Development and validation of a risk prediction model for the recurrence of foot ulcer in type 2 diabetes in China: A longitudinal cohort study based on a systematic review and meta-analysis.

AIMS: To develop and validate a risk prediction model for Chinese patients with type 2 diabetes with the recurrence of diabetic foot ulcers (DFUs) based on a systematic review and meta-analysis. METHODS: A prospective analysis was performed with 1333 participants and followed up for 60 months. Three models were analysed using a derived cohort. The risk factors were screened using meta-analysis and logistic regression, and the missing variables were interpolated by multiple imputation. The internal validation was performed using the bootstrap procedure, and the validation cohort was applied to the external validation. The performance of the model was evaluated in the area under the discrimination Receiver Operating Characteristic Curve (ROC). Calibration and discrimination methods were used for the validation cohort. The variables were selected according to their clinical and statistical importance to construct the nomograms. RESULTS: Three models were developed and validated. Model 1 included seven social and clinical indicators like sex, diabetes mellitus duration, previous DFU, location of ulcer, smoking, history of amputation, and foot deformity. Model 2 included four more indicators besides those in Model 1, which were statin agents used, antiplatelet agents used, systolic blood pressure, and body mass index. Model 3 added further laboratory indicators to Model 2, such as LDL-C, HbA1C, fibrinogen, and blood urea nitrogen. In the derivation cohort, 20.1% (206/1027) participants with DFU recurred as compared to the validation cohort, which was 38.2% (117/306). The areas under the curve in the derivation cohort for Models 1-3 were 0.781 (0.744-0.817), 0.843 (0.813-0.873), and 0.899 (0.876-0.922), respectively. The Youden indexes for Models 1-3 were 0.430, 0.559, and 0.653, respectively. Model 3 showed the highest sensitivity and specificity. All models performed well for both discrimination and calibration. CONCLUSIONS: Models 1-2 were non-invasive, which indicate their role in general screening for patients at a high risk of recurrence of DFU. However, Model 3 offers a more specific screening due to its best performance in predicting the risk of DFU recurrence amongst the three models.

Association between polyunsaturated fatty acids and progression among patients with diabetic kidney disease.

AIMS: Diabetic kidney disease (DKD) is the major complication of diabetes mellitus (DM) and one of the leading causes of end-stage renal disease. Early detection and treatment are contributing to delay the progression of DKD. Dietary management has potential benefits for DKD, especially the intake of polyunsaturated fatty acids (PUFAs). However, there is a lack of sufficient evidence, so we aimed to explore the association between PUFAs intake and DKD progression. METHODS: In the National Heath and Nutrition Examination Survey (NHANES) between 2011-2018, a cross-sectional study was conducted among adults with T2DM. DKD was diagnosed with urine albumin to creatinine ratio (ACR) ≥ 30 mg/g or estimated glomerular filtration rate (eGFR) ＜60 ml/min/1.73 m2. Using Survey package of R to arrange the collected PUFAs intake data in order from small to large and divide them into four equal parts, which were expressed as Q1, Q2, Q3 and Q4 respectively. To investigate the association between PUFAs intake and DKD, a weighted univariate logistic regression analysis was performed and the odds ratio (OR) and 95% confidence interval (CI) were calculated for the association with DKD and PUFAs quartiles. RESULTS: The study involved 3287 participants with T2DM, including 2043 non-DKD and 1244 DKD patients. The results showed that the intake of PUFAs was a protective factor for DKD (p = 0.022), and with the increase of the PUFAs, renal function improved in DKD patients, the adjusted mean of eGFR and Scr changing from 57 (41, 86) in Q1 to 71 (55, 101) ml/min in Q4 (p 0.001), 103 (73, 131) in Q1 to 90 (68, 117) in Q4 (p = 0.031), respectively. CONCLUSION: Our study indicated that intake of more PUFAs may contribute to delay DKD progression, while different n-6/n-3 ratios need to be explored to protect the kidney.

Alleviating vascular calcification with Bushen Huoxue formula in rats with chronic kidney disease by inhibiting the PTEN/PI3K/AKT signaling pathway through exosomal microRNA-32.

BACKGROUND: Vascular calcification (VC) significantly raises cardiovascular mortality in chronic kidney disease (CKD) patients. VC is characterized by the phenotypic transformation of vascular smooth muscle cells (VSMCs) to osteoblast-like cells, mediated by exosomes derived from calcified VSMCs and the exosomal microRNAs (miRNA) which may trigger some signals to recipient VSMCs. Bushen Huoxue (BSHX) formula has demonstrated its clinical efficacy in CKD and its protective role in CKD-VC rats has also been observed. However, little is known about its underlying mechanism. METHODS: To establish a VC model, aortic VSMCs from rats were induced to osteogenic differentiation by high-level phosphate (HP) in vitro. The expression of exosome and calcification makers were analyzed by western blot, including CD9, CD63, α-SMA, BMP-2, and Runx2, respectively. Differential expression of exosomal miRNAs in normal and HP-induced VSMCs were identified by using whole miRNA microarray technology. GO and KEGG analyses were performed to determine the significant enrichment of functions and signaling pathways in the target genes. In vivo, the CKD-VC rat model was established by administering adenine gavage combined with a high phosphorus diet. The rats were divided into normal control, model, low-dose BSHX, medium-dose BSHX, high-dose BSHX groups, and sevelamer groups. The blood biochemical parameters were measured. Renal histopathology and aortic calcification were observed. Western blot detected the levels of the calcification markers. Quantitative real-time PCR (qPCR) assay detected exosomal microRNA-32 (miR-32) mRNA expression in the aorta, the most differentially expressed exosomal miRNA previously identified. Phosphatase and tensin homolog located on chromosome ten (PTEN)/phosphatidylinositol-3 kinase (PI3K)/protein kinase B (AKT) signaling pathway components were also tested by western blot. RESULTS: Exosomal miRNA-32 and PI3K/AKT signaling pathways were highly differentially expressed between normal and HP-induced VSMCs. In vivo, BSHX improved blood biochemical parameters, renal histopathology, and aortic calcification in CKD-VC rats. BSHX increased the expression level of α-SMA and decreased the level of BMP-2 and Runx2. BSHX also lowered the expression level of exosomal miR-32 mRNA, enhanced PTEN expression, therefore, reduced p-PI3K and p-AKT levels in the aorta. CONCLUSION: BSHX alleviated VC in CKD rats by downregulating exosomal miR-32 expression in the aorta, thereby promoting PTEN expression and inhibiting the PI3K/AKT signaling pathway.

Adventitial Vasa Vasorum Neovascularization in Femoral Artery of Type 2 Diabetic Patients with Macroangiopathy Is Associated with Macrophages and Lymphocytes as well as the Occurrence of Cardiovascular Events.

OBJECTIVES: This study was conducted to assess the relationship between adventitial vasa vasorum neovascularization (VVn) in femoral artery of type 2 diabetic patients with macroangiopathy and the recruitment of macrophages and lymphocytes, and to relate the density of VVn to the occurrence of cardiovascular events. MATERIALS: Femoral artery samples were obtained from amputation cases. A total of 55 type 2 diabetic patients with macroangiopathy, 15 autopsy cases with type 2 diabetes without atherosclerosis. METHODS: Hematoxylin and eosin (H&E) staining to observe the histopathological features; Victoria blue staining to analyze the histological features; immunohistochemistry (CD34, CD68, CD20, and CD3) to determine the VVn density and the expression of macrophages, B lymphocytes, and T lymphocytes. RESULTS: Type 2 diabetic patients with macroangiopathy showed a higher mean adventitial VVn density in femoral artery (48.40 ± 9.39 no./mm2) than patients with type 2 diabetes without atherosclerosis (19.75 ± 6.28 no./mm2) (p < 0.01). In addition, the VVn density was positively associated with the expression of CD68 macrophages (r = 0.62, p < 0.01) and CD20 B lymphocytes (r = 0.59, p < 0.01). Type 2 diabetic patients with high VVn density showed more adverse cardiovascular events (27/35 vs. 8/20 events, p = 0.006). In multivariable analysis adjusted for main risk factors for cardiovascular disease, VVn was still independently associated with adverse cardiovascular events (p = 0.01). CONCLUSION: VVn density in type 2 diabetic patients with macroangiopathy is positively correlated with the adventitial immune-inflammatory cell numbers and the development of atherosclerotic lesions. Furthermore, VVn density is associated with adverse cardiovascular events.

QiHuangYiShen Granules Modulate the Expression of LncRNA MALAT1 and Attenuate Epithelial-Mesenchymal Transition in Kidney of Diabetic Nephropathy Rats.

Background: QiHuangYiShen granules (QHYS), a traditional Chinese herbal medicine formula, have been used in clinical practice for treating diabetic kidney disease for several years by our team. The efficacy of reducing proteinuria and delaying the decline of renal function of QHYS has been proved by our previous studies. However, the exact mechanism by which QHYS exerts its renoprotection remains largely unknown. Emerging evidence suggests that lncRNA MALAT1 is abnormally expressed in diabetic nephropathy (DN) and can attenuate renal fibrosis by modulating podocyte epithelial-mesenchymal transition (EMT). Objective: In the present study, we aimed to explore whether QHYS could modulate lncRNA MALAT1 expression and attenuate the podocyte EMT as well as the potential mechanism related to the Wnt/ß-catenin signal pathway. Methods: SD rats were fed with the high-fat-high-sucrose diet for 8 weeks and thereafter administered with 30 mg/kg streptozotocin intraperitoneally to replicate the DN model. Quality control of QHYS was performed using high-performance liquid chromatography. QHYS were orally administered at 1.25, 2.5, and 5 g/kg doses, respectively, to the DN model rats for 12 weeks. Body weight, glycated haemoglobin, blood urea nitrogen, serum creatinine, 24-h proteinuria, and kidney index were measured. The morphologic pathology of the kidney was evaluated by Hematoxylin-eosin and Masson's trichrome staining. The expression level of lncRNA MALAT1 was determined by quantitative real-time polymerase chain reaction. In addition, the expression levels of podocyte EMT protein markers and Wnt/ß-catenin pathway proteins in renal tissues were evaluated by Western blotting and immunohistochemistry. Results: The results showed that QHYS significantly reduced 24-h proteinuria, blood urea nitrogen, kidney index, and ameliorated glomerular hypertrophy and collagen fiber deposition in the kidney of DN rats. Importantly, QHYS significantly downregulated the expression level of lncRNA MALAT1, upregulated the expression of nephrin, the podocyte marker protein, downregulated the expression of desmin and FSP-1, and mesenchymal cell markers. Furthermore, QHYS significantly downregulated the expression levels of Wnt1, ß-catenin, and active ß-catenin. Conclusion: Conclusively, our study revealed that QHYS significantly reduced proteinuria, alleviated renal fibrosis, and attenuated the podocyte EMT in DN rats, which may be associated with the downregulation of lncRNA MALAT1 expression and inhibition of the Wnt/ß-catenin pathway.

Derivation and Validation of a Prediction Model of End-Stage Renal Disease in Patients With Type 2 Diabetes Based on a Systematic Review and Meta-analysis.

Objectives: To develop and validate a model for predicting the risk of end-stage renal disease (ESRD) in patients with type 2 diabetes. Methods: The derivation cohort was from a meta-analysis. Statistically significant risk factors were extracted and combined to the corresponding risk ratio (RR) to establish a risk assessment model for ESRD in type 2 diabetes. All risk factors were scored according to their weightings to establish the prediction model. Model performance is evaluated using external validation cohorts. The outcome was the occurrence of ESRD defined as eGFR<15 ml min-1 1.73 m-2 or received kidney replacement therapy (dialysis or transplantation). Results: A total of 1,167,317 patients with type 2 diabetes were included in our meta-analysis, with a cumulative incidence of approximately 1.1%. The final risk factors of the prediction model included age, sex, smoking, diabetes mellitus (DM) duration, systolic blood pressure (SBP), hemoglobin A1c (HbA1c), estimated glomerular filtration rate (eGFR), and triglyceride (TG). All risk factors were scored according to their weightings, with the highest score being 36.5. External verification showed that the model has good discrimination, AUC=0.807(95%CI 0.753-0.861). The best cutoff value is 16 points, with the sensitivity and specificity given by 85.33% and 60.45%, respectively. Conclusion: The study established a simple risk assessment model including 8 routinely available clinical parameters for predicting the risk of ESRD in type 2 diabetes.

Risk Factors for Multidrug-Resistant Organisms Infection in Diabetic Foot Ulcer.

Objective: The aim of this study is to analyze the microbiological characteristics of diabetic foot ulcer (DFU) and drug resistance of multidrug-resistant organisms (MDROs) and to reveal the potential risk factors for MDROs. This provides a basis for early empiric antibiotic treatment. Methods: This study included 348 patients with diabetic foot ulcer in Chu Hsien-I Memorial Hospital & Metabolic Disease Hospital of Tianjin Medical University between May 2020 and November 2021. A total of 475 strains of bacteria were cultured, among which 240 strains were multidrug-resistant bacteria, accounting for 51%. Binary logistic regression was used to analyze risk factors. First, univariate analysis was used to calculate the p value of variables, and then multivariate analysis was conducted for variables with p < 0.1 to analyze independent risk factors. Risk factors with p < 0.05 in multivariable analysis were considered as independent risk factors. The strength of the association was represented by odds ratio and 95% confidence interval. Results: Univariable logistic regression analysis demonstrated that previous hospitalization, previous antibiotic therapy, ulcer size >4cm2, surgical therapy, D-dimer, and CRP were associated with MDRO infection in patients with DFU. Multivariate logistic regression analysis demonstrated that previous hospitalization (OR = 1.91; 95% CI = 1.11-3.28; p = 0.02), ulcer size >4cm2 (OR = 1.68; 95% CI = 1.03-2.76; p = 0.04), surgical therapy (OR = 2.14; 95% CI = 1.03-4.47; p = 0.04), and CRP (OR = 1.01; 95% CI = 1.00-1.01; p = 0.03) were independent risk factors for MDROs infection in diabetic foot patients. Drug resistance analysis may indicate that the proportion and drug resistance rate of Acinetobacter baumannii in Tianjin, China, have changed. Conclusion: Previous hospitalization, ulcer size >4cm2, surgical therapy and CRP were independent risk factors for MDROs infection in diabetic foot patients. Identifying these risk factors can help us identify the high-risk patients of diabetic foot with MDRO infection early. More attention to high-risk patients and more aggressive isolation precautions may reduce the incidence of MDRO infection in diabetic foot patients.

Development and validation of an incidence risk prediction model for early foot ulcer in diabetes based on a high evidence systematic review and meta-analysis.

OBJECTIVES: To develop and validate a model for predicting the risk of early diabetic foot ulcer (DFU) based on systematic review and meta-analysis. METHODS: Data were analyzed from the risk factors of DFU with their corresponding risk ratio (RR) by meta-analysis. The DFU prediction model included statistically significant risk factors from the meta-analysis, all of which were scored by its weightings, and the prediction model was externally validated using a validation cohort from China. The occurrence of early DFU was defined as patients with type 2 diabetes who were free of DFU at baseline and diagnosed with DFU at follow-up. Evaluation of model performance was based on the area under the discrimination receiver operating characteristic curve (ROC), with optimal cutoff point determined by calculation of sensitivity and specificity. Kaplan-Meier curve were performed tocompare the cumulative risk of different groups. RESULTS: Our meta-analysis confirmed a cumulative incidence of approximately 6.0% in 46,521 patients with diabetes. The final risk prediction model included Sex, BMI, HbA1c, Smoker, DN, DR, DPN, Intermittent Claudication, Foot care, and their RRs were 1.87, 1.08, 1.21, 1.77, 2.97, 2.98, 2.76, 3.77, 0.38, respectively. The total score of all risk factors was 80 points according to their weightings. The prediction model showed good discrimination with AUC = 0.798 (95 %CI 0.738-0.858). At the optimal cut-off value of 46.5 points, the sensitivity, specificity and Youden index were 0.769, 0.798 and 0.567, respectively. The final model stratified the validation cohort into low, low-intermediate, high-intermediate and high-risk groups; Compared with low-risk group, the RR with 95 %CI of developing DFU in high-intermediate and high-risk group were 17.23 (5.12-58.02), p < 0.01 and 46.11 (5.16-91.74), p < 0.01, respectively. CONCLUSION: We have developed a simple tool to facilitates early identification of patients with diabetes at high risk of developing DFU based on scores. This simple tool may improve clinical decision-making and potentially guide early intervention.

Early intervention with Di-Dang Decoction prevents macrovascular fibrosis in diabetic rats by regulating the TGF-ß1/Smad signalling pathway.

Macroangiopathy is a complication of Type II Diabetes Mellitus (T2DM), which is mainly caused by fibrosis of blood vessels. Using T2DM rat models, we investigated whether the traditional Chinese medicine, Di-Dang Decoction (DDD), exhibited anti-fibrotic actions on great vessels. T2DM rats were randomly divided into non-intervention group, early-, middle-, late-stage DDD intervention groups and control groups, including pioglitazone group and aminoguanidine group. After administration of DDD to T2DM rats at different times, we detected the amount of extracellular matrix (ECM) deposition in the thoracic aorta. The results showed that early-stage intervention with DDD could effectively protect great vessels from ECM deposition. Considering that TGF-ß1 is the master regulator of fibrosis, we further validated at the molecular level that, compared to middle- and late-stage intervention with DDD, early-stage intervention with DDD could significantly decrease the expression levels of factors related to the activated TGF-ß1/Smad signalling pathway, as well as the expression levels of downstream effectors including CTGF, MMP and TIMP family proteins, which were directly involved in ECM remodelling. Therefore, early-stage intervention with DDD can reduce macrovascular fibrosis and prevent diabetic macroangiopathy.

Correlation between Insulin Resistance and Thyroid Nodule in Type 2 Diabetes Mellitus.

OBJECTIVE: The present study explored the association between insulin resistance (IR) and the clinical characteristics of thyroid nodules in patients with type 2 diabetes mellitus (T2DM). METHODS: All the patients were newly diagnosed with T2DM. 201 patients with thyroid nodule disease and 308 patients without the nodular thyroid disease. The participants were evaluated by relevant examination. Correlation analyses and regression analyses were performed to examine the relationships between the two groups. RESULTS: HOMA-IR values, serum FT4 (free thyroxine) levels, and age were higher in the thyroid nodule group than in the control group. The proportion of women in the thyroid nodule group is greater than the proportion of women in the control group. Logistic regression analysis showed that age, sex, FT4, and HOMA-IR were positive factors for thyroid nodule. The volume and size of the thyroid nodule were positively correlated with HOMA-IR, irrespective of gender. The thyroid nodule volume and size and the TSH (thyroid stimulating hormone) were greater in females than in males, whereas FT3 (free triiodothyronine) was lower in females. CONCLUSION: IR might be a risk factor for thyroid nodule. Whether alleviating the IR might slow the growth, or diminish the volume and size of the thyroid nodules, is yet to be elucidated.

In vitro, ex vivo, and in vivo evaluation of the effect of saturated fat acid chain length on the transdermal behavior of ibuprofen-loaded microemulsions.

In this study, the effect of the saturated fatty acid (FA) chain length in the oil phase on the behavior of Ibuprofen (IBU)-loaded transdermal microemulsion (ME) was evaluated in vitro, ex vivo, and in vivo. Three oils classified as long (LFA), medium (MFA), and short (SFA) chain length oils, Cremophor RH40 (surfactant) and Transcutol P (cosurfactant) were selected after experimental optimization. The physicochemical properties of ME were characterized, including IBU solubility in excipients, pseudo-ternary phase diagram construction, particle size, zeta potential, viscosity, and stability. Permeation flux and residual amount of IBU ex vivo using Franz cell system occurred in the following order: MFA-based ME > LFA-based ME > SFA-based ME, which correlated well with the results of confocal scanning laser microscopy study and the in vivo retention study. The results of in vitro cytotoxicity study and skin irritation tests measured by differential scanning calorimetry were ranked in the following order: LFA-based ME > MFA-based ME > SFA-based ME. Moreover, MFA-based ME has the highest analgesic activity among all the treatment groups. MFA was found to be an optimal oil phase with appropriate FA chain length for IBU-loaded transdermal ME, which exhibited excellent physicochemical properties, low toxicity, and good permeability profile.

Nanoparticles of 2-deoxy-D-glucose functionalized poly(ethylene glycol)-co-poly(trimethylene carbonate) for dual-targeted drug delivery in glioma treatment.

Based on the facilitative glucose transporter (GLUT) over-expression on both blood-brain barrier (BBB) and glioma cells, 2-deoxy-d-glucose modified poly(ethylene glycol)-co-poly(trimethylene carbonate) nanoparticles (dGlu-NP) were developed as a potential dual-targeted drug delivery system for enhancing the BBB penetration via GLUT-mediated transcytosis and improving the drug accumulation in the glioma via GLUT-mediated endocytosis. In vitro physicochemical characterization of the dual-targeted nanoparticulate system presented satisfactory size of 71 nm with uniform distribution, high encapsulation efficiency and adequate loading capacity of paclitaxel (PTX). Compared with non-glucosylated nanoparticles (NP), a significantly higher amount of dGlu-NP was internalized by RG-2 glioma cells through caveolae-mediated and clathrin-mediated endocytosis. Both of the transport ratios across the in vitro BBB model and the cytotoxicity of RG-2 cells after crossing the BBB were significantly greater of dGlu-NP/PTX than that of NP/PTX. In vivo fluorescent image indicated that dGlu-NP had high specificity and efficiency in intracranial tumor accumulation. The anti-glioblastoma efficacy of dGlu-NP/PTX was significantly enhanced in comparison with that of Taxol and NP/PTX. Preliminary safety tests showed no acute toxicity to hematological system, liver, kidney, heart, lung and spleen in mice after intravenous administration at a dose of 100 mg/kg blank dGlu-NP per day for a week. Therefore, these results indicated that dGlu-NP developed in this study could be a potential dual-targeted vehicle for brain glioma therapy.

Pluronic P105/F127 mixed micelles for the delivery of docetaxel against Taxol-resistant non-small cell lung cancer: optimization and in vitro, in vivo evaluation.

The aim of this work was to establish a novel polymeric mixed micelle composed of Pluronic P105 and F127 copolymers loaded with the poorly soluble antitumor drug docetaxel (DTX) against Taxol-resistant non-small cell lung cancer. A central composite design was utilized to optimize the preparation process, helping to improve drug solubilization efficiency and micelle stability. Prepared by a thin-film hydration method, the average size of the optimized mixed micelle was 23 nm, with a 92.40% encapsulation ratio and a 1.81% drug-loading efficiency. The optimized formulation showed high storage stability in lyophilized form, with 95.7% of the drug content remaining after 6 months' storage at 4°C. The in vitro cytotoxicity assay showed that the IC50 values for Taxotere(®) and mixed micelles were similar for A549, while on A549/Taxol cell lines, DTX-loaded P105/F127 mixed micelles showed a superior hypersensitizing effect; their IC50 value (0.059 µg/mL) was greatly reduced compared to those of Taxotere injections (0.593 µg/mL). The in vivo pharmacokinetic study showed that the mixed-micelle formulation achieved a 1.85-fold longer mean residence time in circulation and a 3.82-fold larger area under the plasma concentration-time curve than Taxotere. In addition, therapeutic improvement of mixed micelles in vivo against A549/Taxol was obtained. The tumor inhibition rate of the micelles was 69.05%, versus 34.43% for Taxotere (P < 0.01). Therefore, it could be concluded from the results that DTX-loaded P105/F127 mixed micelles might serve as a potential antitumor drug delivery system to overcome multidrug resistance in lung cancer.

Enhanced antitumor efficacy by methotrexate conjugated Pluronic mixed micelles against KBv multidrug resistant cancer.

A methotrexate (MTX) conjugated polymeric mixed micelles for MDR cancer therapy was developed in this study. To the best of our knowledge, MTX was firstly reported to be conjugated with Pluronic P105 (P105-MTX). The Pluronic F127 and P105-MTX polymeric mixed micelles (F127/P105-MTX) were fabricated by thin-film hydration technique, and performed superiority over physically entrapped MTX mixed micelles in drug loading capacity. The drug loading of MTX in F127/P105-MTX was found to be 3.42-fold higher than that of physically entrapped MTX mixed micelles. By conjugated to Pluronic, the amount of MTX in mixed micelles was increased 3.42-fold. In vitro cytotoxicity, cell apoptosis and cell cycle arrest studies also demonstrated that F127/P105-MTX had better antitumor efficacy in KBv MDR cells compared to that of physically entrapped mixed micelles. In comparison with MTX injection, F127/P105-MTX can significantly enhance blood circulation time of MTX in rats. Moreover, a much stronger antitumor efficacy in KBv xenografts mice was observed in F127/P105-MTX group than that of MTX. Therefore, MTX-conjugated mixed micelles might be an effective platform for delivering chemotherapeutic agents to MDR tumors.

Pluronic mixed micelles overcoming methotrexate multidrug resistance: in vitro and in vivo evaluation.

A Pluronic polymeric mixed micelle delivery system was developed in this study by using Pluronic P105 and F127 block copolymers to encapsulate the antitumor compound, methotrexate (MTX). The MTX-loaded Pluronic P105/F127 mixed micelle exhibited the spherical shape with about 22 nm in diameter, high encapsulation efficiency (about 85%) and pH-dependent in vitro drug release. In this study, A-549 and KBv cell lines were selected as multidrug resistance tumor cell models, while H-460 and KB cell lines were chosen as sensitive tumor cells. The MTX-loaded Pluronic P105/F127 mixed micelle exhibited significant higher in vitro cytotoxicity in multidrug resistant tumor cells than that of control (MTX injection) mainly because of higher cellular uptake of MTX. The pharmacokinetic studies indicated that the Pluronic micelles significantly prolonged systemic circulation time of MTX compared to MTX injection. Moreover, a much stronger antitumor efficacy in KBv tumor xenografts nude mice was observed in the MTX-loaded Pluronic P105/F127 mixed micelle group, than MTX. Collectively, Pluronic P105/F127 mixed micelles could significantly enhance the antitumor activity of MTX and might be a promising drug delivery platform for multidrug resistance modulation.

Self-aggregated pegylated poly (trimethylene carbonate) nanoparticles decorated with c(RGDyK) peptide for targeted paclitaxel delivery to integrin-rich tumors.

Cyclic RGD peptide-decorated polymeric micellar-like nanoparticles (MNP) based on PEGylated poly (trimethylene carbonate) (PEG-PTMC) were prepared for active targeting to integrin-rich cancer cells. An amphiphilic diblock copolymer, α-carboxyl poly (ethylene glycol)-poly (trimethylene carbonate) (HOOC-PEG-PTMC), was synthesized by ring-opening polymerization. The c(RGDyK) ligand, a cyclic RGD peptide that can bind to the integrin proteins predominantly expressed on the surface of tumor cells with high affinity and specificity, was conjugated to the NHS-Activated PEG terminus of the copolymer. The c(RGDyK)-functionalized PEG-PTMC micellar nanoparticles encapsulating PTX (c(RGDyK)-MNP/PTX) was fabricated by the emulsion/solvent evaporation technique and characterized in terms of morphology, size and zeta potential. Cellular uptake of c(RGDyK)-MNP/PTX was found to be higher than that of MNP/PTX due to the integrin protein-mediated endocytosis effect. In vitro cytotoxicity, cell apoptosis and cell cycle arrest studies also revealed that c(RGDyK)-MNP/PTX was more potent than those of MNP/PTX and Taxol. Pharmacokinetic study in rats demonstrated that the polymeric micellar nanoparticles significantly enhanced the bioavailability of PTX than Taxol. In vivo multispectral fluorescent imaging indicated that c(RGDyK)-MNP/PTX had high specificity and efficiency in tumor active targeting. Therefore, the results demonstrated that c(RGDyK)-decorated PEG-PTMC MNP developed in this study could be a potential vehicle for delivering hydrophobic chemotherapeutic agents to integrin-rich tumors.