As a basic amino acid, histidine has a pK_a close to the acidity of the tumor microenvironment, thus the charge and solubility of histidine are able to vary as the pH changes. Under a neutral environment, histidine is not charged and exhibits hydrophobic properties, while it can be protonated and becomes hydrophilic when exposed to mildly acidic pH, such as tumor microenvironment. Therefore, histidine is widely used in the design of drug delivery systems to target the mildly acidic pH of tumor microenvironment. This article reviews the recent progresses of histidine-based tumor-targeting drug delivery systems, and summarizes the principles on promoting internalization and tuning drug release by taking advantage of histidine. Finally, we point out the common issues on histidine application and illustrate its future prospects.

To develop different methods for determining siRNA content and the entrapment efficiency of siRNA loaded liposomes, SYBR Gold electrophoresis method and Ribogreen fluorospectrophotometry method were used respectively. SYBR Gold electrophoresis method has a good linear relation in a range at 0.2-2.0 micromol x L(-1) (R = 0.9930), and the recovery at the high, middle and low concentrations were 96.35%, 96.92%, and 100.74%, respectively (n = 3). The intra-day and inter-day RSD were far below 5% (n = 5). Ribogreen fluorospectrophotometry method has a good linear relation in a range at 10-50 nmol x L(-1) (R = 0.9971), and the recovery at the high, middle and low concentrations were 98.22%, 99.88% and 99.64%, respectively (n = 3). The intra-day and inter-day RSD were far below 5% (n = 5). The content and the entrapment efficiency of three batches of siRNA cationic liposomes were 98.52%, 97.85% and 99.20%, 96.45%, respectively, with these two methods. And there is no significant difference by ANOVA. Both of the two methods are accurate, sensitive, convenient method for determination of the siRNA content and the entrapment efficiency of siRNA loaded cationic liposomes.
Drug Carriers ; Drug Delivery Systems ; Electrophoresis ; Liposomes ; chemistry ; RNA, Small Interfering ; analysis ; Spectrometry, Fluorescence

In this study, indomethacin (IND) loaded solidified-polymeric micelles (IND-SPM) were prepared. Their in vitro characteristics were investigated. Methoxy-poly(ethylene glycol) poly(D, L-lactide) copolymer (mPEG-PDLLA) was used as IND carrier. The preparation of IND-SPM was conducted by solution-absorption method and evaporation by rotary evaporator. Polyplasdone XL-10 was used as adsorbent. The solution-absorption method was conducted by the following procedure; IND and mPEG-PDLLA were dissolved in acetone, followed by addition of polyplasdone XL-10 and stirred to obtain a suspension. The powder of IND-SPM was simply obtained after the organic solvent was completely evaporated. More than 90% (w/w) of IND (20 mg) in the powder was dissolved in 250 mL PBS within 30 min. DSC, 1H NMR and SEM results proved that IND was encapsulated within mPEG-PDLLA. The solubility of IND in the system increased 4.6 times with the highest amount of copolymer. The solidified particles were found to be suitable for the formulation of tablets or capsules.
Administration, Oral ; Anti-Inflammatory Agents, Non-Steroidal ; administration & dosage ; chemistry ; Drug Carriers ; chemistry ; Drug Compounding ; Drug Delivery Systems ; Indomethacin ; administration & dosage ; chemistry ; Micelles ; Polyesters ; chemistry ; Polyethylene Glycols ; chemistry ; Povidone ; chemistry ; Solubility

This study is to prepare the in situ forming sustained-release injection which can perform sustained release behavior at the periodontal site for 7 days and to evaluate its in vitro and in vivo properties. After preparation of in situ forming sustained-release injection the in situ time was studied. And the surface of the solid injection was characterized by SEM. The rheological curve at 0 degrees C, 25 degrees C, 37 degrees C was determined and the impact of the temperature on the viscosity was examined. The in vitro release behavior was investigated. At last, rabbit periodontitis model was established to study its pharmacokinetics. The injection was stable, hard to stratify and decompose. The in situ forming time was about 6 seconds. It can easily adhere into periodontal pockets. There were lots of holes on the surface of the solid injection for the drug to diffuse. The drug releasing curves could be fit by Korsmeyer-Peppas equation. The drug smoothly released for 7 days at pH 7.4 PBS buffer with a very slight burst release and maintained a certain concentration. In vivo pharmacokinetics results indicated that after administration with the in situ forming injection, achievement of tinidazole (TNZ) concentration in gingival crevicular fluid (GCF) was more comparable and long-lasting than usual solution of TNZ management and relatively constant TNZ levels were attained until 168 h. All these results supported the prospect of tinidazole in situ forming sustained-release injection in clinical applications.
Animals ; Antitrichomonal Agents ; administration & dosage ; pharmacokinetics ; Delayed-Action Preparations ; Drug Carriers ; Drug Compounding ; methods ; Endotoxins ; Gingival Crevicular Fluid ; metabolism ; Injections ; Periodontal Pocket ; metabolism ; Periodontitis ; chemically induced ; metabolism ; Polyesters ; chemical synthesis ; pharmacokinetics ; Polyethylene Glycols ; chemical synthesis ; pharmacokinetics ; Rabbits ; Random Allocation ; Rheology ; Tinidazole ; administration & dosage ; pharmacokinetics

OBJECTIVETo study the related proteins of apoptosis initiation induced by homoharringtonine (HHT) in HL-60 cells.

METHODSAfter establishment of an apoptosis initiation model induced by HHT in HL-60 cells, proteins of untreated and HHT treated HL-60 cells were extracted, and the two-dimensional polyacrylamide gel electrophoresis (2-DE) maps of the extracted proteins were established by using the immobilized pH gradient (IPG) two-dimensional electrophoresis respectively. The alteration protein spots were identified with assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and database searching.

RESULTSProteomics analysis showed that proteins including MHC class I antigen, calbindin D-28K, chloride channel protein 6, oncoprotein 18, zinc finger protein Helios and apoptosis inhibitor like protein 2 were involved in apoptosis initiation induced by HHT.

CONCLUSIONThe present study might conduce to the researches of HL-60 cells carcinogenesis and pave the way to exploit drug precursor related to HHT and initiation of apoptosis in HL-60 cells.

Antineoplastic Agents, Phytogenic ; pharmacology ; Apoptosis ; drug effects ; Calbindins ; Chloride Channels ; analysis ; DNA-Binding Proteins ; analysis ; Electrophoresis, Gel, Two-Dimensional ; methods ; HL-60 Cells ; Harringtonines ; pharmacology ; Histocompatibility Antigens Class I ; analysis ; Humans ; Ikaros Transcription Factor ; Inhibitor of Apoptosis Proteins ; Microtubule Proteins ; Phosphoproteins ; analysis ; Proteins ; analysis ; Proteome ; analysis ; S100 Calcium Binding Protein G ; analysis ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Stathmin ; Transcription Factors ; analysis

OBJECTIVETo study the association between two single nucleotide polymorphisms (SNP), rs2295080 and rs2536, in mammalian target of rapamycin (mTOR) gene and the susceptibility to pediatric epilepsy.

METHODSA case- control study was performed on 480 children with epilepsy (116 cases of refractory epilepsy) and 503 healthy children. SNP rs2295080 and rs2536 in the mTOR gene were detected by polymerase chain reaction restriction and fragment length polymorphisms (PCR-RFLP). Genotype and allele frequencies of SNP rs2295080 and rs2536 were compared between the children with epilepsy and healthy controls.

RESULTSThere were no significant differences in the genotype and allele frequencies of SNP rs2295080 between the children with epilepsy and healthy controls. There were no significant differences in the genotype frequencies of SNP rs2536 between the two groups either, but the frequency of G allele of SNP rs2536 was higher in children with epilepsy than that in healthy controls (P=0.042, OR=1.344, 95%CI: 1.010-1.789).

CONCLUSIONSSNP rs2536 of mTOR gene may be associated with the risk of pediatric epilepsy.

Epilepsy ; etiology ; genetics ; Gene Frequency ; Genetic Predisposition to Disease ; Genotype ; Humans ; Polymorphism, Single Nucleotide ; Risk ; TOR Serine-Threonine Kinases ; genetics

OBJECTIVETo study the mechanism of hepatic carcinoma cell apoptosis induced by small interfering RNA (siRNA)-mediated nuclear factor-kappaB (NF-kappaB) P65 silencing.

METHODSHepatic carcinoma SMMC-7721 cells were exposed to liposome-mediated transfection with NF-kappaB P65 siRNA synthesized by in vitro transcription, and the cells with empty liposome transfection and those without particular treatment served as the control groups. The expression of NF-kappaB P65 in the cells was detected by Western blotting, the cell viability examined by MTT assay, and the cell apoptosis assessed by flow cytometry. Immunohistochemistry was used to examine the expressions of Bcl-2 and Bax.

RESULTSsiRNA transfection significantly inhibited the expression of NF-kappaB P65 in SMMC-7721cells, with inhibition rates of 64.74% compared with the untreated cells and of 34.52% compared with the liposome-treated cells. The siRNA-treated SMMC-7721 cells also exhibited significant decrease in cell proliferation by 33.39% and 27.23% in comparison with the untreated and liposome-treated cells, respectively. NF-kappaB P65 siRNA induced obvious cell apoptosis with down-regulated Bcl-2 and up-regulated Bax expressions.

CONCLUSIONNF-kappaB p65 siRNA can induce SMMC-7721 cell apoptosis via the Bcl-2/Bax pathway.

Apoptosis ; Carcinoma, Hepatocellular ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; Gene Expression Regulation, Neoplastic ; Gene Silencing ; Humans ; Liposomes ; Liver Neoplasms ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; RNA, Small Interfering ; pharmacology ; Transcription Factor RelA ; metabolism ; Transfection ; bcl-2-Associated X Protein ; metabolism

OBJECTIVETo evaluate the quantitative and functional changes of T helper (Th) cell subsets in the bone marrow of severe aplastic anemia (SAA) patients and the relationship between these changes and the patients hematopoietic function.

METHODSBy FACS, the quantity and ratio of Th1 and Th2 cells, the percentage of CD3(+)CD8(+) cells in the bone marrow were detected in 24 patients with SAA at active phase, 15 patients with SAA at recovery phase, and 16 normal controls. By radioimmunoassay, the serum levels of TNF-alpha, or IL-4 in 20 SAA patients at active phase, 12 at recovery phase and 16 normal controls were measured. The relationships between CD3(+)CD8(+) cells, TNF-alpha and Ret, ANC; and between Th1 cells and CD3(+)CD8(+) cells, TNF-alpha or Ret, ANC; between IL-4, balance of Th1/Th2 and Ret, ANC were evaluated.

RESULTSThe percentages of Th1 and Th2 cells, and ratio of Th1/Th2 in bone marrow of SAA patients at active phase were (4.87 +/- 2.64)%, (0.41 +/- 0.26)% and 21.22 +/- 5.07, respectively, being higher than those of normal controls [(0.42 +/- 0.30)% (P < 0.01), (0.24 +/- 0.17)% (P < 0.05) and (1.57 +/- 0.93) (P < 0.01), respectively] and all of them reduced to normal levels of SAA at recovery phase (P > 0.05). The percentage of CD3(+)CD8(+) cells significantly decreased from (32.32 +/- 8.69)% at active phase to (13.76 +/- 2.96)% at recovery phase (P < 0.01). The serum levels of TNF-alpha and IL-4 at active phase was (4.29 +/- 3.15) microg/L and (1.24 +/- 0.73) microg/L, respectively, being higher than those of normal controls (1.21 +/- 1.16) microg/L, (1.18 +/- 0.97) microg/L, but only the difference of TNF-alpha was statistically significant (P < 0.01). In recovery SAA patients, the serum levels of TNF-alpha significantly decreased to (1.46 +/- 1.41) microg/L (P < 0.01), and the levels of IL-4 increased markedly to (3.05 +/- 1.94) microg/L. The CD3(+)CD8(+) cells and TNF-alpha of patients negatively correlated with Ret (P < 0.05; P < 0.05) and ANC (P < 0.05; P < 0.05), Th1 cells correlated with CD3(+)CD8(+) cells and TNF-alpha positively (P < 0.01; P < 0.05), the Ret and ANC negatively (P < 0.01; P < 0.01), IL-4 and the balance of Th1/Th2 positively correlated with Ret and ANC (P < 0.05, P < 0.01; P < 0.01, P < 0.01).

CONCLUSIONThe bone marrow failure in SAA might be caused not only by the increase of Th1 cells, Th1 type effector cells and cytokines, but also by insufficient compensation of Th2 cells and Th2 type cytokines, which shifted the balance of Th1/Th2 favorable to Th1.

Adolescent ; Adult ; Anemia, Aplastic ; blood ; pathology ; physiopathology ; Bone Marrow ; metabolism ; pathology ; CD3 Complex ; blood ; CD8 Antigens ; blood ; Child ; Female ; Hematopoietic System ; metabolism ; pathology ; physiopathology ; Humans ; Interleukin-4 ; blood ; Male ; Middle Aged ; Radioimmunoassay ; T-Lymphocytes, Helper-Inducer ; metabolism ; pathology ; Th1 Cells ; metabolism ; pathology ; Th2 Cells ; metabolism ; pathology ; Tumor Necrosis Factor-alpha ; blood ; Young Adult

OBJECTIVETo measure the subsets of dendritic cells 1 (DC1) in the bone marrow of severe aplastic anemia (SAA) patients and evaluate the relationships between the CD11c+CD83+ cells and Th1 cells, CD3+CD8+ cells or hematopoietic function and explore the role of DC1 in the pathogenesis of SAA.

METHODSBy FACS, the quantities and ratios of CD11c+CD1a+ cells, CD11c+CD83+ cells, Th1 cells, and CD3+CD8+ cells in the bone marrow of SAA patients and normal controls were detected respectively. The relationships between CD3+CD8+ cells and reticulocyte absolute value (Ret) or neutrophil absolute value (ANC), between Th1 cells and CD3+CD8+ cells, Ret or ANC, between CD11c+CD83+ cells, and Th1 cells, CD3+CD8+ cells, Ret or ANC were evaluated.

RESULTSIn normal controls' bone marrow, the percentages of Th1 cells, CD11c+CD1a+ cells, CD11c+CD83+ cells and the ratio of CD11c+CD83+/CD11c+CD1a+ were (0.42 +/- 0.30)%, (0.38 +/- 0.29)%, (0.37 +/- 0.32)% and 1.07 +/- 0.10, respectively. In untreated SAA patients, they were (4.87 +/- 0.54)%, (1.73 +/- 0.24)%, (3.38 +/- 0.56)% and 2.21 +/- 0.32 respectively, which were higher than that in normal controls (P < 0.01). In recovering SAA patients, the percentages of Th1 cells, CD11c+CD1a+ cells and CD11c+CD83+ cells decreased significantly to (0.53 +/- 0.22)%, (0.61 +/- 0.23)%, (0.65 +/- 0.22)%, respectively (P < 0.01). The ratio of CD11c+CD83+/CD11c+ CD1a+ in recovering SAA patients decreased to 1.37 +/- 0.25, which was similar to that in normal controls (P > 0.05). The percentage of CD3+CD8+ cells in untreated SAA patients was (32.32 +/- 10.22)%, and in recovering SAA patients decreased to (13.67 +/- 5.24)% (P < 0.01). The percentage of CD3+CD8+ cells in SAA patients was negatively correlated with their Ret and ANC (P < 0.05), while their Th1 cell percentages were positively correlated with their CD3+CD8+ cells (P < 0.01), and negatively correlated with their Ret and ANC (P < 0.01). SAA patient's CD11c+CD83+ cell percentages were positively correlated with their Th1 cell and CD3+CD8 cells (P < 0.01, P < 0.05), but negatively with their Ret and ANC (P < 0.01).

CONCLUSIONBoth immature DC1 and activated DC1 increased in the bone marrow of SAA patients, and the balance of DC1 subsets shifted from stable form to active one, which might promote Th0 cells to polarize to Th1 cells, and cause the over-function of T lymphocytes and hematopoiesis failure in SAA.

Adolescent ; Adult ; Anemia, Aplastic ; immunology ; Antigens, CD ; immunology ; Antigens, CD1 ; immunology ; Bone Marrow ; immunology ; CD11c Antigen ; immunology ; CD8-Positive T-Lymphocytes ; immunology ; Child ; Dendritic Cells ; immunology ; Female ; Humans ; Immunoglobulins ; immunology ; Male ; Membrane Glycoproteins ; immunology ; Th1 Cells ; immunology ; Young Adult