertiary care hospital in southern Brazil / Análise retrospectiva da eficácia e sobrevida associadas a cTACE e DEB-TACE no tratamento paliativo do carcinoma hepatocelular: experiência de um hospital de cuidado terciário no sul do Brasil

Abstract Objective: To compare conventional transarterial chemoembolization (cTACE) and drug-eluting bead TACE (DEB-TACE) in terms of efficacy, survival, and adverse effects in patients with hepatocellular carcinoma who are not candidates for curative therapy. Materials and Methods: This was a retrospective study of patients with hepatocellular carcinoma who underwent cTACE or DEB-TACE for palliative treatment between January 2009 and December 2021. The Kaplan-Meier method was used for survival analysis. Values of p < 0.05 were considered statistically significant. Results: We evaluated 268 patients, of whom 70 underwent DEB-TACE and 198 underwent cTACE. There was no significant difference between the groups regarding sex, age, or etiology of cirrhosis. The proportion of patients achieving a complete response on imaging examinations was higher in the cTACE group (31.8% vs. 16.1%), whereas that of patients achieving a partial response was higher in the DEB-TACE group (33.9% vs.19.7%), and the differences were significant (p = 0.014). The mortality rate was similar between the groups. The survival rate in the DEB-TACE and cTACE groups, respectively, was 87.0% and 87.9% at one year, 35.1% and 32.9% at three years, and 20.5% and 18.1% at five years (p = 0.661). There was no significant difference between the DEB-TACE and cTACE groups in terms of the frequency of adverse events (7.1% vs. 17.8%; p = 0.052). The most common complication in both groups was post-embolization syndrome. Conclusion: Although a complete response was more common among the patients who underwent cTACE, there was no difference in survival between the groups and the frequency of adverse events was similar.

Resumo Objetivo: Comparar a eficácia, sobrevida e efeitos adversos entre cTACE e DEB-TACE em pacientes com carcinoma hepatocelular não candidatos a terapia curativa. Materiais e Métodos: Estudo retrospectivo de pacientes com carcinoma hepatocelular submetidos a cTACE ou DEB-TACE para tratamento paliativo entre janeiro de 2009 e dezembro de 2021. Foi utilizado o método Kaplan-Meier para análise de sobrevida. Valor de p < 0,05 foi considerado estatisticamente significante. Resultados: Foram avaliados 268 pacientes, dos quais 70 foram submetidos a DEB-TACE e 198 foram submetidos a cTACE. Não houve diferença em relação ao sexo, idade e etiologia da cirrose. O grupo cTACE apresentou maior porcentual de resposta completa em exames de imagem (31,8% vs. 16,1%) e o grupo DEB-TACE apresentou maior porcentual de resposta parcial (33,9% vs.19,7%), com valor de p = 0,014. A mortalidade foi semelhante. As taxas de sobrevivência para os grupos DEB-TACE e cTACE foram 87,0% e 87,9% em um ano, 35,1% e 32,9% em três anos e 20,5% e 18,1% em cinco anos, respectivamente (p = 0,661). Em relação à frequência de eventos adversos, não houve diferença significativa entre os grupos (7,1% na DEB-TACE vs. 17,8% na cTACE; p = 0,052). A complicação mais comum, em ambos os grupos, foi a síndrome pós-embolização. Conclusão: Embora tenha sido observada maior frequência de resposta completa em pacientes submetidos a cTACE, não houve diferença na sobrevida dos pacientes entre os grupos. A taxa de eventos adversos também foi semelhante.

Surface-Enhanced Raman Scattering (SERS) Substrates Based on Ag-Nanoparticles and Ag-Nanoparticles/Poly (methyl methacrylate) Composites.

SERS substrates formed by spherical silver nanoparticles (Ag-NPs) with a 15 nm average diameter adsorbed on Si substrate at three different concentrations and Ag/PMMA composites formed by an opal of PMMA microspheres of 298 nm average diameter were synthesized. The Ag-NPs were varied at three different concentrations. We have observed from SEM micrographs, in the Ag/PMMA composites, the periodicity of the PMMA opals is slightly altered as the Ag-NP concentration is increased; as a consequence of this effect, the PBGs maxima shift toward longer wavelengths, decrease in intensity, and broaden as the Ag-NP concentration is increased in the composites. The performance of single Ag-NP and Ag/PMMA composites as SERS substrates was determined using methylene blue (MB) as a probe molecule with concentrations in the range of 0.5 µM to 2.5 µM. We found that in both single Ag-NP and Ag/PMMA composites as SERS substrates, the enhancement factor (EF) increases as the Ag-NP concentration is increased. We highlight that the SERS substrate with the highest concentration of Ag-NPs has the highest EF due to the formation of metallic clusters on the surface, which generates more "hot spots". The comparison of the EFs of the single Ag-NP with those of Ag/PMMA composite SERS substrates shows that the EFs of the former are nearly 10-fold higher than those of Ag/PMMA composites. This result is obtained probably due to the porosity of the PMMA microspheres that decreases the local electric field strength. Furthermore, PMMA exerts a shielding effect that affects the optical efficiency of Ag-NPs. Moreover, the metal-dielectric surface interaction contributes to the decrease in the EF. Other aspect to consider in our results is in relation to the difference in the EF of the Ag/PMMA composite and Ag-NP SERS substrates and is due to the existing mismatch between the frequency range of the PMMA opal stop band and the LSPR frequency range of the Ag metal nanoparticles adsorbed on the PMMA opal host matrix.

Cost-effectiveness of selective internal radiation therapy with Y-90 resin microspheres for intermediate- and advanced-stage hepatocellular carcinoma in Brazil.

AIMS: Hepatocellular carcinoma (HCC) is a severe condition with poor prognosis that places a significant burden on patients, caregivers, and healthcare systems. Selective internal radiation therapy (SIRT) is a treatment available to patients with HCC which addresses some of the limitations of alternative treatment options. A cost-effectiveness analysis was undertaken into the use of SIRT using Y-90 resin microspheres for the treatment of unresectable intermediate- and late-stage HCC in Brazil. MATERIALS AND METHODS: A partitioned-survival model was developed, including a tunnel state for patients downstaged to receive treatments with curative intent. Sorafenib was the selected comparator, a common systemic treatment in Brazil and for which comparative evidence exists. Clinical data were extracted from published sources of pivotal trials, and effectiveness was measured in quality-adjusted life-years (QALYs) and life-years (LYs). The analysis was conducted from the Brazilian private payer perspective and a lifetime horizon was implemented. Comprehensive sensitivity analyses were conducted. RESULTS: LYs and QALYs were higher for SIRT with Y-90 resin microspheres versus sorafenib (0.27 and 0.20 incremental LYs and QALYs, respectively) and costs were slightly higher for SIRT (R$15,864). The base case incremental cost-effectiveness ratio (ICER) was R$77,602 per QALY. The ICER was mostly influenced by parameters defining the sorafenib overall survival curve and SIRT had a 73% probability of being cost-effective at a willingness-to-pay threshold of R$135,761 per QALY (3-times the per-capita gross domestic product in Brazil). Overall, sensitivity analyses confirmed the robustness of the results indicating that SIRT with Y-90 resin microspheres is cost-effective compared with sorafenib. LIMITATIONS: A rapidly evolving treatment landscape in Brazil and worldwide, and the lack of local data for some variables were the main limitations. CONCLUSIONS: SIRT with Y-90 resin microspheres is a cost-effective option compared with sorafenib in Brazil.

Embryotoxicity and visual-motor response of functionalized nanostructured hydroxyapatite-based biomaterials in zebrafish (Danio rerio).

Hydroxyapatite (HA) is a biomaterial widely used in biomedical applications. Many studies have shown that ionic substituents can be incorporated into HA to produce a mineral composition more similar to natural bone tissue with more favorable biological characteristics for application in bone regeneration. However, its potentially toxic effects need to be evaluated before full approval for human use. For this purpose, an embryotoxicity test was performed on zebrafish according to OECD guideline 236. Zebrafish embryos were exposed to 1 or 3 microspheres of alginate containing nanoparticles of HA and carbonate (CHA), strontium (SrHA), and zinc-substituted HA (ZnHA) from 4 to 120 h post-fertilization (hpf). Lethality and developmental endpoints were evaluated. In addition, larval behavior at 168 hpf was also analyzed to observe whether biomaterials adversely affect optomotor and avoidance responses (neurotoxicity), as well as the oxidative stress pattern through qPCR. After 120 h exposure to all microspheres with different patterns of crystallinity, porosity, nanoparticle size, surface area, and degradation behavior, there was no mortality rate greater than 20%, indicating the non-embryotoxic character of these biomaterials. All experimental groups showed positive optomotor and avoidance responses, which means that embryo exposure to the tested biomaterials had no neurotoxic effects. Furthermore, larvae exposed to one SrHA microsphere showed a better optomotor response than the control. Furthermore, the biomaterials did not change the pattern of mRNA levels of genes related to oxidative stress even after 120 hpf. The growing number of new HA-based biomaterials produced should be accompanied by increased studies to understand the biosafety of these compounds, especially in alternative models, such as zebrafish embryos. These results reinforce our hypothesis that ion-substituted HA biomaterials do not impose toxicological effects, cause development and neuromotor impairment, or increase oxidative stress in zebrafish embryos being useful for medical devices and in the process of bone regeneration.

Diagnostic applications of microsphere-based flow cytometry: A review.

Microsphere-based flow cytometry is a highly sensitive emerging technology for specific detection and clinical analysis of antigens, antibodies, and nucleic acids of interest. In this review, studies that focused on the application of flow cytometry as a viable alternative for the investigation of infectious diseases were analyzed. Many of the studies involve research aimed at epidemiological surveillance, vaccine candidates and early diagnosis, non-infectious diseases, specifically cancer, and emphasize the simultaneous detection of biomarkers for early diagnosis, with accurate results in a non-invasive approach. The possibility of carrying out multiplexed assays affords this technique high versatility and performance, which is evidenced in a series of clinical studies that have verified the ability to detect several molecules in low concentrations and with minimal sample volume. As such, we demonstrate that microsphere-based flow cytometry presents itself as a promising technique that can be adopted as a fundamental element in the development of new diagnostic methods for a number of diseases.

Uterine artery embolization with highly compressible calibrated microspheres for the treatment of uterine fibroids.

Objective: To evaluate the safety and efficacy of using highly compressible calibrated microspheres in uterine artery embolization (UAE) for the treatment of uterine fibroids. Materials and Methods: This was a prospective multicenter study. Thirty-two women with symptomatic uterine fibroids were selected for UAE between January 2019 and March 2020. The participants completed the Uterine Fibroid Symptom and Quality of Life (UFS-QOL) questionnaire, underwent contrast-enhanced pelvic magnetic resonance imaging (MRI), and were submitted to anti-Müllerian hormone measurement, subsequently undergoing UAE with Embosoft microspheres. After six months, the patients again completed the UFS-QOL questionnaire and underwent pelvic MRI. Results: The most common symptoms were abnormal uterine bleeding (in 81.3% of the cases), pelvic pain (in 81.3%), and compression (in 46.9%). Of the 32 patients evaluated, 12 (37.5%) had anemia due to abnormal uterine bleeding. Thirty patients completed the study. Among those patients, we observed median reductions of 21.4% in uterine volume and 15.9% in dominant fibroid volume. We identified no adverse events that could be attributed to the material itself, although there were events attributed to the UAE procedure in general. Conclusion: For the treatment of uterine fibroids, UAE using Embosoft microspheres shows satisfactory results, providing reductions in uterine and dominant fibroid volumes, with a low rate of adverse events, and improving patient quality of life, as well as demonstrating safety and efficacy.

Objetivo: Avaliar a eficácia e segurança da embolização da artéria uterina (EAU) com microesferas calibradas de alta compressibilidade no tratamento de miomas uterinos. Materiais e Métodos: Este foi um estudo prospectivo e multicêntrico. Foram selecionadas 32 mulheres com miomas uterinos sintomáticos para EAU de janeiro de 2019 a março de 2020. As participantes preencheram o questionário Uterine Fibroid Symptom and Quality of Life (UFS-QOL), realizaram ressonância magnética (RM) pélvica com contraste e teste para medição dos hormônios antimüllerianos, seguido de embolização de miomas com microesferas Embosoft. Após seis meses, as pacientes novamente preencheram o UFS-QOL e realizaram RM pélvica. Resultados: Os sintomas mais relatados foram sangramento uterino anormal (81,3%), dor pélvica (81,3%) e compressão (46,9%). Doze pacientes (37,5%) apresentaram anemia consequente a sangramento uterino anormal. Nas 30 pacientes que completaram o estudo, observou-se redução mediana de 21,4% no volume uterino e 15,9% no volume do mioma dominante. Não foram identificados eventos adversos possivelmente relacionados ao material utilizado, apenas em relação ao procedimento de EAU. Conclusão: EAU com microesferas Embrosoft mostrou resultados satisfatórios no tratamento de miomas uterinos, com redução dos volumes uterino e do mioma dominante, baixa taxa de eventos adversos e melhora na qualidade de vida, demonstrando segurança e eficácia.

Uterine artery embolization with highly compressible calibrated microspheres for the treatment of uterine fibroids / Embolização de miomas uterinos com microesferas calibradas de alta compressibilidade

Abstract Objective: To evaluate the safety and efficacy of using highly compressible calibrated microspheres in uterine artery embolization (UAE) for the treatment of uterine fibroids. Materials and Methods: This was a prospective multicenter study. Thirty-two women with symptomatic uterine fibroids were selected for UAE between January 2019 and March 2020. The participants completed the Uterine Fibroid Symptom and Quality of Life (UFS-QOL) questionnaire, underwent contrast-enhanced pelvic magnetic resonance imaging (MRI), and were submitted to anti-Müllerian hormone measurement, subsequently undergoing UAE with Embosoft microspheres. After six months, the patients again completed the UFS-QOL questionnaire and underwent pelvic MRI. Results: The most common symptoms were abnormal uterine bleeding (in 81.3% of the cases), pelvic pain (in 81.3%), and compression (in 46.9%). Of the 32 patients evaluated, 12 (37.5%) had anemia due to abnormal uterine bleeding. Thirty patients completed the study. Among those patients, we observed median reductions of 21.4% in uterine volume and 15.9% in dominant fibroid volume. We identified no adverse events that could be attributed to the material itself, although there were events attributed to the UAE procedure in general. Conclusion: For the treatment of uterine fibroids, UAE using Embosoft microspheres shows satisfactory results, providing reductions in uterine and dominant fibroid volumes, with a low rate of adverse events, and improving patient quality of life, as well as demonstrating safety and efficacy.

Resumo Objetivo: Avaliar a eficácia e segurança da embolização da artéria uterina (EAU) com microesferas calibradas de alta compressibilidade no tratamento de miomas uterinos. Materiais e Métodos: Este foi um estudo prospectivo e multicêntrico. Foram selecionadas 32 mulheres com miomas uterinos sintomáticos para EAU de janeiro de 2019 a março de 2020. As participantes preencheram o questionário Uterine Fibroid Symptom and Quality of Life (UFS-QOL), realizaram ressonância magnética (RM) pélvica com contraste e teste para medição dos hormônios antimüllerianos, seguido de embolização de miomas com microesferas Embosoft. Após seis meses, as pacientes novamente preencheram o UFS-QOL e realizaram RM pélvica. Resultados: Os sintomas mais relatados foram sangramento uterino anormal (81,3%), dor pélvica (81,3%) e compressão (46,9%). Doze pacientes (37,5%) apresentaram anemia consequente a sangramento uterino anormal. Nas 30 pacientes que completaram o estudo, observou-se redução mediana de 21,4% no volume uterino e 15,9% no volume do mioma dominante. Não foram identificados eventos adversos possivelmente relacionados ao material utilizado, apenas em relação ao procedimento de EAU. Conclusão: EAU com microesferas Embrosoft mostrou resultados satisfatórios no tratamento de miomas uterinos, com redução dos volumes uterino e do mioma dominante, baixa taxa de eventos adversos e melhora na qualidade de vida, demonstrando segurança e eficácia.

The American Brachytherapy Society consensus statement for permanent implant brachytherapy using Yttrium-90 microsphere radioembolization for liver tumors.

PURPOSE: To develop a multidisciplinary consensus for high quality multidisciplinary implementation of brachytherapy using Yttrium-90 (90Y) microspheres transarterial radioembolization (90Y TARE) for primary and metastatic cancers in the liver. METHODS AND MATERIALS: Members of the American Brachytherapy Society (ABS) and colleagues with multidisciplinary expertise in liver tumor therapy formulated guidelines for 90Y TARE for unresectable primary liver malignancies and unresectable metastatic cancer to the liver. The consensus is provided on the most recent literature and clinical experience. RESULTS: The ABS strongly recommends the use of 90Y microsphere brachytherapy for the definitive/palliative treatment of unresectable liver cancer when recommended by the multidisciplinary team. A quality management program must be implemented at the start of 90Y TARE program development and follow-up data should be tracked for efficacy and toxicity. Patient-specific dosimetry optimized for treatment intent is recommended when conducting 90Y TARE. Implementation in patients on systemic therapy should account for factors that may enhance treatment related toxicity without delaying treatment inappropriately. Further management and salvage therapy options including retreatment with 90Y TARE should be carefully considered. CONCLUSIONS: ABS consensus for implementing a safe 90Y TARE program for liver cancer in the multidisciplinary setting is presented. It builds on previous guidelines to include recommendations for appropriate implementation based on current literature and practices in experienced centers. Practitioners and cooperative groups are encouraged to use this document as a guide to formulate their clinical practices and to adopt the most recent dose reporting policies that are critical for a unified outcome analysis of future effectiveness studies.

Leukotriene B4 loaded in microspheres regulate the expression of genes related to odontoblastic differentiation and biomineralization by dental pulp stem cells.

BACKGROUND: Leukotriene B4 (LTB4) is a potent lipid mediator that stimulate the immune response. Because dental pulp inflammation and dentin repair are intrinsically related responses, the aim of this research was to investigate the potential of LTB4 in inducing differentiation of dental pulp stem cells. METHODS: Microspheres (MS) loaded with LTB4 were prepared using an oil emulsion solvent extraction evaporation process and sterility, characterization, efficiency of LTB4 encapsulation and in vitro LTB4 release assay were investigated. Mouse dental pulp stem cells (OD-21) were stimulated with soluble LTB4 or MS loaded with LTB4 (0.01 and 0.1 µM). Cytotoxicity and cell viability was determined by lactate dehydrogenase and methylthiazol tetrazolium assays. Gene expression were measured by quantitative reverse transcription polymerase chain reaction after 3, 6, 24, 48 and 72 h. Mineralized nodule formation was assessed after 28 days of OD-21 cell stimulation with LTB4 in mineralized media or not. Groups were compared using one-way ANOVA test followed by Dunnett's post-test (α = 0.05). RESULTS: Treatment with LTB4 or MS loaded with LTB4 (0.01 and 0.1 µm-µM) were not cytotoxic to OD-21 cells. Treatment with LTB4 modulated the expression of the Ibsp (integrin binding sialoprotein) and Runx2 (runt-related transcription factor 2) genes differently depending on the experimental period analyzed. Interestingly LTB4 loaded in microspheres (0.1 µM) allowed long term dental pulp cell differentiation and biomineralization. CONCLUSION: LTB4, soluble or loaded in MS, were not cytotoxic and modulated the expression of the Ibsp and Runx2 genes in cultured OD-21 cells. When LTB4 was incorporated into MS, odontoblast differentiation and mineralization was induced in long term culture.

Short-duration exposure of 3-µm polystyrene microplastics affected morphology and physiology of watermilfoil (sp. roraima).

Microplastics are one of the most widely discussed environmental issues worldwide. Several studies have shown the effect of microplastic exposure on the marine environment; however, studies on freshwater systems are lacking. This study was conducted to investigate the effect of microplastics on hydroponically growing emergent freshwater macrophytes, watermilfoil (sp. roraima) under controlled environmental conditions. Plants were exposed to 0 mg L-1 (control), 0.05 mg L-1, 0.25 mg L-1, 1.25 mg L-1, and 6 mg L-1 of 3-µm polystyrene microspheres for 7 days. The oxidative stress, antioxidant response, pigmentations, Fv/Fm, and growth parameters in the above-water and below-water parts were analyzed separately. Microscopic observations were performed to confirm the tissue absorbance of the microplastics. Exposure to microplastics altered some parameters; however, growth was not affected. The effect of microplastics was not linear with the exposure concentration for most of the parameters and between 1.25 and 6 mg L-1 concentrations. The response trends mostly followed the second-order polynomial distributions. Under the 1.25 mg L-1 exposure, there were significant changes in root length, H2O2 content, catalase activity, anthocyanin content, and Fv/Fm. There were differences in parameters between the above-water and below-water parts, and the responses of the microplastics followed different trends. Microscopic observations confirmed the attachment of microplastic particles onto newly formed roots, except for older roots or shoot tissues.

Insights on Luminescent Micro- and Nanospheres of Infinite Coordination Polymers.

Coordination polymers have been extensively studied in recent years. Some of these materials can exhibit several properties such as permanent porosity, high surface area, thermostability and light emission, as well as open sites for chemical functionalization. Concerning the fact that this kind of compounds are usually solids, the size and morphology of the particles are important parameters when an application is desired. Inside this context, there is a subclass of coordination polymers, named infinite coordination polymers (ICPs), which auto-organize as micro- or nanoparticles with low crystallinity. Specifically, the particles exhibiting spherical shapes and reduced sizes can be better dispersed, enter cells much easier than bulk crystals and be converted to inorganic materials by topotactic transformation. Luminescent ICPs, in particular, can find applications in several areas, such as sensing probes, light-emitting devices and bioimaging. In this review, we present the state-of-the-art of ICP-based spherical particles, including the growth mechanisms, some applications for luminescent ICPs and the challenges to overcome in future commercial usage of these materials.

Influence of Ag Photodeposition Conditions over SERS Intensity of Ag/ZnO Microspheres for Nanomolar Detection of Methylene Blue.

Surface enhanced Raman spectroscopy (SERS) is considered a versatile and multifunctional technique with the ability to detect molecules of different species at very low molar concentration. In this work, hierarchical ZnO microspheres (ZnO MSs) and Ag/ZnO MSs were fabricated and decorated by hydrothermal and photodeposition methods, respectively. For Ag deposition, precursor molar concentration (1.9 and 9.8 mM) and UV irradiation time (5, 15, and 30 min) were evaluated by SEM, TEM, X-ray diffraction and Raman spectroscopy. X-ray diffraction showed a peak at 37.9° corresponding to the (111) plane of Ag, whose intensity increases as precursor concentration and UV irradiation time increases. SEM images confirmed the formation of ZnO MSs (from 2.5 to 4.5 µm) building by radially aligned two-dimensional ZnO nanosheets with thicknesses below 30 nm. The Raman spectra of Ag/ZnO MSs exhibited a vibration mode at 486 cm-1 which can be directly associated to Ag deposition on ZnO MSs surface. The performance of SERS substrate was evaluated using rhodamine 6G. The SERS substrate grown at 9.8 mM during 30 min showed the best SERS activity and the ability to detect methylene blue at 10-9 M.

Micronutrients encapsulation by starch as an enhanced efficiency fertilizer.

Developing different paths to achieve sustainable agriculture is no longer an option; it is a necessity. EEF materials are alternatives to improve the efficacy of the agrochemicals in the soil and plant, reducing wasting and environmental contamination. The present work aims to develop EEF materials based on starch and micronutrients, considering few works address EEFs materials with micronutrients. Monoelementary dispersions of gelatinized starch with micronutrients (Fe, Cu, Mn) were spray-dried and thermally, structurally, and morphologically characterized. We evaluated water-medium nutrient release, release kinetics, and the swelling degree. Different micronutrients affect morphology, size distribution, swelling degree, release, kinetics, and interaction between polymer-nutrient. Bigger particle sizes achieved a higher swelling degree, which led to decreased micronutrient release in the water. The Peppas-Sahlin model mainly ruled the release kinetics (fitted to all the materials). This result confirmed our hypothesis that a swelling starch delays the release.

Synthesis and Study of the Optical Properties of PMMA Microspheres and Opals.

Polymethylmethacrylate (PMMA) microspheres were synthesized by surfactant-free emulsion polymerization. These microspheres were used to obtain opals by the self-assembly method. Monomer and initiator quantities were varied systematically to monitor the size of PMMA microspheres. From SEM and DLS measurements, a trend was observed showing as the monomer and initiator amounts increased the average diameter of PMMA microspheres increased except when a minimum monomer amount was reached, for which the size of the microspheres remained practically constant. Diffuse reflectance spectra were processed by the Kubelka-Munk treatment to estimate the energy band gap (Eg) of the PMMA microspheres. It was found that PMMA microspheres present an indirect transition. From SEM micrographs, it is seen that PMMA opals photonic crystals are formed by microspheres in a uniform periodic face-centered cubic (fcc) array. Variable-angle specular reflectance spectra show that the opals possess a pseudo photonic band gap (PBG) in the visible and near-IR regions. Furthermore, it was found that PBGs shift towards larger wavelengths as the average diameter of the PMMA microspheres increases.

Microcápsulas y microesferas: una visión a la caracterización integral y aplicación para la liberación de medicamentos biotecnológicos / Microcapsules and microspheres: A vision to integral characterization and applications for biotechnological drugs delivery

Resumen Los microacarreadores basados en microcápsulas y microesferas han sido ampliamente estudiados y ensayados para controlar la liberación de medicamentos biotecnológicos (MB), disminuyendo la dosificación o modificando la vía de administración. Los métodos para la obtención de microacarreadores, son complejos y variados, por lo que es necesario determinar los requisitos mínimos que debe cumplir el sistema. El objetivo de este trabajo fue establecer las principales características que deben ser evaluadas en los microacarreadores para garantizar que la actividad biológica de los medicamentos biotecnológicos permanezca intacta a través del proceso de microencapsulación y, por lo tanto, que la seguridad del MB (desarrollo de reacciones inmunes) se mantenga inalterada. Las características a evaluar de un microacarreador deben describir las propiedades del material, tamaño y forma del sistema, carga de la partícula, funcionalidad, eficiencia de la microencapsulación y la cinética de liberación. Mientras que la integridad de los MB puede ser evaluada a partir de parámetros críticos de calidad: estructura y función biológica del MB, pureza del producto, presencia de agregados de alto peso molecular, estructura de orden superior y ensayos de actividad biológica. La caracterización de los microacarreadores debe enfocarse en la seguridad del biopolímero y proteínas ensayadas.

Abstract Microcarriers based on microcapsules and microspheres have been widely studied and tested to control the release of biotechnological drugs (BD), diminishing the dosage or modifying the route of administration. The methods for obtaining microcarriers are complex and varied, so it is necessary to determine the minimum characteristics with which the system must comply. The aim of this work was to establish the main characteristics that should be evaluated in the microcarriers in order to guarantee that the biological activity of biotechnological drugs remains intact through the microencapsulation process, and therefore the safety of the BD (development of immune reactions) remains unaltered. The characteristics of a microcarrier to be evaluated must describe the properties of the material, the size and shape of the system, the particle load, functionalization, the microencapsulation efficiency, and the kinetics of liberation. Whereas the integrity of BD can be evaluated by critical quality parameter such as: structure and biological function of the BD, product purity, presence of high molecular weight aggregations, higher order structure and biological activity tests. The characterization of the microcarriers must focus on the safety of the biopolymer and proteins tested.

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.

Regenerative potential of basic fibroblast growth factor contained in biodegradable gelatin hydrogel microspheres applied following vocal fold injury: Early effect on tissue repair in a rabbit model / Potencial regenerativo do fator básico de crescimento de fibroblastos contido em microesferas biodegradáveis de hidrogel de gelatina aplicadas após lesão de prega vocal: efeito inicial no reparo tecidual em modelo de coelho

Abstract Introduction Postoperative dysphonia is mostly caused by vocal fold scarring, and careful management of vocal fold surgery has been reported to reduce the risk of scar formation. However, depending on the vocal fold injury, treatment of postoperative dysphonia can be challenging. Objective The goal of the current study was to develop a novel prophylactic regenerative approach for the treatment of injured vocal folds after surgery, using biodegradable gelatin hydrogel microspheres as a drug delivery system for basic fibroblast growth factor. Methods Videoendoscopic laryngeal surgery was performed to create vocal fold injury in 14 rabbits. Immediately following this procedure, biodegradable gelatin hydrogel microspheres with basic fibroblast growth factor were injected in the vocal fold. Two weeks after injection, larynges were excised for evaluation of vocal fold histology and mucosal movement. Results The presence of poor vibratory function was confirmed in the injured vocal folds. Histology and digital image analysis demonstrated that the injured vocal folds injected with gelatin hydrogel microspheres with basic fibroblast growth factor showed less scar formation, compared to the injured vocal folds injected with gelatin hydrogel microspheres only, or those without any injection. Conclusion A prophylactic injection of basic fibroblast growth factor -containing biodegradable gelatin hydrogel microspheres demonstrates a regenerative potential for injured vocal folds in a rabbit model.

Resumo Introdução A disfonia pós-operatória é causada principalmente por cicatrizes nas pregas vocais. Tem sido relatado que o manejo cuidadoso da cirurgia das pregas vocais reduz o risco de formação de cicatriz. No entanto, a depender da lesão da prega vocal, o tratamento da disfonia pós-operatória pode ser desafiador. Objetivo Desenvolver uma nova abordagem regenerativa profilática para o tratamento de pregas vocais lesionadas após a cirurgia, com microesferas biodegradáveis de hidrogel de gelatina como sistema de administração de medicamentos para o Fator Básico de Crescimento de Fibroblastos (bFGF). Método A cirurgia laríngea videoendoscópica foi feita para criar lesão nas pregas vocais em 14 coelhos. Imediatamente após esse procedimento, microesferas biodegradáveis de hidrogel de gelatina com bFGF foram injetadas na prega vocal. Duas semanas após a injeção, as laringes foram excisadas para avaliação da histologia das pregas vocais e do movimento da mucosa. Resultados A presença de função vibratória deficiente foi confirmada nas pregas vocais lesionadas. A histologia e a análise de imagem digital demonstraram que as pregas vocais lesionadas injetadas com microesferas de hidrogel de gelatina com bFGF apresentaram menor formação de cicatriz, em comparação com as pregas vocais lesionadas injetadas apenas com microesferas de hidrogel de gelatina ou aquelas sem injeção. Conclusão Uma injeção profilática de microesferas biodegradáveis de hidrogel de gelatina com bFGF demonstra um potencial regenerativo para pregas vocais lesionadas em um modelo de coelho.

Regenerative potential of basic fibroblast growth factor contained in biodegradable gelatin hydrogel microspheres applied following vocal fold injury: Early effect on tissue repair in a rabbit model.

INTRODUCTION: Postoperative dysphonia is mostly caused by vocal fold scarring, and careful management of vocal fold surgery has been reported to reduce the risk of scar formation. However, depending on the vocal fold injury, treatment of postoperative dysphonia can be challenging. OBJECTIVE: The goal of the current study was to develop a novel prophylactic regenerative approach for the treatment of injured vocal folds after surgery, using biodegradable gelatin hydrogel microspheres as a drug delivery system for basic fibroblast growth factor. METHODS: Videoendoscopic laryngeal surgery was performed to create vocal fold injury in 14 rabbits. Immediately following this procedure, biodegradable gelatin hydrogel microspheres with basic fibroblast growth factor were injected in the vocal fold. Two weeks after injection, larynges were excised for evaluation of vocal fold histology and mucosal movement. RESULTS: The presence of poor vibratory function was confirmed in the injured vocal folds. Histology and digital image analysis demonstrated that the injured vocal folds injected with gelatin hydrogel microspheres with basic fibroblast growth factor showed less scar formation, compared to the injured vocal folds injected with gelatin hydrogel microspheres only, or those without any injection. CONCLUSION: A prophylactic injection of basic fibroblast growth factor -containing biodegradable gelatin hydrogel microspheres demonstrates a regenerative potential for injured vocal folds in a rabbit model.

Betulinic Acid Nanogels: Rheological, Microstructural Characterization and Evaluation of their Anti-inflammatory Activity.

BACKGROUND: Betulinic Acid (BA) is a lipophilic compound with proven beneficial results in topical inflammation. Nanogels (NG) are carriers of bioactive compounds with properties that make them good candidates to treat skin diseases. OBJECTIVE: The objective of this study was to evaluate the anti-inflammatory activity of BA carried in NG. METHODS: NG were composed of a nanoemulsion and a crosslinking agent (Carbopol 940®) applied at three concentrations (0.5, 1, and 1.5 %) and three activation times (6, 12 and 24 h). In order to select the optimal formulation, the NG were characterized mechanically and micro-structurally followed by evaluation of the BA anti-inflammatory activity in an in vivo model of auricular edema. We determined the edema inhibition activity as percent weight. Additionally, the anti-inflammatory activity of NG was validated through histological analysis. RESULTS: The formulation with the best viscoelastic properties was the one prepared with 0.5% carbopol and 6 h of activation. Microstructural examination of this formulation showed mostly spherical structures with a mean diameter of 65 nm. From the evaluation of edema and the histological analyses, we established that the NG of BA produced 52% inhibition. In contrast, a conventional gel and free BA produced 28% and 19% inhibition, respectively. CONCLUSION: The NG of BA were found to be good vehicles to treat skin inflammation.