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1.
Braz. j. otorhinolaryngol. (Impr.) ; 87(3): 274-282, May-Jun. 2021. graf
Article in English | LILACS | ID: biblio-1285692

ABSTRACT

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.


Subject(s)
Animals , Vocal Cords/surgery , Gelatin , Rabbits , Fibroblast Growth Factor 2 , Hydrogels , Microspheres
2.
Rev. Ateneo Argent. Odontol ; 64(1): 18-21, 2021. ilus
Article in Spanish | LILACS | ID: biblio-1248258

ABSTRACT

Biomaterial de tercera generación con una tasa de degradabilidad en la zona perirradicular y del foramen apical, con una velocidad similar a la que emplea el organismo para formar tejido calcificado y sellar biológicamente el extremo apical del diente. Mediante el recurso tecnológico de la microencapsulación se produce la liberación lenta y controlada de Ca2+ retenido en la superficie y en el interior de las microesferas de alginato de calcio, sin que se modifique de manera significativa las propiedades reológicas básicas del biomaterial de obturación de conductos, tales como la compresibilidad, plasticidad, extensibilidad, fluidez, viscosidad cinemática, viscosidad de compresión y endurecimiento por trabajo (AU)


Third-generation biomaterial with a degradability rate in the periradicular area and the apical foramen, with a speed similar to that used by the body to form calcified tissue and biologically seal the apical end of the tooth. Through the technological resource of microencapsulation, the slow and controlled release of Ca2+ retained on the surface and inside the calcium alginate microspheres is produced, without significantly modifying the basic rheological properties of the duct sealing biomaterial, such as compressibility, plasticity, extensibility, flowability, kinematic viscosity, compression viscosity, and work hardening (AU)


Subject(s)
Humans , Periapical Diseases/therapy , Root Canal Filling Materials/therapeutic use , Biocompatible Materials , Rheology , Calcium Compounds , Tooth Apex , Drug Compounding , Alginates/chemistry , Microspheres
3.
Chinese Journal of Hepatology ; (12): 648-658, 2021.
Article in Chinese | WPRIM | ID: wpr-888408

ABSTRACT

Liver malignant tumors are one of the most common causes of cancer-related deaths in China. Selective internal yttrium-90 radioembolization therapy ((90)Y-SIRT) is a kind of promising local minimally invasive method, and its effectiveness and safety has been confirmed in clinical application over the past two decades. Moreover, it has been approved by the U.S. National Comprehensive Cancer Network and other international guidelines for the topical treatment of patients with liver malignancies. Taking into account the complexity of the (90)Y-SIRT and the need for multidisciplinary collaboration to improve the safety and success rate of treatment, the Nuclear Medicine Expert Committee of the Chinese society of Clinical Oncology, along with Beijing Nuclear Medicine Quality Control and Improvement Center invited experts from surgical oncology, interventional medicine, nuclear medicine, and other related fields to discuss and form a consensus on the clinical diagnosis, treatment and management, which mainly included definition, indications and contraindications, treatment procedures, postoperative follow-up, adverse reactions and complications, radiation safety management, etc. Herein, we provide the reference guidance to establish (90)Y-SIRT standardized management and treatment system various units for relevant practitioners.


Subject(s)
Carcinoma, Hepatocellular/radiotherapy , China , Consensus , Humans , Liver Neoplasms/radiotherapy , Microspheres , Yttrium Radioisotopes
4.
Chinese Journal of Biotechnology ; (12): 4066-4074, 2021.
Article in Chinese | WPRIM | ID: wpr-921487

ABSTRACT

Different fragments of SARS-CoV-2 nucleocapsid (N) protein were expressed and purified, and a fluorescence immunochromatography method for detection of SARS-CoV-2 total antibody was established. The effect of different protein fragments on the performance of the method was evaluated. The N protein sequence was analyzed by bioinformatics technology, expressed in prokaryotic cell and purified by metal ion affinity chromatography column. Different N protein fragments were prepared for comparison. EDC reaction was used to label fluorescence microsphere on the synthesized antigen to construct sandwich fluorescence chromatography antibody detection assay, and the performance was systemically evaluated. Among the 4 prepared N protein fragments, the full-length N protein (N419) was selected as the optimized coating antigen, N412 with 0.5 mol/L NaCl was used as the optimal combination; deleting 91-120 amino acids from the N-terminal of N412 reduced non-specific signal by 87.5%. the linear range of detection was 0.312-80 U/L, the limit of detection was 0.165 U/L, and the accuracy was more than 95%. A fluorescence immunochromatographic detection method for analysis of SARS-CoV-2 total antibody was established by pairing N protein fragments. The detection result achieved 98% concordance with the commercially available Guangzhou Wanfu test strip, which is expected to be used as a supplementary approach for detection of SARS-CoV-2. The assay could also provide experimental reference for improving the performance of COVID-19 antibody detection reagents.


Subject(s)
Antibodies, Viral , COVID-19 , Chromatography, Affinity , Fluorescent Antibody Technique , Humans , Microspheres , SARS-CoV-2 , Sensitivity and Specificity
5.
Braz. J. Pharm. Sci. (Online) ; 56: e18748, 2020. tab, graf
Article in English | LILACS | ID: biblio-1285513

ABSTRACT

Conventional drug formulations are incapable of adequate delivery of proteins and peptides for therapeutic purposes. As these molecules have very short biological half-life, multiple dosing is required to achieve the desirable therapeutic effects. Microspheres are able to encapsulate proteins and peptide in the polymeric matrix while protecting them from enzymatic degradation. In this study Bovine Serum Albumin (BSA) matrix type microspheres were fabricated using Polylactide-co-glycolide (PLGA) by double emulsion solvent evaporation method. The effects of variables such as homogenizer speed, molecular weight of polymer and the effect of pH of the water phases, were investigated against factors such as drug loading, encapsulation efficiency, morphology, size, drug distribution and release profile of the microspheres. Results, suggested that an increase in homogenization speed leads to a decrease in microsphere size. The increase in homogenization speed also caused a significant effect on the release profile only when higher molecular weight of polymer had been used.. The pH change of the internal aqueous phase led to modification of surface morphology of spheres to a porous structure that significantly increased the total amount of released protein. Integrity of protein structure was intact as shown by SDS-PAGE. According to the results, it can be concluded that we achieved a reproducible method regarding controlled protein delivery for different sizes of particles.


Subject(s)
In Vitro Techniques/methods , Pharmaceutical Preparations/analysis , Proteins , Microspheres , Serum Albumin, Bovine/administration & dosage , Efficiency/classification , Electrophoresis, Polyacrylamide Gel/instrumentation , Emulsions
6.
Braz. J. Pharm. Sci. (Online) ; 56: e18414, 2020. tab, graf
Article in English | LILACS | ID: biblio-1249155

ABSTRACT

Tolmetin sodium (TS) is a powerful non-steroidal mitigating drug for the treatment of rheumatoid joint inflammation, osteoarthritis, and adolescent rheumatoid joint pain. In addition to its gastrointestinal (GIT) problems, TS has a short biological half-life (1 hr). In a trial to overcome these side effects and control the rate of (TS) release, chitosan coated alginate microspheres are recommended. A Box-Behnken experimental design was employed to produce controlled release microspheres of TS in the sodium alginate and chitosan copolymers (Alg-Ch) by emulsification internal gelation methodology. The effect of critical formulation variables namely, drug to polymer ratio (D:P ratio), speed of rotation and span 80% on drug encapsulation efficiency (% EE), drug release at the end of 2 hours (Rel2) and drug release at the end of 8 hours (Rel8) were analyzed using response surface modeling. The parameters were assessed using the F test and mathematical models containing only the significant terms were generated for each parameter using multiple linear regression analysis. The produced microspheres were spherical in shape with extensive pores at D:P ratio 1:1 and small pores at a drug to polymer ratio (D:P ratio) 1:3. Differential scanning calorimetry (DSC) affirmed the steady character of TS in microspheres and revealed their crystalline form. All formulation variables examined exerted a significant influence on the drug release, whereas the speed emerged as a lone factor significantly influencing % EE. Increasing the D: P ratio decreases the release of the drug after two and 8 hours. The increase in speed results in an increase in drug release after two and eight hours. The drug release from the microspheres followed zero order kinetics. TS Alg-Ch microspheres exhibited a significant anti-inflammatory effect on incited rat paw edema after eight hours. These results revealed that the internal gelation technique is a promising method to control TS release and eradicate GIT side effects using Alg-Ch copolymers.


Subject(s)
Tolmetin/analysis , Chitosan/analysis , Alginates/analysis , Microspheres , Calorimetry, Differential Scanning/methods , Pharmaceutical Preparations , Arthralgia/pathology , Drug Liberation , Inflammation/pathology , Joints/pathology
7.
Braz. J. Pharm. Sci. (Online) ; 55: e17536, 2019. tab, graf
Article in English | LILACS | ID: biblio-1055294

ABSTRACT

Tadalafil, a long-acting PED-5 inhibitor, is commonly used for the treatment of pulmonary arterial hypertension (PAH). However, its efficacy and clinical application are severely limited by the poor water solubility, low bioavailability and a series adverse effects (e.g. headaches, indigestion). In this study, tadalafil was prepared and loaded into biodegradable PLGA (poly(lactic-co-glycolic acid)) microspheres (TDF-PLGA-MS) via emulsification-solvent evaporation. The resulting microspheres were processed into pulmonary inhalant by freeze drying. The TDF-PLGA-MS was spherical and uniform, with an average particle diameter ~10.29 µm. The encapsulation efficiency and drug loading yield of TDF-PLGA-MS were 81.68% and 8.52%, respectively. The investigation of micromeritics showed that the TDF-PLGA-MS had low moisture content. The fluidity of powders was relatively good. The aerodynamic diameter and emptying rate of microspheres powders were 3.92 µm and 95.41%, respectively. Therefore, the microspheres powders were easy to be atomized, and can meet the requirements of pulmonary administration. In vitro release results showed that the microspheres group released slowly. The cumulative release in 24 h and 10 d was 46.87% and 84.06%, respectively. The in vitro release profile of TDF-PLGA-MS was in accordance with the Weibull model. The results of Pharmacokinetics showed that tadalafil from microspheres slowly released into the blood after intratracheal instillation. The pulmonary drug residue in 0.5 h was 3.5 times compared with solution group. The residual concentration in lung after 10d was still higher than that of solution group in 48 h. The t1/2β and MRT0-∞ were 3.10 times and 3.96 times that of solution group, respectively. Moreover, the Cmax and AUC of drug residues in lung ​​were 3.48 times and 16.36 times that of solution group, respectively. The results of tissue distribution showed that the Re in lung was 16.358, which indicated the lung targeting. In conclusion, the TDF-PLGA-MS for pulmonary administration in this study can significantly improve the pulmonary targeting, increase efficacy of tadalafil and reduce other non-target organs toxicity. This study will have an important clinical significance for PAH patients who need long-term drug therapy.


Subject(s)
Pharmacokinetics , Tadalafil/adverse effects , Pulmonary Arterial Hypertension/drug therapy , Microspheres , Patients/classification , Solubility/drug effects , In Vitro Techniques/instrumentation , Pharmaceutical Preparations/administration & dosage , Drug Therapy , Lung
8.
J. appl. oral sci ; 27: e20180051, 2019. tab, graf
Article in English | LILACS, BBO | ID: biblio-975887

ABSTRACT

Abstract The efficacy of whitening toothpastes is questionable and controversial. Clinicians, patients and researchers have expressed concern with whitening toothpastes due to the risk of wearing the dental structure and the potential for disappointment if the advertised cosmetic results are not achieved. Objective: This study compared the whitening performance of toothpastes with different whitening technologies after initial and continued use. Material and Methods: Ninety bovine incisors were stained using a concentrated solution of black tea. They were randomly distributed into 6 groups, according to the toothpaste whitening technology: activated charcoal (B&W), blue covarine (WAD), hydrogen peroxide (LWA), microbeads (Oral B 3D White Perfection - 3DW) and optimized abrasives (XW4D). They were compared to a traditional toothpaste without a whitening agent (TA - control). Specimens underwent a brushing machine with controlled pressure, time and temperature. A calibrated examiner measured the color using a VITA-Classical scale before the first brushing cycle (T0), after the first brushing cycle (TI), and after a brushing cycle that simulates continuous use (TCU). Whitening performance was evaluated by the difference of shades (ΔSGU) between T0-TI and T0-TCU timepoints, using the Kruskal-Wallis and Dunn's non-parametric test. The Wilcoxon test was used to evaluate the cumulative effect (α=0.05). Results: Statistically significant differences were observed between toothpastes in both TI and TCU (p<0.05). The time of use also had a significant effect (p<0.05). Conclusion: Only WAD and 3DW showed whitening performance after the first use (TI). The greatest whitening performance after continuous use was obtained by WAD, followed by LWA and 3DW. The use of conventional toothpaste (TA) promotes no tooth whitening. Clinical relevance: Microbead abrasives (3DW) and blue covarine (WAD) were the active technology tested that presented the best global tooth whitening performance.


Subject(s)
Animals , Cattle , Tooth Bleaching/methods , Toothpastes/chemistry , Charcoal/chemistry , Isoindoles/chemistry , Tooth Bleaching Agents/chemistry , Hydrogen Peroxide/chemistry , Metalloporphyrins/chemistry , Microspheres , Reference Values , Surface Properties , Time Factors , Tooth/drug effects , Toothbrushing/methods , Random Allocation , Reproducibility of Results
9.
Braz. oral res. (Online) ; 33: e086, 2019. tab, graf
Article in English | LILACS | ID: biblio-1019605

ABSTRACT

Abstract Treatment of patients with bisphosphonate usage is a significant concern for oral surgeons because it interferes with jaw bone turnover and regeneration. In case of adverse effects manifesting related to bisphosphonate use, oral surgeons are usually treating and keep the patient's symptoms under control. In this study, we aimed to investigate a new treatment protocol for medication-related osteonecrosis of the jaw (MRONJ). This treatment protocol consisted of administering human parathyroid hormone (hPTH) loaded chitosan microspheres which were prepared by ionotropic gelation method or/and the prepared microspheres were suspended in a poloxamer gel. After in-vitro optimization studies, the efficacy of the chosen formulations was evaluated in-vivo studies. Zoledronic acid was administered daily to forty-eight adult female Sprague-Dawley rats, divided into four experimental groups, at a daily concentration of 0.11 mg/kg over three weeks to induce the MRONJ model. At the end of this period, maxillary left molar teeth were extracted. In the first group, the subjects received no treatment. In the negative control group, poloxamer hydrogel containing empty microspheres were immediately applied to the soft tissues surrounding the extraction socket. The treatment group-1 was treated with local injections of poloxamer hydrogel containing hPTH. The treatment group-2 was treated with a single local injection of poloxamer hydrogel containing hPTH-loaded chitosan microspheres. Both treatment groups received a total of 7 µg of hPTH at the end of the treatment protocol. Our study demonstrates successful attenuation of MRONJ through a local drug delivery system combined with hPTH, as opposed to previously attempted treatment strategies.


Subject(s)
Humans , Animals , Female , Parathyroid Hormone/pharmacology , Chitosan/pharmacology , Bone Density Conservation Agents/pharmacology , Maxilla/drug effects , Parathyroid Hormone/therapeutic use , Rats, Sprague-Dawley , Poloxamer/administration & dosage , Poloxamer/chemistry , Models, Animal , Delayed-Action Preparations , Chitosan/therapeutic use , Bone Density Conservation Agents/adverse effects , Bone Density Conservation Agents/therapeutic use , Bisphosphonate-Associated Osteonecrosis of the Jaw , Bisphosphonate-Associated Osteonecrosis of the Jaw/drug therapy , Zoledronic Acid/adverse effects , Maxilla/pathology , Microspheres
10.
Article in English | WPRIM | ID: wpr-786505

ABSTRACT

Radioembolization using ⁹⁰Y microspheres (glass or resin) has been introduced as an effective intraarterial therapy for unresectable primary and metastatic liver cancers. Although the basic therapeutic effect of chemoembolization results from ischemia, the therapeutic efficacy of radioembolization comes from radiation. Furthermore, compared with surgical resection and local ablation therapy, radioembolization is available with less limitation on the sites or number of liver cancers. The radioisotope ⁹⁰Y is a β-radiation emitter without γ-radiation, with the emission of secondary bremsstrahlung photons and small numbers of positrons. Administration of ⁹⁰Y microspheres into the hepatic artery can deliver a high dose of radiation selectively to the target tumor with limited radiation exposure to the surrounding normal parenchyma, and has low systemic toxicity. In general, radioembolization has been considered for patients with unresectable primary or metastatic liver-only or liver-dominant cancers with no ascites or other clinical signs of liver failure, life expectancy of > 12 weeks, and good performance status. Here, we review the current radioactive compounds, pretreatment assessment, and indications for radioembolization in patients with hepatocellular carcinoma, intrahepatic cholangiocarcinoma, and liver metastases from colorectal cancer.


Subject(s)
Ascites , Carcinoma, Hepatocellular , Cholangiocarcinoma , Colorectal Neoplasms , Electrons , Hepatic Artery , Humans , Ischemia , Life Expectancy , Liver Failure , Liver Neoplasms , Liver , Microspheres , Neoplasm Metastasis , Photons , Radiation Exposure
11.
Article in English | WPRIM | ID: wpr-786466

ABSTRACT

The foundations of nuclear medicine in Vietnam were established from 1970. Until now, after 48 years of development, in Vietnam, we have some basic equipment including 31 SPECT, 4 SPECT/CT machines, 11 PET/CT scanners, five cyclotrons, and one nuclear reactor.Many nuclearmedicine techniques in diagnosis and treatment have been routinely performed at provincial and central level health facilities such as tumor scintigraphy, thyroid scintigraphy, bone scintigraphy, kidney scintigraphy, cardiac scintigraphy, and radio-isotope therapy with I-131 and P-32. Selective internal radiation therapy with Y-90 microsphere and I-125 radioactive seed implantation has been also successfully applied in some big hospitals. However, there are still many difficulties for Vietnam as the lack of new widely used radioisotopes such as Ga-67, Cu-64, Samarium-153, and Lutetium-177 and the lack of nuclear medicine specialists. In the future, we are putting our efforts on the applications of new isotopes in diagnosis and treatment of cancers (theranostic) like Ga-68-DOTATATE, Lutetium-177-DOTATATE, Ga-68-PSMA, and Lutetium-177-PSMA, equipping modern nuclear medicine diagnostic tools, strengthening the human resources training in nuclear medicine. At the same time, we are trying our best to strengthen the cooperation with international nuclear medicine societies in over the world.


Subject(s)
Cyclotrons , Diagnosis , Foundations , Health Facilities , Humans , Isotopes , Kidney , Microspheres , Nuclear Medicine , Positron Emission Tomography Computed Tomography , Radioisotopes , Radionuclide Imaging , Specialization , Theranostic Nanomedicine , Thyroid Gland , Tomography, Emission-Computed, Single-Photon , Vietnam
12.
Article in English | WPRIM | ID: wpr-786453

ABSTRACT

Nuclear theranostics functions as a bridge which connects targeted diagnosis to targeted therapy, just like Turkey functions as a geographical bridge which connects Asia to Europe. This unique geographical site of the country plays an important role with regard to introduction of novel scientific and technologic improvements, which originate from one continent to another, in the era of accelerated information. The first nuclear medicine practice in Turkey started in the beginning of 1950s with the first radioiodine treatment, which actually was a debut for nuclear theranostics in Turkey, years before many other countries in the world. For the time being, along with radioiodine treatment, many other theranostic applications such as I-131 MIBG treatment, Lu-177/Y-90 DOTA peptide treatment, Lu-177 PSMA treatment, Y-90 microsphere treatment, and bone palliative treatment are being performed in many centers countrywide. As science and technology improves, novel theranostic applications are eagerly awaited to be introduced in near future. This paper summarizes the story of nuclear theranostics in Turkey and aims to give an overview on the current status of theranostic applications in Turkey.


Subject(s)
3-Iodobenzylguanidine , Asia , Diagnosis , Europe , Microspheres , Nuclear Medicine , Palliative Care , Theranostic Nanomedicine , Turkey
13.
Article in English | WPRIM | ID: wpr-762742

ABSTRACT

BACKGROUND: Currently, dermal fillers need to be 25 µm or larger to reduce in vivo degradation by macrophages. However, the large size of fillers may cause side effects, including interruption of blood flow and nodule formation. Therefore, using rats, we tested a polycaprolactone copolymer hydrogel with nanoscale particles that could maintain a low in vivo degradation rate. METHODS: Thirty-six 6-week-old Sprague-Dawley rats were divided into group A (normal saline), group B (polycaprolactone microsphere filler), and group C (polycaprolactone copolymer nanosphere hydrogel). The corresponding materials were injected into the dermal layer of the scalp of the rats. At 4, 8, and 12 weeks after injection, blood biochemical and kidney and liver histological analyses were performed. Tissues were examined using hematoxylin-eosin staining to observe tissue infiltration of materials. Collagen formation in the dermal tissue of the scalp was observed with Masson trichrome staining and the collagen content was quantified using a soluble collagen assay kit. RESULTS: The histologic examination for organ infiltration showed no abnormal findings. All blood test results were within the normal ranges. The amount of collagen at 12 weeks increased by 1.22 mg/g in group C and by 0.6 mg/g in group B. CONCLUSIONS: The results reveal that the nanosphere complex near the injection site induced collagen formation. Regardless of the sphere size, aggregation of the copolymer prevented macrophage phagocytosis. The polycaprolactone copolymer nanosphere hydrogel was effective for more than 3 months when injected in the scalp dermal tissue of Sprague-Dawley rats and can be used safely.


Subject(s)
Animals , Collagen , Dermal Fillers , Hematologic Tests , Hydrogels , Kidney , Liver , Macrophages , Microspheres , Nanospheres , Phagocytosis , Rats , Rats, Sprague-Dawley , Reference Values , Scalp
14.
Article in Chinese | WPRIM | ID: wpr-772683

ABSTRACT

OBJECTIVE@#The purpose of this study is to investigate the effects of different drying methods on the physical properties and drug delivery of chitosan microspheres.@*METHODS@#Three types of drying methods were utilized, including air drying and freeze drying after freezing at -20 ℃ (slow cooling) and at -80 ℃ (fast cooling). The physical properties of microspheres were characterized. Utilizing bovine serum albumin (BSA) as the model drug, the in-vitro release behaviors of drug-loaded beads were investigated.@*RESULTS@#By comparing the physical properties of the different drying methods, the microspheres' diameters, porosities, and surface area were observed to increase successively from air drying and slow cooling to fast cooling, whereas the pore size and the swelling and degradation rates varied. The drug-loading experiments revealed that the loading capacity of air-dried microspheres was the lowest and the release rate was the slowest. Although the loading capacity of fast cooling microspheres was high, an obvious burst release was observed. The loading capacity of slow cooling microspheres was similar to that of the fast cooling microspheres and the loaded BSA can be released continuously.@*CONCLUSIONS@#The results indicate that different drying methods can affect the physical properties of chitosan microspheres, which further influence drug loading and release.


Subject(s)
Chitosan , Drug Carriers , Drug Compounding , Microspheres , Particle Size
15.
Article in English | WPRIM | ID: wpr-719599

ABSTRACT

Conventional transcatheter arterial chemoembolization (c-TACE) is a widely used first-line palliative treatment for patients with unresectable hepatocellular carcinoma (HCC). Despite the effectiveness of c-TACE, to date, technique and procedure scheduling has not yet been standardized. Drug-eluting microspheres (DEMs) were therefore introduced to ensure more sustained and tumor-selective drug delivery for permanent embolization. These DEMs can load various drugs and release them in a sustained manner over a prolonged period. This approach ensures the delivery of high concentrations of chemotherapeutic agents to tumors, without increasing systemic concentrations, and promote tumor ischemia and necrosis. This review summarizes the recent advances in the use of DEM-TACE to treat HCC.


Subject(s)
Carcinoma, Hepatocellular , Humans , Ischemia , Liver , Microspheres , Necrosis , Palliative Care
16.
Article in English | WPRIM | ID: wpr-788032

ABSTRACT

Metastases to the liver can be found in various malignancies, most commonly originating from the colon, rectum, pancreas, stomach, esophagus, breast, lung, and melanoma. Surgical resection of liver metastasis is generally considered to be the definitive therapy fore cure. However, many patients are unable to undergo surgical resection due to medical comorbidities or multifocal extent of malignant disease affecting the liver. Among patients not eligible for surgery, other therapies exist for treatment in order to down stage the disease for surgical resection or for palliation. Radioembolization of hepatic metastases has shown to improve outcomes among patients with variety of malignancies including more common malignancies such as colorectal cancer. Yttrium-90 (Y-90) radioembolization has been successfully used in the management of hepatic metastases. A small series of metastatic sarcoma to the liver treated with radioembolization showed a promising response. We report a case of metastatic gastric leiomyosarcoma to the liver treated with Y-90 glass microspheres therapy using the radiation segmentectomy approach, previously described for hepatocellular carcinoma.


Subject(s)
Breast , Carcinoma, Hepatocellular , Colon , Colorectal Neoplasms , Comorbidity , Esophagus , Glass , Humans , Leiomyosarcoma , Liver , Lung , Mastectomy, Segmental , Melanoma , Microspheres , Neoplasm Metastasis , Pancreas , Rectum , Sarcoma , Stomach
17.
Article in English | WPRIM | ID: wpr-812402

ABSTRACT

In the present study, a gastric retention floating system for Brucea javanica oil, composed of alginate and carrageenan, was prepared using ionotropic gelation. Parameters for floatability, drug load, encapsulation efficiency, bead morphology, in vitro release, and in vivo gastric retention were evaluated. The optimized formulation via Box-Behnken design consisted of 1.7% alginate (W/V), 1.02% carrageenan (W/V), 1.4% CaCO (W/V), and a gelling bath of pH 0.8. The alginate-carrageenan-Brucea javanica oil beads had a porous structure and exhibited up to 24 h of in vitro floatability with a load capacity of 45%-55% and an encapsulation efficiency of 70%-80%. A 6-h sustained release was observed in vitro. The beads had a prolonged gastric retention (> 60% at 6 h) in fasted rats, compared to non-floating beads (15% at 6 h), as measured by gamma scintigraphy with single-photon emission tomography/computed tomography (SPET/CT). In conclusion, the alginate-carrageenan-Brucea javanica oil system showed enhanced oil encapsulation efficiency, excellent floating and gastric retention abilities, and a favorable release behavior.


Subject(s)
Alginates , Chemistry , Animals , Biological Availability , Brucea , Chemistry , Carrageenan , Chemistry , Delayed-Action Preparations , Chemistry , Pharmacokinetics , Drug Carriers , Chemistry , Drug Delivery Systems , Methods , Drug Evaluation, Preclinical , Gastric Mucosa , Metabolism , Glucuronic Acid , Chemistry , Hexuronic Acids , Chemistry , Microspheres , Plant Oils , Chemistry , Pharmacokinetics , Rats , Rats, Sprague-Dawley
18.
Article in English | WPRIM | ID: wpr-691371

ABSTRACT

<p><b>OBJECTIVE</b>To study the effects of Astragalus polysaccharide (APS), the primary effective component of the Chinese herb medicine Astragalus membranaceus (frequently used for its anti-hepatic fibrosis effects), on nanoscale mechanical properties of liver sinusoidal endothelial cells (SECs).</p><p><b>METHODS</b>Using endothelial cell medium as the control, 5 experimental groups were established utilizing different concentrations of APS, i.e. 12.5, 25, 50, 100, and 200 μg/mL. By using atomic force microscopy along with a microcantilever modified with a silicon dioxide microsphere as powerful tools, the value of Young's modulus in each group was calculated. SAS 9.1 software was applied to analyze the values of Young's modulus at the pressed depth of 300 nm. Environmental scanning electron microscopy was performed to observe the surface microtopography of the SECs.</p><p><b>RESULTS</b>The value of Young's modulus in each APS experimental group was significantly greater than that of the control group: as APS concentration increased, the value of Young's modulus presented as an increasing trend. The difference between the low-concentration (12.5 and 25 μg/mL) and high-concentration (200 μg/mL) groups was statistically significant (P<0.05), but no significant differences were observed between moderateconcentration (50 and 100 μg/mL) groups versus low- or high-concentration groups (P>0.05). Surface topography demonstrated that APS was capable of increasing the total area of fenestrae.</p><p><b>CONCLUSIONS</b>The values of Young's modulus increased along with increasing concentrations of APS, suggesting that the stiffness of SECs increases gradually as a function of APS concentration. The observed changes in SEC mechanical properties may provide a new avenue for mechanistic research of anti-hepatic fibrosis treatments in Chinese medicine.</p>


Subject(s)
Animals , Astragalus Plant , Chemistry , Biomechanical Phenomena , Elastic Modulus , Endothelial Cells , Cell Biology , Liver , Cell Biology , Microscopy, Atomic Force , Microspheres , Nanotechnology , Polysaccharides , Pharmacology , Rats , Silicon Dioxide , Chemistry , Surface Properties
19.
Article in English | WPRIM | ID: wpr-714013

ABSTRACT

Radioembolization using beta-emitting yttrium-90 microspheres is being increasingly used for the treatment of primary and metastatic liver cancers. It is a form of intra-arterial brachytherapy which delivers intense radiation to liver tumors with little embolic effect; this mode of action results in unique post-treatment imaging findings. It is important to understand these imaging findings to avoid misinterpretation of tumor response and to determine further management of the disease. Herein, we discuss the current concepts for assessing tumor response, common post-treatment imaging features, and associated complications following radioembolization.


Subject(s)
Brachytherapy , Liver Neoplasms , Liver , Microspheres
20.
Article in English | WPRIM | ID: wpr-773613

ABSTRACT

In the present study, a gastric retention floating system for Brucea javanica oil, composed of alginate and carrageenan, was prepared using ionotropic gelation. Parameters for floatability, drug load, encapsulation efficiency, bead morphology, in vitro release, and in vivo gastric retention were evaluated. The optimized formulation via Box-Behnken design consisted of 1.7% alginate (W/V), 1.02% carrageenan (W/V), 1.4% CaCO (W/V), and a gelling bath of pH 0.8. The alginate-carrageenan-Brucea javanica oil beads had a porous structure and exhibited up to 24 h of in vitro floatability with a load capacity of 45%-55% and an encapsulation efficiency of 70%-80%. A 6-h sustained release was observed in vitro. The beads had a prolonged gastric retention (> 60% at 6 h) in fasted rats, compared to non-floating beads (15% at 6 h), as measured by gamma scintigraphy with single-photon emission tomography/computed tomography (SPET/CT). In conclusion, the alginate-carrageenan-Brucea javanica oil system showed enhanced oil encapsulation efficiency, excellent floating and gastric retention abilities, and a favorable release behavior.


Subject(s)
Alginates , Chemistry , Animals , Biological Availability , Brucea , Chemistry , Carrageenan , Chemistry , Delayed-Action Preparations , Chemistry , Pharmacokinetics , Drug Carriers , Chemistry , Drug Delivery Systems , Methods , Drug Evaluation, Preclinical , Gastric Mucosa , Metabolism , Glucuronic Acid , Chemistry , Hexuronic Acids , Chemistry , Microspheres , Plant Oils , Chemistry , Pharmacokinetics , Rats , Rats, Sprague-Dawley
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