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1.
Nutrients ; 16(8)2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38674880

RESUMO

This study aimed to determine whether patients with type 2 diabetes can benefit from a meal plan designed based on diabetes management guidelines to improve blood glucose levels. Participants were divided into intervention and control groups. The intervention group consumed a diabetic diet for 2 weeks, while the control group consumed their normal diet. After 2 weeks, the groups switched their dietary regimens. The participants' demographic and clinical characteristics were evaluated, including factors such as blood pressure, blood lipid levels, weight and waist circumference, blood glucose levels (self-monitored and continuously monitored), nutritional status, and blood-based markers of nutrient intake. The dietary intervention group improved waist circumference, body fat percentage, low-density lipoprotein cholesterol, triglyceride levels, and glucose. The energy composition ratio of carbohydrates and proteins changed favorably, and sugar intake decreased. In addition, the proportion of continuous glucose monitoring readings within the range of 180-250 mg/dL was relatively lower in the intervention group than that of the control group. Meals designed based on diabetes management guidelines can improve clinical factors, including stable blood glucose levels in daily life, significantly decrease the carbohydrate energy ratio, and increase the protein energy ratio. This study can help determine the role of dietary interventions in diabetes management and outcomes.


Assuntos
Glicemia , Estudos Cross-Over , Diabetes Mellitus Tipo 2 , Refeições , Humanos , Diabetes Mellitus Tipo 2/dietoterapia , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/terapia , Masculino , Feminino , Glicemia/metabolismo , Glicemia/análise , Pessoa de Meia-Idade , Idoso , Dieta para Diabéticos , Ingestão de Energia , Controle Glicêmico/métodos , Estado Nutricional
2.
Clin Nutr Res ; 12(4): 245-256, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37969940

RESUMO

A randomized, double-blind, placebo-controlled trial was conducted to confirm whether collagen peptide supplementation for 12 week has a beneficial effect on body fat control in older adults at a daily physical activity level. Participants were assigned to either the collagen group (15 g/day of collagen peptide) or the placebo group (placebo drink). Body composition was measured by bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DEXA). In total, 74 participants (collagen group, n = 37; placebo group, n = 37) were included in the final analysis. The collagen group showed a significant reduction in total body fat mass compared with the placebo group, as evidenced by both BIA (p = 0.021) and DEXA (p = 0.041) measurements. Body fat mass and percent body fat of the whole body and trunk reduced at 12 weeks compared with baseline only in the collagen group (whole body: body fat mass, p = 0.002; percent body fat, p = 0.002; trunk: body fat mass, p = 0.001; percent body fat, p = 0.000). Total fat mass change (%) (collagen group, -0.49 ± 3.39; placebo group, 2.23 ± 4.20) showed a significant difference between the two groups (p = 0.041). Physical activity, dietary intake, and biochemical parameters showed no significant difference between the groups. The results confirmed that collagen peptide supplementation had a beneficial effect on body fat reduction in older adults aged ≥ 50 years with daily physical activity level. Thus, collagen peptide supplementation has a positive effect on age-related changes.

3.
Behav Sci (Basel) ; 13(10)2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-37887518

RESUMO

Compared to the driving group, the driving cessation group in this study was found to be a high-risk population in terms of their life satisfaction. This study evaluated data from 315 older adults, aged 55 or older, using the 2018 Korean Older Adults Driving and Mobility Service Trend Survey. These data were collected from 17 representative cities and provinces in South Korea. To minimize the potential for selection bias and the confounding factors inherent in observational studies, this study employed the propensity score matching (PSM) method. Following the matching, multivariate regression analyses were conducted to compare the driving cessation group (n = 65) with the driving group (n = 50) in terms of their life satisfaction. After adjusting for demographic and health-related variables, the older adults who had ceased driving were found to have lower life satisfaction (Coef. = -1.39, p-value = 0.018). Our results highlight the importance of establishing preliminary evidence to guide the development of tailored programs for older adults-especially for those likely to experience diminished life satisfaction and heightened risk-to address the mobility challenges stemming from driving cessation.

4.
Nutrients ; 15(6)2023 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-36986111

RESUMO

Considering that Korea's aging population is rapidly increasing, health serves as an indicator of older adults' quality of life, and dietary life directly affects their health. For health maintenance and improvement, preventive healthcare measures including safe food selection and nutritional supply are needed. This study aimed to evaluate the effect of senior-friendly diet on nutrition and health status improvement in older adults receiving community care. A total of 180 older adults were analyzed, with 154 and 26 in the senior-friendly diet intervention group and the general diet group, respectively. Surveys, blood tests, and frailty evaluations were conducted before and after the study. After 5 months of intervention, the blood status, nutrient intake, and frailty level were evaluated. The participants' mean age was 82.7 years, and 89.4% of them were living alone. In both groups, energy, protein, vitamin A, vitamin D, vitamin C, calcium, and magnesium intake were insufficient initially but generally improved after the intervention. Especially in the intervention group, energy, protein, vitamin D, vitamin C, and folic acid intake significantly increased. The frailty level also slightly improved, and the malnutrition rate was reduced. Even after the passage of time, the improvement effect size significantly differed between the groups. Therefore, resolving and supporting meals corresponding to the physiological needs of the older adults has a great impact on improving their quality of life, and such special consideration is a reasonable way to respond to a super-aged society.


Assuntos
Fragilidade , Estado Nutricional , Humanos , Idoso , Idoso de 80 Anos ou mais , Fragilidade/prevenção & controle , Fragilidade/epidemiologia , Vida Independente , Qualidade de Vida , Dieta , Vitamina D , Ácido Ascórbico , Idoso Fragilizado
5.
Nurs Rep ; 13(1): 549-560, 2023 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-36976702

RESUMO

To prevent discontinuity of long-term care service and guarantee the quality of care, it is important to clarify the determinants of turnover intentions of long-term care workers. They are at a higher risk of experiencing violence-including physical, emotional, and sexual-from patients or their families, possibly leading to high turnover intention. This study aims to verify how having experienced client violence affect turnover intention of long-term care workers and to suggest implications to prevent frequent turnover in long-term care field. Logistic regression analysis was conducted between groups who have experienced client violence and who have not, using 2019 Korean LTC Survey data. Results revealed that, first, there were differences in determinants of turnover intention depending on groups. Second, having experienced client violence had a different effect on turnover intention based on personal characteristics. Third, gender and occupational differences were found. Based on our results, we highlighted the need for discussions on interventions to address client violence exposure among long-term care workers.

6.
Healthcare (Basel) ; 10(5)2022 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-35627917

RESUMO

Long-term Care Insurance (LTCI) was created for the elderly, to provide various types of medical and care services, along with the National Health Insurance (NHI). However, the elderly must choose one of these systems, which leads to some of them being unable to receive services and care/medical care based on their needs, because the LTCI only provides limited services, regardless of the needs of the elderly. In order to establish the best solution between the LTCI and NHI, I conducted a utilization effect analysis; using the difference in difference (DID) and difference in difference in difference (DDD) methods with National Health Insurance Services-senior (NHIS-senior) cohort data from 2008 to 2013. The results of the study confirmed that medical expenses are significantly reduced for LTCI users (B = -3.176, p ≤ 0.001). Furthermore, when the services meet the older person's needs, the overall medical expenses are significantly reduced (B = -1.034, p = 0.05). These results clearly show that the LTCI is much more suitable for those who need care services. To provide services that more efficiently fulfil their needs, and for better population coverage from the two different systems (the NHI and the LTCI), collaborative work, such as a linkage system, is required.

7.
Foods ; 11(7)2022 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-35407137

RESUMO

This study evaluates whether blood glucose response differs upon consuming rice cooked in a carbohydrate (carb)-reducing rice cooker. Rice cooked this way exhibited 19% reduced total carbohydrate (34.0 ± 0.3 vs. 27.6 ± 0.9 g/100 g rice) and 20% reduced total calorie (149.0 ± 1.0 vs. 120.8 ± 3.7 kcal/100 g rice) contents. We measured the blood glucose response (at 0, 15, 30, 45, 60, 90, and 120 min) in 13 healthy participants after consuming 6 different rice types: regular white rice (regular WR, 50 g of available carbohydrate (AC)), low-carb WR with equivalent weight as regular WR (low-carb WR (EW)), low-carb WR with equivalent carb as regular WR (low-carb WR (EC), regular mixed-grain rice (regular MR), low-carb MR (EW) as regular MR, and low-carb MR (EC) as regular MR. All rice samples were prepared in an electric carb-reducing rice cooker. Postprandial blood glucose, sensory, and appetite were assessed after each test meal. The incremental area under the curve of 15 and 30 min after rice consumption was significantly lower in low-carb WR (EW) than that in regular WR. These results suggest possible health benefits of low-carb WR in reducing early postprandial spikes in blood glucose level without significant differences in satiety and satisfaction.

8.
J Affect Disord ; 296: 380-387, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34606797

RESUMO

BACKGROUND: Despite the adverse health outcomes of holding negative attitudes toward aging, little attention has been paid to these attitudes' role in mental health among the aging population. OBJECTIVES: Drawing on the stress coping theory, this study examines whether negative attitudes toward aging and low levels of active coping are associated with greater depressive symptoms, and whether active coping attenuates the increased risk of depression caused by negative aging attitudes. We also investigate how these associations differ in middle-aged and older adults. METHODS: A nationwide sample of 500 Koreans aged 55 or above was analyzed. Multivariate linear regression analyses were performed separately by age groups to investigate the independent effects of attitudes toward aging and active coping as well as their interactive effects on depressive symptoms. RESULTS: Our findings showed that more negative attitudes toward aging were related to higher levels of depressive symptoms. There were age group differences in the independent and moderating effects of active coping. For the middle-aged, those with higher levels of active coping had fewer depressive symptoms, while no such significant association was found among older adults. On the contrary, active coping buffered the adverse effects of endorsing negative aging attitudes on depressive symptoms only for the older adult group. LIMITATIONS: A causality cannot be inferred by our findings due to the cross-sectional design. CONCLUSIONS: The findings provide some of the first insights into how one's aging attitudes and coping style may protect against the risk of depression and how it differs by age group.


Assuntos
Envelhecimento , Depressão , Adaptação Psicológica , Idoso , Atitude , Estudos Transversais , Depressão/epidemiologia , Humanos , Pessoa de Meia-Idade , República da Coreia/epidemiologia
9.
Artigo em Inglês | MEDLINE | ID: mdl-34360213

RESUMO

Health literacy is closely associated with poor health outcomes and mortality. However, only a handful of studies have examined the association between health literacy and frailty status. The current study used data from a nationwide sample of Korean adults aged 70-84 collected from 10 cities, each of which represents a different region of South Korea (n = 1521). We used the propensity score matching (PSM) method to minimize the potential selection bias and confounding factors that are present in observational studies. After PSM, demographic and health-related characteristics between the limited health literacy (n = 486) and the nonlimited health literacy (n = 486) groups were not significantly different. Multinomial logistic regression analyses were conducted for the PSM-matched sample to examine the association between health literacy and frailty outcomes, where the robust group was set as a reference. Limited health literacy significantly increased the risk of pre-frailty (RRR = 1.45, p = 0.02) and frailty (RRR = 2.03, p = 0.01) after adjusting for demographic and health-related factors. Our findings underscore the need to foster health literacy programs and provide preliminary evidence to inform tailored intervention programs so that we might attenuate the risk of frailty in the older population.


Assuntos
Fragilidade , Letramento em Saúde , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Estudos Transversais , Idoso Fragilizado , Fragilidade/epidemiologia , Avaliação Geriátrica , Humanos , Vida Independente , República da Coreia/epidemiologia
10.
Genes (Basel) ; 11(8)2020 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-32727090

RESUMO

(1) Background: Autoimmune thyroid diseases (AITDs) are female predominant and much attention has been focused on G protein-coupled receptor 174 (GPR174) and integral membrane protein 2A (ITM2A) on the X chromosome as Grave's disease (GD) susceptible locus. (2) Methods: We genotyped four single nucleotide polymorphisms (SNPs), rs3810712, rs3810711, rs3827440, and rs5912838, of GPR174 and ITM2A in 115 Korean children with AITD (M = 25 and F = 90; GD = 74 (14.7 ± 3.6 years), HD = 41 (13.4 ± 3.2 years); GD-thyroid-associated ophthalmopathy (TAO) = 40, GD-non-TAO=34) and 204 healthy Korean individuals (M = 104 and F = 100). The data were analyzed by sex-stratified or combined. (3) Results: Three SNPs, rs3810712, rs3810711 and rs3827440, were found to be in perfect linkage disequilibrium (D' = 1, r2 = 1). In AITD, HD, GD, GD-TAO, and GD-non-TAO patients, rs3827440 TT/T and rs5912838 AA/A were susceptible and rs3827440 CC/C and rs5912838 CC/C were protective genotypes. When analyzed by sex, rs3827440 TT and rs5912838 AA were susceptible and rs3827440 CC and rs5912838 CC were protective genotypes in female AITD, GD, GD-TAO, and GD-non-TAO subjects. In male AITD patients, rs3827440 T and rs5912838 A were susceptible and rs3827440 C and rs5912838 C were protective genotypes. (4) Conclusions: Polymorphisms in GPR174 and ITM2A genes on the X chromosome might be associated with AITD in Korean children.


Assuntos
Cromossomos Humanos X/genética , Proteínas de Membrana/genética , Polimorfismo de Nucleotídeo Único , Receptores Acoplados a Proteínas G/genética , Tireoidite Autoimune/genética , Adolescente , Estudos de Casos e Controles , Feminino , Predisposição Genética para Doença , Humanos , Masculino , República da Coreia , Tireoidite Autoimune/epidemiologia
11.
Endocrinology ; 161(8)2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32498091

RESUMO

Autoimmune thyroid disease (AITD) is predominant in females and has been focused on the sexual diploid in immune response. The IL-1 receptor-associated kinase 1 (IRAK1) gene on the X chromosome was recently suggested as strong autoimmune disease-susceptible loci, second to the major histocompatibility complex region. We investigated the frequency of IRAK1 single-nucleotide polymorphisms (SNPs) in children with AITD. In this study, we observed that SNPs of IRAK1 including rs3027898, rs1059703, and rs1059702 in 115 Korean AITD pediatric patients (Graves' disease = 74 [females = 52/males = 22]; Hashimoto disease [HD] = 41 [females = 38/males = 3]; thyroid-associated ophthalmopathy [TAO] = 40 (females = 27/males = 13); without TAO = 75 (females = 63/males = 12); total males = 25, total females = 90; mean age = 11.9 years) and 204 healthy Korean individuals (males = 104/females = 100). The data from cases and controls were analyzed from separate sex-stratified or all combined by χ 2 test for categorical variables and Student t test for numerical variables. Our study revealed that SNPs of IRAK1-associated HD and without TAO but Graves' disease and TAO were not found significant. When cases and controls were analyzed by separate sex, we found that rs3027898 AA, rs1059703 AA, and rs1059702 GG showed disease susceptibility in female AITD, HD, and without TAO. Also, all rs3027898, rs1059703, and rs1059702 were found to be in strong linkage disequilibrium (D' = 0.96-0.98, r2 = 0.83-0.97). The haplotype of 3 SNPs was higher in AITD than in controls (CGA, r2 = 5.42, P = 0.019). Our results suggest that IRAK1 polymorphisms may contribute to the pathogenesis of HD, AITD, and without thyroid-associated ophthalmopathy for females.


Assuntos
Doença de Hashimoto/genética , Quinases Associadas a Receptores de Interleucina-1/genética , Polimorfismo de Nucleotídeo Único , Adolescente , Estudos de Casos e Controles , Criança , Pré-Escolar , Cromossomos Humanos X/genética , Feminino , Frequência do Gene , Predisposição Genética para Doença , Doença de Graves/epidemiologia , Doença de Graves/genética , Oftalmopatia de Graves/epidemiologia , Oftalmopatia de Graves/genética , Doença de Hashimoto/epidemiologia , Humanos , Masculino , República da Coreia/epidemiologia
12.
Vet Comp Oncol ; 16(4): 616-621, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30188000

RESUMO

The use of the well-known powerful antioxidant ascorbate has recently become more widespread in human medicine. Intravenous administration of high-dose ascorbate has been demonstrated to exert anticancer effects. It has resulted in effective cell death in vitro and inhibition of tumour growth in vivo. The aim of the current study was to evaluate the effects of high-dose ascorbate on canine melanoma in vitro. Four canine melanoma cell lines, UCDK9M1, UCDK9M3, UCDK9M4 and UCDK9M5 were treated with ascorbate for 2 hours at a range of millimolar concentrations (0-20 mM) to investigate the resulting effects on cell viability. All four canine melanoma cell lines exhibited reduced viability in a dose-dependent manner. Further investigation demonstrated that high-dose ascorbate induced apoptosis via the activation of Bax. These findings suggest that high-dose ascorbate has an anticancer effect on canine melanoma cell lines in vitro. With regard to clinical application, further in vivo investigation should be conducted.


Assuntos
Antineoplásicos/uso terapêutico , Ácido Ascórbico/uso terapêutico , Doenças do Cão/tratamento farmacológico , Melanoma/veterinária , Animais , Antineoplásicos/administração & dosagem , Apoptose/efeitos dos fármacos , Ácido Ascórbico/administração & dosagem , Western Blotting/veterinária , Catalase/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cães , Relação Dose-Resposta a Droga , Citometria de Fluxo/veterinária , Melanoma/tratamento farmacológico
13.
J Biomed Mater Res A ; 105(6): 1637-1645, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28032681

RESUMO

Chitosan, produced from chitin, is one of the polymers with promising applications in various fields. However, despite diverse research studies conducted on its biocompatibility, its uses are still limited. The main reason is the degree of deacetylation (DOD), which represents the proportion of deacetylated units in the polymer and is directly correlated with its biocompatibility property. In this article, the in vivo biocompatibility of three chitosan-hydroxyapatite composite films composed of chitosan with different DOD values was investigated by traditional biological protocols and novel optical spectroscopic analyses. The DOD of the chitosan obtained from three different manufacturers was estimated and calculated by Raman spectroscopy, Fourier transform infrared spectroscopy, and proton nuclear magnetic resonance spectroscopy. The chitosan with the higher DOD induced a higher incidence of inflammation in skin cells. The amino group density, biodegradability, and crystallinity of chitosan are the three possible factors that need to be considered when determining the biocompatibility of the films for in vivo application, as they led to complicated biological results, resulting in either better or worse inflammation even when using chitosan products with the same DOD. This basic study on the relationship between the DOD and inflammation is valuable for the development of further chitosan-based researches. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1637-1645, 2017.


Assuntos
Materiais Biocompatíveis/efeitos adversos , Materiais Biocompatíveis/química , Quitosana/efeitos adversos , Quitosana/química , Durapatita/efeitos adversos , Durapatita/química , Inflamação/induzido quimicamente , Acetilação , Animais , Inflamação/patologia , Espectroscopia de Ressonância Magnética , Masculino , Ratos Sprague-Dawley , Pele/efeitos dos fármacos , Pele/patologia , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Alicerces Teciduais/efeitos adversos , Alicerces Teciduais/química
14.
J Control Release ; 157(3): 493-9, 2012 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-21945679

RESUMO

Macromolecular nanoparticles can extravasate and accumulate within tumor tissues via the passive targeting system, reflecting enhanced permeability and the retention effect. However, the unsatisfactory tumor therapeutic efficacy of the passive-targeting system, attributable to the retention of extravasated nanoparticles in the vicinity of tumor vessels, argues that a new system that facilitates intracellular delivery of nanoparticles within tumors is needed. Here, we developed hydrophobically modified glycol chitosan (HGC) nanoparticles conjugated with interleukin-4 receptor (IL-4R) binding peptides, termed I4R, and tested them in mice bearing IL-4R-positive tumors. These HGC-I4R nanoparticles exhibited enhanced IL-4R-dependent cellular uptake in tumors compared to nonconjugated nanoparticles, leading to better therapeutic and imaging efficacy. We conclude that I4R facilitates and enhances cellular uptake of nanoparticles in tumor tissues. This study suggests that the intracelluar uptake of nanoparticles in tumors is an essential factor to consider in designing nanoparticles for tumor-targeted drug delivery and imaging.


Assuntos
Portadores de Fármacos/administração & dosagem , Nanopartículas/administração & dosagem , Neoplasias/metabolismo , Oligopeptídeos/administração & dosagem , Receptores de Interleucina-4/administração & dosagem , Animais , Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/química , Linhagem Celular Tumoral , Quitosana/administração & dosagem , Quitosana/química , Portadores de Fármacos/química , Humanos , Camundongos , Camundongos Nus , Nanopartículas/química , Transplante de Neoplasias , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Oligopeptídeos/química , Paclitaxel/administração & dosagem , Paclitaxel/química , Receptores de Interleucina-4/química , Carga Tumoral/efeitos dos fármacos
15.
J Control Release ; 144(2): 259-66, 2010 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-20188131

RESUMO

Herein, we evaluated the tumoral low pH targeting characteristics of pH-responsive polymer micelles in cancer targeting therapy. To design the pH-responsive polymeric micelles, hydrophilic methyl ether poly(ethylene glycol) (MPEG) and pH-responsive/biodegradable poly(beta-amino ester) (PAE) were copolymerized using a Michael-type step polymerization, resulting in an MEPG-PAE block copolymer. The amphiphilic MPEG-PAE block copolymer formed polymeric micelles with nano-sized diameter by self-assembly, which showed a sharp pH-dependant micellization/demicellization transition at the tumoral acidic pH value (pH 6.4). For the cancer image and therapy, fluorescence dye, tetramethylrhodamine isothiocyanate (TRITC), or anticancer drug, camptothecin (CPT), was efficiently encapsulated into the pH-responsive polymeric micelles (pH-PMs) by a simple solvent casting method. The TRITC or CPT encapsulated pH-PMs (TRITC-pH-PMs or CPT-pH-PMs) showed rapid release of TRITC or CPT in weakly acidic aqueous (pH 6.4) because they still presented a sharp tumoral acid pH-responsive micellization/demicellization transition. The pH-PMs with 10wt.% of TRITC could deliver substantially more fluorescence dyes to the target tumor tissue in MDA-MB231 human breast tumor-bearing mice, compared to the control polymeric micelles of PEG-poly(l-lactic acid) (PEG-PLLA). Importantly, CPT-pH-PMs exhibited significantly increased therapeutic efficacy with minimum side effects by other tissues in breast tumor-bearing mice, compared to free CPT and CPT encapsulated PEG-PLLA micelles. The tumoral acidic pH-responsive polymeric micelles are highly useful for cancer targeting therapy.


Assuntos
Ácidos/uso terapêutico , Ésteres/uso terapêutico , Micelas , Neoplasias/tratamento farmacológico , Polímeros/uso terapêutico , Animais , Camptotecina/uso terapêutico , Humanos , Lactatos , Ácido Láctico/uso terapêutico , Camundongos , Camundongos Nus , Neoplasias/patologia , Polietilenoglicóis/uso terapêutico
16.
Bioconjug Chem ; 21(2): 208-13, 2010 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-20073455

RESUMO

Herein, we prepared tumor-targeting peptide (AP peptide; CRKRLDRN) conjugated pH-responsive polymeric micelles (pH-PMs) in cancer therapy by active and pH-responsive tumor targeting delivery systems, simultaneously. The active tumor targeting and tumoral pH-responsive polymeric micelles were prepared by mixing AP peptide conjugated PEG-poly(d,l-lactic acid) block copolymer (AP-PEG-PLA) into the pH-responsive micelles of methyl ether poly(ethylene glycol) (MPEG)-poly(beta-amino ester) (PAE) block copolymer (MPEG-PAE). These mixed amphiphilic block copolymers were self-assembled to form stable AP peptide-conjugated and pH-responsive AP-PEG-PLA/MPEG-PAE micelles (AP-pH-PMs) with an average size of 150 nm. The AP-pH-PMs containing 10 wt % of AP-PEG-PLA showed a sharp pH-dependent micellization/demicellization transition at the tumoral acid pH. Also, they presented the pH-dependent drug release profile at the acidic pH of 6.4. The fluorescence dye, TRITC, encapsulated AP-pH-PMs (TRITC-AP-pH-PMs) presented the higher tumor-specific targeting ability in vitro cancer cell culture system and in vivo tumor-bearing mice, compared to control pH-responsive micelles of MPEG-PAE. For the cancer therapy, the anticancer drug, doxorubicin (DOX), was efficiently encapsulated into the AP-pH-PMs (DOX-AP-pH-PMs) with a higher loading efficiency. DOX-AP-pH-PMs efficiently deliver anticancer drugs in MDA-MB231 human breast tumor-bearing mice, resulted in excellent anticancer therapeutic efficacy, compared to free DOX and DOX encapsulated MEG-PAE micelles, indicating the excellent tumor targeting ability of AP-pH-PMs. Therefore, these tumor-targeting peptide-conjugated and pH-responsive polymeric micelles have great potential application in cancer therapy.


Assuntos
Portadores de Fármacos/química , Micelas , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Oligopeptídeos/química , Sequência de Aminoácidos , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Doxorrubicina/química , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Portadores de Fármacos/metabolismo , Portadores de Fármacos/farmacocinética , Humanos , Concentração de Íons de Hidrogênio , Camundongos , Oligopeptídeos/metabolismo , Polietilenoglicóis/química , Polímeros/química , Fatores de Tempo , Distribuição Tecidual
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