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1.
NPJ Prim Care Respir Med ; 34(1): 23, 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39164292

RESUMO

Electronic inhalers provide information about patterns of routine inhaler use. During a 12-week study, 360 asthma patients using albuterol Digihaler generated 53,083 inhaler events that were retrospectively analyzed. A total of 41,528 (78%) of the recorded inhalation events were suitable for flow analysis (having a PIF ≥ 18 L/min and <120 L/min). Median PIF, inhalation volume, inhalation duration, and time to PIF for these events steadily decreased between the first and last 10 days of the study, by 5.1%, 12.6%, 15.9%, and 6.4%, respectively. Continuous short-acting beta2-agonist (SABA) overuse, defined as ≥2 SABA inhalations/week throughout the study period, was seen in 29% (n = 104) of patients. Of 260 patients with ≥1 instance of acute short-term SABA overuse, 55 (21%) had a confirmed exacerbation. Electronic recording of real-life inhaler use can capture valuable, objective information that could inform disease management and clinical decision-making.


Assuntos
Asma , Nebulizadores e Vaporizadores , Humanos , Asma/tratamento farmacológico , Masculino , Feminino , Estudos Retrospectivos , Pessoa de Meia-Idade , Adulto , Administração por Inalação , Albuterol/administração & dosagem , Albuterol/uso terapêutico , Broncodilatadores/administração & dosagem , Broncodilatadores/uso terapêutico , Idoso , Adulto Jovem , Agonistas de Receptores Adrenérgicos beta 2/administração & dosagem , Agonistas de Receptores Adrenérgicos beta 2/uso terapêutico , Adolescente
2.
Cureus ; 16(6): e61483, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38952601

RESUMO

This research study explores of the effectiveness of a machine learning image classification model in the accurate identification of various types of brain tumors. The types of tumors under consideration in this study are gliomas, meningiomas, and pituitary tumors. These are some of the most common types of brain tumors and pose significant challenges in terms of accurate diagnosis and treatment. The machine learning model that is the focus of this study is built on the Google Teachable Machine platform (Alphabet Inc., Mountain View, CA). The Google Teachable Machine is a machine learning image classification platform that is built from Tensorflow, a popular open-source platform for machine learning. The Google Teachable Machine model was specifically evaluated for its ability to differentiate between normal brains and the aforementioned types of tumors in MRI images. MRI images are a common tool in the diagnosis of brain tumors, but the challenge lies in the accurate classification of the tumors. This is where the machine learning model comes into play. The model is trained to recognize patterns in the MRI images that correspond to the different types of tumors. The performance of the machine learning model was assessed using several metrics. These include precision, recall, and F1 score. These metrics were generated from a confusion matrix analysis and performance graphs. A confusion matrix is a table that is often used to describe the performance of a classification model. Precision is a measure of the model's ability to correctly identify positive instances among all instances it identified as positive. Recall, on the other hand, measures the model's ability to correctly identify positive instances among all actual positive instances. The F1 score is a measure that combines precision and recall providing a single metric for model performance. The results of the study were promising. The Google Teachable Machine model demonstrated high performance, with accuracy, precision, recall, and F1 scores ranging between 0.84 and 1.00. This suggests that the model is highly effective in accurately classifying the different types of brain tumors. This study provides insights into the potential of machine learning models in the accurate classification of brain tumors. The findings of this study lay the groundwork for further research in this area and have implications for the diagnosis and treatment of brain tumors. The study also highlights the potential of machine learning in enhancing the field of medical imaging and diagnosis. With the increasing complexity and volume of medical data, machine learning models like the one evaluated in this study could play a crucial role in improving the accuracy and efficiency of diagnoses. Furthermore, the study underscores the importance of continued research and development in this field to further refine these models and overcome any potential limitations or challenges. Overall, the study contributes to the field of medical imaging and machine learning and sets the stage for future research and advancements in this area.

4.
Pathogens ; 12(11)2023 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-38003804

RESUMO

Lactobacillus rhamnosus (LBS) is a well-documented probiotic strain in oncology and has a pivotal role in clinical applications. Here, we have investigated the protective effect of Lactobacillus rhamnosus on intestinal mucositis induced by cisplatin (CP) and explored the underlying mechanisms targeting inflammatory proteins, as well as the histological changes in the intestinal tissue of mice, in addition, the bacterial strains that may be related to the health-enhancing properties. BALB/c mice were pre-treated with or without LBS via oral gavage, followed by mucositis induction with cisplatin. Our results revealed that the LBS-treated groups significantly attenuated proinflammatory cytokine levels (IL-1ß, IL-6, and TNF-α) compared to the CP group. Furthermore, LBS mitigated the damaged tight junction integrity caused by CP via up-regulating the levels of claudin, occludin, ZO-1, and mucin-2 protein (MUC-2). Finally, the 16S rRNA fecal microbiome genomic analysis showed that LBS administration enhanced the growth of beneficial bacteria, i.e., Firmicutes and Lachnospiraceae, while the relative abundance of the opportunistic bacteria Bacteroides and Proteobacteria decreased. Collectively, LBS was found to beneficially modulate microbial composition structure and functions and enrich the ecological diversity in the gut.

5.
Molecules ; 28(19)2023 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-37836692

RESUMO

Inflammatory bowel disease (IBD) is a persistent, lifelong inflammation of the digestive system. Dextran sulfate sodium is commonly used to induce colitis in experimental animal models, which causes epithelial damage, intestinal inflammation, mucin depletion, and dysbiosis of the gut microbiota. Various prebiotics, polysaccharides, and polypeptides are used for IBD treatment. In this study, we used a murine model utilizing BALB/c mice, with 10 mice per group, to investigate the treatment effect of sea conch peptide hydrolysate (CPH) on DSS-induced colitis mice. Colitis was induced through the administration of 2.5% DSS in drinking water over a seven-days period. Furthermore, on the eighth day of the experiment, sea conch peptide hydrolysate (CPH) at low (100 mg/kg), medium (200 mg/kg), and high (400 mg/kg) doses, which were continued for 14 days, were assessed for medicinal purposes in DSS-induced colitis mice. Our results showed that CPH treatment significantly alleviated the severity and symptoms of colitis. The epithelial integrity and histological damage were improved. Intestinal inflammation and inflammatory cell infiltration were improved. Furthermore, the expression of pro-inflammatory cytokines was reduced, and intestinal barrier integrity was restored by elevating the tight junction proteins. Moreover, 16s RNA sequencing revealed dysbiosis of the gut microbiota was observed upon DSS treatment, which was reinstated after CPH treatment. An increased level of Firmicutes and Lactobacillus was observed in the treatment groups. Finally, our results suggest that CPH would be recommended as a functional food source and also have the potential to be used as a medicinal product for different gastrointestinal disorders.


Assuntos
Colite , Microbioma Gastrointestinal , Doenças Inflamatórias Intestinais , Camundongos , Animais , Disbiose/induzido quimicamente , Disbiose/tratamento farmacológico , Colite/induzido quimicamente , Colite/tratamento farmacológico , Doenças Inflamatórias Intestinais/patologia , Citocinas/metabolismo , Inflamação/patologia , Sulfato de Dextrana/efeitos adversos , Camundongos Endogâmicos C57BL , Modelos Animais de Doenças , Colo/metabolismo
6.
J Allergy Clin Immunol Pract ; 11(9): 2781-2791.e4, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37182565

RESUMO

BACKGROUND: With the expanding treatment landscape for asthma, the process of identifying best-fit, individualized management options is becoming increasingly complicated. Understanding patients' preferences can inform shared decision-making between clinicians and patients. OBJECTIVES: To examine preferences of adults with asthma for therapeutic and management attributes and determine how these preferences vary among patients. METHODS: We conducted an online discrete choice experiment survey in US adults with asthma. Patient preferences were analyzed using logit models. Factors affecting patients' preferences were identified by least absolute shrinkage and selection operator analysis. RESULTS: A total of 1,184 patients completed the survey (60% female; mean [SD] age, 49.2 [15.0] years). Patients most valued fewer asthma attacks requiring urgent health care professional visits, fewer exacerbations requiring oral corticosteroids, and a reduced risk for oral thrush. Higher value was placed on reducing the risk of short-term (oral thrush) versus long-term side effects (diabetes). Patients were willing to increase rescue medication use in exchange for decreasing exacerbations requiring oral corticosteroids and attacks requiring urgent health care professional visits. Patients preferred a single inhaler for rescue and maintenance and least valued asthma action plans. Demographic, socioeconomic, and clinical factors affected patient preferences. CONCLUSIONS: Patients sought convenient management options that focused mainly on decreasing the short-term morbidity associated with asthma exacerbations and therapies. Preferences varied by demographics, clinical factors, and socioeconomics. It is important for shared decision-making discussions to include conversations about morbidity and how available therapeutic options align with individual patient preferences.


Assuntos
Antiasmáticos , Asma , Adulto , Humanos , Feminino , Pessoa de Meia-Idade , Masculino , Preferência do Paciente , Asma/tratamento farmacológico , Corticosteroides/uso terapêutico , Nebulizadores e Vaporizadores , Gerenciamento Clínico , Antiasmáticos/uso terapêutico
7.
Front Nutr ; 9: 984695, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36276816

RESUMO

Type 2 diabetes mellitus (T2DM) is a health issue that causes serious worldwide economic problems. It has previously been reported that natural polysaccharides have been studied with regard to regulating the gut microbiota, which plays an important role in T2DM. Here, we investigate the effects of Morchella esculenta polysaccharide (MEP) on a high-fat diet (HFD) and streptozotocin (STZ)-induced T2DM in BALB/c mice. The administration of MEP effectively regulated hyperglycemia and hyperlipidemia and improved insulin sensitivity. We also determined an improvement in gut microbiota composition by 16sRNA pyrosequencing. Treatment with MEP showed an increase in beneficial bacteria, i.e., Lactobacillus and Firmicutes, while the proportion of the opportunistic bacteria Actinobacteria, Corynebacterium, and Facklamia decreased. Furthermore, the treatment of T2DM mice with MEP resulted in reduced endotoxemia and insulin resistance-related pro-inflammatory cytokines interleukin 1ß (IL-1ß), tumor necrosis factor-alpha (TNF-α), and interleukin 6 (IL-6). Moreover, MEP treatment improved intestinal permeability by modulating the expression of the colon tight-junction proteins zonula occludens-1 (ZO-1), occludin, claudin-1, and mucin-2 protein (MUC2). Additionally, MEP administration affects the metagenome of microbial communities in T2DM mice by altering the functional metabolic pathways. All these findings suggested that MEP is a beneficial prebiotic associated with ameliorating the gut microbiota and its metabolites in T2DM.

8.
J Asthma Allergy ; 15: 1511-1526, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36313858

RESUMO

Purpose: The US National Asthma Education and Prevention Program updates and Global Initiative for Asthma report encourage considering the patient perspective to improve asthma control. The objective of the present study was to collect data about the perceptions, experiences, and concerns of adult patients and caregivers of children with asthma regarding rescue, maintenance, and oral corticosteroid treatments. Patients and Methods: In-person focus groups were conducted in three cities across the US. Participants also completed patient-reported outcome measures assessing asthma control and experiences. Results: Focus groups were conducted in demographically and clinically diverse adults with asthma (five groups, n=34), caregivers of children with asthma (five groups, n=35), and adults with a dual diagnosis of asthma and chronic obstructive pulmonary disease (one group, n=5). Only 28% of patients were well-controlled by Asthma Control Test/Asthma Control Test-Caregiver Report and 18% by Asthma Impairment and Risk Questionnaire. Forty-four percent of participants reported not following their prescribed medical plan. Four key themes emerged from the focus groups: (1) asthma symptom control and monitoring are often inadequate; (2) treatments are often used incorrectly; (3) communication between health care professionals and patients or caregivers is often ineffective; and (4) concerns related to treatment and desires to improve treatment. Conclusion: Control of asthma symptoms is suboptimal in the vast majority of patients and both patients and caregivers do not feel sufficiently informed about asthma. Health care providers should be encouraged to engage patients and caregivers in shared decision making for managing asthma and selecting treatments that integrate patient values, preferences, and lifestyles.

9.
Gut Pathog ; 14(1): 39, 2022 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-36115959

RESUMO

Type-1 Diabetes Mellitus (T1DM) is regarded as a multifunctional, immune-related disease which causes massive destruction of islet ß-cells in pancreas resulting in hyperglycemic, hypoinsulinemia and hyperlipidimic conditions. The aim of the present study, was to investigate the hypothesis that streptozotocin (STZ)-induced T1DM in Balb/c mice when treated with crude polysaccharide from seaweed, Dictyopteris divaricata (CDDP) depicts improvement in diabetes-related symptoms. Treatment with CDDP resulted in decreased body weight loss, improved food consumption and water intake disbalances. The CDDP effectively improved fasting blood glucose, oral glucose tolerance (OGTT), serum insulin, insulin secretion, rejuvenation of ß-cells mass, serum lipid profile and pro-inflammatory cytokines levels. Additionally, treatment with CDDP increased the population of beneficial bacteria such as Firmicutes, Bacteroidetes and Lactobacillus at phylum, family and genus levels by 16S rRNA sequencing. Furthermore, immunohistological examination confirmed that CDDP reduces the inflammation and restored the structural morphology of colon and upraised the levels of insulin receptor substrate-1 (IRS-1), Mucin-2 (MUC-2) and tight-junction proteins (TJs) whereby maintaining the gut structures and barrier permeability. Thus, the above presented data, highlights the safe and therapeutic effects of crude polysaccharide (CDDP) from D. divaricata in the treatment and restoration of T1DM disorders and can be used as a food supplement alternative to diabetes medicine.

10.
J Food Biochem ; 46(9): e14251, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35633198

RESUMO

Bioactive peptides are naturally found in various foods and were shown to have various distinct physiological as well as medicinal benefits. In this study shrimp peptide hydrolysate (SPH) was prepared to investigate its immunomodulatory effect against cyclophosphamide (CTX) induced immunosuppressed mice. The SPH effect was also analyzed on murine macrophage (RAW264.7 cells). The findings show that SPH stimulates macrophages to form multiple pseudopodia, has no cytotoxic effect, and increases phagocytic activity in RAW264.7 cells. Furthermore, the immunosuppressed in-vivo model illustrates the improvement in various aspects, that is body weight, escalation in immune organ index, and ameliorates histopathological transformation of thymus along with the spleen. SPH enhances cell-mediated immunity by facilitating splenocyte proliferation and inhibit excessive apoptosis. Moreover, the significant outcome had been observed with the upregulation of cytokines interferon-gamma (IFN-ϒ), interleukin-2 (IL-2) level and simultaneously downregulate certain genes include interleukin-4 (IL-4) and interleukin-10 (IL-10). Additionally, SPH expedites cellular immunity by enhancing the regulation of immunoglobulin A (IgA) and immunoglobulin M (IgM). However, these findings support the hypothesis that SPH is an effective immunomodulatory agent capable of preventing immune system hypofunction. It is necessary to investigate the detailed mechanism to rule out any unforeseen effects of SPH in future research. PRACTICAL APPLICATIONS: Chemotherapy medications, despite their dominating detrimental effects of damaging immunological organs such as the spleen and thymus, extend the treatment process as well as the destruction of the self-immune system. This study found that SPH is an effective immunomodulatory agent capable of avoiding immune organ hypofunction and improving cell mediate immunity by enhancing macrophage activation, phagocytosis, spleenocyte proliferation, suppressing apoptosis, and elevating cytokines and antibodies. As a result, SPH can be utilized as a nutritional and functional dietary supplement to boost immunological modulation in combination with chemotherapy medications in order to lessen their adverse effects.


Assuntos
Hospedeiro Imunocomprometido , Fatores Imunológicos , Animais , Ciclofosfamida/efeitos adversos , Citocinas , Modelos Animais de Doenças , Imunidade , Fatores Imunológicos/farmacologia , Camundongos , Peptídeos/farmacologia
11.
Molecules ; 27(5)2022 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-35268821

RESUMO

The gut microbiota is important in regulating host metabolism, maintaining physiology, and protecting immune homeostasis. Gut microbiota dysbiosis affects the development of the gut microenvironment, as well as the onset of various external systemic diseases and metabolic syndromes. Cyclophosphamide (CTX) is a commonly used chemotherapeutic drug that suppresses the host immune system, intestinal mucosa inflammation, and dysbiosis of the intestinal flora. Immunomodulators are necessary to enhance the immune system and prevent homeostasis disbalance and cytotoxicity caused by CTX. In this study, shrimp peptide hydrolysate (SPH) was evaluated for immunomodulation, intestinal integration, and microbiota in CTX-induced immunosuppressed mice. It was observed that SPH would significantly restore goblet cells and intestinal mucosa integrity, modulate the immune system, and increase relative expression of mRNA and tight-junction associated proteins (Occludin, Zo-1, Claudin-1, and Mucin-2). It also improved gut flora and restored the intestinal microbiota ecological balance by removing harmful microbes of various taxonomic groups. This would also increase the immune organs index, serum levels of cytokines (IFN-ϒ, IL1ß, TNF-α, IL-6), and immunoglobin levels (IgA, IgM). The Firmicutes/Bacteroidetes proportion was decreased in CTX-induced mice. Finally, SPH would be recommended as a functional food source with a modulatory effect not only on intestinal microbiota, but also as a potential health-promoting immune function regulator.


Assuntos
Microbioma Gastrointestinal , Animais , Ciclofosfamida/efeitos adversos , Disbiose/metabolismo , Imunidade , Mucosa Intestinal/metabolismo , Camundongos , Peptídeos/farmacologia
12.
AMB Express ; 11(1): 160, 2021 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-34855004

RESUMO

Hepatocellular carcinoma is one of the leading causes of cancer-associated death across the globe. Malignant ascites are the major clinical attributes in cancer patients. Despite the advancements in HCC treatments such as chemotherapy, radiotherapy, surgery, and hormonal therapy, researchers are pursuing novel natural edible compounds for the treatment of cancer to eliminate dreadful side effects. Pleurotus ostreatus is one of the most edible cuisines in Asia as well as all over the world. It has been a source of nutritious diet since it was classified as an edible mushroom with no or negligible side effects. The present study focused on the natural anti-cancerous and anti-ascites capabilities of polysaccharides extracted from Pleurotus ostreatus in-vivo as well as in-vitro. Administration of polysaccharide Pleurotus ostreatus showed a significant decrease in tumor cell metastasis while the increase in the survival period among mice models of H22 malignant ascites. Downregulation of regenerative genes Foxp3 and Stat3 and secretion of immunological factors such as IL-2, TNF α, and INF γ were observed after treating with the partially pure extracted polysaccharide. Twining with the hypothesis of tumor suppression in-vivo model polysaccharide showed a decrease in invasion and migration abilities and henceforth responsible for the gene regulation such Cytochrome C which supposedly induced the chain of gene regulation process resulting in apoptosis in HCC cell lines observed in-vitro experiments. Collective research findings manifested that polysaccharide extracted from Pleurotus ostreatus bears anti-proliferative activity and thus influence tumor suppression in-vivo and in-vitro against hepatocellular carcinoma and can be used for therapeutic purposes as a potential anti-cancerous source in the future.

13.
Ann Allergy Asthma Immunol ; 120(4): 395-400.e1, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29452259

RESUMO

BACKGROUND: Mobile health applications for asthma are increasingly being developed. However, there are no published randomized controlled trials evaluating efficacy in decreasing exacerbations. OBJECTIVE: To evaluate the impact of a mobile asthma application for asthma-related urgent health care usage. METHODS: We conducted a 6-month prospective randomized controlled trial for patients (6 months-21 years old) with persistent asthma presenting with an asthma exacerbation to the emergency department of a pediatric academic medical center. Participants were randomized to AsthmaCare (application providing medication and trigger reminders and treatment plan) or the control (online asthma information). Primary outcome measures were comparison of emergency department and urgent care visits and hospitalizations 6 months before and after randomization. RESULTS: AsthmaCare participants (n = 98) were slightly older (7.84 vs 6.24 years; P = .02) than controls (n = 95) but similar for sex (55% vs 62% boys), race (83% vs 77% African American), and insurer (89% vs 98% Medicaid). The 2 groups were similar in having more than 2 comorbidities (34% vs 32%) and receiving National Heart, Lung, and Blood Institute step 3 treatment or higher (69% vs 57%). There was no significant decrease in emergency department or urgent care visits or hospitalizations between the intervention and control groups. AsthmaCare participants were more likely to report improvement in asthma management 6 months after study enrollment (79% vs 64%; P = .06). CONCLUSION: This randomized controlled trial did not demonstrate a significant decrease in asthma-related emergency department visits or hospitalizations among children who used a mobile health application. TRIAL REGISTRATION: ClinicalTrials.gov, Identifier NCT02333630.


Assuntos
Asma/terapia , Aplicativos Móveis , Adolescente , Adulto , Assistência Ambulatorial/estatística & dados numéricos , Criança , Pré-Escolar , Serviço Hospitalar de Emergência/estatística & dados numéricos , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Lactente , Masculino , Telemedicina , Adulto Jovem
16.
Virtual Mentor ; 13(3): 152-5, 2011 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-23127314
17.
Am J Med Sci ; 338(1): 45-7, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19593103

RESUMO

Osteoporosis and heart failure are 2 highly prevalent conditions, particularly among the elderly, both of which account for significant morbidity and mortality. In this review, we describe the epidemiology of osteoporosis and osteoporotic-related fractures in persons with heart failure. A review of the current literature regarding shared risk factors for heart failure and osteoporosis is presented, and potential common pathophysiologic mechanisms for these disorders are discussed.


Assuntos
Fraturas Ósseas , Insuficiência Cardíaca , Osteoporose , Idoso , Fraturas Ósseas/etiologia , Fraturas Ósseas/patologia , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/fisiopatologia , Humanos , Osteoporose/complicações , Osteoporose/epidemiologia , Osteoporose/fisiopatologia , Fatores de Risco
18.
J Biomed Mater Res A ; 90(1): 70-81, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18481785

RESUMO

The development and characterization of collagen-coupled poly(ethylene glycol)/poly(acrylic acid) (PEG/PAA) interpenetrating polymer network hydrogels is described. Quantitative amino acid analysis and FITC-labeling of collagen were used to determine the amount and distribution of collagen on the surface of the hydrogels. The bioactivity of the coupled collagen was detected by a conformation-specific antibody and was found to vary with the concentration of collagen reacted to the photochemically functionalized hydrogel surfaces. A wound healing assay based on an organ culture model demonstrated that this bioactive surface supports epithelial wound closure over the hydrogel but at a decreased rate relative to sham wounds. Implantation of the hydrogel into the corneas of live rabbits demonstrated that epithelial cell migration is supported by the material, although the rate of migration and morphology of the epithelium were not normal. The results from the study will be used as a guide toward the optimization of bioactive hydrogels with promise in corneal implant applications such as a corneal onlay and an artificial cornea.


Assuntos
Materiais Biocompatíveis , Epitélio Corneano , Hidrogéis , Polímeros , Cicatrização , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/metabolismo , Bovinos , Linhagem Celular , Colágeno/genética , Colágeno/metabolismo , Epitélio Corneano/metabolismo , Epitélio Corneano/patologia , Humanos , Hidrogéis/química , Hidrogéis/metabolismo , Teste de Materiais , Polímeros/química , Polímeros/metabolismo , Coelhos , Propriedades de Superfície , Técnicas de Cultura de Tecidos
19.
Curr Eye Res ; 33(1): 29-43, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18214741

RESUMO

Epithelialization of a keratoprosthesis requires that the implant material be sufficiently permeable to glucose. We have developed a poly(ethylene glycol)/poly(acrylic acid) (PEG/PAA) interpenetrating polymer network (IPN) hydrogel that can provide adequate passage of glucose from the aqueous humor to the epithelium in vivo. A series of PEG/PAA IPNs with varying PEG macromonomer molecular weights were synthesized and evaluated through swelling studies to determine their water content and diffusion experiments to assess their permeability to glucose. One of the PEG/PAA hydrogels prepared in this study had a glucose diffusion coefficient nearly identical to that of the human cornea (approximately 2.5 x 10(-6) cm(2)/sec). When implanted intrastromally in rabbit corneas, this hydrogel was retained and well-tolerated in 9 out of 10 cases for a period of 14 days. The retained hydrogels stayed optically clear and the epithelium remained intact and multilayered, indicating that the material facilitated glucose transport from the aqueous humor to the anterior part of the eye. The results from these experiments indicate that PEG/PAA hydrogels are promising candidates for corneal implant applications such as keratoprostheses and intracorneal lenses, and that the PEG/PAA IPN system in general is useful for creating permeable substrates for ophthalmic and other biomedical applications.


Assuntos
Órgãos Artificiais , Substância Própria/cirurgia , Glucose/metabolismo , Hidrogéis/metabolismo , Próteses e Implantes , Implantação de Prótese , Animais , Permeabilidade , Projetos Piloto , Coelhos
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